The URL can be used to link to this page

Home My WebLink AboutNC0024392_Application_20230331 (2)F)I Clean Water Act §316(b) Compliance Submittal Prepared for: Duke Energy Carolinas, LLC Prepared by: HDR is July 12, 2019 �� ESN RGY.. F' � FN This page intentionally left blank. FN Acknowledgements and Document Review This report was prepared with substantial assistance from Normandeau Associates, Inc., who conducted the two-year Entrainment Characterization Field Study including laboratory analyses, and Veritas Economic Consulting, who performed the Social Cost and Social Benefit evaluations. Both of these firms also supported the development and review of this document. Cover photo credit Murr Rhame (https://commons.wikimedia.org/w/index.php?curid=26447078) Report Verification This document has been reviewed for accuracy and quality commensurate with the intended application and has undergone technical/peer review prior to submittal. Program Manager Biology Lead Engineering Lead Technical Editor Ty Ziegler, PE 8/09/2019 Misty Huddleston, PhD 8/09/2019 Scott Loughery, PE 8/09/2019 Kerry McCarney-Castle, PhD 8/09/2019 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal �� Contents Contents Contents ExecutiveSummary.................................................................................................................................E-1 Introduction.......................................................................................................................................E-1 MainIntake.............................................................................................................................E-1 LowLevel Intake....................................................................................................................E-2 StationDescription...........................................................................................................................E-2 RegulatoryNexus.............................................................................................................................E-3 Impingement Mortality Compliance..................................................................................................E-4 Impingement Mortality Characterization.................................................................................E-6 Summary of Selected Impingement Mortality Compliance Options.......................................E-8 Analyses Performed in Support of an Entrainment BTA Determination ........................................E-10 Entrainment Characterization Study — §122.21(r)(9)...........................................................E-10 Comprehensive Technical Feasibility and Cost Evaluation Study — §122.21(r)(10)............ E-10 Benefits Valuation Study —§122.21(r)(11)...........................................................................E-14 Non -water Quality Environmental and Other Impacts Study — §122.21(r)(12) ....................E-16 Peer Review —§122.21(r)(13)..............................................................................................E-16 Entrainment BTA Factors that Must Be Considered......................................................................E-17 Numbers and Types of Organisms Entrained......................................................................E-17 Impacts of Changes in Air Emissions of Particulates and Other Pollutants .........................E-20 Land Availability Related to Technology Retrofit Options ....................................................E-21 Remaining Useful Plant Life.................................................................................................E-21 Quantitative and Qualitative Social Benefits and Costs of Available Entrainment Technologies...........................................................................................................E-22 Summary of Must Factors Analysis......................................................................................E-26 Entrainment BTA Factors that May Be Considered.......................................................................E-27 Entrainment Impacts on the Waterbody...............................................................................E-27 Thermal Discharge Impacts.................................................................................................E-28 Credit for Flow Reductions...................................................................................................E-28 Impacts on the Reliability of Energy Delivery.......................................................................E-28 Impacts on Water Consumption...........................................................................................E-29 Availability of Alternate Water Sources for Reuse as Cooling Water ..................................E-29 Summary of May Factors Analysis.......................................................................................E-29 Conclusions....................................................................................................................................E-31 Compliance Submittal Document.............................................................................................................. 1 1 Introduction.......................................................................................................................................... 1 2 Source Water Physical Data[§122.21(r)(2)1.......................................................................................6 2.1 Description of Source Waterbody............................................................................................. 6 2.2 Characterization of Source Waterbody..................................................................................... 8 2.2.1 Geomorphology............................................................................................................8 2.2.2 Hydrology..................................................................................................................... 9 2.2.3 Water Quality................................................................................................................ 9 2.3 Determination of Area of Influence.......................................................................................... 13 2.3.1 Area of Influence Regulatory Background................................................................. 13 Duke Energy I i Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal Contents 3 4 5 2.3.2 Impingement versus Entrainment Area of Influence ........................................ 2.3.3 Area of Influence Estimation Method.............................................................. 2.3.4 Results............................................................................................................ Cooling Water Intake Structures [§122.21(r)(3)].................................................................... 3.1 CWIS Configuration...................................................................................................... 3.1.1 Main Intake....................................................................................................... 3.1.2 Low Level Intake(LLI)..................................................................................... 3.2 Latitude and Longitude of CWIS.................................................................................. 3.3 Engineering Drawings of CWIS..................................................................................... Source Water Baseline Biological Characterization Data[§122.21(r)(4)].............................. 4.1 List of Unavailable Biological Data................................................................................ 4.2 List of Species and Relative Abundance in the Vicinity of the CWIS........................... 4.2.1 Spring Electrofishing....................................................................................... 4.2.2 Fall Purse Seine Sampling.............................................................................. 4.2.3 Hydroacoustic Surveys................................................................................... 4.2.4 Creel Surveys.................................................................................................. 4.2.5 Summary.......................................................................................................... 4.3 Identification and Evaluation of Primary Growth Period ............................................... 4.3.1 Reproduction and Recruitment....................................................................... 4.3.2 Period of Peak Abundance for Relevant Taxa................................................ 4.4 Daily and Seasonal Activities of Organisms in the Vicinity of the CWIS....................... 4.5 Species and Life Stages Susceptible to Impingement and Entrainment ...................... 4.5.1 Impingement.................................................................................................... 4.5.2 Entrainment...................................................................................................... 4.5.3 Summary......................................................................................................... 4.6 Threatened, Endangered, and Other Protected Species Susceptible to Impingement and Entrainment at the CWIS...................................................................................... 4.7 Documentation of Consultation with Services.............................................................. 4.8 Information Submitted to Obtain Incidental Take Exemption or Authorization from Services........................................................................................................................ 4.9 Methods and Quality Assurance Procedures for Field Efforts ..................................... 4.10 Protective Measures and Stabilization Activities.......................................................... 4.10.1 Annual Spring Reservoir Level Stabilization Project ....................................... 4.10.2 Annual Summer Monitoring of the Low Level Intake ....................................... 4.11 Fragile Species.............................................................................................................. Cooling Water System Data[§122.21(r)(5)]............................................................................ 5.1 Cooling Water System Operation................................................................................. 5.1.1 Main Intake...................................................................................................... 5.1.2 Low Level Intake(LLI)..................................................................................... 5.2 Description of Intake Flows........................................................................................... 5.2.1 Seasonal Operations....................................................................................... 5.2.2 Proportion of Design Flow Used in the Cooling Water System ...................... 5.2.3 Distribution of Water Reuse and use of Grey Water ....................................... 5.2.4 Reductions in Total Water Withdrawals.......................................................... 5.2.5 Water Used in Manufacturing Processes........................................................ 5.2.6 Proportion of Source Waterbody Withdrawn ................................................... 13 14 15 18 18 18 21 23 23 24 25 26 26 29 30 31 31 31 32 32 34 34 35 36 37 38 41 41 42 42 42 43 44 45 45 45 46 48 53 53 53 54 54 54 Duke Energy I ii Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal Contents !' Ce 7 0 0 10 5.3 Design and Engineering Calculations..................................................................... 5.4 Existing Impingement and Entrainment Reduction Measures ................................ Chosen Method(s) of Compliance with Impingement Mortality Standard [§122.21(r)(6)]. 6.1 Main Intake - Regulatory Determination of de Minimis Rate of Impingement......... 6.2 Low Level Intake - Regulatory Determination of de Minimis Rate of Impingement Entrainment Performance Studies [§122.21(r)(7)]............................................................ 7.1 Site -Specific Studies............................................................................................... 7.2 Studies Conducted at Other Locations................................................................... 7.3 Summary................................................................................................................. Operational Status [§ 122.21 (r)(8)] .................................................................................... 8.1 Description of Operating Status.............................................................................. 8.2 Utilization for Previous 5 Years............................................................................... 8.3 Major Upgrades in Last 15 Years............................................................................ 8.4 Descriptions of Consultation with Nuclear Regulatory Commission ....................... 8.5 Other Cooling Water Uses for Process Units.......................................................... 8.6 Current and Future Production Schedules at Manufacturing Facilities ................... 8.7 Plans or Schedules for New Units Planned within 5 years ..................................... Entrainment Characterization Study [§122.21(r)(9)]......................................................... 9.1 Entrainment Data Collection Methods..................................................................... 9.1.1 Sampling Gear and Collection Protocol ..................................................... 9.1.2 Laboratory Sample Processing.................................................................. 9.1.3 Data Analysis............................................................................................. 9.2 Results — Entrainment Characterization.................................................................. 9.2.1 Species Composition.................................................................................. 9.2.2 Size Distribution......................................................................................... 9.2.3 Temporal and Spatial Patterns in Abundance ........................................... 9.2.4 Monthly and Annual Entrainment Estimates .............................................. 9.3 Summary................................................................................................................. Comprehensive Technical Feasibility and Cost Evaluation Study [§122.21(r)(10)].......... 10.1 Approach to Feasibility and Cost Evaluation........................................................... 10.1.1 Approach for Feasibility Evaluation............................................................ 10.1.2 Assumptions and Cost Basis..................................................................... 10.2 Technical Feasibility................................................................................................ 10.2.1 Technologies and Operational Measures Considered ............................... 10.3 Closed -cycle Recirculating Systems....................................................................... 10.3.1 Description of Existing Cooling System ..................................................... 10.3.2 Cooling Tower Principles........................................................................... 10.3.3 Cooling Tower Terminology....................................................................... 10.3.4 Review of Candidate Approaches.............................................................. 10.3.5 Existing Condensers.................................................................................. 10.3.6 Description of Selected CCRS Technology ............................................... 10.3.7 Alternate Cooling Tower Locations............................................................ 10.3.8 Construction Sequence and Outage.......................................................... 10.3.9 Feasibility Discussion................................................................................. 10.3.10 Permitting Requirements............................................................................ 10.3.11 Anticipated Schedule.................................................................................. ....... 55 ....... 55 ....... 56 ....... 57 ....... 58 ....... 60 ....... 60 ....... 61 ....... 61 ....... 62 ....... 62 ....... 63 ....... 64 ....... 64 ....... 65 ....... 65 ....... 65 ....... 66 ....... 67 ....... 67 ....... 71 ....... 72 ....... 73 ....... 73 ....... 75 ....... 75 ....... 77 ....... 79 ....... 81 ....... 82 ....... 82 ....... 82 ....... 86 ....... 86 ....... 87 ....... 87 ....... 88 ....... 90 ....... 93 ..... 103 ..... 106 ..... 122 ..... 124 ..... 125 ..... 131 ..... 131 Duke Energy I iii Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� Contents r 10.3.12 Costs........................................................................................................................ 133 10.3.13 Uncertainty...............................................................................................................138 10.4 Fine -Mesh and Fine -Slot Screen Retrofit [§122.21(r)(10)(i)]................................................ 140 10.4.1 Existing CWIS and Screens..................................................................................... 140 10.4.2 Typical Screen Types............................................................................................... 141 10.4.3 Fine -mesh Traveling Water Screens........................................................................ 143 10.4.4 Fine -Slot Wedgewire Screens.................................................................................. 157 10.5 Summary of Social Costs......................................................................................................165 10.6 Alternate Cooling Water Sources [§122.21 (r)(1 0)(i)(C)] ....................................................... 170 10.6.1 Description of Water Uses within the Facility........................................................... 171 10.6.2 Description of Alternate Water Sources................................................................... 171 10.7 Summary of Findings — Technical Feasibility........................................................................ 174 10.7.1 Summary of Evaluation Findings and Reasoning .................................................... 174 10.7.2 Technologies Retained for Biological Efficacy and Cost Evaluations ...................... 176 11 Benefits Valuation Study [§122.21 (r)(1 1)] ....................................................................................... 177 11.1 Introduction and Background................................................................................................ 177 11.2 Review of Model Development and Valuation Methods....................................................... 177 11.2.1 Baseline Losses of Fish and Shellfish...................................................................... 178 11.3 Candidate Entrainment Reduction Technology Scenarios Modeled for McGuire ................. 184 11.3.1 Determining Losses under Without -Entrainment Scenario ...................................... 185 11.3.2 Determining Losses under Fine -Mesh Screens and an Aquatic Organism Return System Scenario..........................................................................................185 11.3.3 Determining Losses under Mechanical Draft Cooling Towers Scenario .................. 185 11.3.4 Summary of Incremental Losses under Entrainment and Impingement Reduction Scenarios................................................................................................ 186 11.4 Basis for Estimates of Changes in Stock Size or Harvest Levels ......................................... 187 11.4.1 Model Development................................................................................................. 188 11.4.2 Basis for Monetized Values Assigned to Changes in Stock Size and Harvest Levels....................................................................................................................... 192 11.4.3 Discussion of Mitigation Efforts Made Prior to the Rule ........................................... 200 11.5 Technology -Specific Findings............................................................................................... 200 11.5.1 Estimated Stock and Harvest Losses under Each Compliance Scenario ......... 200 11.5.2 Summary of Estimated Changes in Stock and Harvest, and Monetization of Benefits for Candidate Measures............................................................................. 210 11.5.3 Summary of Monetized Benefits.............................................................................. 211 11.5.4 Summary of Social Costs and Net Benefits............................................................. 212 11.5.5 Discussion, with Quantification and Monetization where Possible, of Other Benefits.................................................................................................................... 215 11.5.6 Discussion of Benefits Resulting from Reductions in Thermal Discharges ............. 215 11.6 Uncertainty Analyses............................................................................................................. 216 11.7 Baseline Entrainment and Impingement Summary ............................................................... 217 12 Non -water Quality Environmental and Other Impacts Study [§122.21(r)(12)]................................ 219 12.1 Background Information........................................................................................................ 219 12.1.1 McGuire Nuclear Station Population Distribution.....................................................219 12.1.2 Evaluation Approach for Compliance with §122.21(r)(12)....................................... 222 12.2 Closed -cycle Recirculating System.......................................................................................223 12.2.1 Energy Consumption................................................................................................ 223 Duke Energy I iv Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal Contents' 13 14 12.2.2 Air Pollutant Emissions, Environmental Impacts, and Human Health 12.2.3 Changes in Noise............................................................................... 12.2.4 Safety Impacts.................................................................................... 12.2.5 Station Reliability................................................................................ 12.2.6 Consumptive Use of Water................................................................ 12.3 Fine -mesh Screens......................................................................................... 12.3.1 Energy Consumption.......................................................................... 12.3.2 Air Pollutant Emissions, Environmental Impacts, and Human Health 12.3.3 Impact Mitigation Methods................................................................. 12.3.4 Changes in Noise............................................................................... 12.3.5 Safety Impacts.................................................................................... 12.3.6 Station Reliability................................................................................ 12.4 Alternate Water Sources................................................................................. 12.5 Engineering Summary..................................................................................... Peer Review[§122.21(r)(13)].................................................................................... 13.1 Peer Reviewers............................................................................................... 13.2 Peer Review Process...................................................................................... 13.3 Comment Response Criteria........................................................................... 13.4 Peer Review Results....................................................................................... References................................................................................................................ 14.1 Executive Summary References..................................................................... 14.2 Section 1 through Section 8 References......................................................... 14.3 Section 9 References...................................................................................... 14.4 Section 10 References.................................................................................... 14.5 Section 11 References.................................................................................... 14.6 Section 12 References.................................................................................... ..... 228 ..... 236 ..... 240 ..... 249 .... 250 ..... 256 ..... 256 ..... 259 ..... 259 ..... 260 ..... 261 ..... 261 ..... 262 ..... 262 ..... 264 ..... 264 ..... 265 ..... 267 ..... 268 ..... 269 ..... 269 ..... 270 ..... 276 ..... 278 ..... 282 ..... 285 Duke Energy I v Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Contents r Tables Table E-1. Impingement Mortality Compliance Options............................................................................E-4 Table E-2. Summary of Feasibility of Impingement Mortality Compliance Options...................................E-6 Table E-3. Species and Life Stage -Specific Estimated Annual Impingement Loss Estimates for 2016 and 2017 based on Actual Water Withdrawals at McGuire Nuclear Station .......................................E-7 Table E-4. Summary of Estimated Impingement Mortality under Existing Conditions Excluding Fragile Species at McGuire Nuclear Station.............................................................................................E-8 Table E-5. Components of the Social Costs of Entrainment Reduction Technologies ...........................E-12 Table E-6. Total Engineering and Social Costs of Feasible Technology Options at McGuire ................E-13 Table E-7. Summary of Recreational Social Benefits of Entrainment Reduction Alternatives at McGuire (Source: Veritas 2018)................................................................................................................E-15 Table E-8. 2016 and 2017 Annual Entrainment Loss Estimates for Entrainment Reduction Compliance Scenarios at McGuire Nuclear Station........................................................................................E-19 Table E-9. Percent Reduction of Entrainment Loss Estimates for Compliance Technology Scenarios Relative to the Baseline Actual Water Withdrawals Scenario at McGuire Nuclear Station ........E-20 Table E-10. Impacts to Air Emissions under Entrainment Reduction Technology Scenarios Evaluated for McGuireNuclear Station.............................................................................................................E-21 Table E-11. Net Benefits of Alternative Impingement and Entrainment Reduction Technologies at McGuire .................................................................................................................................................... E-23 Table E-12. Summary of Must Factors Analysis ....................................... E-Error! Bookmark not defined. Table E-13. Summary of May Factors Analysis.......................................................................................E-31 Table 1-1. Facility and Flow Attributes and Permit Application Requirements ............................................. 2 Table 1-2. Existing Facilities Submittal Requirements for Compliance Under Clean Water Act §316(b) §122.21(r)(2)-(13)............................................................................................................................. 4 Table 2-1. Lake Norman Characteristics...................................................................................................... 8 Table 2-2. Annual Mean Surface Concentration for Select Limnological Parameters Documented in the Southern Portion of Lake Norman, 2012-20161 ............................................................................. 11 Table 2-3. Approximate Area of Influence at the Main Intake by Select Threshold Velocities ................... 16 Table 2-4. Area of Influence of the Low Level Intake for Impingement and Entrainment under Two Operational Scenarios.................................................................................................................... 17 Table 3-1. Intake Structure Characteristics, McGuire Nuclear Station....................................................... 23 Table 3-2. Coordinates of the Main Intake and Low Level Intake at McGuire Nuclear Station .................. 23 Table 3-3. Design Drawings of the Main Intake and Low Level Intake at McGuire Nuclear Station .......... 23 Table 4-1. Total Number as Catch Per Unit Effort* by Species from Electrofishing Surveys, 2012-2016 in Zone1............................................................................................................................................ 28 Table 4-2. Relative Abundance (Percent) of the Five Most Abundant Centrarchids Captured During Electrofishing Surveys in Zone 1, 2012-2016................................................................................29 Table 4-3. Period of Reproduction for Species Present in Lake Norman, North Carolina' ........................ 33 Table 4-4. Summary of Rare, Threatened, or Endangered (RTE) Species Listed for Mecklenburg County, North Carolina, and Record of Occurrence or Assessment of Potential to Occur in Lake Norman ....................................................................................................................................................... 40 Table 5-1. McGuire Nuclear Station Pumping Capacity from Lake Norman .............................................. 49 Table 5-2. Main Intake Cooling Water (RC) Actual Withdrawal Rates (MGD) from January 2015 through December2017.............................................................................................................................. 50 Table 5-3. Low Level Intake Service Water (RN) Actual Withdrawal Rates (MGD) from January 2015 throughDecember 2017................................................................................................................ 50 Table 5-4. Days in Service for the RC Water Withdrawal from the Main Intake from January 2015 through December2017.............................................................................................................................. 51 Duke Energy I A Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Contents r Table 5-5. Monthly Average LLI Pump Withdrawal Rates (MGD) from January 2015 through December 2017............................................................................................................................................... 52 Table 5-6. Monthly LLI Pump Operation (days) from January 2015 through December 2017................... 52 Table 5-7. Percent of Time the LLI Pumps were in Operation from January 2015 through December 2017 ....................................................................................................................................................... 53 Table 6-1. Summary of Estimated Impingement Mortality under Actual Water Withdrawals Excluding Fragile Species at McGuire Nuclear Station.............................................................................................. 58 Table 8-1. McGuire Nuclear Station Winter Gross Generating Capacity (Duke Energy 2017a)................ 63 Table 8-2. Monthly Gross Generation (MW) for McGuire Nuclear Station for the 5-Year Period January 2013 through December 2017 (Duke Energy 2018)...................................................................... 63 Table 8-3. Average Monthly Capacity Utilization Factors', Expressed as a Percent, for McGuire Nuclear Station for the 5-Year Period from January 2013 through December 2017 (Duke Energy 2018). 64 Table 9-1. Ichthyoplankton Sampling Details.............................................................................................. 70 Table 9-2. Summary of Ichthyoplankton by Family Collected during the Entrainment Characterization Study at McGuire Nuclear Station, 2016-2017......................................................................................... 73 Table 9-3. Composition and Relative Abundance of Taxa Collected in the Entrainment Characterization Study at McGuire Nuclear Station, March to October 2016 and 2017.......................................... 74 Table 9-4. Total Number Collected by Life Stage during the Entrainment Characterization Study performed at McGuire Nuclear Station, March to October 2016 and 2017..................................................... 75 Table 9-5. Total Monthly Volume (ml) Withdrawn at Design Pump Capacity and Based on Actual Operations (January 2016 through December 2017) and the Percent Reduction in Withdrawal Volume at McGuire Nuclear Station, 2016-2017............................................................................................. 78 Table 10-1. AACE Costing Categories (AACE 2016).................................................................................84 Table 10-2. Comparison Matrix of Cooling Tower Types (EPRI 2011, CTI 2003, Maulbetsch and Stallings 2012, EPRI 2002)......................................................................................................................... 100 Table 10-3. Pertinent Design Parameters from the Existing Condenser Specification ............................ 105 Table 10-4. Estimated Water Use in Cooling Towers............................................................................... 107 Table 10-5. Cooling Tower Sizing Information for Unit 1 and Unit 2 (Source: SPX 2016b) ..................... 108 Table 10-6. Hypothetical MDCT Implementation Schedule...................................................................... 132 Table 10-7. Hypothetical MDCT Capital Costs......................................................................................... 134 Table 10-8. Hypothetical MDCT Capital Cost Outlay............................................................................... 136 Table 10-9. Hypothetical MDCT Annual O&M Cost Outlay (Excluding Electricity) ................................... 137 Table 10-10. Through -Screen Velocity and Headloss for 2.0-mm and 3/8-inch Mesh ............................. 146 Table 10-11. Hypothetical Fine -mesh Modified-Ristroph Screen Implementation Schedule ................... 151 Table 10-12. Hypothetical Fine -mesh Modified-Ristroph Screen Capital Costs ....................................... 153 Table 10-13. Hypothetical Fine -mesh Modified-Ristroph Screen Annual O&M Costs ............................. 154 Table 10-14. Hypothetical Fine -mesh Modified-Ristroph Screen Capital Cost Outlay ............................. 155 Table 10-15. Hypothetical Fine -mesh Modified-Ristroph Screen Annual O&M Cost Outlay .................... 156 Table 10-16. Wedgewire Screen Design Criteria for 2.0-mm Slots.......................................................... 159 Table 10-17. Total Engineering and Social Costs of Feasible Technology Options at McGuire .............. 167 Table 10-18. Timing Specified for Feasible Technologies........................................................................ 168 Table 10-19. Alternate Water Source Evaluation Criteria......................................................................... 170 Table 10-20. Grey Water Alternate Water Source Evaluation.................................................................. 172 Table 10-21. Groundwater Alternate Water Source Evaluation................................................................ 174 Table 10-22. Summary of Evaluation Findings......................................................................................... 175 Table 10-23. Technologies Retained for Further Evaluation.................................................................... 176 Table 11-1. Species and Life Stage -Specific Annual Entrainment Loss Estimates for 2016 based on Actual Water Withdrawals at McGuire Nuclear Station.......................................................................... 179 Table 11-2. Species and Life Stage -Specific Annual Entrainment Loss Estimates for 2017 based on Actual Water Withdrawals at McGuire Nuclear Station.......................................................................... 180 Duke Energy I vii Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Contents r Table 11-3. Species and Life Stage -Specific Estimated Annual Impingement Loss Estimates for 2016 based on Actual Water Withdrawals at McGuire Nuclear Station.......................................................... 181 Table 11-4. Species and Life Stage -Specific Estimated Annual Impingement Loss Estimates for 2017 based on Actual Water Withdrawals at McGuire Nuclear Station.......................................................... 182 Table 11-5. Summary of Estimated Impingement Mortality under Existing Conditions Excluding Fragile Species at McGuire Nuclear Station............................................................................................ 184 Table 11-6. Summary of Compliance Alternative Scenarios for the Benefits Valuation Study ................ 184 Table 11-7. Summary of Incremental Losses due to Entrainment by Compliance Technology Scenario for 2016 and 2017............................................................................................................................. 186 Table 11-8. Summary of Incremental Losses due to Impingement by Compliance Technology Scenario for 2016 and 2017............................................................................................................................. 186 Table 11-9. QC Procedures for the McGuire Benefits Valuation Biological Modeling Process ................ 191 Table 11-10. Timing Specified for Feasible Technologies at McGuire ..................................................... 195 Table 11-11. Annual Entrainment Loss Estimates by Compliance Scenario for 2016 and 2017 at McGuire NuclearStation............................................................................................................................. 201 Table 11-12. Annual Impingement Loss Estimates by Compliance Scenario for 2016 and 2017 at McGuire NuclearStation............................................................................................................................. 201 Table 11-13. Estimated Entrainment Losses with Fine Mesh Screens at McGuire Nuclear Station........ 209 Table 11-14. Percent Reductions under Entrainment Compliance Technology Scenarios Relative to the Baseline Condition at McGuire Nuclear Station........................................................................... 210 Table 11-15. Percent Reductions under Impingement Compliance Technology Scenarios Relative to the Baseline Condition at McGuire Nuclear Station........................................................................... 211 Table 11-16. Summary of Monetized Recreational Social Benefits of Entrainment Reduction Alternatives at McGuire Nuclear Station (Source: Veritas 2018)......................................................................... 212 Table 11-17. Net Benefits of Alternative Impingement and Entrainment Reduction Technologies at McGuire ..................................................................................................................................................... 213 Table 12-1. Energy Consumption due to Hypothetical MDCT Retrofit.....................................................226 Table 12-2. Energy Loss due to Construction Outage for Hypothetical MDCT Retrofit ........................... 226 Table 12-3. Estimated PM Emissions due to Hypothetical MDCT Operation ........................................... 233 Table 12-4. Increased CO2 Emissions Due to McGuire Downtime and McGuire Cooling Tower Energy Consumption (Veritas 2018)........................................................................................................ 234 Table 12-5. Increased SO2 Emissions Due to McGuire MDCT Tie-in Downtime and McGuire MDCT Energy Consumption (Veritas 2018)........................................................................................................ 234 Table 12-6. Increased NOX Emissions Due to MDCT Tie-in Downtime and MDCT-related Recurring Energy Losses(Veritas 2018).................................................................................................................. 235 Table 12-7. Common Noise Levels (Cowan 1994)...................................................................................237 Table 12-8. Noise Level Compared to Distance....................................................................................... 238 Table 12-9. Days with Fog Reported at WMO Station 723140*............................................................... 246 Table 12-10. Days with a Recorded Freezing Temperature at WMO Station 723140* ............................ 247 Table 12-11. Summary of Historical Evaporation Rates between 2014 and 2016 (Duke Energy 2017).251 Table 12-12. Estimated Cooling Tower Evaporation................................................................................ 253 Table 12-13. Percent Difference between Once -through Cooling Forced Evaporation and Cooling Tower Evaporation for the Period 2014 through 2016............................................................................ 255 Table 12-14. Increase in Energy Consumption due to a Fine -mesh Traveling Water Screen Retrofit..... 258 Table 12-15. Increase in Emissions at McGuire from Replacing Coarse -mesh Screens with FMS......... 259 Table 12-16. Summary of Engineering Evaluations................................................................................. 262 Duke Energy I viii Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Contents r Figures Figure E-1. Comparison of Social Benefits and Costs at McGuire ..........................................................E-24 Figure 1-1. McGuire Nuclear Station Vicinity Map........................................................................................3 Figure 2-1. Catawba-Wateree Project, North and South Carolina............................................................... 7 Figure 2-2. Duke Energy Maintenance Monitoring Program Water Quality Sampling Zones and 2014-2016 Data Collection Locations (Source: Duke Energy 2017b) (Note: MNS = McGuire Nuclear Station; MSS = Marshall Steam Station)..................................................................................................... 10 Figure 2-3. Surface Temperature (°C) and Dissolved Oxygen Trends from 1990 to 2016 in the Southern Portion of Lake Norman (Source: Duke Energy 2017b)................................................................ 12 Figure 2-4. Impingement and Entrainment Area of Influence at the Main Intake at Select Threshold Values .......................................................................................................................................................16 Figure 3-1. Site Layout at McGuire Nuclear Station................................................................................... 19 Figure 3-2. Schematic of the Main Intake Structure at McGuire Nuclear Station, Huntersville, North Carolina (Duke Power 2003)........................................................................................................................ 20 Figure 3-3. Plan View of McGuire Nuclear Station Main Intake Structure (Alden 2004) ............................ 20 Figure 3-4. Main Intake Structure Cross -sectional View, McGuire Nuclear Station (Alden 2004) ............. 21 Figure 3-5. Schematic of Low Level Intake Structure at Cowans Ford Dam, McGuire Nuclear Station, Huntersville, North Carolina (Duke Energy 2009).......................................................................... 22 Figure 4-1. Zones and Locations of Fish Sampling Events, 2012-2013..................................................... 27 Figure 4-2. Estimated Total Number Caught and Relative Abundance of Alewife and Threadfin Shad in Purse Seine Samples from Zones 1, 2, and 5, of Lake Norman, 1993-2013................................ 30 Figure 4-3. Forage Fish Density Estimates in Lake Norman from Hydroacoustic Surveys, 1997-2013 (Source: Duke Energy 2015)......................................................................................................... 30 Figure 4-4. Search Area for Federally Listed Species................................................................................ 39 Figure 5-1. Water Balance Diagram Illustrating the Routing and Uses of Cooling Water Withdrawn at the McGuire Nuclear Station Intakes on Lake Norman, Huntersville, North Carolina (Sources: Duke Energy2014b)................................................................................................................................ 47 Figure 9-1. Schematic of Flotation and Anchoring System for In -Water Sampler Deployment at McGuire NuclearStation............................................................................................................................... 68 Figure 9-2. Gas -powered Pump and 100-gallon Collection Tank System used for Ichthyoplankton Sampling at McGuire Nuclear Station............................................................................................................ 69 Figure 9-3. Location for Collection Tank and Pump and Associated Piping for the Sampling Location Upstreamof Unit 2......................................................................................................................... 69 Figure 9-4. Total Average Ichthyoplankton Densities (No./100 m3) by Diel Period Collected during the Entrainment Characterization Study performed at McGuire Nuclear Station, March to October 2016 and 2017 (Note: bars are standard error bars).............................................................................. 77 Figure 10-1. Condenser and Cooling Tower Water Temperature Relationship ......................................... 91 Figure 10-2. Cross -Section Schematic of a Parallel Path Wet/Dry Cooling Tower (CTI 2010).................. 95 Figure 10-3. Aerial Photograph of an Air-cooled Condenser (Direct Dry Cooling) (Enexio 2016) ............. 97 Figure 10-4. Schematic of an Indirect Dry Cooling Tower.......................................................................... 97 Figure 10-5. Topography in the Vicinity of McGuire................................................................................. 111 Figure 10-6. Schematic Showing Cooling System Components and Piping before and after Hypothetical CoolingTower Retrofit................................................................................................................. 112 Figure 10-7. Wind Rose Summary for Charlotte, NC (WMO 2016).......................................................... 114 Figure 10-8. Existing Cooling Water Piping (Duke Energy 2012b)........................................................... 116 Figure 10-9. Hypothetical Cooling Tower Locations................................................................................. 117 Figure 10-10. Existing Conventional Wastewater Treatment System to be Relocated (Duke Energy 2014b) ..................................................................................................................................................... 119 Figure 10-11. Schematic of Repurposing the LLI Pump Structure (Duke Energy 2014b)........................ 120 Figure 10-12. Alternate Cooling Tower Locations.................................................................................... 123 Duke Energy I ix Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Contents r Figure 10-13. Unit 2 Takeoff Location (Duke Energy 2012b)................................................................... 128 Figure 10-14. Preliminary Study Corridor of New Alignment of Highway 73 Widening and Relocation Project (MUMPO 2011)............................................................................................................................ 139 Figure 10-15. Schematic of a Through -flow Traveling Water Screen (left) and Close -Up View of Fish Buckets, Fish Return, and Debris Return (right) (courtesy of Evoqua Water Technologies 2016) ..................................................................................................................................................... 142 Figure 10-16. Wedgewire Screens out of Water (Image Courtesy of ISI 2016)....................................... 142 Figure 10-17. Through -Screen Velocity and Headloss Curves (US Filter 2016)...................................... 145 Figure 10-18. Aquatic Organism Return System for the Hypothetical FMS Retrofit ................................. 149 Figure 10-19. Wedgewire Screen Dimensions for 2.0-mm Slots..............................................................160 Figure 10-20. Wedgewire Screen Intake Structure...................................................................................161 Figure 10-21. Wedgewire Screen Section View....................................................................................... 162 FeasibilityDiscussion................................................................................................................................ 162 Figure 10-22. Groundwater Wells and WWTPs within a 5-mile Radius of McGuire (Source: USEPA 2013; NCREDC 2000; NCDEQ 2015)................................................................................................... 173 Figure 11-1. Change in Recreational Yield with Technology Installation (Example) ................................ 193 Figure 11-2. Location of Sites with Affected Catch Rates, Location of Substitute Sites, and the Concentration of Anglers (Source: Veritas 2018)........................................................................ 196 Figure 11-3. Change in Expected Catch per Trip by Species at Lake Norman (Source: Veritas 2018)... 197 Figure 11-4. Estimated Trip Change with Elimination of Entrainment at McGuire (Source: Veritas 2018) ..................................................................................................................................................... 198 Figure 11-5. Change in Welfare with Elimination of Entrainment at McGuire (Veritas 2018)................... 199 Figure 11-6. Direct Changes in Recreational Fish Stocks as Equivalent Adults with Elimination of Entrainment at McGuire Nuclear Station (Source: Veritas 2018)................................................ 203 Figure 11-7. Direct Changes in Forage Fish Stocks as Biomass (Ibs) with Elimination of Entrainment at McGuire Nuclear Station (Source: Veritas 2018)......................................................................... 204 Figure 11-8. Trophic Transfer -Based Changes in Pounds of Biomass with Elimination of Entrainment at McGuire Nuclear Station (Source: Veritas 2018)......................................................................... 205 Figure 11-9. Total (Direct and Indirect) Changes in Recreational Yield with Elimination of Entrainment at McGuire Nuclear Station (Source: Veritas 2018)......................................................................... 207 Figure 11-10. Example of Optimal Compliance Alternatives in a Benefit -Cost Analysis ..........................213 Figure 11-11. Comparison of Social Benefits and Costs at McGuire....................................................... 214 Figure 12-1. Population Density Surrounding McGuire Nuclear Station — Census Block Group Level (U.S. Census2014)...............................................................................................................................220 Figure 12-2. Population Density Surrounding McGuire Nuclear Station — Census Block Level (U.S. Census 2014)............................................................................................................................................ 221 Figure 12-3. Cooling Tower Alternate Locations and Distance to Property Boundary (Mecklenburg County 2017)............................................................................................................................................ 239 Figure 12-4. Road Network Surrounding McGuire................................................................................... 242 Figure 12-5. Intake Distance to Property Boundary (Mecklenburg County 2016a)..................................260 Figure 13-1. Peer Review Process Flow Chart......................................................................................... 266 Duke Energy I x Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Contents r Appendices 1 AppendixSection 1-A McGuire Nuclear Station §122.21(r)(2)-(13) Submittal Requirement Checklist 3 3-A Cooling Water Intake Structure Design Drawings 4-A Species -specific life history information for typical species found in Lake Norman 4 4-13 Duke Energy Maintenance Monitoring Reports (2012-2016) 5 5-A Engineering Calculations for Through -Screen Velocity - Main Intake Engineering Calculations for Through -Screen Velocity - LLI 6 6-A Impingement Reduction Compliance Alternatives 8 8 A McGuire Nuclear Station Units 1 and 2 Issuance of Amendments Regarding Measurement Uncertainty recapture Power Uprate may 16, 2013 9 A Entrainment Characterization Study Report Entrainment Characterization Study Plan 9 9-13 Quality Assurance Plan and SOPS for Entrainment Sampling at McGuire Nuclear Station 9-C Entrainment and Impingement Calculations 10-A Estimated Evaporation due to a Hypothetical Cooling Tower 10-B Pump and Pipe Selection Calculations for the Cooling Tower Retrofit 10-C Social Costs of Purchasing and Installing Entrainment Reduction Technologies: McGuire 10 Nuclear Station 10-D Engineering Estimates of Through -Screen Velocity for Existing Screens 10-E Evaluation of Biological Efficacy of Fine -Mesh Screen Sizes at McGuire 10-F Engineering Estimates of Through -Screen Velocity of Hypothetical Fine -Mesh Screens 11-A Addressing Anomalous Species Collections in Modeled Entrainment and Impingement Loss Results 11-B Compliance Alternative Modeling Outputs 11-C Best Professional Judgment Decisions Made in Life History Table Development for 11 Compliance Alternative Modeling 11-D Entrainment Reduction Benefits Valuation Study: McGuire Nuclear Station 11-E Uncertainty Analysis of Select Life History Table Parameters for Inland Silverside and Channel Catfish 12-A Estimated Increase in Energy Consumption due to MDCT Retrofit 12-B Estimated Particulate Matter Emissions 12-C Estimated Forced Evaporation from Existing Cooling Water System 12 12-D Estimated Increase in Energy Consumption due to Fine -Mesh Screen Retrofit 12-E Estimated Carbon Dioxide Emissions due to Fine -Mesh Screen Retrofit 12-F Estimated Emissions of Sulfur Dioxide due to Fine -Mesh Screen Retrofit 12-G Estimated Emissions of Nitrogen Oxides due to Fine -Mesh Screen Retrofit 13-A Peer Reviewer Resumes 13-B Peer Reviewer Correspondence Log 13 13-C Peer Reviewer Comments 13-D Responses to Peer Reviewer Comments Duke Energy I xi Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal �� Contents Acronyms and Abbreviations °C................................................................................................................................. degrees Celsius 7............................................................................................................................degrees Fahrenheit AT ......................................................................................................delta T or temperature differential AACE..................................................................... Association for the Advancement of Cost Engineering ACC..........................................................................................................................air cooled condenser AIF............................................................................................................................... actual intake flow AOI................................................................................................................................ area of influence $B...................................................................................................................................... billion dollars BPJ.............................................................................................................. Best Professional Judgment BTA................................................................................................................ Best Technology Available BTU........................................................................................................................... British thermal units CCRS...................................................................................................... closed -cycle recirculating system CFR..................................................................................................... U.S. Code of Federal Regulations cfs.........................................................................................................................cubic feet per second COC...................................................................................................................... cycles of concentration CPUE............................................................................................................................ catch per unit effort CWA................................................................................................................................. Clean Water Act CWIS............................................................................................................ cooling water intake structure CWRT............................................................................................................. cooling water residence time dB.............................................................................................................................................. decibels DBA........................................................................................................................ design -basis accident DIF.............................................................................................................................. design intake flow Director...................................................................................................................... NPDES permit Director DO............................................................................................................................... dissolved oxygen Duke Energy.................................................................................................... Duke Energy Carolinas, LLC EA................................................................................................................................ equivalent adults EFH........................................................................................................................ Essential Fish Habitat ESA................................................................................................................... Endangered Species Act EPRI......................................................................................................Electric Power Research Institute Eq.............................................................................................................................................. Equation EY............................................................................................................equivalent yield FIR................................................................................................................................ Federal Register FERC........................................................................................... Federal Energy Regulatory Commission FMS............................................................................................................................... fine -mesh screen fps.................................................................................................................................. feet per second ft.............................................................................................................................................. foot/feet ft msl.................................................................................................................feet above mean sea level gpm..............................................................................................................................gallons per minute GWhr..................................................................................................................................... gigawatt-hour hp........................................................................................................................................ horsepower HUC......................................................................................................................... Hydrologic Unit Code ID................................................................................................................................ internal diameter IM........................................................................................................................impingement mortality IMOption................................................................................................................................. IM BTA Option IPAC........................................................................................ Information for Planning and Consultation LLI................................................................................................................................ Low Level Intake Duke Energy I xii Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal �� Contents LOCA..................................................................................................................... loss -of -coolant accident Ibm....................................................................................................................................... pound -mass Ibs............................................................................................................................................... pounds $M..................................................................................................................................... million dollars m.................................................................................................................................................. meter m3.......................................................................................................................................cubic meters m3/d..........................................................................................................................cubic meters per day mm............................................................................................................................................millimeter MMP................................................................................Duke Energy Maintenance Monitoring Program Marshall...................................................................................................................... Marshall Steam Station MDCT.......................................................................................................... mechanical draft cooling tower McGuire....................................................................................................................McGuire Nuclear Station MGD....................................................................................................................... million gallons per day MGY...................................................................................................................... million gallons per year mg/L.............................................................................................................................. milligrams per liter MMP................................................................................Duke Energy Maintenance Monitoring Program mph.................................................................................................................................... miles per hour MW..........................................................................................................................................megawatts MWhr................................................................................................................................. megawatt -hours NCDT................................................................................................................. natural draft cooling tower NCDENR.............................................. North Carolina Department of Environment and Natural Resources NCDEQ....................................................................... North Carolina Department of Environmental Quality NCNHP..........................................................................................North Carolina Natural Heritage Program NCWRC................................................................................North Carolina Wildlife Resources Commission NEPA..................................................................................................... National Environmental Policy Act NMFS..................................................................................................... National Marine Fisheries Service NPDES............................................................................. National Pollutant Discharge Elimination System NPV............................................................................................................................... net present value O&M............................................................................................................... operation and maintenance PF........................................................................................................................... production foregone PM............................................................................................................................... particulate matter ppm..................................................................................................................................parts per million PROSYM.......................................................................................... Duke Energy Power System Simulation psi..................................................................................................................... pounds per square inch psia...................................................................................... pounds per square inch, absolute pressure QA............................................................................................................................... quality assurance QC.....................................................................................................................................quality control RC............................................................................. Main Condenser Cooling Water (reactor coolant) RF/RY.......................................................................................................................Fire Protection System RL...................................................................................... Conventional Low Pressure Service Water RN....................................................................................................................... Nuclear Service Water rpm........................................................................................................................revolutions per minute RTE.................................................................................................. Rare, Threatened, and Endangered Rule............................................................................................................ Clean Water Act §316(b) rule RV................................................................................... containment ventilation cooling water system SNSWP............................................................................................... Standby Nuclear Service Water Pond SPX........................................................................................................ SPX Cooling Technologies, Inc. Duke Energy I xiii Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal �� Contents Study..................................................................................Entrainment Characterization Study TDS.......................................................................................................................... total dissolved solids TSS....................................................................................................................... total suspended solids TSV......................................................................................................................through-screen velocity UHS............................................................................................................................... ultimate heat sink USACE...........................................................................................................U.S. Army Corps of Engineers USDOE................................................................................................................U.S. Department of Energy USEPA..............................................................................................U.S. Environmental Protection Agency USFWS........................................................................................................... U.S. Fish and Wildlife Service USGS...................................................................................................................... U.S. Geological Survey USNRC............................................................................................... U.S. Nuclear Regulatory Commission Veritas............................................................................................................. Veritas Economic Consulting WMO....................................................................................................World Meteorological Organization WOTUS...............................................................................................................Waters of the United States WWTP................................................................................................................wastewater treatment plant pg/L........................................................................................................................... micrograms per liter Pm................................................................................................................................................ micron PS/cm ........................................................................................................... micro Siemens per centimeter Duke Energy I xiv F)I This page intentionally left blank. Clean Water Act §316(b) Evaluation to Support 40 CFR §122.21 (r) McGuire Nuclear Station Executive Summary Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal Executive Summary Introduction In accordance with Section 316(b) of the Federal Register (79 FR, 48299)40 Code of Federal Regulations (CFR) §122 and §125, Duke Energy Carolinas, LLC (Duke Energy) submits the enclosed Clean Water Act (CWA) §316(b) study reports and supporting information for the McGuire Nuclear Station (McGuire). This Executive Summary provides an overview of the §122.21(r)(2) through (r)(13) study reports, which are included in Sections 2 through 13 of the Compliance Submittal Document. Duke Energy requests that determinations for impingement and entrainment best technology available (BTA) be provided separately for the stations' two intake structures: • Main Intake: withdraws raw water for cooling purposes through a shoreline -situated intake structure. Low Level Intake (LLI): withdraws water through a secondary intake to provide service water (continuously) and to support cooling system needs (on an infrequent basis) for thermal efficiency. Main Intake Based on the current design and operations of the Main Intake, Duke Energy requests the following determinations based on the supporting information listed below. 1. A determination of de minimis rate of impingement, based on the following: • A 2002 study documented low rates of impingement (2.2 to 2.3 fish/day excluding fragile species) and species diversity; as summarized in Section 4.5.1. Operations at McGuire (detailed in Section 5) and the fish community documented in Lake Norman (detailed in Section 4) have remained consistent since the 2002 impingement study, thus the data are valid and representative of current conditions. • The cost -benefit analyses (Section 11) indicated that the potential benefits of implementing an impingement -reduction technology for McGuire's Main Intake does not justify the potential social costs, as each potential alternative technology evaluated resulted in net negative benefits. 2. A determination of de minimis rate of entrainment, and thus no additional control requirements are necessary beyond existing facility controls and operational measures, based on the following: Results of a two-year entrainment characterization study performed at McGuire's Main Intake (Section 9) demonstrated that entrainment at McGuire consists primarily of post yolk -sac larvae of forage species (Clupeidae) and White Perch; however, data from ongoing annual monitoring (Section 4) demonstrates that Lake Norman continues to support a healthy forage fish base supportive of predatory species such as temperate and warm water basses. As such, reduction of clupeid losses due to entrainment and impingement is not expected to provide a substantial benefit to the fishery, as evidenced by a low equivalent yield impact of the various compliance scenarios (see Section 11). Duke Energy I E-1 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal Executive Summary The cost -benefit analyses (Section 11) indicated that the potential benefits of implementing an entrainment -reduction technology for McGuire's Main Intake does not justify the potential social costs, as each potential technology evaluated resulted in net negative benefits. Low Level Intake Based on the current design and operations of the LLI (secondary intake used for nuclear service water and thermal compliance during peak demand of late summer), Duke Energy requests the following determinations based on the supporting information listed below. 1. A determination of de minimis rate of impingement, based on the following: • Continuous operation of service water pumps results in through -screen velocities (TSVs) of less than 0.5 feet per second (fps) at the LLI. TSVs at the LLI structure are greater than 0.5 fps only when the LLI pumps operate, which is limited to one to five weeks during the warmest part of the year when the potential for impingement is low (i.e., during peak reservoir stratification). • The design depth and restriction of operations to during peak summer temperatures support the withdrawal of hypoxic water from the hypolimnion of a thermally stratified Lake Norman, when fish are least likely to occur at the depth of the LLI, and thus reducing the susceptibility of fish to impingement at the LLI. • The operational precautions employed prior to pump initiation and periodically during pump operation (periodic hydroacoustic monitoring of LLI to determine fish presence and density near the intake). 2. A determination of de minimis rate of entrainment, and thus no additional control requirements are necessary beyond existing facility controls and operational measures, based on the following: • Continuous operation of service water pumps results in TSVs of less than 0.5 fps at the LLI. TSVs at the LLI structure are greater than 0.5 fps only when the LLI pumps operate, which is limited to one to five weeks during the warmest part of the year when the potential for entrainment is low (i.e., during peak reservoir stratification). • The design depth and restriction of operations to during peak summer temperatures support the withdrawal of hypoxic water from the hypolimnion of a thermally stratified Lake Norman, when fish are least likely to be present at the depth of the LLI, and thus reducing the susceptibility of fish to impingement at the LLI. Station Description McGuire is a two -unit nuclear steam electric generating station in Huntersville, North Carolina, and is owned and operated by Duke Energy. Commercial operation of Unit 1 began in 1981, followed by Unit 2 in 1984 (Duke Energy 2017). McGuire uses once -through (open -cycle) condenser cooling and withdraws more than 125 million gallons per day (MGD) of raw water through a shoreline -situated Duke Energy I E-2 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal Executive Summary cooling water intake structure (CWIS) referred to as the Main Intake. Raw water is also withdrawn at a second intake (LLI) for nuclear service water (continuously) and to support cooling system needs (on an infrequent basis) for thermal efficiency and/or for compliance with a CWA §316(a) thermal effluent variance as identified in the National Pollutant Discharge Elimination System (NPDES) permit. Nuclear service water is piped directly to the two nuclear units via two 17,500 gallons per minute (gpm) (25 MGD) pumps. Cooling water is pumped via three 150,000 gpm (216 MGD) pumps and routed through a pipe to the Main Intake. The discharge of the non -contact cooling water withdrawn via McGuire's Main Intake is currently authorized under NPDES Permit No. NC0024392. Regulatory Nexus On August 15, 2014, the U.S. Environmental Protection Agency (USEPA) published in the Federal Register the NPDES — Final Regulations to Establish Requirements for Cooling Water Intake Structures at Existing Facilities and Amend Requirements at Phase I Facilities, referred to as the Final Rule (Rule) (USEPA 2014). The Rule establishes requirements under §316(b) of the CWA to ensure that the location, design, construction, and capacity of a CWIS reflect the BTA for minimizing impingement and entrainment at the CWIS. The Rule applies to existing facilities that withdraw more than 2 MGD from Waters of the United States (WOTUS), use at least 25 percent of that water exclusively for cooling purposes, and have an NPDES permit. The Rule is applicable to McGuire due to the following: • McGuire withdraws raw water from Lake Norman, the source waterbody, through the Main Intake for use in a once -through cooling water system and from the LLI for service water and to support (on an infrequent basis) the station's cooling system. • McGuire meets the minimum 2 MGD withdrawal rate criteria for actual intake flows (AIF) and design intake flows (DIF). The total DIF at McGuire is 2,969 MGD (2,926 MGD at the Main Intake and 43 MGD at the LLI). Based on data from January 2015 through December 2017, average annual AIF was 2,604 MGD at the Main Intake and 27 MGD at the LLI. • McGuire uses greater than 25 percent of the water withdrawn from Lake Norman exclusively for cooling water purposes (approximately 98.5 percent, or 2,926 MGD). Because McGuire is subject to the Rule, Duke Energy has prepared technical information required under CFR §122.21(r)(2) through (r)(13) (see Table 1-1 of Section 1) for submittal to the North Carolina Department of Environmental Quality (NCDEQ) Division of Water Resources NPDES permit Director (Director) to facilitate the determination of BTA for the facility. Under the Rule, the owner or operator of a facility must choose from one of seven compliance options for impingement mortality (IM) reduction or an alternate exemption, as provided by the Rule. The facility must also provide results from site -specific entrainment studies and information identified at §122.21(r)(2) through (r)(13) and §125.98 to the permitting authority to aid in the determination of whether site -specific controls would be required to reduce entrainment. At §125.98, the Rule identifies specific information that the Director Must (§125.98(f)(2)) consider and information that the Director May (§125.98(f)(3)) consider in a site -specific entrainment BTA determination. This Executive Summary describes the evaluation of these compliance options and the Must and May factors for the Director to consider, as they relate to McGuire. Duke Energy I E-3 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Executive Summary r Impingement Mortality Compliance Per §122.21(r)(6), the owner of a facility must identify the chosen method of compliance with the IM standard for the entire facility, or for each CWIS. Facilities may select one of seven IM BTA compliance options (IM Options) provided in §125.94(c) paragraphs (1) through (7) unless pursuing compliance under paragraphs (c)(11) de minimis rate of impingement or (c)(12) low capacity utilization power generating units (Table E-1). The facility must also provide sufficient information and justification to support the selected alternative compliance approach. Methods used to assess the compliance options for addressing the requirements of §122.21(r)(6) of the Rule are summarized in Section 6 of this document. Table E-1. Impingement Mortality Compliance Options Option 1' A closed -cycle recirculating system Option 2' A CWIS with a maximum design through -screen velocity of 0.5 feet per second (fps) Option 3 A CWIS with a maximum actual through -screen velocity of 0.5 fps Option 4' An existing2 offshore velocity cap located a minimum of 800 feet offshore with bar screens or some other marine mammal, sea turtle, and large aquatic organism exclusion device A modified traveling screen system (i.e., modified Ristroph screens with a fish handling and Option 5 return system, dual flow screens with smooth mesh with fish handling systems, or rotary screens with fish returns or vacuum returns) Any combination or system of technologies, management practices, and operational Option 6 measures that achieve a 12-month performance standard of no more than 24 percent mortality including latent mortality for all non -fragile species Perform a 12-month impingement mortality study consisting of at least monthly monitoring Option 7 and an assessment of latent mortality (measured 18 to 96 hours). For compliance under this option, results must demonstrate no more than 24 percent impingement mortality, inclusive of latent mortality, for each CWIS or total facility. De Minimis Rate Option available for facilities that can demonstrate, to the director's satisfaction, impingement of Impingement rates low enough to justify that additional impingement controls are not warranted. Low Capacity Option available for facilities or individual unit and CWIS systems that operate with low Utilization Rate frequency and can demonstrate less than 8 percent capacity utilization, averaged over a 24- (CUR) month period 'Represents streamlined technologies that are pre -approved and that do not require facilities to perform biological studies or biological compliance monitoring associated with the IM standard. 2Per the Rule at §125.94(c), to be compliant, the existing offshore velocity cap must have been installed on or before October 14, 2014. Duke Energy I E-4 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal Executive Summary Duke Energy performed a screening -level evaluation of IM reduction technologies and alternative operational measures for the LLI and the Main Intake to identify feasible options that could be implemented to reduce impingement at McGuire. Alternatives that were not considered feasible were removed from further consideration. The remaining (i.e., short-listed) options were evaluated in greater detail and the findings, which are presented in Section 6, identify the technology or technologies that could result in the greatest benefit while minimizing implementation, maintenance, and operational costs. The compliance options were evaluated using the following step -wise process: 1. Determine if McGuire is currently compliant with BTA for impingement under IM Options 1, 2, or 3, based on existing design and operational data. 2. Evaluate existing impingement data to determine if impingement rates support a de minimis rate of impingement determination by the Director. 3. Calculate the most recent three-year average low capacity utilization rate (CUR) to determine if it is below the 8 percent average capacity factor threshold established in the Rule. 4. Assess the potential efficacy, technical feasibility, and relative costs of IM reduction technologies and operational measures applicable to open -cycle cooling systems (IM Options 4, 5, and 6). 5. Evaluate the potential efficacy, technical feasibility, and relative costs of ceasing operations. McGuire is an open -cycle system withdrawing more than 125 MGD of raw water and the existing design and operation of the Main Intake results in TSV estimates of greater than 0.5 fps; therefore, it does not comply with BTA Options 1, 2, or 3. Nuclear service water is withdrawn continuously via the LLI structure resulting in TSVs less than 0.5 fps at the LLI. During limited periods (i.e., one to five weeks per year), the additional LLI pumps are operated to supply raw water from the bottom of Lake Norman to the Main Intake, resulting in TSVs greater than 0.5 fps at the LLI. Additionally, based on existing conditions, McGuire does not currently comply with IM BTA compliance Option 4 (typically applies to facilities in coastal environments) or Option 7 (not applicable as the most recent impingement study performed at McGuire did not include an assessment of latent mortality). Further, McGuire does not meet the requirements for compliance based on Low Capacity Utilization Rate (CUR) as a year-round, base load facility (Table E-2). Therefore, Duke Energy performed a screening -level evaluation of IM reduction technologies and alternative operational measures for the Main Intake and LLI to identify feasible options that could be implemented to reduce impingement at McGuire and achieve compliance under the remaining IM BTA options (provided in Section 6 and Appendix 6-A). The results of this evaluation were used to identify the de minimis rate of impingement as the preferred compliance option for McGuire's Main Intake and LLI, as described in the following sections and summarized in Table E-2. Duke Energy I E-5 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Executive Summary r Table E-2. Summary of Feasibilitv of Impingement Mortalitv Compliance Options Closed -cycle recirculating McGuire is an open -cycle system withdrawing > 125 system (CCRS) MGD. CWIS with design TSV <0.5 fps No Main Intake and LLI design TSVs > 0.5 fps. W0 Main Intake and LLI operations (during warm Option 3 p CWIS with actual TSV <0.5 No temperatures) result in actual TSVs > 0.5 fps. fps 0 Typical LLI operations (service water) result in actual TSVs < 0.5 fps. Option 4' Existing offshore velocity cap No Not applicable or feasible at McGuire. Option 5 Modified fish -friendly traveling Yes Feasible but not warranted based on low IM. screen system A system of technologies and operational controls Option 6 System of technologies No are used to adaptively manage the LLI to minimize impingement. Option 7 Comply with 12-month IM No No current study has been performed. standard De Minimis Impingement rates sufficiently LLI is adaptively managed to avoid operation when Rate of low to justify no additional Yes impingeable-sized fish are present. Impingement controls Low Capacity Facility, unit, or CWIS Utilization Rate operates with frequency less No Typically operations exceed 8 percent CUR. (CUR) than 8 percent averaged over 24-month period 'Represents streamlined technologies that are pre -approved and that do not require facilities to perform biological studies or biological compliance monitoring associated with the IM standard. Impingement Mortality Characterization Although not required by the Rule, data from an impingement characterization study were analyzed (see Section 4) to support the evaluation of IM Options summarized in Table E-1. The study was performed at the Main Intake from December 2000 to November 2002 (Duke Power 2003) and these results were used to estimate annual IM losses representative of actual water withdrawals during 2016 and 2017 (Table E-3). Based on the Duke Power (2003) impingement study summarized in Section 4 and actual volumes withdrawn at McGuire (from 2016 and 2017), annual IM was estimated at 2,175 fish in 2016 and 2,113 fish in 2017 (Table E-3) for an estimated two-year average of 2,144 fish. Discounting the fragile species (clupeids with impingement survival rates of less than 30 percent) from the annual IM estimates resulted in revised annual estimates of 826 and 797 fish for 2016 and 2017, respectively, or a loss of approximately 2.2 to 2.3 non -fragile fish per day (Table E-4). Duke Energy I E-6 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Executive Summary r Table E-3. Species and Life Stage -Specific Estimated Annual Impingement Loss Estimates for 2016 and 2017 based on Actual Water Withdrawals at McGuire Nuclear Station CommonEMM .. MM . . Threadfin Shad Dorosoma Fragile 257 633 890 253 633 886 petenense Alewife Alosa Fragile 318 18 336 296 16 313 pseudoharengus Black Crappie Pomoxis Robust 12 3 15 13 3 16 nigromaculatus Blue Catfish Ictalurus furcatus Robust 22 -- 22 22 -- 22 Bluegill Lepomis Robust 103 40 143 101 37 138 macrochirus Catfish Species Ictaluridae Robust 7 8 15 7 8 15 Channel Catfish Ictalurus Robust 30 33 63 29 31 60 punctatus Common Carp Cyprinus carpio Robust -- 4 4 -- 4 4 Eastern Silvery Hybognathus Robust 2 -- 2 2 -- 2 Minnow regius Flathead Catfish Pylodictis olivaris Robust 40 2 42 39 2 41 Gizzard Shad Dorosoma Fragile 22 35 56 21 32 53 cepedianum Golden Shiner Notemigonus Robust 23 17 41 23 17 40 crysoleucas Herring Species Alosa spp. Fragile 7 6 13 6 5 11 Hybrid Sunfish Lepomis spp. Robust 6 -- 6 6 -- 6 Largemouth Micropterus Robust 7 11 18 7 11 18 Basso salmoides Quillback Carpiodes Robust -- 1 1 -- 1 1 cyprinus Redbreast Lepomis auritus Robust 26 15 41 26 15 41 Sunfish Redear Sunfish Lepomis Robust 18 2 20 18 2 20 microlophus Spotted Bass5 Micropterus Robust 7 4 11 6 4 10 punctulatus Striped Bass Morone saxatilis Robust -- 77 77 -- 72 72 Duke Energy I E-7 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Executive Summary r Common Name Scientific Name Vulnerability Juv Age 1+ Species Juv Age 1+ Spec Total Tot MoroneTemperate Bass .. Robust Species Unidentified Unidentified Fish Robust 26 28 54 26 28 54 Osteichthyes Warmouth Lepomis gulosus Robust 20 -- 20 20 -- 20 White Bass Morone chrysops Robust 21 56 77 21 54 75 Pomoxis White Crappie Robust 23 -- 23 24 -- 24 annularis Morone White Perch Robust 43 103 146 42 92 134 americana Yellow Perch Perca flavescens Robust 22 -- 22 22 -- 22 Total 1,072 1,103 2,175 1,040 1,073 2,113 (--) Indicates that this species was not collected during the identified sampling year; Juv = juvenile Table E-4. Summary of Estimated Impingement Mortality under Existing Conditions Excluding Fragile Species at McGuire Nuclear Station 2016 2,175 1,349 (62.0%) 826 2.3 2017 2,113 1,316 (62.3%) 797 2.2 The 10-year-old study employed methodologies that are consistent with contemporary methods and quality assurance/quality control (QA/QC) protocols. Further, the withdrawal rates and screen operations at McGuire have remained consistent over time (see Sections 3 and 5) and are therefore representative of current conditions at the facility. Based on Duke Energy's annual Maintenance Monitoring Program data, the biological community of Lake Norman has remained consistent over the past twenty years, with expected, routine annual variation observed in the abundance of specific clupeid species (Duke Energy 2015). As such, these data indicate that the impingement data collected during the 2000-2002 study performed at McGuire are representative of existing conditions at the Main Intake the fish community in Lake Norman is not adversely impacted by operations at McGuire. Summary of Selected Impingement Mortality Compliance Options Duke Energy performed a screening -level evaluation of IM reduction technologies and alternative operational measures for the LLI and the Main Intake to identify feasible options that could be Duke Energy I E-8 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal Executive Summary implemented to reduce impingement at McGuire. The evaluation supports a determination of de minimis rate of impingement for McGuire's LLI and Main Intake located on Lake Norman. Main Intake Based on the evaluations and data presented in Section 4 and Section 11, annual impingement at McGuire's Main Intake was estimated to be between 2,113 (based on 2016 operations) and 2,175 (based on operations in 2017) fish per year. Over half (approximately 62 percent) of the estimated total annual impingement losses presented for 2016 and 2017 were comprised of fragile clupeid species (as defined at 40 CFR §125.92(m)), which exhibit inherently low impingement survival (less than 30 percent survival as defined by the Rule) and are not subject to the IM standard. Excluding these fragile species, total annual impingement at McGuire is estimated at 826 and 797 fish per year, or approximately 2.3 and 2.2 fish per day in 2016 and 2017, respectively. The estimated annual IM losses at McGuire are relatively low with respect to the natural life history of the resident fish species in Lake Norman. In general, fish have reproductive strategies which promote early maturity with high fecundity and no parental care (referred to as r-selection reproductive strategy [MacArthur and Wilson 1967]). Therefore, fish spawn many eggs but few survive through the developmental stages, from eggs to larvae to adults. The high reproductive capacity (fecundity) compensates for the high natural mortality rates experienced in early life stages. For example, the low end of estimated fecundity rates of Bluegill (Lepomis macrochirus) or Largemouth Bass (Micropterus salmoides) is approximately 10,000 eggs per female per spawning event. Assuming 99 percent of eggs do not reach adulthood (EPRI 2004a), 25 reproducing adult fish would replace the number of fish lost annually to impingement at McGuire. Based on the species composition (high numbers of fragile species), minimal estimated annual IM losses, low rate of impingement, and estimated equivalent adult, production foregone, and equivalent yield losses to the fishery (see Section 11), a determination of de minimis rate of impingement is requested as the IM BTA for McGuire's Main Intake, as defined by the Rule and summarized in Table E-1. Further, Lake Norman is a managed fishery that continues to support a balanced and productive fish community. These data demonstrate that the current design and operations result in minimal IM and that the cost of implementing an impingement -reduction technology for McGuire's Main Intake does not justify the potential social benefits. Low Level Intake Results from the screening -level evaluation (Section 6) support the selection of the de minimis rate of impingement compliance option for the McGuire LLI, as defined by the Rule, based on the following factors: 1. Continuous operation of service water pumps results in TSVs of less than 0.5 fps at the LLI; 2. TSVs at the LLI structure are greater than 0.5 fps only when the additional LLI pumps intermittently operate, which is limited to one to five weeks per year and only occurs during the period of peak reservoir stratification when the potential for impingement is low; 3. The design depth and restriction of operations to during peak summer temperatures support the withdrawal of hypoxic water from the hypolimnion of a thermally stratified Lake Norman, when fish are least likely to be present at the depth of the LLI, and thus reducing the susceptibility of fish to impingement at the LLI; and Duke Energy I E-9 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Executive Summary r 4. The operational precautions employed prior to pump initiation and periodically during pump operation (periodic hydroacoustic monitoring of LLI to determine fish presence and density near the intake). These factors represent a framework for evaluating and adaptively managing LLI operations to minimize the risk of operating when impingeable-sized fish are present near the LLI, and minimizes the susceptibility of aquatic organisms in Lake Norman to impingement during LLI operations. Analyses Performed in Support of an Entrainment BTA Determination This section summarizes the analyses required by the Rule for submission to the Director in support of a site -specific best professional judgment (BPJ) review and entrainment BTA determination. Although information presented under the requirements of §122.21(r)(2) through (r)(8) of the Rule (i.e., Sections 2-8 of this document) provides useful perspective on the location, design, and operation of the existing facility, this section focuses on those reports prepared under §122.21(r)(9) through (r)(13) of the rule (i.e., Sections 9-13), which offer perspective on entrainment BTA. The process and results for evaluating the social costs, social benefits, and other environmental impacts related to entrainment BTA, as prepared under §122.21(r)(9) through (r)(12), are outlined along with a description of and results from the peer review process in §122.21(r)(13). Entrainment Characterization Study — §122.21(r)(9) A two-year Entrainment Characterization Study (Study) was performed at McGuire in 2016 and 2017. The Study plan was reviewed by the North Carolina Department of Environmental Quality (NCDEQ) and comments were incorporated into the Study plan report. Section 9 of this document summarizes the two-year entrainment Study and the final report is provided in Appendix 9-A. Twice -monthly entrainment samples were collected at the entrance to the Main Intake structure on Lake Norman, upstream of the bar racks and screens, using a pumped sampling technique. Sampling was performed from March 1 through October 31 in 2016 and 2017 (16 sampling events in each year). Mean daily densities for days between each of the twice -monthly sampling events were determined through linear interpolation. The daily densities were then used to calculate the mean rate of entrainment by month, which was multiplied by the total monthly cooling water volume withdrawn at McGuire (see Section 5) to estimate total annual entrainment losses at the McGuire Main Intake for 2016 and 2017 using actual water withdrawal volumes. These data were also used to develop annual entrainment loss estimates under hypothetical maximum water withdrawals at McGuire. Comprehensive Technical Feasibility and Cost Evaluation Study — §122.21(r)(10) The Rule requires an evaluation of feasibility and costs for alternative entrainment control measures to support an entrainment BTA determination by the Director. Potential social costs of alternative entrainment control measures must be estimated and compared to potential social benefits. Due to the diversity in organism biology, habitat requirements, and different body sizes of entrainable organisms, the available technologies and measures expected to be reasonably effective at reducing Duke Energy I E-10 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal Executive Summary entrainment are relatively limited. An evaluation of potential entrainment reduction technologies for McGuire was performed to identify those that are feasible and practicable to address requirements listed at §122.21(r)(10). The process for developing this information for McGuire included: • Evaluating potential siting locations to identify options posing minimal impact on station operations and the surrounding community; • Assessing potential for impact on nuclear safety'; • Assessing potential for overcoming operational problems (e.g., no negative impacts to intake velocities or flows, does not exceed pressure specifications of condensers); • Evaluating potential for impacting operational reliability of McGuire; • Evaluating facility -level Operation and Maintenance (O&M) costs associated with each technology; and • As required by the Rule, considering the feasibility and costs of three potential technologies that could reduce rates of entrainment at McGuire, which include: 1. Retrofit to closed -cycle cooling; 2. Installation and operation of fine -mesh screens (FMS) with an aquatic organism return system (includes fine -slot wedgewire screens and/or dual -flow screens) at the Main Intake; and 3. Use of alternate water sources to replace all or some of the water used in the once -through cooling system. Assessment of Compliance Technology Feasibility A cursory assessment of aquatic filter barriers', porous dikes, and variable speed pumps' indicated these technologies are infeasible and/or impractical at McGuire; thus, they were excluded from further consideration. Alternate water supply sources were identified; however none could provide the amount of water needed to replace the significant volume of McGuire's intake flow, and thus were excluded from further consideration. However, conversion to closed -cycle cooling (mechanical ' The Rule (§125.94[f]) states that if compliance with the Rule conflicts with the safety requirements established by the U.S. Nuclear Regulatory Commission (USNRC), the Director must make a site -specific determination that would resolve the conflict with such safety requirements. The retrofit therefore attempts to avoid interfering with or modifying the station's nuclear safety system or modifying the nuclear safety water intake structure. Modifications to the station would need to be approved by the USNRC. ' The small pore sizes associated with filter barriers and porous dikes would necessitate construction of an approximately 1,200-foot-long barrier, which would enclose a portion of Lake Norman, potentially leading to fish entrapment within the intake cove. 3 McGuire is a base load nuclear station, therefore generation does not fluctuate to allow load -following and flow reduction. During cooler months, one or more pumps are turned off. Duke Energy I E-11 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Executive Summary r draft cooling towers [MDCT]) and installing FMS with an aquatic organism return system were considered technically feasible retrofit technologies for McGuire; these two technologies were retained for further evaluation. For the two potentially feasible technologies, a conceptual design, including location of infrastructure, costs associated with engineering, scheduling, permitting, and constructing the retrofit, and O&M costs through the remaining life of the station were developed. The net present value (NPV) of the social costs of each technology was then developed based on the estimated start of operations for each technology and estimated retirement date for the facility. The complete process and results of the evaluations are provided in Section 10. A summary of the results are presented below. Costs of Compliance Technologies Social Costs Social costs were used to determine whether the potential entrainment reduction technology costs would result in the plant becoming economically unfeasible to operate. Since a premature shutdown of McGuire would result in social costs (i.e., lost jobs, income, and tax base, and increased generation costs and emissions), installing entrainment reducing technologies at McGuire to comply with the Rule represents additional operational costs that would most likely be passed onto Duke Energy's electric customers in the form of higher rates. Thus, the social costs were determined assuming that Duke Energy would incur these additional costs and pass them on to electric customers. The social costs of installing entrainment reduction technologies are estimated by determining the design, construction, and installation costs of the evaluated technologies along with the operation and maintenance (O&M), power system, externality, and permitting costs. Following the requirements of the Rule, Table 1 evaluates social costs under two discount rates: 3 and 7 percent (79 FR 158, 48428). Social costs include costs associated with compliance with governmental regulations, power system effects, and externalities (Table E-5). Table E-5. Components of the Social Costs of Entrainment Reduction Technologies •. Compliance Costs (Capital and O&M) Outages Property Value Effects Government Regulatory Costs Back Pressure and Equipment Load Water Consumption Effects Energy Penalties Winter Fishery Effects 4 The remaining life of each generating unit and technology impacts O&M costs, potential future technology repair costs (if the life of the unit is longer than the anticipated life of the technology), and benefits. For the purpose of the analyses, McGuire generating units were assumed to operate through June 2041 (Unit 1) and March 2043 (Unit 2), based on existing licensing information from the USNRC (2002). Duke Energy I E-12 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Executive Summary r The estimated social costs (in 2018 dollars) of potential compliance technologies at McGuire are presented in Table E-6. The analysis discounts the future stream of each of these social costs at the relevant discount rate and sums them over the years they are specified to occur to develop the total social cost estimate presented in the next to last column in Table E-6; annual social costs for each technology are presented in the last column. Also shown on Table E-6 are the compliance costs. Compliance costs are assumed to occur over a 13-year period for the cooling tower retrofit scenario and over the remaining life of the station (a 19- year period) for FMS scenario, as discussed in Section 10.1.2. Power system costs are due to construction -related outage impacts and efficiency and auxiliary load impacts during operation. Table E-6. Total Engineering and Social Costs of Feasible Technology Options at McGuire Closed - Cycle Cooling Retrofit Total Design, Annual Power Construction, O&M Compliance S stem Externalii & Installation Costs Costs2 Costs2 Costs3 Costs 0. $1.49B $6.4M $922.10M $277.1 M $8.1 M 2.0-mm Fine -Mesh Ristroph $34.45M $2.42M $29.01 M $0.36M $01M Traveling Screens $0.21M $1.47B $113.2M $4.2K $51.2M $2.69M $0.1 M $733.6M $56.4M $2.81K $29.4M $1.55M Note: $M = million dollars; $B = billion dollars 'The compliance costs are undiscounted and in 2018 dollars. The social costs associated with each technology are discounted at 3 and 7 percent using the timing of technologies (see Section 10, Table 10-17). 2Costs that contribute to increases in electricity prices. 3 Externality costs include decreases in social wellbeing resulting from property value, water consumption (i.e., lost hydroelectric generation), and winter fishery (i.e., recreation) impacts. Other Costs Under certain compliance technology scenarios, the reduction or elimination of warm water discharges at McGuire could occur, and could potentially lead to the loss of the thermal refugia that supports the existing winter fishery and associated social costs (from reduced angler catch rates) and benefits (potential localized improvements in water quality parameters such as dissolved oxygen). However, DO does not typically decrease to levels below the North Carolina water quality standards within the McGuire discharge zone; therefore, the reduction in thermal discharges may not alter water quality substantially in this area (Duke Energy 2017, 2018). Duke Energy I E-13 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal Executive Summary The fish species composition found in the vicinity of the discharge may also change in response to reduced warm water discharges. Depending on the species, this may be seen as either a cost or a benefit. Introduced species native to tropical regions may find refuge in the discharge areas of power plants, which allows these species to persist in their non-native range and the reduction or elimination of this refuge would be seen as a benefit. However, an example of a species which may use the thermal discharge as refuge in Lake Norman is the Threadfin Shad, which also provides an important forage base for recreational predator species. Annual fish community sampling throughout Lake Norman shows that abundance and size structure of representative important species (defined as Largemouth Bass, Alabama Bass, Bluegill, and Redbreast Sunfish) are not statistically different between thermally -influenced zones and non - influenced zones (Duke Energy 2017, 2018). Therefore, the effects (i.e., benefits) of reducing thermal discharges with the installation of MDCTs at McGuire are not expected to be substantial. Benefits Valuation Study — §122.21(r)(11) The goal of the Benefits Valuation Study was to demonstrate the estimated social benefits that would be derived from impingement and entrainment reductions based on implementation of one or more technologies at McGuire. Estimates of Changes in Stock Size or Harvest Levels Baseline (existing) impingement and entrainment losses (under actual and maximum water withdrawals) and impingement and entrainment losses under selected compliance technologies (MDCT and FMS) were estimated using 2016 and 2017 entrainment data collected at McGuire (Section 9). The estimated reductions in entrainment were calculated for the MDCT scenario assuming a percent reduction in water withdrawal volumes estimated based on preliminary design assumptions, while the FMS scenario was estimated by applying an exclusion calculation based on body size dimensions and a 2.0-mm mesh opening. The potential benefits to the fishery, due to changes in stock size or harvest levels, of the estimated entrainment reductions were then estimated using commonly applied population and harvest models (EPRI 2004a, 2012) that use numeric and mass based data in the Production Foregone (PF) model, Equivalent Adult (EA) model, and Equivalent Yield (EY) model. These three models were used to determine the potential entrainment reduction benefits (for both "use" and "nonuse" scenarios) on commercials and recreational harvest, as well as the effects of loss of forage associated with the entrainment of other finfish. Parameters used in population modeling were derived from the literature (EPRI 2004a; USEPA 2006) and also reflect site -specific information on the fishery of Lake Norman (when available) and data specific to the recreational uses of the fishery. An evaluation of model uncertainty was performed and is discussed in Appendix 11-E. In evaluating the potential social benefits of entrainment reducing technologies determined to be feasible for McGuire, a third option was evaluated: a complete or 100 percent reduction in entrainment. This option assumes a shutdown and subsequent retirement of both units at McGuire, s Since McGuire does not currently support a commercial fishery, this evaluation focused on recreational harvest. Duke Energy I E-14 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Executive Summary r as described in Section 11. To develop the NPV estimates, the benefits estimated for each alternative were discounted at 3 and 7 percent annually and summed over the specified time period used in the analysis. Monetization of Benefits The benefits of reductions in entrainment and impingement losses of early life stage fish are best evaluated by translating losses to an ecological or human -use context, and assessing differences in total losses among compliance technology scenarios discussed in Section 10. The methodology for developing species and life -stage specific estimates of the potential incremental reductions in entrainment or impingement among compliance technology scenarios is detailed in Section 11. The estimation of social benefits was based on use benefits derived from potential changes in recreational fishing stocks (e.g., equivalent adults, forage production foregone, and equivalent yield) and their associated economic effects annualized over the remaining useful plant life (Section 10.1.2). Based on an evaluation of the potential for nonuse benefits of entrainment reduction at McGuire, and given the precepts of nonuse values, the nonuse benefits of reducing entrainment at McGuire are anticipated to be low. Specifically, given estimated entrainment reduction costs and benefits, and the absence of federal or state listed species in entrainment (Section 9), impingement (Section 4 and Section 6), and source waterbody assessments (Section 4), correctly measured nonuse benefits would not impact a BTA determination that considers benefits and costs based on historically applied criteria. The present and annual recreational benefit values for each evaluated technology are presented in Table E-7. To develop the present value estimates, the benefits estimated for each feasible alternative are discounted at 3 and 7 percent annually and summed over the specified time period used in the analysis. 2016 Entrainment Data 2017 Entrainment Data Discount Technology 9Y Present Annual Present Annual Value Value Value Value 100% Reduction $314,188 $24,168 $25,121 $1,932 3% Mechanical Draft Cooling Towers $309,275 $23,790 $24,723 $1,902 2.0-mm Fine Mesh Screens $478,043 $25,160 $25,790 $1,357 100% Reduction $139,283 $10,714 $10,632 $818 7% Mechanical Draft Cooling Towers $137,106 $10,547 $10,463 $805 2.0-mm Fine Mesh Screens $238,348 $12,545 $11,906 $627 Note: Higher values for FMS are due to the timing of the technologies (which includes remaining useful plant life) and the discount factors applied to the benefits (see Section 10, Table 10-18 for timing of technologies) Other Benefits Other benefits from reducing entrainment can include ecosystem effects such as population resilience and support, nutrient cycling, natural species assemblages, and ecosystem health and Duke Energy I E-15 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal Executive Summary integrity (79 FR 158, 48371). The fisheries benefits study (summarized in Section 11) does not evaluate other effects on the fish community, such as density -dependent influences including increased competition, predation, or increased introduced species populations. Increased survival of forage species would increase competition among the forage fishes, as well as provide a greater forage base for predators. The dynamic effects among native and non-native predators are not known (for instance, improved Largemouth Bass relative weight [Duke Energy 2017], or greater increases in the Spotted Bass population). The existing Main Intake does not include an aquatic organism return system and has no means to return biomass to the source waterbody. A reduction in entrainment or impingement, as well as the installation of an organism return system would allow carbon (as live or dead fish) to be returned to Lake Norman. Live returned organisms would then be made available as prey or to grow as adults, and dead organisms would be made available as a resource for scavengers, detritivores, or decomposers. Non -water Quality Environmental and Other Impacts Study — §122.21(r)(12) The Rule at §122.21(r)(12) calls for assessment of other non -water quality environmental impacts, including estimates of the level of impact, for each technology or operational measure considered under §12.21(r)(10). It also calls for discussion of reasonable efforts to mitigate the impacts; this information is presented in Section 12. The evaluation must address, if relevant to the alternative technology being assessed, the following items: • Estimates of changes to energy consumption, including but not limited to, auxiliary power consumption and turbine backpressure energy penalty; • Estimates of increases in air pollutant emissions; • Estimates of changes in noise generation; • A discussion of potential impacts to safety; • A discussion of facility reliability; • Estimation of changes in water consumption; and • Discussion of efforts to mitigate these adverse impacts. The conceptual approach to each technology (e.g., location and design of the cooling towers), as defined in Section 10, has an important effect on the level of impacts discussed in Section 12. The quantitative engineering and costing analyses presented in Section 10 includes an evaluation of potential impacts and incorporates reasonable estimates of impact mitigation and associated costs, thus concepts and approaches presented in Section 10 and 12 are related. Peer Review — §122.21(r)(13) As required by the Rule at §122.21(r)(13), the reports prepared under §122.21(r)(10)—(r)(12) underwent external peer -reviewed by subject matter experts. Four expert peer reviewers were selected in fields relevant to the material presented in the submittal package (i.e., power plant engineering, aquatic biology, and resource economics). The qualifications of the peer reviewers were submitted to NCDEQ on July 27, 2015. Consistent with the Rule's requirements, Section 13 of this document provides a summary of the peer reviewer qualifications (Appendix 13-A), Duke Energy I E-16 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal Executive Summary documentation of formal peer review comments and responses to those comments, and includes confirmation from reviewers of their satisfaction with responses to comments and recommended revisions. Additionally, informal peer review and guidance was requested during project development regarding the overall approach to developing the Study Plans for entrainment characterization as well as specifics on key technical issues related to entrainment -related reports. Entrainment BTA Factors that Must Be Considered The Rule requires that the Director consider several factors in the written explanation of the proposed entrainment BTA determination. The following Must factors to be considered for entrainment BTA (§125.98(f)(2)) are: • Numbers and types of organisms entrained, including federally listed, threatened and endangered species, and designated critical habitat (e.g., prey base, glochidial host species); • Impact of changes in particulate emissions or other pollutants associated with entrainment technologies; • Land availability as it relates to the feasibility of entrainment technology; • Remaining useful plant life; and • Quantitative and qualitative social benefits and costs of available entrainment technologies. While each of the Must factors are considered separately in Section 10 for the potential technologies considered (i.e., MDCT and FMS with an aquatic organism return), a brief summary of findings for each factor is presented below along with references to the relevant section(s) of the report. Numbers and Types of Organisms Entrained Sections 9 and 11 present the number and type of organisms entrained based on the two-year Study at McGuire, which were then annualized and adjusted for station flows (design and actual intake flows) to estimate total annual entrainment at McGuire. The annual estimates are presented separately for 2016 and 2017 based on the rates of entrainment documented during the 2016-2017 Study. Total annual entrainment at McGuire, based on the actual water withdrawn6 over the two-year period, was estimated at 476.8 million ichthyoplankton in 2016 and 374.7 million ichthyoplankton in 2017. Annual entrainment at McGuire included 12 distinct species from 8 families of fish, and consisted primarily of post yolk -sac larvae (48 percent) and young -of -year (51 percent) in 2016, and post yolk -sac larvae (98 percent) in 2017. The primary period of ichthyoplankton entrainment at the McGuire CWIS occurred during late spring to early summer, from March through June (see Section 9). The period of entrainment observed in the Study is consistent with observations made at other southeastern U.S. reservoirs (EPRI 2011). It 6 Actual water withdrawals as referenced here and in Sections 9 and 11 are based on volumes withdrawn during the two-year Study and are not the same as the actual intake flow (AIF) values as defined by the Rule at §125.95(a). Duke Energy I E-17 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal Executive Summary is also consistent with documented life history information for the species entrained at McGuire (summarized in Appendix 4-A). Annual entrainment loss estimates for the young -of -year life stage are primarily based on a single event collection of a relatively large number of Inland Silverside (Menidia beryllina). This collection is considered an anomaly and represents the first documented occurrence of this species in Lake Norman; as such, a sensitivity analysis was performed to quantify model response to inclusion of this species (see Appendix 11-A). Excluding this introduced species from the data, the 2016 entrainment losses were dominated by post yolk -sac larvae (95 percent), similar to 2017. These data indicate that post yolk -sac larvae of introduced White Perch (Morone americans) and several species from the Clupeidae family are most susceptible to entrainment at the McGuire CWIS (Main Intake). With the exclusion of anomalous Inland Silverside, clupeids represented 82 to 90 percent of entrainment and other than White Perch, few recreational species were entrained. No endangered or threatened species were collected during either year of the Study, and based on the absence of documented occurrences in Lake Norman, none are anticipated to be susceptible to entrainment at the McGuire Main Intake. It is important to place the rates of entrainment at McGuire into the context of the trends documented for Lake Norman, the source waterbody (see Section 4): • Duke Energy has monitored the Lake Norman fishery for over 30 consecutive years; this monitoring has demonstrated a stable and balanced, self-sustaining population with a healthy forage fish base supportive of predatory species such as temperate and black basses (Duke Energy 2017). • Some interannual variation has been documented in Lake Norman, which shows a shifting species composition in response to introduction of non-native species; however, these trends are not associated with or impacted by operations at McGuire (Duke Energy 2017). • The direct and indirect effects of the loss of organisms at McGuire, as demonstrated through modeling (specifically designed to overestimate effects), resulted in a non -observable impact to the recreational fishery (see Section 11). These findings are interrelated and driven by the same factors: (1) species and life stages entrained at McGuire exhibit high natural mortality, and (2) entrainment losses affect a very small portion of the total resources available in Lake Norman. The majority of entrainable organisms at McGuire were common fragile forage species resulting in a non -observable impact on the recreational fishery and minimal nonuse value impacts. Recreational species entrained at McGuire represented between 4.2 percent (2016) and 17.4 percent (2017) of total annual entrainment, with the majority of those consisting of post yolk -sac larvae. The largest contribution to these values was from White Perch with an estimated average 32.5 million post yolk -sac larvae entrained between 2016 and 2017. The relatively small portion of White Perch eggs that were entrained (approximately 1.1 million) was likely due to the demersal, adhesive nature of White Perch eggs (Rohde et al. 1994). To put these entrainment numbers into context, a single White Perch female (depending on age) can produce between 50,000 and 360,000 eggs per spawning event (Rohde et al. 1994). Because this species reaches reproductive maturity early in life (as early as age 1), exhibits high fecundity (50,000 and 360,000 eggs per spawning Duke Energy I E-18 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Executive Summary r event), and is a habitat generalist during spawning, White Perch can rapidly become established in reservoirs and has been shown to outcompete other natives in the fish community (Rohde et al. 1994). Further, White Perch was introduced into Lake Norman, and has been implicated as one of several introduced species likely responsible for declining populations of the native Largemouth Bass (Duke Energy 2017). Based on this information and the high fecundity of this species, the entrainment of White Perch at McGuire is not anticipated to have a negative impact on the species diversity and abundance of Lake Norman. The estimated numbers of individual fish and shellfish lost due to entrainment at McGuire, including recreational and non -recreational finfish (no shellfish were collected) are provided in Table E-8. Based on the estimated annual losses under existing conditions, the total annual foregone fishery yield was estimated to be 16,682 pounds (Ibs) in 2016 and 542 Ibs in 2017. Foregone fishery yield represents the total annual biomass lost from the recreational fishery due to entrainment at McGuire. However, these values likely represent a conservative estimate (i.e., overestimate) of lost yield in response to multiple assumptions and BPJ decisions (i.e., 100 percent mortality of entrained organisms, all entrainment losses affect recreational taxa, absence of density -dependent effects in the model that would occur in the biological population, and BPJ decisions on surrogate species or values to utilize in the model) employed during model development to maximize benefits of evaluated technologies (see Section 11). The incremental reductions in estimated entrainment losses, and their impact to fishery production and yield were modeled for each of the potential compliance scenarios described in Section 11, and summarized in Table E-8 and Table E-9. The variability in FMS efficacy between the two years was driven by differences in species composition and abundance; with a large number of post yolk -sac larvae and juvenile Inland Silverside collected in 2016 samples only. These small -bodied fish would be easily excluded on a 2-mm FMS, thus increasing the exclusion efficiency results for 2016. As such, the number and type of organisms entrained (primarily non -protected, forage species) do not provide a compelling basis under the Rule to evaluate additional entrainment measures. The rates of entrainment at McGuire are not believed to negatively affect the Lake Norman fishery. Table E-8. 2016 and 2017 Annual Entrainment Loss Estimates for Entrainment Reduction Compliance Scenarios at McGuire Nuclear Station Baseline Actual Water Withdrawals MDCT FMS FMS Converts' FMS Total Baseline Actual Water Withdrawals 2016 Annual Entrainment Loss Estimates 476,766,186 42,946 2,958 674,086 16,682 7,628,259 687 47 10,785 267 223,512,171 3,021 987 47,828 101 115,471,528 18,189 911 284,965 7,554 338,983,699 21,210 1,898 332,793 7,655 2017 Annual Entrainment Loss Estimates 374,721,425 19,119 7,446 65,065 542 Duke Energy I E-19 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Executive Summary r MDCT 5,995,543 306 119 1,041 9 FMS 372,500,482 18,508 7,063 64,438 284 FMS Converts' 1,738,032 322 202 584 136 FMS Total 374,238,514 18,830 7,265 65,022 420 'FMS converts represents the estimated losses (based on the on -screen survival data compiled from the literature) that would occur from those organisms converted from entrainment to impingement on the FMS. Convert mortalities are combined with FMS mortalities to provide total estimated FMS losses at McGuire. Table E-9. Percent Reduction of Entrainment Loss Estimates for Compliance Technology Scenarios Relative to the Baseline Actual Water Withdrawals Scenario at McGuire Nuclear Station 2016 Annual Entrainment Loss Estimates Baseline Actual Water NA NA NA NA NA Withdrawals MDCT 98.4 98.4 98.4 98.4 98.4 FMS 53.1 93.0 66.6 92.9 99.4 FMS Total 28.9 50.6 35.8 50.6 54.1 2017 Annual Entrainment Loss Estimates Baseline Actual Water NA NA NA NA NA Withdrawals MDCT 98.4 98.4 98.4 98.4 98.4 FMS 0.6 3.2 5.1 1.0 47.6 FMS Total 0.13 1.51 2.43 0.07 22.52 Impacts of Changes in Air Emissions of Particulates and Other Pollutants The assessment of entrainment technologies for BTA considers changes in pollutant air emissions in Section 12. The increase in emissions is associated with two factors: (1) particulate matter (PM) emissions from the cooling tower associated with the concentration of total dissolved solids (TDS) and total suspended solids (TSS) in the make-up water, and (2) loss of generation capacity associated with parasitic loads and loss of efficiency based on the entrainment technology operating requirements. As shown in Table E-10, increased emissions are estimated to be far more substantial for a potential retrofit to cooling towers than a retrofit to FMS. Duke Energy I E-20 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Executive Summary r Table E-10. Impacts to Air Emissions under Entrainment Reduction Technology Scenarios Evaluated for McGuire Nuclear Station PM2.5 (tons/year) PM10 (tons/year) Increase in CO2, S02, NOX Emissions CO2 S02 NOx Increase in PM Emissions: 1.03 — 2.63 1.03 - 2.63 n/a n/a 1.80 — 5.42 1.80 - 5.42 (tons/year) Approximately 500,000 Approximately 300 Approximately 300 n/a n/a (tons/year) (tons/year) 1,404 1,404 0.7 0.7 1.0 1.0 'This scenario assumes 2.0-mm fine -mesh modified Ristroph screens with organism return system. Also, there is no increase in particulate emissions associated with a FMS retrofit (this only applies to the MDCT retrofit scenario). Note: CO2 = carbon dioxide; S02 = sulfur dioxide; Nox = nitrogen oxides Particulate emissions were estimated to travel 2,500 to 3,600 feet (ft) from the cooling towers and not anticipated to result in damage to vegetation and/or infrastructure near McGuire. Emissions associated with replacement of lost generation (approximately 18 percent of Duke Energy's base load generation) would be dominated by carbon dioxide with substantially lower amounts of sulfur dioxide, nitrogen oxides, and PM. These increased emissions are assumed to occur at off -site fossil -fuel fired generators in the area. No attempt was made to monetize the social costs of the increased emissions. Land Availability Related to Technology Retrofit Options The availability of space for infrastructure associated with retrofitting for entrainment technologies was considered in the assessment of entrainment BTA for McGuire. While available land at McGuire is limited, space was identified for the placement of two sets of cooling towers, one set for each of the two units, and the piping required to transmit cooling water. Although this retrofit is potentially feasible, the constrained site results in higher estimated installation costs, which affect the social cost estimates for the MDCT scenario. The space constraints related to the FMS scenario were substantially reduced in comparison to the closed -cycle cooling scenario. Remaining Useful Plant Life The remaining life of each generating unit impacts technology selection, O&M costs, potential future technology repair costs (if the life of the unit is longer than the anticipated life of the technology), and the benefits. Operating licenses for McGuire are due to expire in June 2041 for Unit 1 and in March 2043 for Unit 2 (USNRC 2002). A potential second license renewal could extend the station's life by another 20 years, but for the purposes of this evaluation, McGuire generating units were assumed to Duke Energy I E-21 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal Executive Summary operate through June 2041 and March 2043. If the original entrainment reduction technology is in good operating order at the respective retirement date, it is assumed that the technology would be retired (no salvage value has been evaluated). If the anticipated life of the technology is shorter than the anticipated life of the units, this evaluation assumes that the technology would be repaired or rebuilt and remain in service until the unit is retired. Quantitative and Qualitative Social Benefits and Costs of Available Entrainment Technologies Consistent with the Rule's requirements, and with review and input from external expert peer reviewers, Duke Energy has developed rigorous estimates of both social costs and social benefits of the two feasible entrainment BTA technologies for McGuire (i.e., MDCT and FMS with aquatic organism return system). The methodologies and assumptions associated with these estimates are discussed in detail in Section 10 and Section 11, and summarized in the previous section. Quantitative Cost to Benefit Comparison The Director must consider the social costs (summarized above and detailed in Section 10) and benefits (summarized above and detailed in Section 11) of each evaluated entrainment compliance option when determining the maximum entrainment reduction warranted. In benefit -cost analysis, determinations of compliance alternatives are made based on application of the concept of economic efficiency under increasing costs and diminishing benefits. In this context, compliance alternatives are economically efficient if they either have higher benefits and higher costs or lower benefits and lower costs than other compliance alternatives; compliance alternatives with higher costs and lower benefits are ruled out. When these economically efficient technologies are ordered by increasing cost (or benefit), net benefits (benefits minus costs) increase, reach a maximum, and then decrease. The Rule, at §125.98(f)(4), indicates that where evaluated technologies result in social costs that are in disproportion to and do not justify the social benefits, or result in unacceptable adverse impacts that cannot be mitigated, the Director has the option of determining that no additional control requirements are necessary beyond the existing technologies and operational measures. Directly comparing social costs and social benefits is a sound approach to determining if a potentially feasible technology represents entrainment BTA on a BPJ basis. In the event that the net benefits of a proposed entrainment technology or measure are negative (i.e., social costs outweigh social benefits), there is no reasonable justification for the selection of that technology/measure as BTA for entrainment. A summary of the total social cost, total impingement and entrainment benefits, and net benefits associated with each feasible compliance alternative identified for McGuire is provided in Table E- 11. The table shows that the selected IM BTA option for McGuire has a net negative benefit of - $457. The incremental impact of entrainment compliance to the IM BTA requirement of the Rule is that the net benefits become increasingly negative, estimated between-$50.7M for FMS to-$1.47B for closed -cycle retrofit (MDCT), indicating that the disparity between social costs and social benefits increases with increasing investment in entrainment reduction technologies, especially in relation to the costs required for the IM compliance component of the Rule. Duke Energy I E-22 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Executive Summary r Table E-11. Net Benefits of Alternative Impingement and Entrainment Reduction Technoloaies at McGuire De Minimis $457 $0 $0 $0 -$457 2.0-mm Fine -mesh $51.2M $457 $0.48M $0.481M -$50.7M Screens Closed -Cycle $1.47B $397 $0.31 M $0.31 M-$1.47B Retrofit 'Social Costs and Social Benefits are presented in 2018 dollars using a 3% discount rate. 2Entrainment benefits are based on 2016 entrainment data to present benefits associated with the most conservative or highest social benefit and social cost values. In addition to presenting the estimated social costs and benefits of each evaluated entrainment technology, Figure E-1 compares them to the chosen IM BTA compliance option (de minimis rate of impingement) presented in Section 6. This comparison provides context for what is warranted for entrainment versus what is required for impingement. As Figure E-1 indicates, the potential benefit of a reduction in IM. The comparison indicates that the social costs (gray bar) of entrainment reduction technologies at McGuire clearly outweigh the social benefits (green bar), and the net benefits (red bar) of both alternatives (MDCT and FMS) are substantially negative. Further, the 100 percent reduction scenario (i.e., immediate retirement of McGuire), does not overcome the substantial social costs associated with either the MDCT or FMS technologies; while the lost generation capacity would have a significant impact on the operations and costs of electricity production for Duke Energy, which would be passed onto electricity customers. Duke Energy I E-23 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Executive Summary r Total Social Costs and Benefits ($) $1,500M , $1,000M Legend Total Total Social —W-3.. F Social BenefitCost Net Benefits IRanafi+¢ minas¢ rn +¢l Impingement Compliance N Entrainment Compliance Alternatives Option $51.2M $1.4713 $50M l l l I $D.SM $0.5M r r $0.3M' I $500 $457 r $D ' r r r -S500 -$457 r r De Minimis -$50M §125.94(c)(11) -S50.7M r 2-0-mm Fine -Mesh r Screens i i -S 1.0001v1 i i i i i r -$1,500M 51.47B Net Benefits ($) Mechanical Draft (Benefits minus Costs) Cooling Towers Notes- Social benefits are estimated using the 2016 entrainment data to present the benefits ■ � associated with the highest observed entrainment- Social costs and social benefits V E R I T A S are discounted at 3%. ' The total benefits far cooling towers are less than the total benefits for fine -mesh screens Economic Consulting because fine mesh screens will be in operation longer. Figure E-1. Comparison of Social Benefits and Costs at McGuire Duke Energy I E-24 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� Executive Summary r As the top portion of Figure E-1 shows, the total social costs are greater than the social benefits for each of the entrainment compliance options. McGuire's chosen method to comply with the impingement compliance requirement (de minimis rate of impingement) has zero net benefits: the social benefits and social costs are the same. By comparison, 2.0-mm fine mesh screens have net benefits of-$50.7M and mechanical draft cooling towers have net benefits of-$1.47B. Given that the net benefits beyond what is required for impingement are negative, neither entrainment compliance option is warranted as the BTA for meeting the site -specific entrainment requirement. As such, in reviewing this application package for McGuire, NCDEQ has the discretion to "reject otherwise available entrainment controls if the costs of the controls are not justified by their associated benefits (taking into account monetized, quantified, and qualitative benefits), and the other factors discussed in the Rule." Based on the evaluation of social costs and benefits of each technology, McGuire's current configuration represents BTA for meeting the site -specific entrainment requirements. Figure E-1 demonstrates the basis of this conclusion given that each of the potentially feasible compliance options evaluated for McGuire have negative net benefits, meaning that the social costs of each of the entrainment compliance options are greater than the social benefits: • 2.0-mm fine -mesh screens have negative net benefits of-$50.7M and • MDCTs have negative net benefits of-$1.47B. Qualitative Cost to Benefit Comparison The qualitative costs and benefits of reducing entrainment and IM are difficult to evaluate and therefore are not quantified in the benefits valuation discussed in Section 11. These qualitative effects, however, may result in ecosystem benefits such as increased population resilience and support, and overall health and integrity of the ecosystem (79 FR 158, 48371). The reduction in entrainment losses could also result in qualitative costs to the fish community due to density - dependent influences such as increased competition, predation, or increased population size of introduced species. However, based on the species composition and numbers of entrainment losses documented at McGuire, qualitative benefits are not expected to be significant or sufficient to outweigh the disproportionate social costs of entrainment and IM reduction controls. The elimination of warm water discharges at McGuire is a potential outcome under the MDCTs scenario (see Section 11), which could lead to social costs or benefits. The warm water discharges provide a thermal refuge for fish, thereby creating a winter fishery near McGuire. Threadfin Shad, an important forage species, is one example of a species that would potentially be impacted by the loss of thermal refuge provided by warm water discharges at McGuire. Thus the loss of the warm water discharges can be viewed as a social cost, especially to anglers that rely on the winter fishery each year. The elimination of warm water in Lake Norman near McGuire's discharge zone could also have a benefit in the form of improved water quality, which could result in increased dissolved oxygen (DO) concentrations during peak summer temperatures when water temperatures are already warm. However, since the DO levels in McGuire's discharge zone do not typically decrease to levels below the North Carolina water quality standards, the impact (i.e., benefit) to water quality would not be substantial. Duke Energy I E-32 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� Executive Summary r Summary of Must Factors Analysis A summary of the information relevant to the Must factors at McGuire is presented in Error! Reference source not found.. Table E-12. Summary of Must Factors Analysis • 2016 — 2017 entrainment sampling yielded low overall numbers of organisms entrained. • The primary period of entrainment occurred from spring to early summer, from March through June. • At least 12 species from 8 families, predominantly post yolk -sac larvae, were entrained during the Study. • No federal or state -listed fish or shellfish, or their designated critical habitat (e.g., prey base, glochidial hosts) have been impacted by entrainment at McGuire. • Recreational species comprised between 4.2 and 17.4 percent of annual entrainment losses based on actual water withdrawals, the majority of which were White Perch, an introduced species. • Fragile clupeids comprised between 82 and 90 percent of total annual entrainment losses. A reduction in entrainment from the installation of FMS with an aquatic organism return system would therefore have limited recreational or economic benefit to the majority of species entrained at McGuire. • Increased emissions are estimated to be more substantial for a retrofit to cooling towers than a retrofit to FMS. • PM emissions were estimated to travel 2,500 to 3,600 ft from the cooling towers and were not anticipated to result in damage to vegetation and/or infrastructure near McGuire. • Land is available at and around the facility. • 2041 for Unit 1 (i.e., 22 years) and 2043 for Unit 2 (i.e., 24 years). • Social costs including electricity rate increases resulting from compliance costs, power system costs, externality costs (impacts to property value, hydroelectric generation, and winter fishery), and government regulatory costs were estimated at $51.2M for FMS and $1.47B for MDCTs (at a 3% discount rate) and $29AM for FMS and $733.61M for MDCTs (at a 7% discount rate). • Social benefits including the effects to the recreational fishery (through increased catch rates) and effects to angler well-being were estimated at $478,043 for FMS and $309,275 for MDCTs (at a 3% discount rate) and $238,348 for FMS and $137,106 for MDCTs (at a 7% discount rate). Note these values were derived from the 2016 entrainment data which is considered to be the more conservative estimate of entrainment losses at McGuire than estimates based on 2017 entrainment data'. 2017 entrainment losses were substantially lower than in 2016 and are likely more representative of conditions (i.e., typical) at McGuire. A comparison of the social costs and social benefits estimated using 2017 entrainment data would result in even greater net negative benefits due to the reduced social benefits estimated using 2017 entrainment loss rates. Duke Energy I E-32 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Executive Summary r • The direct and indirect effects of the loss of organisms at McGuire, as demonstrated through modeling (specifically designed to overestimate effects), resulted in a modest measurable impact to the recreational fishery. • The social cost to social benefit comparison indicates that all modeled scenarios result in zero or net -negative benefits. • The potential qualitative benefits of an entrainment and impingement mortality reduction at McGuire are not substantial and would not warrant the qualitative costs associated with the reduction. BTA Factors that May Be Considered e ay ac ors o e considered for entrainment BTA (§125.98(f)(3)) are: • Entrainment impacts on the waterbody; • Thermal discharge impacts; • Credit for reductions in flow associated with the retirement of units occurring within the ten years preceding October 14, 2014; • Impacts on the reliability of energy delivery within the immediate area; • Impacts on water consumption; and • Availability of process water, grey water, waste water, reclaimed water, or other waters of appropriate quantity and quality for reuse as cooling water. The information from this list is included or addressed in detail in the study reports and supporting documentation provided in Sections 2 through 12 of the compliance submittal document. The findings of the entrainment BTA assessment relative to the factors that NCDEQ may consider are provided below. Entrainment Impacts on the Waterbody Based on the information presented above and in Sections 2 through 12, entrainment at McGuire does not result in substantial or adverse impacts to Lake Norman, with no observable or measureable impacts occurring based on the stability of the fishery and presence of a balanced indigenous population (Sections 4 and 9). Duke Energy has over 30 years of biological data to support this conclusion as detailed in Section 4. This was confirmed with quantitative modeling of the effects of entrainment, using recent entrainment monitoring data collected at McGuire in 2016 and 2017 (Section 9), including direct losses of recreational species as well as indirect losses from trophic transfer of forage species to consumers or predators (see Section 11). An assessment of cooling water residence time (CWRT), a volumetric rate, was performed for McGuire. The CWRT, an alternative approach to defining the proportion of the source waterbody that is withdrawn at the CWIS, is appropriate for a lacustrine waterbody and presents a theoretical estimate of the time required for cooling water that exits the discharge to be withdrawn by the intake in the recirculation process. Lake Norman, which was created to provide cooling water for both McGuire and Marshall Steam Station, a facility owned by Duke Energy to the north of McGuire, has a volume of approximately 356,374 million gallons. The combined AIF for McGuire's Main Intake and Duke Energy I E-32 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� Executive Summary r LLI is 2,631 MGD based on the three most recent years of data. Based on this withdrawal volume, Lake Norman's CWRT is approximately 135 days. Additionally, estimates of the Main Intake and LLI area of influence (AOI) were developed based on existing operations and targeted TSV thresholds of 0.5 fps (impingement) and 0.1 and 0.3 fps (entrainment). At the most protective entrainment TSV threshold (0.1 fps), the AOI extends 400 ft from the front of the Main Intake, an area representing approximately 5.77 acres or approximately 0.02 percent of the total volume of Lake Norman. Therefore, the AOI of the Main Intake is contained within the small intake cove, between the floating debris boom and the intake structure. The AOI at the LLI structure with just the nuclear service water pumps running is estimated at 3 ft (0.5 fps velocity threshold) and 13 ft (0.1 fps velocity threshold). During the one to five week period each summer when both the nuclear service water pumps and LLI pumps are running, the AOI at the LLI structure is estimated at 43 ft (0.5 fps velocity threshold) and 212 ft (0.1 fps velocity threshold). However, as discussed in Section 6, the potential implications of the impingement AOI for the LLI are reduced based on the location and depth of the structure, timing, frequency, and duration of LLI operations, and adaptive management strategies that minimize potential impacts resulting from LLI operations. Thermal Discharge Impacts The thermal discharge from McGuire is authorized under the facility's NPDES permit and a §316(a) thermal variance based on a review that determined the variance is protective of the balanced indigenous community in Lake Norman. Further, the thermal discharge from McGuire provides thermal refuge for fish during cold winter months, and is currently supporting a recreational winter fishery. As such, the reduction in thermal loading that would occur with a potential cooling tower retrofit would not have a meaningful beneficial effect on the nearby aquatic community, and instead, would eliminate a winter fishery that provides social and economic value to the community. See Section 10 for additional details. Credit for Flow Reductions No unit retirements or associated reductions in flow occurred at McGuire within the preceding 10- year period. Impacts on the Reliability of Energy Delivery McGuire is a large generating asset that supplies zero carbon electricity to Duke Energy's customers. Maintaining safe and reliable energy delivery is imperative to Duke Energy, their customers, and their shareholders, and has been considered in this entrainment BTA assessment in the following manner: • During the conceptual design phase for potential entrainment technologies, consideration was given to the location, configuration, operational requirements, and other design specifics for each potential technology to improve generation reliability. This information was incorporated into capital and social costs estimated for each potential retrofit option. • Power system modeling (PROSYM) was performed by Duke Energy to evaluate extent and system -wide impact of loss of generation capacity associated with potential retrofit options to ensure reliable energy delivery and to estimate the social costs of securing it. Duke Energy I E-32 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� Executive Summary r Under the MDCT retrofit scenario, the station would need to operate at reduced power during the warmest and most humid periods; the reduction is anticipated to result in reliability impacts due to main condenser backpressure energy penalty. Additionally, during periods of peak demand in winter, there would be potential for icing at McGuire's switchyard and/or on off -site transmission lines. During normal winters, heat emanating from the cables may be sufficient to prevent or minimize icing impacts. However, transmission corridors and switchyards may be at increased risk during severe ice storm events potentially jeopardizing nuclear generation safety. The MDCT could be designed for the maximum wet bulb temperature to mitigate the likelihood of reduced power at McGuire, however, this option would result in a significantly larger footprint and increased costs. Under the FMS retrofit scenario, the primary source of reliability impacts would be due to screen fouling or clogging, which would be mitigated by the assumed continuous rotation of the screens and the use of pressure wash system. Therefore, the FMS retrofit scenario is not anticipated to have substantial impacts to station reliability. Impacts on Water Consumption Section 12.2.6 considers changes in water consumption for candidate technologies evaluated in Sections 10 through 12. Potential changes in water consumption with FMS would be negligible. Monthly water consumption due to increased consumptive evaporation with the use of cooling towers was quantified and compared to the monthly increased evaporation associated with discharge of heated effluent from the once -through cooling system (forced evaporation). The results of such an analysis are dependent on ambient weather conditions. Depending on the month, cooling towers were estimated to increase water loss by 33 to 42 percent compared to the once -through cooling system. Such losses would potentially require Duke Energy to release water from upstream reservoirs to support Lake Norman pond elevations, or reduce zero carbon hydropower generation at Cowans Ford Hydroelectric Station and six downstream hydroelectric stations to mitigate the increased evaporative losses. Availability of Alternate Water Sources for Reuse as Cooling Water Based on a review of several potential sources of water in the area, no alternate source of cooling water was found to be feasible. Factors considered in this assessment include the potential quantity of water available and the distance of the source from McGuire. Groundwater and wastewater supplies within 5 miles of McGuire were determined to be insufficient to support even a fraction of McGuire's cooling water requirements. Summary of May Factors Analysis A summary of the information relevant to the May factors at McGuire is presented in Duke Energy I E-32 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� Executive Summary r Table E-13. Duke Energy I E-30 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� Executive Summary r Table E-13. Summary of May Factors Analysis • Long-term monitoring (30-plus years) program indicates no impacts to the Lake Norman aquatic community or water quality from once -through cooling operations. • The Area of Influence for entrainment at the Main Intake affects approximately 0.02 percent of the total area of Lake Norman. • The thermal variance is protective of a balanced and indigenous fish community in Lake Norman • Loss of winter fishery would have negative social impacts, including local economic impacts. • No credits available associated with flow reductions over the past 10 years. • McGuire is a large, zero carbon base load facility. Reduced power production, or reduced facility availability (e.g., retrofit) would have negative effects from backpressure energy penalty, and winter transmission line icing impacts. • Changes in water consumption for FMS would be negligible. • Closed -cycle cooling tower retrofit would increase consumptive use by 33 to 42 percent, resulting in lower Lake Norman water levels and loss of zero carbon generation at Cowans Ford Hydroelectric Station, as well as downstream hydroelectric stations along the Catawba-Wateree River. • No other viable source with necessary yield. Conclusions Based on the current design (location and depth) and operations of the Main Intake and low rate and composition of impingement (2.2 to 2.3 non -fragile fish/day), a determination of de minimis rate of impingement is requested as the IM Option for McGuire's Main Intake. Further, based on the current design (location and depth), operations (frequency, timing, and duration), and adaptive management (periodic hydroacoustic monitoring for fish presence and density) of the LLI, Duke Energy requests a determination of de minimis rate of impingement as the compliance approach for the LLI. The data presented in Section 6 and summarized in this Executive Summary demonstrate that the current design and operations at McGuire result in minimal IM and that the cost of implementing an impingement -reduction technology for McGuire's Main Intake or LLI does not justify the potential social benefits. As outlined in the Rule, the requirements of the NPDES Director include the following (40 CFR §125.98(f), Site -specific Entrainment Requirements): (4) If all technologies considered have social costs not justified by the social benefits, or have unacceptable adverse impacts that cannot be mitigated, the Director may Duke Energy I E-31 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� Executive Summary r determine that no additional control requirements are necessary beyond what the facility is already doing. The Director may reject an otherwise available technology as a BTA standard for entrainment if the social costs are not justified by the social benefits. Model -based estimates of the direct and indirect effects of the loss of organisms at McGuire, based on conservative assumptions and BPJ decisions, indicated a non -observable impact to the recreational fishery of Lake Norman. These data were then used to assess the social costs and social benefits of potential entrainment reduction technologies, including: (1) a potential retrofit to closed -cycle cooling (MDCT) and (2) the installation of FMS with an organism return system. Monetized social costs and social benefits were estimated for both technologies to provide a common basis for comparison, which is consistent with the goals and requirements of the Rule. The estimates were based on conservative assumptions (e.g., all entrained organisms were considered to affect recreational fisheries either directly as EAs or indirectly through trophic transfer of PF) and include evaluations of uncertainty at multiple stages of the development process. The social cost to social benefit comparison yielded substantial net -negative benefits for the modeled entrainment reduction technologies, and unavoidable adverse effects were identified for both technologies evaluated; however, a potential retrofit to closed -cycle cooling (MDCT) would also result in increased air emissions, increased noise, loss of zero carbon generation output, and potential impacts to system reliability. Based on over 30 years of historical biological monitoring data, historical impingement monitoring, and results of the entrainment Study presented in Section 9, Lake Norman supports a diverse and balanced fishery in the presence of ongoing McGuire operations. No federal or state threatened or endangered species are known to occur in Lake Norman, none were collected in Duke Energy monitoring studies or the historical impingement study, and none were collected during the 2016- 2017 entrainment sampling activities. These data, combined with the evaluations described in Sections 10 through 12, demonstrate that the two entrainment reduction technologies (MDCT and FMS) are not justified as BTA for entrainment at McGuire as they would result in adverse effects and the social costs would be wholly disproportionate compared to the potential social benefits. The Director must consider the social costs and benefits of each evaluated entrainment compliance option when determining the maximum entrainment reduction warranted. Based on the evaluation of social costs and benefits of each technology, McGuire's current configuration represents BTA for meeting the site -specific entrainment requirements. Duke Energy I E-32 Clean Water Act §316(b) Evaluation to Support 40 CFR §122.21 (r) McGuire Nuclear Station Compliance Submittal Document IL- Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Introduction r 1 Introduction Section 316(b) was enacted under the 1972 U.S. Environmental Protection Agency (USEPA) Clean Water Act (CWA), which also introduced the National Pollutant Discharge Elimination System (NPDES) permit program. Certain facilities with NPDES permits are subject to §316(b) requirements, which mandate that the location, design, construction, and capacity of the facility's cooling water intake structure (CWIS)8 reflect Best Technology Available (BTA) for minimizing potential adverse environmental impacts. Cooling water intakes can cause adverse environmental impacts by drawing early life -stage fish and shellfish into and through cooling water systems (entrainment) or trapping juvenile or adult fish against the screens at the opening of an intake structure (impingement). On August 15, 2014, §316(b) of the final CWA rule for existing facilities (Rule) was published in the Federal Register (FR) with an effective date of October 14, 2014. The Rule applies to existing facilities that withdraw more than 2 million gallons per day (MGD) from waters of the United States (WOTUS), use at least 25 percent of that water exclusively for cooling purposes, and have an NPDES permit. Owner(s) of a facility subject to the Rule must develop and submit technical information, as identified in the Rule, to the NPDES permit Director (Director) to facilitate the determination of BTA for the facility. The actual intake flow (AIF)9 and design intake flow (DIF)10 at a facility is used to identify the entrainment -specific reporting requirements, while all facilities will generally be required to select from the impingement compliance options contained in the Rule. Facilities with an AIF greater than of 125 MGD are required to address both impingement and entrainment and provide specific entrainment information (Table 1-1), which may involve extensive field studies, and the analysis of alternative methods to reduce entrainment (40 U.S. Code of Federal Regulations [CFR] §122.21(r)(9)-(13)). The compliance schedule under the Rule is dependent on the facility's NPDES permit renewal date. The Duke Energy Carolinas, LLC (Duke Energy) McGuire Nuclear Station (McGuire) is a two -unit nuclear steam electric generating station located on Lake Norman in Huntersville, North Carolina (Figure 1-1). Commercial operation of Unit 1 began in 1981, followed by Unit 2 in 1984 (Duke Energy 2016a). McGuire withdraws greater than 125 MGD of raw water from the CWIS on Lake Norman and the facility uses more than 25 percent of the total water withdrawn exclusively for 8 CWIS is defined as the total physical structure and any associated constructed waterways used to withdraw cooling water from WOTUS. The CWIS extends from the point at which water is first withdrawn from WOTUS up to, and including, the intake pumps. 9 AIF is defined as the average volume of water withdrawn on an annual basis by the CWIS over the past 3 years initially and past 5 years for NPDES Permit Applications submitted after Oct. 14, 2019. The calculation of AIF includes days of zero flow. AIF does not include flows associated with emergency and fire suppression capacity. 10 DIF is defined as the value assigned during the CWIS design to the maximum instantaneous rate of flow of water the CWIS is capable of withdrawing from a source waterbody. The facility's DIF may be adjusted to reflect permanent changes to the maximum capabilities of the cooling water intake system to withdraw cooling water, including pumps permanently removed from service, flow limit devices, and physical limitations of the piping. DIF does not include values associated with emergency and fire suppression capacity or redundant pumps (i.e., back-up pumps). Duke Energy 1 1 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal �� Introduction cooling purposes; after which, the non -contact cooling water is discharged back into Lake Norman, as authorized under NPDES Permit No. NC0024392. As such, McGuire is subject to the requirements of the Rule. Table 1-1. Facility and Flow Attributes and Permit Application Requirements Facility and Flow Attributes Permit Application Requirements Existing facility with DIF of 2 MGD or less, or less than 25 percent of AIF used for cooling purposes Best Professional Judgment of Director Existing facility with DIF greater than 2 MGD and AIF less §122.21(r)(2)-(8) than 125 MGD Existing facility with DIF greater than 2 MGD and AIF §122.21(r)(2)-(13)* greater than 125 MGD* *Identifies permit application requirements applicable to McGuire based on facility and flow attributes. This document is arranged into sections that correspond with the headings listed for each of the §122.21(r)(2)-(13) compliance reporting requirements summarized in Table 1-2. Appendix 1-A provides a checklist of the submittal requirements under §122.21(r)(2)-(13) and summarizes how each of the requirements is addressed in this document. Duke Energy 1 2 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Introduction r LEGEND Major Interstate Alexander Co. Highway Davie Co. • Station Location North Carolina -� County Boundaries redill Co! e Lake Norman 40 I 0 Miles 10 Catawba Co. Lincoln Co. Cleveland Co. Rock Hill Figure 1-1. McGuire Nuclear Station Vicinity Map Rowan Co. McGuire Concord Nuclear Station Cabarrus Co. burg Co. Stanly Co. Union Co. Duke Energy 1 3 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal �� Introduction Table 1-2. Existing Facilities Submittal Requirements for Compliance Under Clean Water Act §316(b) §122.21(r)(2)-(13) (2) Source Water Physical Characterization of the source waterbody including intake area of Data influence. (3) Cooling Water Intake Characterization of the cooling water intake system; includes drawings Structure Data and narrative; description of operation; water balance. Characterization of the biological community in the vicinity of the Source Water Baseline intake; life history summaries; susceptibility to impingement and (4) Biological entrainment; existing data; identification of missing data; threatened Characterization Data and endangered species and designated critical habitat summary for action area; identification of fragile fish and shellfish species list (<30 percent impingement survival). Narrative description of cooling water system and intake structure; Cooling Water System proportion of design flow used; water reuse summary; proportion of (5) Data source waterbody withdrawn (monthly); seasonal operation summary; existing impingement mortality and entrainment reduction measures; flow/MW efficiency. Chosen Method of Provides facility's proposed approach to meet the impingement (6) Compliance with mortality requirement (chosen from seven options); provides detailed Impingement Mortality study plan for monitoring compliance, if required by selected Standard compliance option; addresses entrapment where required. Provides summary of relevant entrainment studies (latent mortality, (7) Entrainment technology efficacy); can be from the facility or elsewhere with Performance Studies justification; studies should not be more than 10 years old without justification; new studies are not required. Provides operational status for each unit; age and capacity utilization for the past 5 years; upgrades within last 15 years; uprates and U.S. (8) Operational Status Nuclear Regulatory Commission relicensing status for nuclear facilities; decommissioning and replacement plans; current and future operation as it relates to actual and design intake flow. Entrainment (9) Characterization Study Comprehensive (10) Technical Feasibility and Cost Evaluation Study Provides detailed information regarding the study methodology, data collection period and frequency, and analytical techniques used to identify and document the life stages of fish and shellfish in the vicinity of the cooling water intake structure(s) that are susceptible to entrainment, including any organisms identified by the Director, and any species protected under Federal, State, or Tribal law, including threatened or endangered species with a habitat range that includes waters in the vicinity of the cooling water intake structure. The owner or operator of the facility must identify and document how the location of the cooling water intake structure in the waterbody and the water column are accounted for by the data collection locations. An evaluation of the technical feasibility of closed cycle recirculating systems as defined at §125.92(c), fine -mesh screens with a mesh size of 2 millimeters or smaller, and water reuse or alternate sources of cooling water. Duke Energy 1 4 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal �� Introduction 11) (12) (13) In addition, this study must provide a discussion of: (A) All technologies and operational measures considered (including alternative designs of closed -cycle recirculating systems such as natural draft cooling towers, mechanical draft cooling towers, hybrid designs, and compact or multi -cell arrangements); (B) Land availability, to include an evaluation of adjacent land, and acres potentially available due to generating unit retirements, production unit retirements, other buildings and equipment retirements, and potential for repurposing of areas devoted to ponds, coal piles, rail yards, transmission yards, and parking lots; (C) Available sources of process water, grey water, waste water, reclaimed water, or other waters of appropriate quantity and quality for use as some or all of the cooling water needs of the facility; and (D) Provide documentation of factors other than cost that may make a candidate technology impractical or infeasible for further evaluation. Provide documentation of the incremental changes in the numbers of individual fish and shellfish lost due to impingement mortality and entrainment. Provides a description of basis for estimated changes in the stock sizes or harvest levels of commercial and recreational fish or shellfish species or forage fish species. Provides a description of the basis for monetized values assigned to Benefits Valuation changes in the stock size or harvest levels of commercial and Study recreational fish or shellfish species, forage fish, and to any other ecosystem or nonuse benefits. Details mitigation efforts completed prior to October 14, 2014 (as relevant) including how long they have been in effect and how effective they have been. Discusses, with quantification and monetization, where possible, of other benefits expected to accrue to the environment and local communities, including but not limited to improvements for mammals, birds, and other organisms and aquatic habitats. Estimates of changes to energy consumption, including but not limited to auxiliary power consumption and turbine backpressure energy penalty. Non -water Quality Environmental and Estimates of air pollutant emissions and of the human health and Other Impacts Study environmental impacts associated with such emissions. Estimates of changes in noise and a discussion of impacts to safety, including documentation of the potential for plumes, icing, and availability of emergency cooling water. If the applicant is required to submit studies under §122.21(r)(10) to Peer Review (r)(12), the applicant must conduct an external peer review of each report to be submitted with the permit application. Duke Energy 1 5 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Source Water Physical Data [§122.21(r)(2)] r 2 Source Water Physical Data [§122.21(r)(2)] The information required to be submitted per §122.21(r)(2), Source Water Physical Data, is outlined as follows: (i) A narrative description and scaled drawings showing the physical configuration of all source water bodies used by your facility, including areal dimensions, depths, salinity and temperature regimes, and other documentation that supports your determination of the waterbody type where each cooling water intake structure is located; (ii) Identification and characterization of the source waterbody's hydrological and geomorphological features, as well as the methods you used to conduct any physical studies to determine your intake's area of influence within the waterbody and the results of such studies; (iii) Locational maps; and (iv) For new offshore oil and gas facilities that are not fixed facilities, a narrative description and/or locational maps providing information on predicted locations within the waterbody during the permit term in sufficient detail for the Director to determine the appropriateness of additional impingement requirements under § 125.134(b) (4). Each of these requirements is addressed in the following subsections. 2.1 Description of Source Waterbody The CWIS at McGuire withdraws raw water for cooling purposes from a shoreline -situated CWIS on Lake Norman, the source waterbody. Lake Norman is part of the Catawba River Basin, which is situated in the south-central portion of western North Carolina and originates in the eastern slopes of the Blue Ridge Mountains in Old Fort, McDowell County, North Carolina. From its source, the Catawba River flows eastward, then southward toward the city of Charlotte (Figure 2-1). Lake Norman, an impoundment of the Catawba River, was formed by the construction of the Cowans Ford Dam and is part of the Catawba-Wateree Project (Federal Energy Regulatory Commission [FERC] No. 2232), a series of 11 reservoirs formed by 13 Duke Energy -owned hydroelectric dams (Figure 2-1). Construction of the hydroelectric developments began in the early 1900s and the final development, Cowans Ford on Lake Norman, was completed in 1963. Duke Energy 1 6 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Source Water Physical Data [§122.21(r)(2)] r Lake Hickory Janes Lake Rhodhiss Lookout ShoaWLake Marshall Steam Station Norman McGuire Nuclear Station Cowan's Ford Dam Mountr Island L ORTH C ROILINA ICharlotte. N S CAR IN[r Lake VVylie LEGEND Station Location • NC (Charlotte C is ta,, bt11' R iv er _ Reservoirs Fishing Creek Lake - State Bot111dary 0 CotlntYBotlndary Great Falls ReservoirDrainage Basin CedarCreek _ Revoi r"� a mik -: Lake Wateree Figure 2-1. Catawba-Wateree Project, North and South Carolina Duke Energy 1 7 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Source Water Physical Data [§122.21(r)(2)] r Lake Norman extends approximately 34 miles upstream from the Cowans Ford Hydroelectric Station to Duke Energy's Lookout Shoals Hydroelectric Station (Duke Energy 2016a; Duke Energy 2007). Lake Norman's full pond elevation is 760 feet above mean sea level (ft msl) and is retained by the east abutment dike with a crest elevation of 780 ft msl (Duke Energy 2007; Duke Energy 1975). The tailwater of Cowans Ford Dam is the Catawba River and the upper limit of the river forms Mountain Island Lake, an impoundment formed by Duke Energy's Mountain Island Hydroelectric Station (Duke Energy 2007) situated approximately 9 miles downstream of Cowans Ford Dam. General characteristics of Lake Norman are summarized in Table 2-1. Table 2-1. Lake Norman Characteristics Watershed Drainage Surface Area Volume Full Pond Elevation Maximum Depth Mean Depth Average Discharge (from Cowans Ford Hydroelectric Station ) Retention Time Sources: Duke Energy 1975, 2007; LEDA 2013 1,790 square miles 32,510 acres 356,374 million gallons 760 ft 110 ft 33.5 ft 2,670 cubic feet per second 239 days McGuire is located in Mecklenburg County, North Carolina, approximately 17 miles north-northwest of Charlotte on the southern end of Lake Norman (Figure 2-1). Duke Energy owns approximately 30,000 acres of property surrounding Lake Norman (Duke Energy 2007), including Marshall Steam Station (Marshall) and a 2,500-foot (ft) radius Exclusion Area. Marshall is located on the northern end of Lake Norman approximately 11.5 miles north of McGuire. No commercial activity is permitted within the Exclusion Area; however, some limited non-commercial activities are allowed such as highway traffic on NC-73 and recreational use on Lake Norman (Duke Energy 2007) Other designated recreational use areas in the vicinity of McGuire include five parks owned by Mecklenburg County, as well as the Cowans Ford Wildlife Refuge and the Cowans Ford Waterfowl Refuge (Duke Energy 2001). Lands surrounding McGuire are predominantly residential and rural, with a small amount of land being used to support beef cattle production and farming (Duke Energy 2007). Due to the recreational opportunities provided by Lake Norman, the transient, recreational population of the area increases during the summer months (Duke Energy 2007). 2.2 Characterization of Source Waterbody 2.2.1 Geomorphology McGuire is situated within the Southern Outer Piedmont ecoregion, a northeast to southwest trending zone of modest relief, irregular plains, and rolling hills. The site is underlain by metamorphic, sedimentary, and intrusive igneous rocks (Duke Energy 2001; 2007). A thick saprolite Duke Energy 1 8 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal Source Water Physical Data [§122.21(r)(2)] layer and red, clayey subsoils typically overlie gneiss, schist, and granite bedrock (Griffith et al. 2002). Elevations in the vicinity of McGuire vary from 650 to 800 ft msl (Duke Energy 2007). The only current and foreseeable use for groundwater in the project vicinity is for domestic water supply for residential properties immediately surrounding the site (Duke Energy 2007). 2.2.2 Hydrology The Catawba River has a 1,790-square mile drainage area at the point where it enters Lake Norman (USGS 2017). The Catawba River and the Broad and Saluda Rivers (i.e., Congaree River) form the headwaters of the Santee River (Hydrologic Unit Code [HUC] 030501). The Catawba River Basin originates in western North Carolina and flows east south-east through the Piedmont to Lake Wateree (near Lugoff, South Carolina), where it becomes the Wateree River. The river flows south from Lake Wateree approximately 76 miles until it meets the Congaree River, which enters Lake Marion before flowing east as the Santee River to the Atlantic Ocean. The nearest gaging station upstream of McGuire is the Catawba River below Lookout Shoals Dam near Sharon, NC (U.S. Geological Survey [USGS] 02144102) with a drainage area of 1,450 square miles. The nearest downstream gaging station is the Catawba River at RR bridge AB NC 73 at Cowans Ford, NC (USGS 0214264790) with a drainage area of 1,790 square miles. Groundwater in the area is derived entirely from local precipitation and groundwater elevation at McGuire is primarily controlled by the water level in Lake Norman. Most groundwater flow" near the project is governed by local topography, where the valleys and topographic highs result in water table depths that vary by more than 100 ft (Duke Energy 2007). 2.2.3 Water Quality Duke Energy collects water quality data as part of a long-term and ongoing Maintenance Monitoring Program (MMP) on Lake Norman. Sample locations for 2016 are shown on Figure 2-2. The MMP targets water quality data as well as information on phytoplankton, zooplankton, benthic invertebrates, and fish communities (Duke Energy 2017b). Under the MMP, water chemistry data is collected at two discrete depths (near -surface and near -bottom) using a Kemmerer or Van Dorn sampler. Water temperature and dissolved oxygen (DO) data are measured monthly at 3.3-ft intervals from the water surface to the lake bottom using a Hydrolab° data sonde. Water quality, water chemistry, and limnological data collected from Lake Norman from 2012-2016 are summarized in Table 2-2. The only groundwater recharge areas within the influence of McGuire are adjacent to the Standby Nuclear Service Water Pond and the Waste Water Collection Basin (Duke Energy 2007). Duke Energy 1 9 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal Source Water Physical Data [§122.21(r)(2)] 50.0 72.0 Sampling Locations: D Water Quality + Productivity ■ Electrofishing Hwy 150 • Denver Hwy16 2.0 1.0 O O 4.0 ■ o�s�ni4re s ■ Cowans ■ • ■ Ford Dam McGulre Nuclear -__ atian 0 1 2 4 Miles 0 1.5 3 6 Kilometers 1. ' 69.0 Lake Zones: A MNS Themal Influence B MNS Background C MSS Thermal Influence D MSS Background E Riverine/Lake Transition 62.0 00 Marshall - Steam Station - (MSS) 4.0 Zone C 13.0 � m n q Zone Zone A 2.0 ® (D 5.0 1.0 1. ' Cowans Ford Dam McGuire Nuclear Charlotte Station (MNS) (14 mi.) 1 Mooresville (2 mi.) ■ Davidson Hwy 73 Figure 2-2. Duke Energy Maintenance Monitoring Program Water Quality Sampling Zones and 2014-2016 Data Collection Locations (Source: Duke Energy 2017b) (Note: MNS = McGuire Nuclear Station; MSS = Marshall Steam Station) Duke Energy 1 10 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Source Water Physical Data [§122.21(r)(2)] r Table 2-2. Annual Mean Surface Concentration for Select Limnological Parameters Documented in the Southern Portion of Lake Norman, 2012-20161 SamplingConstituent Location Near Intake Near Intake Turbidity (NTU) OW1.16W Y2.0'U - Secchi Depth (ft) 8.94 8.37 9.51 -- Nutrients (pg/L) Ammonia-N 82.5 103.5 98.0 -- Nitrate + Nitrite-N 137 150 Total Phosphorus 9.5 9.0 9.0 8.0 mmrr Chlorophyll a 4.08 4.92 3.59 3.36 3.22 Ions (mg/L) Calcium 4.2 3.6 4.2 3.9 3.0 Chloride 7.2 5.5 5.1 5.7 5.0 Magnesium 1.9 1.8 1.8 1.9 1.7 Sodium 4.5 3.9 3.6 4.2 3.7 Sulfate 4.2 3.6 3.4 3.4 3.4 Metals Aluminum, Total (pg/L) 31.5 43.5 36.5 <50 70 Iron, Total (mg/L) 0.085 0.229 0.265 0.115 0.074 Manganese, Total (pg/L) 214.0 695.5 672.5 293.3 289.0 Water quality data summarized from Duke Energy (2014a; 2015; 2016d; 2016e; 2017b) mg/L: milligrams per liter; NTU: nephelometric turbidity units; pg/L: micrograms per liter Based on monitoring data collected between 2012 and 2016, water quality in Lake Norman has remained generally consistent between surveyed years (Table 2-2). Trace metal concentrations were typically low, with no values exceeding the North Carolina water quality criteria. Elevated iron, manganese, and aluminum concentrations have been documented infrequently, typically in samples collected during summer months. During stratified conditions in Lake Norman, concentrations of these metals in the lower hypolimnion can increase substantially depending on sediment metal concentrations. The stratified layers within the lake become mixed during annual lake turnover in the fall, which allows the increased metal concentrations in the hypolimnion to mix with surface waters in the epilimnion. This is a common process and is typical for southeastern reservoirs such as Lake Norman (Duke Energy 2017b). Nutrient concentrations, chlorophyll a, and Secchi depths in Lake Norman exhibit a negative spatial gradient from the northern end of the reservoir to Cowans Ford Dam (Duke Energy 2014a, 2015, 2016d, 2016e, 2017b, Brey et al. 2012, NCDWQ 2013, Buetow 2016) (Table 2-2). These data are Duke Energy 1 11 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal Source Water Physical Data [§122.21(r)(2)] consistent with an oligotrophic to oligo-mesotrophiC12 lake classification, and the observed concentrations and spatial trends are consistent with typical limnological patterns in response to upstream nutrient inputs in reservoir systems (Green et al. 2015). Many factors influence water temperature throughout the reservoir, including contributing inflow from the watershed, solar energy, thermal inputs from industrial and municipal discharges, and physical characteristics such as depth, clarity, and reservoir retention time (Duke Energy 2017b). The most recent Maintenance Monitoring Report (Duke Energy 2017b) shows that temperatures in Lake Norman Zones A and B, which are the areas closest to McGuire (Figure 2-2) have remained generally consistent since 1990 (Figure 2-3). Annual DO concentrations in Lake Norman typically follow a spatial and temporal pattern, with concentrations increasing during the cooler winter months, and declining during the warm spring and summer months (Duke Energy 2017b). As the lake begins to stratify with increasing summer temperatures, rapid DO depletion in the metalimnion (middle layer of the water column) causes a heterograde oxygen curve, where a pronounced layer of low DO is positioned between the upper and lower layers of higher DO content. DO in this layer continues to decline over the summer until anoxia occurs, typically at depths greater than 32 ft throughout much of the reservoir. DO concentrations begin to increase again with cooler temperatures in the fall until lake turnover, when the mixing of the water column occurs. Time series data (1990-2016) demonstrate that surface DO levels in the southern portion of Lake Norman nearest to McGuire have not fallen below the North Carolina instantaneous water quality criteria of 4 milligrams per liter (mg/L) (Duke Energy 2016e). a o 0 30 a I'A o A � a d QQ a 0 20 4 O*� �Ma�a o go 4+ a E 0 10 a aA +B J 1a 1 z M a a 1a @ o 4 c c, z QA +B 1990 1995 2000 2005 2010 2015 2020 Date Figure 2-3. Surface Temperature (°C) and Dissolved Oxygen Trends from 1990 to 2016 in the Southern Portion of Lake Norman (Source: Duke Energy 2017b) 12 Oligotrophic to oligo-mesotrophic is a classification for lakes or impoundments with low nutrient levels, low phytoplankton production, high water clarity, and limited fish and plant communities (Dobson and Frid 2009). Duke Energy 1 12 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Source Water Physical Data [§122.21(r)(2)] r 2.3 Determination of Area of Influence For this study, the area of influence (AOI) is defined as the portion of the source waterbody where water flow may be hydraulically influenced by the withdrawal of water at the CWIS. This report provides conservative estimates to define the AOI that should not be interpreted as the area of direct impact, or the area for which organisms have a high probability of being withdrawn by the intake structure. Actual entrainment and impingement at McGuire would be the result of a combination of many dynamic physical and biological factors that vary over space, time, and species. 2.3.1 Area of Influence Regulatory Background The AOI of a CWIS is not formally defined in the Rule; however, it is referenced in the Federal Register (79 FR 158, 4829913): • 79 FR 158, 48363, under "§122.21(r)(2) Source Water Physical Data", states that information on "the methods used to conduct any physical studies to determine the intake's area of influence in the waterbody and the results of such studies" is required to be submitted; • 79 FR 158, 48363, under "§122.21(r)(4) Source Water Baseline Biological Characterization Data", states: "The study area should include, at a minimum, the area of influence of the cooling water intake structure"; • 79 FR 158, 48367, under "§122.21(r)(11) Benefits Valuation Study", states: "The study must also include discussion of recent mitigation efforts already completed and how these have affected fish abundance and ecosystem viability in the intake structure's area of influence." • 79 FR 158, 48363, §122.21(r)(2)(ii) states: "Identification and characterization of the source waterbody's hydrological and geomorphological features, as well as the methods you used to conduct any physical studies to determine your intake's area of influence within the waterbody and the results of such studies". • 79 FR 158, 48363, §122.21(r)(4)(viii) states: "The study area should include, at a minimum, the area of influence of the cooling water intake structure". While neither a formal definition of the AOI nor guidance for its estimation are provided in the Rule, it is assumed that the AOI is that area of the source waterbody from which organisms are drawn into the intake and either impinged or entrained. 2.3.2 Impingement versus Entrainment Area of Influence 2.3.2.1 Impingement AOI For impingeable-sized organisms (i.e., generally juvenile and adult fish and shellfish), the AOI can be defined as the region extending outwards from the intake screens in which organisms are not capable of overcoming the current velocities created by water withdrawals at the CWIS, and thus 13 National Pollutant Discharge Elimination System — Final Regulations to Establish Requirements for Cooling Water Intake Structures at Existing Facilities and Amend Requirements at Phase I Facilities, 79 FR 158, 48299 (August 15, 2014). Duke Energy 1 13 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal Source Water Physical Data [§122.21(r)(2)] become impinged upon an intake screen (EPRI 2007). A conservative definition of the A0I14 for impingement is the area encompassed by the velocity contour created by the 0.5 feet per second (fps)15 through -screen velocity (TSV) threshold identified at §125.94(c). At this boundary and beyond it, the potential for impingement is minimal. Within the 0.5-fps boundary, the potential for impingement increases. However, because juvenile and adult fish have varying swimming abilities and preferred habitats, including those that involve velocities above 0.5 fps (Leonard and Orth 1988), fish within the area contained by the 0.5-fps velocity threshold will not necessarily become impinged. 2.3.2.2 Entrainment AOI The threshold velocity for entrainment is defined by the velocity above ambient current velocities created by the CWIS, where plankton may be drawn into the intake structure rather than transported away in the ambient waterbody flow. At a location where the intake -induced velocity is less than 0.1 fps to 0.3 fps16, the ambient wind -induced currents17 will likely dominate the flow patterns and the hydraulic influence of the intake structure would no longer be significant (Golder Associates 2005). Physical and temporal factors that may influence the entrainment AOI of an intake structure include (EPRI 2004): a.) the speed, direction, and distribution of flow in the waters that surround the intake structure; b.) the bathymetry of the waters that surround the intake structure; c.) the intake flow rate and variability of flow to the intake; and d.) the design of the intake. 2.3.3 Area of Influence Estimation Method The desktop calculation for the AOI of a CWIS is based on the principles of conservation of mass and continuity. The boundary of the AOI is the location where the velocity induced by the intake structure is equal to a specified threshold velocity (i.e., 0.5 fps velocity contour for impingement and 0.1 and 0.3 fps velocity contours for entrainment). The radius of the AOI (RA01) for an arc angle of 180' (i.e., consistent with a shoreline intake structure) can be estimated from a continuity equation (Eq.): 14 This approach was proposed to the Ohio Environmental Protection Agency by Dayton Power & Light in their Proposal for Information Collection for the Stuart Generating Station on the Ohio River. Their approach was accepted and also recommended as a model for other facilities on the Ohio River (EPRI 2007). 15 Per the Rule, and discussed in Section 6 of this document, a TSV of less than 0.5 fps meets the impingement mortality (IM) reduction standards through IM Options 2 and 3 (§125.94(c)(2)-(3)) for design and actual intake flows, respectively. 16 The exact threshold value would fall somewhere between these two numbers based on the speed and duration of the wind in the vicinity of the intake structure (Golder Associates 2005). 17 Wind -induced surface drift velocities are typically two to three percent of the average wind speed (Wiegel 1964). Duke Energy 1 14 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal Source Water Physical Data [§122.21(r)(2)] Qi = rr x RAOI x d x V Eq. 2-1 where, Qi = Intake Flow (in cfs) RAOI = Radius of Area of Influence d = Water depth at RAOI (in feet) V = Threshold velocity Rearranging terms in Eq. 2-1 gives: RAOI = Qi / (rr x d x V) for the shoreline intake Eq. 2-2 To develop a conservative estimate of AOI, the calculations presented below are based on water depths determined at low water elevation. As described in Section 3, McGuire withdraws cooling water from Lake Norman through two separate intake structures, a surface water intake structure (Main Intake) and a subsurface Low Level Intake (LLI) structure. The invert elevation of the Main Intake is 715 ft msl and the FERC-authorized maximum (non - emergency) drawdown water elevation for Lake Norman is 751 ft msl (FERC 2006); therefore, the reasonable low water depth in the immediate vicinity of the Main Intake is 36 feet (i.e., 751 ft msl minus 715 ft msl). Since the LLI is completely submerged even at the low water elevation, the AOI was conservatively calculated using the height of the intake opening, which is 16 feet (i.e., top of the opening [670 ft msl] minus the invert elevation [654 ft msl]). 2.3.4 Results 2.3.4.1 Main Intake The impingement and entrainment AOIs were calculated at the Main Intake based on a DIF of 2,926 MGD (4,527.3 cubic feet per second [cfs]), and a depth of 36 feet at the maximum, non -emergency, drawdown elevation (Table 2-3). Velocity contour lines were created from multiple points along the front of the intake structure, as the equations described above represent only a single measurement point. For each velocity threshold scenario, the total area encompassed by the overlapping contours was merged into a single velocity contour providing a more representative depiction of AOI, as illustrated in Figure 2-4. Duke Energy 1 15 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Source Water Physical Data [§122.21(r)(2)] r Table 2-3. Approximate Area of Influence at the Main Intake by Select Threshold Velocities Intake Flow (cfs) 4,527.3 Water depth (ft) 36 Threshold Velocity Approximate Radius of Area of Influence (ft) Approximate Area (acres) Impingement (0.5 fps) 80 0.68 Entrainment (0.3 fps) 133 1.18 Entrainment (0.1 fps) 400 5.77 Based on these calculations, a conservative impingement AOI at the Main Intake is represented as the area defined by the combined arcs extending approximately 80 feet from the front of the Main Intake which is equivalent to 0.68 acres of lake area (Figure 2-4). A conservative entrainment AOI at the Main Intake is represented by a contour extending approximately 133 feet (at 0.3 fps threshold velocity, representing 1.18 acres) to 400 feet (at 0.1 fps threshold velocity, representing 5.77 acres) from the front of the Main Intake structure. At the outer entrainment threshold velocity of 0.1 fps, the AOI affects approximately 0.02 percent of the total volume of Lake Norman and is located between the Main Intake and the floating debris boom. Figure 2-4. Impingement and Entrainment Area of Influence at the Main Intake at Select Threshold Values Duke Energy 1 16 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Source Water Physical Data [§122.21(r)(2)] r 2.3.4.2 Low Level Intake Using Eq. 2-2, impingement and entrainment AOIs were also calculated for the LLI under two withdrawal scenarios: a constant service water withdrawal of 66.8 cfs and a combined service water and cooling water withdrawal of 1,069.4 cfs (a scenario that occurs briefly only during the warmest period of the year). These AOI results are presented in Table 2-4. Table 2-4. Area of Influence of the Low Level Intake for Impingement and Entrainment under Two Operational Scenarios Intake Flow (cfs) 66.8 1,069.4 Water depth (ft)* 16 16 ■ Radius of Area of Influence (ft) Impingement (0.5 fps) 3 43 Entrainment (0.3 fps) 4 70 Entrainment (0.1 fps) 13 212 *The height of the Low Level Intake structure opening was used in the AOI calculations since the structure is located on the bottom of the lake and does not withdraw water from the entire water column. Duke Energy 1 17 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal Cooling Water Intake Structures [§122.21(r)(3)] 3 Cooling Water [§ 122.21 (r) (3)] Intake Structures The information required to be submitted per §122.21(r)(3), Cooling Water Intake Structure Data, is outlined as follows: (i) A narrative description of the configuration of each of the cooling water intake structures and where it is located in the waterbody and in the water column; (ii) Latitude and longitude in degrees, minutes, and seconds for each of the cooling water intake structures; (iii) A narrative description of the operation of each of the cooling water intake structures, including design intake flows, daily hours of operation, number of days of the year in operation and seasonal changes, if applicable; (iv) A flow distribution and water balance diagram that includes all sources of water to the facility, recirculating flows, and discharges; and (v) Engineering drawings of the cooling water intake structure. Each of these requirements is addressed in the following subsections. 3.1 CWIS Configuration McGuire withdraws raw water from Lake Norman through two separate intake structures; the Main Intake structure and the LLI. The Main Intake at McGuire is located to the east of the Cowans Ford Dam and is oriented in a north-northwest direction. The LLI is located on the bottom of Lake Norman, on the east side of the Cowans Ford Dam (Figure 3-1). 3.1.1 Main Intake The shoreline -situated Main Intake is located within an embayment created by the original shoreline morphology and topography (Duke Energy 2007). The entrance to the embayment has an approximately 750-ft-long floating debris boom. An underwater intake channel within the embayment aids in directing water to the Main Intake during low water level conditions (Duke Energy 1975; 2007). The width of the channel bottom is approximately the same width as the Main Intake and has channel side slopes of 2 to 1 horizontal to vertical (2:1) (Duke Energy 2007). The embayment has a bottom elevation of 715 ft msl, which is the same as the Main Intake structure invert elevation at the entrance of the intake structure. The bottom of the intake structure gradually increases from 716 ft msl near the traveling water screens to 722 ft msl at the downstream end of each intake bay (Duke Energy 1971; 2007). The Main Intake withdraws water from between elevation 715 ft msl and 745 ft msl (Duke Energy 2001). The top deck of the intake structure is at elevation 770 ft msl. The 247-ft-wide Main Intake structure (Duke Energy 2016c) is comprised of eight intake bays (four per unit). Each intake bay is 26 feet wide and is equipped with two conventional vertical traveling water screens, each of which are 11.2 feet wide. Condenser cooling water is pumped via eight circulating water pumps (four per unit). Schematics illustrating the Main Intake configuration are provided on Figure 3-2 and Figure 3-3. Duke Energy 1 18 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal �� Cooling Water Intake Structures [§122.21(r)(3)] Figure 3-1. Site Layout at McGuire Nuclear Station Duke Energy 1 19 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal �� Cooling Water Intake Structures [§122.21(r)(3)] UNIT 1 UNIT 2 Unit 1 CGW PUN{PS Unit 2 CGW PUl41PS 1!k i B 1 C 1 E} 2A 2B 2C 2Q TRAVELING SCpI=FNC FRBV FL.IM1IG RCRFFNG 1Ai MLjLj7MM L 2A7 @A2 xF3i 2g� 2Ci xCx xoi 2U2 ❑IHECTION OF INTAKE FLOW Figure 3-2. Schematic of the Main Intake Structure at McGuire Nuclear Station, Huntersville, North Carolina (Duke Power 2003) Water Flow 1 2a 7.3 I 26.0' 11 2 TRASH RACK (7'YP) LOW LEVEL C.C.W. PIPING Ll . TRAHEQNG * WATER SCREENS rn — — — — —{—�i — — — — — C CIRCULATING WATER PUMPS Ln M. n-F n: F1 nn nn nl* Figure 3-3. Plan View of McGuire Nuclear Station Main Intake Structure (Alden 2004) Duke Energy 1 20 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Cooling Water Intake Structures [§122.21(r)(3)] r Water withdrawn from Lake Norman passes through trash racks located at the outer edge of the intake structure prior to entering the intake bays. The traveling water screens are located within each intake bay approximately 23 ft downstream of the trash racks (Figure 3-4). The traveling water screens are equipped with 10-ft-wide baskets with 3/8-inch stainless steel mesh panels (Link -Belt Company 2006). Eight Allis-Chalmers vertical pumps (four per unit) are located approximately 16.7 feet downstream of the traveling water screens (Figure 3-4). Each pump has a capacity of 254,000 gpm (366 MGD). The bell mouth inlets of the circulating water pumps are at elevation 725.8 ft msl. The discharge pipes from the pumps have a centerline elevation of 760.5 ft msl (Duke Power Company 1974). H. W.L. EL. 760.0 F T —z- N,W_L. EL. 756.0 FT— L. W. L. EL. 751.0 FT —x- TRASH RACK EL. 715.0 FT _,_ q CIRCULATING WATER PUMP TRAVELING WATER SCREENS 69.4' (L DISCHARGE LINE ALDEN Figure 3-4. Main Intake Structure Cross -sectional View, McGuire Nuclear Station (Alden 2004) 3.1.2 Low Level Intake (LLI) The LLI is located on the bottom of Lake Norman on the east side of Cowans Ford Dam (Figure 3-1). The LLI structure withdraws water through three intake openings between 654 ft msl and 670 ft msl (Duke Energy 2001). The LLI openings are composed of upper and lower sections. The lower section is composed of flat screen panels with 3/4-inch mesh; the upper section includes box screens (also 3/4-inch mesh) extending from the face of the LLI structure. The LLI has a total screen area of approximately 1,681 square feet (Duke Energy 2008). The LLI is inspected and cleaned annually by divers. Duke Energy 1 21 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal Cooling Water Intake Structures [§122.21(r)(3)] Lake Normal Full Pond 17,3' A Top of LLI Structure 1 r I• r "Note- This illustration reflects the anginal design of the low level intake (LLI), Since construction, box screens covering the upper portion of each mesh panel have been installed. Figure 3-5. Schematic of Low Level Intake Structure at Cowans Ford Dam, McGuire Nuclear Station, Huntersville, North Carolina (Duke Energy 2009) Water withdrawn via the LLI structure is used for service water and to supplement cooling water, as needed, at the Main Intake. Nuclear station service water is piped directly to the two nuclear units via two 17,500 gpm (25 MGD) pumps18. Cooling water is pumped via three19 150,000 gpm (216 MGD) pumps and routed through a 127-inch diameter pipe to the Main Intake where it discharges near the surface between the trash racks and traveling water screens. Physical characteristics of the Main Intake and the LLI are summarized in Table 3-1. 18 There are four RN pumps; however, only two operate at any given time while the remaining two are redundant. 19 There were originally six LLI cooling water pumps; the three pumps associated with Unit 2 have been retired (only the Unit 1 LLI pumps are operable). Duke Energy 1 22 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Cooling Water Intake Structures [§122.21(r)(3)] r Table 3-1. Intake Structure Characteristics, McGuire Nuclear Station Invert Elevation (ft msl) 715 Depth (from full pond elevation) (feet) 45 Width (feet) 247 Depth of Water Withdrawal (ft msl) 715-745 Number of Screens 16 traveling water screens (8 per unit) Number of Intake Bays 8 (4 per unit) Bay Width (feet) 26 Circulating Water Pumps 8 Screen Mesh (inches) 3/8 *Unit 1 only (Unit 2 pumps have been retired) 644 116 38, 39, and 41 654-670 9 fixed panel screens 3 38, 39, and 41 3* 3/4 3.2 Latitude and Longitude of CWIS The geographic coordinates (in degrees, minutes, and seconds) of the CWIS on Lake Norman are provided in Table 3-2. Table 3-2. Coordinates of the Main Intake and Low Level Intake at McGuire Nuclear Station Main Intake Low Level Intake (LLI) 35°26'03.3"N 35°26'06.3"N 3.3 Engineering Drawings of CWIS 80°57'02.3"W 80°57'23.5"W — A list of design drawings for the CWIS on Lake Norman is provided in Table 3-3. The drawings are provided in Appendix 3-A. Table 3-3. Design Drawings of the Main Intake and Low Level Intake at McGuire Nuclear Station Drawing No. Drawing Title. Main Intake Plan & Sections MC-1341-1 General Arrangement Plan and Sections Main Intake Plan & Sections CF-398 Miscellaneous Steel Trash Racks & Embedded Pipe Sections & Details Low Level Plan & Sections CF-394 Concrete Outline Plan & Elevation Intake Duke Energy 1 23 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal Source Water Baseline Biological Characterization Data [§122.21(r)(4)] 4 Source Water Baseline Biological Characterization Data [§122.21(r)(4)] The information required to be submitted per §122.21(r)(4), Source Water Baseline Biological Characterization Data, is outlined as follows: (i) A list of the data in paragraphs (r)(4)(ii) through (vi) of this section that are not available and efforts made to identify sources of the data; (ii) A list of species (or relevant taxa) for all life stages and their relative abundance in the vicinity of the cooling water intake structure; (iii) Identification of the species and life stages that would be most susceptible to impingement and entrainment. Species evaluated should include the forage base as well as those most important in terms of significance to commercial and recreational fisheries; (iv) Identification and evaluation of the primary period of reproduction, larval recruitment, and period of peak abundance for relevant taxa; (v) Data representative of the seasonal and daily activities (e.g., feeding and water column migration) of biological organisms in the vicinity of the cooling water intake structure; (vi) Identification of all threatened, endangered, and other protected species that might be susceptible to impingement and entrainment at the cooling water intake structures; (vii) Documentation of any public participation or consultation with Federal or State agencies undertaken in development of the plan; and (viii) If information requested in paragraph (r)(4)(i) of this section is supplemented with data collected using field studies, supporting documentation for the Source Water Baseline Biological Characterization must include a description of all methods and quality assurance procedures for sampling, and data analysis including a description of the study area; taxonomic identification of sampled and evaluated biological assemblages (including all life stages of fish and shellfish); and sampling and data analysis methods. The sampling and/or data analysis methods used must be appropriate for a quantitative survey and based on consideration of methods used in other biological studies performed within the same source waterbody. The study area should include, at a minimum, the area of influence of the cooling water intake structure. (ix) In the case of the owner or operator of an existing facility or new unit at an existing facility, the Source Water Baseline Biological Characterization Data is the information in paragraphs (r)(4)(i) through (xii) of this section. Duke Energy 1 24 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal Source Water Baseline Biological Characterization Data [§122.21(r)(4)] (x) For the owner or operator of an existing facility, identification of protective measures and stabilization activities that have been implemented, and a description of how these measures and activities affected the baseline water condition in the vicinity of the intake. (xi) For the owner or operator of an existing facility, a list of fragile species, as defined at 40 CFR §125.92(m), at the facility. The applicant need only identify those species not already identified as fragile at 40 CFR §125.92(m). New units at an existing facility are not required to resubmit this information if the cooling water withdrawals for the operation of the new unit are from an existing intake. (xii) For the owner or operator of an existing facility that has obtained incidental take exemption or authorization for its cooling water intake structure(s) from the United States Fish and Wildlife Service or the National Marine Fisheries Service, any information submitted in order to obtain that exemption or authorization may be used to satisfy the permit application information requirement of paragraph 40 CFR §125.95(f) if included in the application Each of these requirements is addressed in the following subsections. 4.1 List of Unavailable Biological Data The biological data needed to prepare the information required for compliance with §122.21(r)(4) are available. Data reviewed for this section of the report includes: • 2000-2002 Impingement Study (Duke Power 2003); • 2006-2007 Creel Surveys (NCWRC 2008); • 2006-2007 Impingement Study and Assessment of Adverse Environmental Impact (EPRI 2010a); • 2012-2016 Maintenance Monitoring Reports: electrofishing, gill netting and purse seine data (Duke Energy 2014a, 2015, 2016d, 2016e, 2017b); and • 2016-2017 Entrainment Characterization Study (HDR 2019). These data were compiled and analyzed and are summarized below. The biological characterization of the source waterbody presented in this section consists of data collected on Lake Norman and supplemented with regionally -relevant, species -specific life history information. In the absence of entrainment data at McGuire, Duke Energy developed an Entrainment Characterization Study Plan. This plan was reviewed and approved by the North Carolina Department of Environmental Quality (NCDEQ) prior to commencement of field data collections. The 2016-2017 Entrainment Characterization Study (Study) collected entrainment data at the McGuire CWIS from March through October in 2016 and 2017. The Study is summarized in Section 4.5.2 and is described in detail in Section 9;the Study report is included in Appendix 9-A. Duke Energy 1 25 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Source Water Baseline Biological Characterization Data [§122.21(r)(4)] r 4.2 List of Species and Relative Abundance in the Vicinity of the CWIS As discussed in Section 2.2.3, Duke Energy has been performing annual fisheries surveys through the MMP since 1987 (Duke Energy 2017b). These studies include lake -wide surveys of water quality/chemistry, phytoplankton, zooplankton, and fish communities. For studies performed from 2012-2013, the lake was divided into six zones (Figure 4-1). For those studies performed from 2014- 2016, the lake was divided into five zones (refer to Figure 2-2). Duke Energy personnel collected data within each zone using a variety of methodologies, including shoreline electrofishing (1988- 2016), purse seine sampling in pelagic zones (1993-2013), and pelagic hydroacoustic surveys (1997-2013). The results from recent studies performed in the vicinity of the McGuire CWIS are summarized in the following sections. These data illustrate the species composition and abundance of the Lake Norman biological community. 4.2.1 Spring Electrofishing Annual spring electrofishing surveys in Lake Norman were performed in the littoral areas of Zones 1 through 5 per Figure 4-1, and as described below. In 2012-2013, ten 300-meter (m) transects (total length of 3,000-m) were electrofished in each of three zones, and beginning in 2014, five 300-m transects (total length of 1,500-m) were sampled in each of four zones. Sampling was performed during daylight hours when water temperature was expected to be between 15-20 degrees Celsius (°C). Transects include habitats representative of those found in Lake Norman and are identical to historical locations surveyed since 1993. A summary of electrofishing results from 2012 through 2016, presented as catch per unit effort (CPUE) by year, is provided in Table 4-1 (Duke Energy 2014a, 2015, 2016d, 2016e, 2017b). Catch per unit effort was reported as number per total distance (in meters) sampled. The following section highlights data collected in Zone 1 and describes the composition and relative abundance of species nearest to the McGuire CWIS from 2012 to 2016. Data presented for 2012 and 2013 were reported as number collected per 3,000-m of transect searched, while data from 2014 through 2016 were reported as number per 1,500-m of transect searched. To facilitate direct comparison between years, CPUE presented in Table 4-1 has been standardized to represent total catch per 1,500-m of transect sampled. Total fish abundance during spring electrofishing surveys was highest in 2016 with 2,076 fish collected and lowest in 2013 with 368 fish collected (Table 4-1). The total number of distinct taxa was highest in 2012 (16 taxa) and lowest in 2015 and 2016 (9 taxa each, however the total number of fish caught in 2016 was more than double the total number captured in 2015). Duke Energy 1 26 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal �� Source Water Baseline Biological Characterization Data [§122.21(r)(4)] Zone 6 LEGEND # Station Locations Fish Sampling Location n 0 Electrofishing Zone 5 41E� Purse seine Marshall Steam St at io n Zone 4 . V 4 rb Zone 3 , ,tea e d Zone 2 Zone 1 0 Miles 3 McGuire Nuclear Station MTASOUMM:USG3Mw1al F�c ogFapF7 M6se1aM Rke Biagi 201fl Figure 4-1. Zones and Locations of Fish Sampling Events, 2012-2013 Duke Energy 1 27 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Source Water Baseline Biological Characterization Data [§122.21(r)(4)] r Table 4-1. Total Number as Catch Per Unit Effort* by Species from Electrofishing Surveys, 2012-2016 in Zone 1 ICatch Per Unit Effort' 1,500-m Common Name Scientific Name (No. per M AbL- sampled) Centrarchidae Bluegill Lepomis macrochirus 58�EV'176 319 20'MW5'92 Redbreast Sunfish Lepomis auritus 171 .' 84 213 111 242 Alabama Bass2 Micropterus henshalli 57 51 15 25 Hybrid Sunfish Lepomis spp. 9 13 6 16 Warmouth Lepomis gulosus 9 f 4 2 -- 3 Redear Sunfish Lepomis microlophus 6 6 15 10 58 Green Sunfish Lepomis cyanellus 24 22 55 31 50 Largemouth Bass Micropterus salmoides 3 1 2 9 4 Hybrid Black Bass Micropterus salmoides 1 1 -- -- -- x M. henshalli Black Crappie Pomoxis 1 nigromaculatus Cyprinidae Greenfin Shiner Cyprinella chloristia 1 2 -- -- -- Common Carp Cyprinus carpio 1 1 1 -- -- Whitefin Shiner Cyprinella nivea 1 -- -- -- -- Ictaluridae Flathead Catfish Pylodictis olivaris 3 2 4 3 2 Channel Catfish Ictalurus punctatus 1 1 1 -- -- Clupeidae Alewife Alosa pseudoharengus -- -- -- 13 -- Gizzard Shad Dorosoma cepedianum 7 1 3 3 -- Threadfin Shad Dorosoma petenense -- -- -- -- 46 Catostomidae Quillback Carpiodes cyprinus 1 -- 1 -- -- Lepisosteidae Longnose Gar Lepisosteus osseus -- 1 -- -- -- Total Number Caught 886 368 1,360 806 2,076 Total Distinct Taxa3 16 14 12 9 9 Note: -- indicates no specimens collected in the specified year. Sources: Duke Energy 2014a, 2015, 2016d, 2016e, 2017b. 'CPUE was defined as the total number of fish collected from sampling 5 transects totaling 1,500 m of transect sampled. Numbers were rounded to the nearest whole fish. 2Formerly known as Spotted Bass 3When counting the number of distinct taxa collected, general taxonomic designations at the genus, family, and higher taxonomic levels were dropped if there was one valid lower -level designation for that group (e.g., Hybrid Sunfish was not counted as a distinct taxa since this could potentially include several species crosses and they were identified only as Lepomis spp.) However, Hybrid Black Bass was included in the Total Distinct Taxa because in Lake Norman, this hybrid is likely Largemouth Bass x Alabama Bass (Brey et al. 2012). Between 2012 and 2016, electrofishing samples were numerically dominated by centrarchids (95-96 percent of total catch, Table 4-2). Bluegill (Lepomis macrochirus) were the dominant centrarchid (at least 46.9 percent of total catch and as high as 66.3 percent), followed by Redbreast Sunfish (Lepomis auritus), Alabama Bass (Micropterus henshalli), Green Sunfish (Lepomis cyanellus), and Hybrid Sunfish (Lepomis spp.). These five most -abundant taxa collectively totaled greater than 89.1 percent of the total catch and as high as 96.5 percent across the 5-year data range. Duke Energy 1 28 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Source Water Baseline Biological Characterization Data [§122.21(r)(4)] r Table 4-2. Relative Abundance (Percent) of the Five Most Abundant Centrarchids Captured During Electrofishing Surveys in Zone 1, 2012-2016 Bluegill 66.3 48.5 46.9 50.1 57.0 Redbreast Sunfish 19.4 23.1 31.3 27.5 23.3 Alabama Bass 5.2 15.7 7.5 3.7 2.4 Green Sunfish 2.7 5.9 8.1 7.7 4.8 Hybrid Sunfish 2.9 2.3 1.9 1.5 1.5 Total Relative Abundance (%) 96.5 95.5 95.7 90.6 89.1 (Sources: Duke Energy 2014b; 2015; 2016d; 2016e; 2017b) The dominance of centrarchids in the littoral zone is typical of reservoirs in the Catawba-Wateree Project and the southeastern Piedmont region (FERC 2009; Duke Energy 2013; Duke Energy Progress 2013a and 2013b). The littoral zone where electrofishing was performed consisted of shallow water, riprap shorelines, woody debris, structures associated with shoreline development, and limited vegetation, all of which are preferred habitat for sunfish and bass. Sunfish are prolific spawners and function as a significant source of prey for predators such as Largemouth Bass (Micropterus salmoides) and Alabama Bass. Largemouth Bass captures have declined since the introduction of the Alabama Bass, likely due to congeneric competition for habitat and forage (Duke Energy 2017b). However, competition and predation by other introduced species, such as Alewife (Alosa pseudoharengus) and White Perch (Morone americana), may have also contributed to the observed population decline (Duke Energy 2015). 4.2.2 Fall Purse Seine Sampling Duke Energy completed annual purse seine sampling during the fall from 1993 to 2013 (Duke Energy 2014, 2015). Sampling was performed in areas deep enough for unhindered net deployment (Zones 1, 2, and 5) (Figure 4-2), with a 122.0 x 9.1-m purse seine with 4.8-millimeter (mm) mesh. A subsample of forage fish collected from each area (i.e., zone) was used to estimate total species composition and size distribution. Threadfin Shad (Dorosoma petenense) consistently dominated purse seine collections since 1993, with relative abundance in samples from 75 to 100 percent (Figure 4-2). Alewife and Gizzard Shad (Dorosoma cepedianum) are the only two other species collected in purse seine nets. Most fish captured were young -of -year. Alewife were introduced to Lake Norman in the late 1990's and have fluctuated in relative abundance over the last two decades, achieving a peak relative abundance of 25 percent in 2002. While Gizzard Shad and Threadfin Shad have historically been collected via purse seines in other reservoirs of the Catawba-Wateree Project, Threadfin Shad largely dominates the limnetic forage fish community on Lake Norman and downstream reservoirs (FERC 2009). The persistence of Threadfin Shad in the lake can be attributed to the thermal refuge provided by the heated effluent discharged from McGuire (and Marshall) during winter months. Duke Energy 1 29 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal Source Water Baseline Biological Characterization Data [§122.21(r)(4)] 50,000 t m 40,000 0 Z 30,000 Y c y 20,000 Y E 10,000 W OLA, t1r, MIN - en a u1 to n oo rn o � N rrr eT u1 � r• 00 C1 0 ,� ry r*e eY ri ri rl N rl rl N N N N N N N N N N N N N N Year Total Forage Fish Threadfin Shad Alewife Source: Duke Energy 2014, 2015 100% 90% 80% u 70% 6ME, _ a 50% c 4M. Y 30% fO GJ Figure 4-2. Estimated Total Number Caught and Relative Abundance of Alewife and Threadfin Shad in Purse Seine Samples from Zones 1, 2, and 5, of Lake Norman, 1993-2013 4.2.3 Hydroacoustic Surveys Fall hydroacoustic surveys have shown substantial variability in forage fish densities across zones and years, which is typical of biological populations (Figure 4-3). General trends show a negative gradient in fish abundance from uplake (Zone 5) to downlake (Zone 1) (Figure 4-1), consistent with typical nutrient distribution patterns in Lake Norman and other southeastern reservoirs (Green et al. 2015). 25.000 20.000 ea t 15.000 Fq co C m L 10.000 VI �1 IG 5.000 f Zane 1 —*---Zone 2 - 7--- 0 7--- A r— Do Cm a N C'7 v u7 CO r— av am O N C7 rn rn am o o v o 0 o a o 0 0 rn v� rn o o o o o 0 0 0 o a N N N N N hr cV N N N N N N tV Year Figure 4-3. Forage Fish Density Estimates in Lake Norman from Hydroacoustic Surveys, 1997-2013 (Source: Duke Energy 2015) Duke Energy 1 30 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal Source Water Baseline Biological Characterization Data [§122.21(r)(4)] As discussed in Section 9 and 10, forage dominated entrainment samples at MNS. Duke Energy's long term sampling of this community suggests there is no obvious trend of decline due to entrainment, and instead is reflective of a natural biological population Duke Energy 2014a, 2015. 4.2.4 Creel Surveys The North Carolina Wildlife Resources Commission (NCWRC) has performed creel surveys every decade since the 1970's to estimate angling effort, catch, and harvest on Lake Norman (NCWRC 2008). The surveys also include an estimation of angler expenditures, bank boat access (private and public), night fishing, and fishing tournaments. According to the most recent surveys completed in 2006-2007, the primary species of sport fish targeted on Lake Norman are black bass (Micropterus spp., 42 percent), Striped Bass (16 percent), crappie (Pomoxis spp., 10 percent), and catfish (several species from the Ictaluridae family, 6 percent). Anglers spent approximately 136,000 angler - hours targeting black bass, followed by approximately 51,000 angler -hours for Striped Bass, 32,000 angler -hours for crappie, and 20,600 angler -hours for catfish. At approximately $13.45 per angler - hour, the total estimated angler expenses accrued on Lake Norman in 2007 is over $3.2 million dollars (M). 4.2.5 Summary Lake Norman supports a typical southeastern Piedmont fishery, with a littoral zone community dominated by centrarchids and a pelagic community dominated by clupeids (Duke 2017b). The Lake Norman fish community has primarily been impacted by non-native species introductions, including Alewife, White Perch, Alabama Bass, Green Sunfish, and Flathead Catfish (Duke Energy 2017b). The NCWRC currently stocks Striped Bass -White Bass (Morone chrysops) hybrids instead of Striped Bass (Morone saxatilis) because of the hybrid bass' higher tolerance to the temperature -oxygen (horizontal) squeeze. Regardless of the evolving species composition, abundant littoral zone and pelagic forage fish species continue to provide a regular and diverse prey base for predators. The annual lake monitoring studies suggest that Lake Norman supports a balanced fish community (Duke Energy 2017b). Lake Norman's diverse fish community continues to support a strong sport fishery with annual angler expenditures estimated at over $3.2M (NCWRC 2008). It is expected that with continued human population growth in and around the Charlotte area, fishing pressure and expenditures will increase accordingly in future years on Lake Norman. 4.3 Identification and Evaluation of Primary Growth Period The primary growth period for freshwater fish species in the southeast occurs when water temperatures are 10°C or above and directly follows the spring hatch. Generally, growth is fastest in the spring and early summer, slows in the late summer and fall, and virtually stops during winter (Gebhart and Summerfelt 1978). The majority of fish populations have highest densities shortly after hatching occurs, when larvae are concentrated and natural mortality has not yet reduced numbers. Feeding competition is especially important during late spring through early summer, when most fish are in their early life stages and more susceptible to starvation (May 1974). This is a critical stage in development, where larval fish have a short time period to initiate exogenous feeding before starving (Ehrlich 1974; Miller et al. 1988). Duke Energy 1 31 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Source Water Baseline Biological Characterization Data [§122.21(r)(4)] r 4.3.1 Reproduction and Recruitment Fish species present in Lake Norman consist of nest builders (such as centrarchids) or broadcast spawners (such as clupeids). Nest builders usually exhibit parental care until hatching and the swim - up stage, whereas broadcast spawners do not construct nests and provide no parental care. Eggs for both types of spawners are usually demersal and/or adhesive, or may initially be adhesive prior to losing this characteristic (such as Alewife). Nest -building species with adhesive eggs are less susceptible to entrainment. Fish spawning is typically triggered when water temperatures reach the species -specific temperature threshold (Etnier 1993). Fish reproduction has the potential to produce high yields; however, mortality rates are typically higher compared to other organisms. Additionally, most fish spawn only once per year, regardless of prior success. The number of eggs a female produces (fecundity) can vary depending on the life history of the species and individual size. Species -specific spawning information is summarized in Appendix 4-A. For most species, peak larval recruitment is expected to occur near the end of the spawning season, after eggs hatch. Young of year ichthyoplankton abundance is typically highest shortly after the spring and summer spawning period (Page and Burr 2011). 4.3.2 Period of Peak Abundance for Relevant Taxa Fish spawning is a direct function of water temperature and most activity is constrained to the spring and early summer months. As a result, an influx of egg, larval, and juvenile fishes occurs in Lake Norman in the spring of each year when water temperatures begin to rise. Based on a literature review, peak abundance for early life stage and juvenile fishes of most species in Lake Norman occurs between April and June (Table 4-3). Generally, recruitment to the juvenile life stage in North Carolina follows the peak spawning window and continues until April or May of the succeeding year, depending on the life history strategy of individual species (Page and Burr 2011). Duke Energy 1 32 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Source Water Baseline Biological Characterization Data [§122.21(r)(4)] r Table 4-3. Period of Reproduction for Species Present in Lake Norman, North Carolina' W"MUMMOMMOMMMUM Atherinopsidae Silverside 23 1MEMEMMEMEM Black Cappie3 MEN MENEM Bluegill --_------ Green Sunfish ■■■■■■■■ Largemouth Bass EN IMMEM Centrarchidae Hybrid Bassi MEN490000 Redbreast Sunfish 010019MEM Redear MEMEMMEMSunfish Bass ONEMJEEE Warmouth -_------ Alewife3 -_-�'_-- Clu eidae Gizzard Shad3 ONE A p Threadfin Shad3 ONE Common Carpi EMMA Cyprinidae S hitefin Shiner 00:3 Golden Shiner MENNEN Channel Catfish3 mom Ictaluridae Blue Catfish -_- ■ Flathead Catfish ■■■ Moronidae White Perch 3 WIENE Percidae Swamp NONE Darter3 Sources: Rohde et al. 1994, 2009 Note: The species presented in this table were identified from a review of biological survey data (Maintenance Monitoring Reports summarized in Section 4.2), historical impingement data (discussed in Section 4.5.1), and recent entrainment data (see Section 4.5.2). 'This table illustrates the potential spawning window and potential peak spawning period in Lake Norman based on a review of available literature on Lake Norman and comparable southeastern reservoirs. Lighter shade indicates the spawning window and darker shading indicates the peak spawning period. 2Spawning window for Inland Silverside reflects that of marine/estuarine individuals (February through April). Window was lengthened for the period of collection documented during the McGuire entrainment study. 3Spawning windows were evaluated and lengthened, as necessary, to reflect Lake Norman -specific spawning periods (for species in the vicinity of the McGuire CWIS) as indicated by the recent entrainment study. Duke Energy 1 33 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Source Water Baseline Biological Characterization Data [§122.21(r)(4)] r 4.4 Daily and Seasonal Activities of Organisms in the Vicinity of the CWIS The typical habitat preferred by littoral zone species includes submerged woody debris (roots, logs), boulders, rocks, riprap shorelines, artificial structures such as docks and piers, and vegetated areas. Pelagic species, such as clupeids, form large schools in open water areas. Some predators (i.e., Largemouth Bass and Alabama Bass) utilize both the littoral and pelagic zones (Matthias et al. 2014) while Striped Bass -White Bass hybrids occupy the pelagic zone. Appendix 4-A provides a summary of species -specific preferred daily habitat and diet information. Daily migrations, such as diel vertical migration (or water column migration), are typical for fish species that inhabit lacustrine environments. During a daily cycle, zooplankton and fish exhibit synchronized movements up and down in the water column (Brierley 2014). The primary trigger for diel vertical migration in freshwater fish is the diel change in light intensity. Declining light at dusk triggers the ascent to the surface, and increasing light at dawn triggers the return to deeper water (Mehner 2012). This is the typical pattern for many species; however, reverse migration can also occur. Additional triggers for vertical migration include hydrostatic pressure and water temperature, which may guide fish into particular limnological zones at night, particularly during stratification (Mehner 2012). Pelagic (open water) organisms use diel vertical migration to balance the competing objectives of growing quickly and minimizing predation risk. Most fish species that perform diel vertical migration are planktivorous, and live primarily in the pelagic zone of thermally stratified lakes (Mehner 2012). Many freshwater fish species in Lake Norman, particularly during ichthyoplankton or juvenile life stages, exhibit diel vertical migration in the water column. Variation in seasonal behavior of fishes is primarily associated with spawning activities. Since it is an impoundment with multiple impassable downstream barriers, there are no diadromous fish species in Lake Norman. Most species undergo short or local migrations for spawning and/or overwintering, such as pelagic species moving to the shoreline, or Blue Catfish moving upstream (Rhode et al. 2009). 4.5 Species and Life Stages Susceptible to Impingement and Entrainment An impingement study carried out by EPRI in 2006-2007 assessed the "adverse environmental impact" from fishery losses due to impingement, applying the USEPA's Framework for Ecological Risk Assessment (EPRI 2010a). Adverse environmental impacts were defined as an unacceptable reduction in biological integrity (measured in terms of aquatic community species composition, diversity, and function) or human use of the aquatic resources of Lake Norman (particularly, fishing opportunity or quantity/quality of catch). The EPRI 2006-2007 study was performed to help evaluate impingement data collected by Duke Energy in 2000-2002 (Duke Power 2003) and assess possible adverse environmental impacts to the fishery. The EPRI study, summarized in Section 4.5.1, concluded that there was no evidence to support that impingement at McGuire was causing an adverse environmental impact in Lake Norman (EPRI 2010a). The following section summarizes the species and life stages that may be susceptible to impingement and entrainment at the McGuire CWIS, as indicated by ongoing monitoring data, historical impingement data, and the recent entrainment studies performed at the facility. Duke Energy 1 34 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal Source Water Baseline Biological Characterization Data [§122.21(r)(4)] 4.5.1 Impingement Vulnerability to impingement exhibited by adult and juvenile fish species depends upon biological and behavioral factors including seasonal fish community structure, spawning effects (proximity of spawning, nursery, and foraging habitat to the CWIS), high flow events, health status, and attraction to the flow associated with the intake. In addition, swimming speed, intake velocity, trash rack spacing, and other intake configurations will also affect the susceptibility of an organism to impingement. For example, clupeids have high susceptibility to impingement based on multiple factors such as schooling behavior, distribution in the water column, rheotactic response to intake flows, and poor swimming performance in winter months due to lower water temperatures (Loar et al. 1978; EPRI 2008, 2011). Duke Energy performed an impingement study of the Main Intake screens from December 2000 to November 2002 (Duke Power 2003). The study represented a complete census of impingement at McGuire (rather than a sampling). Screens were washed at the beginning of the study, and weekly thereafter. Fish and debris were collected using wire -coated baskets placed in the sluiceway and sorted. Fish were enumerated, measured, and identified to the lowest practical taxon. Surface water temperature was also recorded during each sampling event. A total of 2,388 fish consisting of 23 species, 8 families, and 1 hybrid complex were collected during the study. In the first year of sampling, 1,690 fish were collected, with Threadfin Shad (51.5 percent) the most abundant species, followed by Alewife (12.7 percent) and Bluegill (5.7 percent). In the second year, 698 fish were collected, with Alewife (23.8 percent) the most abundant species, followed by Threadfin Shad (19.2 percent) and White Perch (15.3 percent). Threadfin Shad were more abundant in samples during the winter, while Alewife, White Perch, and Bluegill were frequently collected in impingement samples in summer and fall. Lengths of fish impinged during the study varied by species. Lengths for Threadfin Shad, Alewife, and Bluegill were generally less than 120 mm. Moderate -sized specimens, those with total lengths between 150 and 300 mm, were predominantly White Perch. Blue Catfish, Flathead Catfish, and Striped Bass were the largest fish impinged; however, due to their size, typical [healthy] swimming ability, and advanced state of decay (indicating that the fish were dead prior to being impinged), it is suspected the mortality of these individuals was related to angling or other causes, rather than impingement. Increased Threadfin Shad impingement rates are generally observed when water temperatures decline below 5-10°C during winter (Loar et al. 1978; EPRI 2008). Decreasing temperatures stress the fish and impair swimming ability, which leaves fish unable to avoid the current associated with water withdrawals. Water quality data collected over the two-year impingement study showed lower water temperatures in the first year of study when compared to the second. The increased temperatures during the second year of the study corresponded with a decrease in Threadfin Shad impingement at McGuire. 4.5.1.1 2005 Efficiency Study and Revised Impingement Estimates Concerns regarding the frequency of screen washing during the 2000-2002 study and possible fish losses due to predation or decay resulted in a study performed in 2006-2007 (EPRI 2010a). Over a one -week period in July 2005, a total of 1,600 fish were marked and placed in front of all 16, freshly - washed, Main Intake screens at specific time intervals. Four hundred marked fish were introduced to a set of four (of 16) randomly -selected screens at the intake structure seven, five, three, and one day Duke Energy 1 35 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal Source Water Baseline Biological Characterization Data [§122.21(r)(4)] prior to screen washing and sampling. All screens were washed and marked fish were collected at the end of the seven-day period. Because this study was performed in mid -summer with relatively higher water temperatures, fish losses due to decay resulted in conservative estimates (overestimating losses) compared to cooler months with lower decay rates. Of the marked fish released during the study, a total of 243 of the 400 released fish were recovered after screen washings at the end of the seven-day period. The number of fish recovered declined over time, from 98 fish collected after one day on the screens, to 93, 36, and 16 fish after three, five, and seven days on the screens, respectively. This trend suggests a steady, cumulative loss of impinged fish due to decay, predation, or other reasons. To address the cumulative loss of impinged fish between screen wash days, the collection efficiency of the study was determined by calculating the number of marked fish recovered from all screens, divided by the number of fish estimated to have been originally impinged and multiplied by 100. Based on the calculated collection efficiency of 62 percent, a correction factor of 38 percent was applied to the study data (EPRI 2010a). Accounting for this, revised estimates of fish impingement mortality (IM) at McGuire based on the 2000-2002 data were 2,726 fish for the first year of study and 1,126 for the second year of study. Based on results of the study, estimated annual impingement consisted of 37.6 percent young -of -year and 46.6 percent yearling, with 15.8 percent unidentifiable. After incorporating the correction factor, total annual impingement estimates remained relatively low for McGuire (Duke Power 2003). Impinged organisms collected on screens at the McGuire CWIS were predominantly pelagic broadcast spawners (i.e., clupeids). The composition and seasonality of occurrence in impingement samples was generally similar to observations at other southeastern steam electric stations (Duke Power 2003). A review of the draft results of the impingement study by the U.S. Nuclear Regulatory Commission (USNRC 2002) concluded that impacts of impingement on the fish and shellfish community are small at the McGuire CWIS. 4.5.2 Entrainment Ichthyoplankton (the egg and larval life stage of fishes) exhibit the highest degree of susceptibility to entrainment based on body size and swimming ability. Therefore, an organism is only susceptible to entrainment for a portion of its life cycle. Larger juvenile and adult life stages have the swimming ability to avoid entrainment and are often size -excluded by the mesh screen. Life history characteristics can influence the vulnerability of a fish species to entrainment. For example, broadcast spawners with non -adhesive, free-floating eggs can drift with water currents and may become entrained in a CWIS, while nest -building species with adhesive eggs are less susceptible to entrainment during early life stages (King et al. 2010). 4.5.2.1 1978 Predictive Study Limited entrainment information is available for McGuire, however, the USNRC reviewed a 1978 predictive study provided by Duke Power Company (1978) in 2002 (USNRC 2002). The study consisted of bi-weekly ichthyoplankton samples collected from 1974 to 1977 at the Main Intake at a depth of 49 feet. Ichthyoplankton losses to entrainment were primarily Threadfin Shad eggs and larvae. Following review of the predictive study, the USNRC reasoned that most fish species that reside near the Main Intake, such as Bluegill, spawn in shallow shoreline areas and produce demersal Duke Energy 1 36 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal Source Water Baseline Biological Characterization Data [§122.21(r)(4)] adhesive eggs that would not be subject to entrainment. Other species known to spawn in the McGuire intake cove are Threadfin Shad, Black Crappie (Pomoxis nigromaculatus), and Yellow Perch (Perca flavescens). The report also states that larval fish entrainment at the LLI pumps is expected to be low when the LLI pumps are operational during the warm summer months because few ichthyoplankton are present in the cold, low -oxygen waters of the hypolimnion. The USNRC concluded that "because of the rapid Threadfin Shad reproduction rate and the presence of more suitable spawning habitat outside of the influence of the intake structures, losses do not have a measurable effect on the standing crop of shad... the potential impacts of the cooling water intake system's entrainment of fish and shellfish in the early life stages are SMALL, and additional mitigation is not warranted" (USNRC 2002). 4.5.2.2 2016-2017 Entrainment Characterization Study To supplement data from the 1978 Predictive Study (Duke Power Company 1978), a two-year Study was performed at McGuire from 2016 to 2017 (see Section 9 and Appendix 9-A). A total of 2,568 fish representing at least 12 distinct taxa from eight families were collected in ichthyoplankton samples during the Study. The ichthyoplankton samples were dominated by species in the Clupeidae family (Alewife, Gizzard Shad, and Threadfin Shad; an average 62.5 percent across the two years), Inland Silverside (50.3 percent in 2016, only), and White Perch (8.7 percent across 2016 and 2017). No Inland Silverside were collected during 2017. The Inland Silverside is not native to Lake Norman and has not previously been collected in fisheries surveys performed by Duke Energy or the NCWRC. Average daily ichthyoplankton density by month for all taxa and life stages were reviewed for temporal (seasonal and diel) trends. In general, the two years of sampling exhibited similar seasonal trends with the highest ichthyoplankton densities coinciding with peak spawning of Clupeidae during the spring. Considering a combined sample data set from 2016 and 2017 together, peak ichthyoplankton densities occurred in the months of April (132.78 organisms/100 cubic meters [m3]), May (80.61 organisms/100 m3), and June (55.92 organisms/100 m3). However, discounting the collection of Inland Silverside, which consisted of 79 percent of the total collection, peak ichthyoplankton densities occurred in April and May for both years. Samples collected in 2016 predominantly consisted of young -of -year (50.5 percent) and post yolk - sac larvae (47.6 percent) life stages. Few egg or yolk -sac larvae were collected in 2016, with each of the life stages consisting of no more than one percent of the total collected. Post yolk -sac larvae accounted for nearly the entire (98 percent) 2017 ichthyoplankton totals, followed by yolk -sac larvae (2 percent). Few egg or young -of -year were collected in 2017, with each comprising no more than one percent of the collection. Ichthyoplankton densities within diel periods were variable. Ichthyoplankton density was lowest during the daytime hours during both 2016 and 2017, while highest densities occurred during night and morning hours in 2016 and during night hours in 2017. Details of the Study methods, analysis, and results are presented in Section 9 and in Appendix 9-B. 4.5.3 Summary All species in Lake Norman have the potential to be impinged or entrained at the CWIS; however, as demonstrated by the recent studies, clupeids (such as Threadfin Shad, Alewife, and Gizzard Shad) have the greatest likelihood of impingement and entrainment at McGuire, followed by the introduced Duke Energy 1 37 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Source Water Baseline Biological Characterization Data [§122.21(r)(4)] r White Perch. White Perch, while considered a game fish, have no length or creel limits because of prolific reproduction and aggressive predation on native fish eggs and larvae (Price 2018). They were introduced illegally and are considered a nuisance species by the NCWRC due to impacts to native species. The annual maintenance monitoring surveys typically demonstrate a range of littoral zone species, collected via electrofishing, that are few or absent from impingement and entrainment samples. Conversely, some species collected in entrainment or impingement sampling have not typically been reported in annual maintenance monitoring studies, such as White Perch. White Perch are not a target species of Duke Energy's MMP and not frequently collected using the current sampling gear and methodologies. Regardless of the standing stock size of this nuisance species in Lake Norman, their prevalence in the entrainment and impingement studies is a product of this species life history and reproductive strategies which increase their abundance in Lake Norman, and thus their susceptibility to impingement and entrainment at McGuire. However, due to their high fecundity and potential for prolific population growth, entrainment and impingement of White Perch at McGuire are not anticipated to result in adverse impacts on White Perch populations in Lake Norman. Species collected at the CWIS better resemble the species composition of that collected by purse seine collections from 2009-2013 (Section 4.2.2). Clupeids have an increased likelihood of entrainment due to their reproductive behavior as broadcast spawners. However, due to their high fecundity, it is unlikely that these species populations are substantially affected due to entrainment. 4.6 Threatened, Endangered, and Other Protected Species Susceptible to Impingement and Entrainment at the CWIS The Rule requires the permittee to document federally listed species and designated critical habitat in the Action Area (see §125.98[f]). For the purpose of defining listed species, the Action Area for McGuire consists of Lake Norman and the area encompassed by a 1-mile radius of the Lake Norman shoreline, as shown on Figure 4-4. A desktop review of available resources was performed to develop a list of species with protected, endangered, or threatened status with the potential to be impacted by the continued operation of McGuire. This evaluation included an assessment of those species that might be susceptible to impingement and entrainment at McGuire's Main Intake or LLI on Lake Norman. The U.S. Fish and Wildlife Service (USFWS) map -based search tool (Information for Planning and Consultation [I PAC]) was used to identify state or federally listed rare, threatened, or endangered species or designated critical habitat within the Action Area (USFWS 2018). Duke Energy 1 38 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Source Water Baseline Biological Characterization Data [§122.21(r)(4)] r LEGEND • Station Locations r7Action Area = Lake Norman G4TA IOUMZF a,Ck�.-�G:us -bum aid tin GIS :bc-Ca..n� a ru5les ti p5�f Marshall Steam Station McGuire Nuclear Station J Z,,,nnwS r 01— Designated Critical Habitat (Carolina Heelsplitwo Figure 4-4. Search Area for Federally Listed Species Additionally, the North Carolina Natural Heritage Program (NCNHP) Species and Community search tool was consulted to identify Rare Animal Species of North Carolina that occur or potentially occur within the vicinity of the McGuire intake structures (NCNHP 2018). A summary of state or federally listed rare, threatened, or endangered species and designated critical habitat (including potential fish hosts of mussel glochidia) with the potential to occur in the vicinity of the McGuire Main Intake or LLI, as well as species of concern that have legal protection status in the state of North Carolina, is provided in Table 4-4 (USFWS 2018; NCNHP 2018). Federal species of concern and candidate species were omitted from the list (unless they were also state threatened or endangered), as there are no requirements to address those species under the Rule or Section 7 of the Endangered Species Act (USFWS 1973). Duke Energy 1 39 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Source Water Baseline Biological Characterization Data [§122.21(r)(4)] r Table 4-4. Summary of Rare, Threatened, or Endangered (RTE) Species Listed for Mecklenburg County, North Carolina, and Record of Occurrence or Assessment of Potential to Occur in Lake Norman OccurCommon and Protected � Potential to Scientific Name Status' Habitat Requirements the CWIS Impingement Cool, clean, well -oxygenated Unlikely — Lake Norman is water with silt -free stream an impoundment that lacks bottoms and stable, well- suitable, lotic stream habitat Carolina Heelsplitter 2 vegetated stream banks3, near the Main Intake or (Lasmigona decorata) FE, DCH primarily located in LLI , the closest known Unlikely headwater streams. Host population of Carolina fish for mussel glochidia for Heelsplitter is located this species are not known4. approximately 26 miles from Lake Norman Northern Long-eared Bat (Myotis FT Terrestrial' No No septentrionalis) Dwarf -flowered Heartleaf (Hexastylis FT, ST Terrestrial No No naniflora) Michaux's Sumac FE Terrestrial No No (Rhus michauxii) Schweinitz's FE, SE Sunflower (Helianthus Terrestrial No No schweinitzii) Smooth Coneflower FE Terrestrial No No (Echinacea laevigata) Bald Eagle BGEPA6, (Haliaeetus ST Terrestrial No No leucocephalus) Carolina Birdfoot- trefoil (Acmispon SSCV Terrestrial No No helleri) Northern Cup -plant ST Terrestrial No No (Silphium perfoliatum) Includes federally listed endangered (FE), threatened (FT), and species of concern (FSOC), as well as those identified from the IPaC search (USFWS 2018a), or species identified in the USFWS 2016 7-year National Listing Workplan (USFWS 2016). Also includes state listed endangered (SE), threatened (ST), and special concern or vulnerable species (SSCV), which have legal protection status in North Carolina (Wildlife Resources Commission) as presented on the North Carolina Natural Heritage Data Explorer (NCNHDE) report (NCNHP 2018a). Does not include species with the non -regulatory "significantly rare" designation (NCNHP 2018a). 2 Critical habitat is designated (DCH) for this species, but the nearest designated habitat is over 26 miles away from McGuire, 3USFWS 2015;' USFWS 2017; 5 McGuire CWIS is located on Lake Norman, an impoundment of the Catawba River. 6 Protected under the Bald and Golden Eagle Protection Act (BGEPA). Duke Energy 1 40 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Source Water Baseline Biological Characterization Data [§122.21(r)(4)] r All but one of the species listed in Table 4-4 are terrestrial and are not expected to occur in Lake Norman or near the McGuire intake structures. No effects to these species are expected or anticipated; therefore, terrestrial species are not discussed further. The McGuire CWIS is located in a freshwater environment; as such, no federally listed marine or anadromous species, designated critical habitat, essential fish habitat, or habitat areas of particular concern under NMFS jurisdiction were identified in the Action Area (NMFS 2018; NMFS 2018). One federally listed aquatic species, the Carolina Heelsplitter (Lasmigona decorata), was identified as having potential to occur within the Action Area (Table 4-4; USFWS 2018). The endangered Carolina Heelsplitter is a freshwater mollusk occurring in cool, clean, well - oxygenated water with silt -free stream bottoms and stable, well -vegetated streambanks (USFWS 2015). This habitat does not exist near McGuire. There are only six known remaining populations of the federally listed Carolina Heelsplitter; two in North Carolina and four in South Carolina. The North Carolina populations are located in Goose Creek (Pee Dee River Basin) and Waxhaw Creek (Catawba River Basin) in Union County. These locations also include designated critical habitat for this species (USFWS 2002). However, the closest population and designated critical habitat for the Carolina Heelsplitter is located approximately 26 miles from Lake Norman, well outside of the Action Area (Figure 4-4). Life history characteristics, including fish host species, are still largely unknown for the Carolina Heelsplitter (USFWS 2017). However, a study by Bakuneeta et al. (2010) evaluated multiple fish species collected from two North Carolina river basins where critical habitat has been designated, to determine if any of the fish would serve as viable glochidial hosts for the this species. The results were variable, but indicated some successful glochidial transformation within the gills of the host fish species dependent on the source river basin they were collected from. Species that demonstrated the greatest transformation rates included: Creek Chub (Semotilus atromaculatus), Bluehead Chub (Nocomis leptocephalus), Satinfin Shiner (Cyprinella analostana), Golden Shiner (Notemigonus crysoleucas), Whitefin Shiner (Cyprinella nivea), and Rosyside Dace (Clinostomus funduloides). Based on a comparison of the habitat requirements of these mussel species and the available habitat within the Action Area, the Carolina Heelsplitter is not likely to occur near or within the AOI of the McGuire intake structures and thus would not be susceptible to impingement or entrainment. Additionally, no protected species have been collected in historical sampling surveys at or near the McGuire intake structures (Duke Power 2003; NCWRC 2008; EPRI 2010a; Duke Energy 2014; 2015; 2016; 2017), or during the recent 2016-2017 Entrainment Characterization Study completed at McGuire (HDR 2019) and presented in Section 9 of this document. 4.7 Documentation of Consultation with Services In preparing this package for compliance with the Rule, there has been neither public participation, nor coordination undertaken with USEPA, NMFS, or USFWS, collectively known as the Services. 4.8 Information Submitted to Obtain Incidental Take Exemption or Authorization from Services As noted in Section 4.6, no federally listed fish or aquatic species have been collected in Lake Norman near the McGuire CWIS, and none are believed to occur near the CWIS. Therefore, an incidental take exemption or authorization for the McGuire CWIS has neither been required by Duke Energy 1 41 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Source Water Baseline Biological Characterization Data [§122.21(r)(4)] r USFWS nor sought by Duke Energy. 4.9 Methods and Quality Assurance Procedures for Field Efforts Data presented in Section 4 were compiled from Duke Energy's historical and ongoing MMP and historical impingement study on Lake Norman. Efforts during the MMP collected electrofishing data to characterize the fishery for Lake Norman (Duke Energy 2003). Impingement data was collected at McGuire from 2006 to 2007 (EPRI 2010a). Entrainment data at McGuire was collected from March through October of 2016 and 2017 (Section 9; HDR 2019). These data were collected following Duke Energy procedures and quality assurance (QA) protocols. A list of relevant Duke Energy MMP reports is provided in Appendix 4-B and full citations are provided in the references list located in Section 14.2. MMP reports are available upon request. 4.10 Protective Measures and Stabilization Activities 4.10.1 Annual Spring Reservoir Level Stabilization Project As required by the Catawba-Wateree Project Comprehensive Relicensing Agreement (FERC No. 2232), Duke Energy implements an Annual Spring Reservoir Level Stabilization Program to promote fish spawning (FERC 2006). The program consists of four main elements: (1) trigger points, (2) surface water temperature monitoring locations (one or more locations on Lake Norman), (3) reservoir level variability, and (4) a stabilization period. Duke Energy is required to stabilize lake levels in Lake Norman for a period of three weeks when any one of the following trigger point events occur: • Surface water temperatures within the reservoir reach 65 degrees Fahrenheit (OF) or greater for four consecutive days; • Bass spawning is observed in Lake Norman by a Licensee representative; or • A resource agency representative notifies the Licensee that bass spawning has been observed in Lake Norman. Under the Annual Spring Reservoir Level Stabilization Program, Duke Energy is required to "endeavor in good faith" to maintain the water level in Lake Norman within a range between 1 ft below and 2 ft above the elevation at the time stabilization is triggered. The program must be implemented unless Duke Energy is operating under the FERC-approved Low Inflow Protocol or the Maintenance and Emergency Protocol (FERC 2006). Additional monitoring activities are performed under the MMP, which include temperature and DO monitoring at both the Main Intake and the LLI. The monitoring data are used in conjunction with an operational agreement where Duke Energy has committed to minimizing the operational season of the LLI. The LLI is typically operated for cooling water purposes from one to five weeks per year, during peak summer temperatures. RN withdrawal at the LLI is continuous with plant operations. Duke Energy 1 42 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal Source Water Baseline Biological Characterization Data [§122.21(r)(4)] 4.10.2 Annual Summer Monitoring of the Low Level Intake Duke Energy implements an annual summer monitoring program to support decision -making regarding LLI pump operations. The monitoring program, which typically runs from mid -June until the end of August, includes water quality sampling and split -beam hydroacoustic data collection during the period of thermal stratification of the reservoir. Information collected from the monitoring program is used for two primary purposes; (1) to monitor the availability of cooler water in the hypolimnion (during reservoir stratification) for withdrawal to facilitate compliance with the thermal discharge limits established in McGuire's NPDES permit, and (2) to minimize the potential for debris blockage of the LLI (including impinged fish), which also results in reduced IM at the LLI through adaptive management of LLI pump operations. Water quality data (i.e., temperature and DO along a depth profile) are collected, at a single location in the Cowans Ford Forebay, concurrently with hydroacoustic data which are collected along two transects. The first transect parallels Cowans Ford Dam across the submerged weir20 to the LLI structure, and the second transect is run from Cowans Ford Dam uplake approximately 2.8 km. The temperature and DO profiles are overlain with the results from the hydroacoustic imaging to determine the location of fish in relation to the thermocline and the LLI. This monitoring program begins in mid -June of each year and extends until stratification of the reservoir pushes the hypoxic metalimnetic layer lower in the water column. A reduction in suitable habitat occurs during late summer when the reservoir is fully stratified due to the resulting hypoxic conditions that occur at the depth of the LLI, which results in the reduction (often elimination) of impingeable-sized fish near the LLI structure. Forage fish typically observed near the LLI are generally non-native, fragile species (e.g., Alewife). Large, predatory fish have also been documented near the LLI; however, they are not likely to be susceptible to impingement due to swimming capabilities (EPRI 2000). When impingeable sized fish are observed near the LLI, the LLI pumps can be adaptively managed to reduce or eliminate cooling water withdrawal, thus reducing the potential blockage of the LLI with impinged fish and decreasing the potential for impingement -related mortalities. The decision to operate the LLI pumps is based on; (1) monitoring data which indicates low or zero DO concentrations at the depth of the LLI opening, and (2) when fish of impingeable size are not observed within the AOI of the LLI. Seasonal operation of the LLI pumps is halted when monitoring data and subsequent calculations indicate that McGuire can meet the NPDES thermal discharge limits exclusively with surface water or the usable quantity of cool water from the hypolimnion has been depleted. 20 The submerged weir was constructed in the Cowans Ford forebay area to preserve cooler water in Lake Norman during thermal stratification. Water used to generate electricity at Cowans Ford is pulled from the surface of Lake Norman over the top of the weir, thus maintaining thermal stratification in the vicinity of McGuire's Main Intake and LLI. Duke Energy 1 43 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal Source Water Baseline Biological Characterization Data [§122.21(r)(4)] 4.11 Fragile Species Fragile species are defined as fish and shellfish that are least likely to survive any form of impingement, with survival rates of 30 percent or less ((§125.92(m)). The Rule identifies 14 species representing 7 families as fragile species, but states that this list is not meant to be exhaustive, and does not include all potential fragile species. The Rule provides that the Director may accept additional species as "fragile species" when presented with sufficient justification from the applicant (79 FR 158, 48364). Two of the Rule -identified fragile species, Alewife and Gizzard Shad, have been documented in Lake Norman during periodic maintenance monitoring studies (Duke Energy 2014b, 2015, 2016d, 2016e, and 2017b; Duke Power 2003; HDR 2019). The remaining species included at §125.92(m) are marine or coastal anadromous species, with the exception of Rainbow Smelt, which has only been found in the Upper Tennessee River basin in northeastern North Carolina (Fuller et al. 2019) and is not found in Lake Norman. Threadfin Shad, although not included on USEPA's "non-exclusive" list of fragile species, is a semi- tropical member of the Clupeidae family and a relative (sharing the same family or genus) to several Rule -identified fragile species, and is expected to have low post -impingement survival. Threadfin Shad are not indigenous to Lake Norman or other waterbodies in North Carolina (Fuller and Neilson 2019). Further, Threadfin Shad is provided in the Rule as an example of a species not specifically identified at 125.92(m), but that is prone to die -off events when temperatures drop to low levels in fall and winter months (79 FR 158, 48364). Historical impingement monitoring at McGuire (see Section 4.5.1) found that Threadfin Shad comprise up to 97.1 percent of fish impinged during the winter months (December and January). Therefore, this species should be considered fragile at this facility. Threadfin Shad are consistently collected in purse seines during period maintenance monitoring studies performed on Lake Norman fishery (Section 4.2.2). Annual trends in sampling show that of the two dominant clupeids collected on Lake Norman, Threadfin Shad consistently dominant samples and exhibit stable population trends. As such, despite the fragile nature of Threadfin Shad and temperature -induced seasonal die -offs, Threadfin Shad populations in Lake Norman are balanced and stable. Furthermore, due to their low tolerance of cool temperatures, the long-term success of this species in Lake Norman may be owed, in part, to the thermal influence of McGuire on Lake Norman (creating a winter fishery) during low temperature events. Based on these data, Threadfin Shad in Lake Norman are consistent with the Rules definition of fragile species. Although Threadfin Shad were collected in entrainment and impingement samples at McGuire, the continued presence of robust and balanced Threadfin Shad populations in maintenance monitoring studies of Lake Norman indicates that the McGuire CWIS is not having an adverse effect on their populations. Duke Energy 1 44 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Cooling Water System Data [§122.21(r)(5)] r 5 Cooling Water System Data [§ 122.21 (r)(5)] The information required to be submitted per §122.21(r)(5), Cooling Water System Data, is outlined as follows: (i) A narrative description of the operation of the cooling water system and its relationship to cooling water intake structures; the proportion of the design intake flow that is used in the system; the number of days of the year the cooling water system is in operation and seasonal changes in the operation of the system, if applicable; the proportion of design intake flow for contact cooling, non -contact cooling, and process uses; a distribution of water reuse to include cooling water reused as process water, process water reused for cooling, and the use of gray water for cooling; a description of reductions in total water withdrawals including cooling water intake flow reductions already achieved through minimized process water withdrawals; a description of any cooling water that is used in a manufacturing process either before or after it is used for cooling, including other recycled process water flows; the proportion of the source waterbody withdrawn (on a monthly basis); (ii) Design and engineering calculations prepared by a qualified professional and supporting data to support the description required by paragraph (r)(5)(i) of this section; and, (iii) Description of existing impingement and entrainment technologies or operational measures and a summary of their performance, including but not limited to reductions in impingement mortality and entrainment due to intake location and reductions in total water withdrawals and usage. Each of these requirements is addressed in the following subsections. 5.1 Cooling Water System Operation Two intake structures, Main Intake and LLI, provide flows for Main Condenser Cooling Water (reactor coolant [RC]), Conventional Low Pressure Service Water (RL), Fire Protection System (RF/RY), RN, and Containment Ventilation Cooling Water System (Duke Energy 2009). A water balance diagram illustrating the routing and uses of cooling water is provided in Figure 5-1. Note the flows provided in Figure 5-1 are representative of typical station operations and not necessarily representative of design (or maximum capacity) flows. 5.1.1 Main Intake The Main Intake provides once -through, non -contact cooling water to the RC system via eight circulating water pumps (four per unit) as described in Section 3.1.1. The RC system removes heat rejected from the main, feedwater pump turbine condensers, and other miscellaneous heat exchangers (Duke Energy 2014b). Each RC pump has a design capacity of 254,000 gpm (366 MGD) for a combined RC system DIF of 2,032,000 gpm (2,926 MGD). The traveling water screens are rotated at least once -per -week for cleaning unless more cleanings are required during periods of high debris loading. During cleaning, each screen is backwashed with Duke Energy 1 45 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal Cooling Water System Data [§122.21(r)(5)] untreated lake water using a high-pressure spray system. The backwash system is capable of cleaning two screens at a time (HDR 2015). Debris is washed into a debris sluice and discharged into trash baskets on either side of the intake structure (Duke Energy 2007). 5.1.2 Low Level Intake (LLI) The LLI structure houses the LLI pumps and the Auxiliary Building houses the RN pumps. The LLI pumps provide cooler water from the bottom of Lake Norman to the Unit 1 side of the Main Intake structure and the RN pumps supply the Station's service water systems. The four RN pumps provide water to safety -related systems within the Auxiliary Building via withdrawals from the LLI structure and that water is routed for use within the station. Each RN pump has a capacity of 17,500 gpm (25 MGD), however, under normal conditions, only two typically operate at any given time while the remaining two are for redundancy. The piping configuration also allows for the LLI to provide water to the Standby Nuclear Service Water Pond to maintain temperature and elevation requirements either through gravity alignment or use of the RN pumps. The cooler, hypolimnetic water pumped from the LLI mixes with the warmer surface water at the Main Intake and helps to reduce the temperature of water entering the station. To help maintain compliance with McGuire's NPDES thermal discharge limits, the LLI pumps are typically operated infrequently and only during warmer summer months (typically 1 to 5 weeks per year) under the annual summer monitoring and adaptive management conditions described in Section 4.10.2. During times of high surface water temperatures in the lake, the three 150,000 gpm (216 MGD) LLI pumps21 can withdraw water from the bottom of Lake Norman (i.e., via the LLI structure) and route it to the Main Intake, discharging the cooler water on the Unit 1 plant -side of the trash racks. The cooler, hypolimnetic water pumped from the LLI mixes with the warmer surface water at the Main Intake and helps to reduce the temperature of water entering the station. To help maintain compliance with McGuire's NPDES thermal discharge limits, the LLI pumps are typically operated infrequently and only during warmer summer months (typically 1 to 5 weeks per year) under the annual summer monitoring and adaptive management conditions described in Section 4.10.2. 21 There were originally six LLI cooling water pumps; the three pumps associated with Unit 2 have been retired (only the Unit 1 LLI pumps are operable). Duke Energy 1 46 Standby Nuclear Service Water Pond f— SNSWP y ■ • LAKE NORMAN Nuclear Service 0-1 Water RN ' i LFF _ i I Law Level Intake _ _3 Condenser Cooling Water RC i Last Revised July 10, 2014 __ 11 i Law Pressure i Semioe Water RL i � - i r Filtered Water ti - i t i i Storm Drains 22-2 MGD 2.604 MGD Reverse Osmosis Unit RO Water Treatment .:Fti Room Sump i ' T-11 ------ _ 'NDE Photographic ' i Waste Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal �� Cooling Water System Data [§122.21(r)(5)] Appendix I McGuire Nuclear Station NPDES Flow Diagram NC002439 ----0 Normal Flowpath - - - - - i Alternate Flowpath 2.626 Total MGD LAKE NORMAN DISCHARGE AL ' WWOO'I i 0.0079 MGD - i ` i i I♦I i -------------- Primary System I i Rad aste System Demineralized Coolart Drainage i WaterYlN and Leakage i WW004 -{WMI v a Ventilation Unit -Garage Vehicle Condensate Drain ' Wash Area Secondary System N Tanks (VUCOT) i 'Landfill Leachate Drainage and Leakage O.0015 MGD i f - - - - 4y - - - - - - i Conventional v Waste Treatment 'Island Lab Waste C_ _ System ■--- i 'Island i-IVAC Tune i (WC) ' ' Cooling Towers Building Sump I WWO42 i 'Oil Water I Storm Drains O.3485 MGD- Separators —"- - - Waste Water 1 t—_ _ _J CATAWBA ! Collection Basin I TotaRIVER ' (WWCI i l: 9 MGD 0.981, --------WWOO5 O.6334MG ------.------► D - i i i------------------------------------------------------------------ --i Figure 5-1. Water Balance Diagram Illustrating the Routing and Uses of Cooling Water Withdrawn at the McGuire Nuclear Station Intakes on Lake Norman, Huntersville, North Carolina (Sources: Duke Energy 2014b) Duke Energy 1 47 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal Cooling Water System Data [§122.21(r)(5)] 5.2 Description of Intake Flows Per the Regulations at §125.92(g), DIF is defined as "the maximum instantaneous rate of flow of water the cooling water intake system is capable of withdrawing from a source waterbody". The regulations allow the DIF to reflect any permanent changes to the system, such as removing pumps from service. The combined DIF associated with the eight Main Intake RC pumps is 2,032,000 gpm (2,926 MGD). The combined DIF associated with the two LLI RN pumps is 30,000 gpm (43 MGD).22 Therefore, the total station DIF is 2,062,000 gpm (2,969 MGD). A summary of pumping capacity, by type and unit, is provided in Table 5-1. The capacity of the three 150,000 gpm (216 MGD) LLI cooling water pumps is not included in the total DIF because the LLI pumps are not directly connected to the cooling water system. Rather, raw water from the LLI cooling water pumps are discharged to the surface between the Main Intake trash racks and traveling water screens, thereby displacing water that would have otherwise been withdrawn from the surface by the RC pumps (Duke Energy 2016b). In addition, while McGuire's RF/RY includes two jockey pumps (each rated at 200 gpm) and three main fire pumps (each rated at 2,500 gpm), the definition of DIF states that it "does not include values associated with emergency and fire suppression capacity or redundant pumps (i.e., back-up pumps)." The AIF is defined by Regulations at §125.92(a) as "the average volume of water withdrawn on an annual basis by the cooling water intake structures" and includes days of zero flow. The average AIF rate for the three most recent years23 (January 2015 through December 2017) is 2,631 MGD (2,604 MGD for RC pumps plus 27 MGD for RN pumps). Monthly average RC and RN withdrawals are provided in Table 5-2 and Table 5-3, respectively. 22 The capacity of each RN pump is 17,500 gpm (25 MGD), however, a system piping restriction results in a maximum pipe flow capacity of 30,000 gpm (43 MGD) (Duke Energy, 2007). 23 Pursuant to the definition, prior to October 14, 2019, the AIF should include the previous three years of flow data; after October 14, 2019, the AIF should include the previous five years of flow data. Duke Energy 1 48 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Cooling Water System Data [§122.21(r)(5)] r Table 5-1. McGuire Nuclear Station Pumping Capacity from Lake Norman 1A (RC) 254,000 365.76 1A 1 B (RC) 254,000 365.76 1 B 1 1 C (RC) 254,000 365.76 1 C 1 D (RC) 254,000 365.76 1 D 2A (RC) 254,000 365.76 2A 213 (RC) 254,000 365.76 2B 2 2C (RC) 254,000 365.76 2C 2D (RC) 254,000 365.76 2D Sub -Total 8 pumps" 2,032,000 2,926 8 Bays Unit 1 (RN) 17,500 25.2 LLI Service Water Unit 2 (RN) 17,500 25.2 LLI Sub -Total 11g1j, 30,000* 43.2* 3 Panels Total DIF _2,062,000 2,969 1 ' 150,000 216 LLI LLI Cooling Water Pumps 2 I 150,000 216 LLI 3 150,000 216 LLI Total 3 pumps NA24 �Vr 3 Panels Note: Asterisk (*) total pump capacity values provided represent maximum capacity based on a piping restriction that prevents the pumps from achieving a combined 35,000 gpm (50.4 MGD). 24 Raw water from the LLI cooling water pumps is discharged to the surface between the Main Intake trash racks and traveling water screens, thereby displacing water that would have otherwise been withdrawn from the surface by the RC pumps (Duke Energy 2016b). As such, this volume is not included in the DIF calculation Duke Energy 1 49 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Cooling Water System Data [§122.21(r)(5)] r Table 5-2. Main Intake Cooling Water (RC) Actual Withdrawal Rates (MGD) from January 2015 through December 2017 2015 2016 2017 Month Three Year Station Station Station Average Unit 1 Unit 2 Total Unit 1 Unit 2 Total Unit 1 Unit 2 Total January 1,230 1,248 2,479 1,248 1,248 2,497 February 1,248 1,248 2,497 1,248 1,248 2,497 March 1,248 1,248 2,497 748 1,250 1,998 April 1,295 1,292 2,587 949 1,324 2,274 May 1,463 1,455 2,918 1,463 1,463 2,926 June 1,463 1,463 2,926 1,463 1,463 2,926 July 1,463 1,463 2,926 1,463 1,463 2,926 August 1,463 1,463 2,926 1,463 1,463 2,926 September 1,463 565 2,028 1,463 1,463 2,926 October 1,463 953 2,416 1,463 1,298 2,761 November 1,411 1,411 2,822 1,248 1,251 2,500 December 1,248 1,248 2,497 1,248 1,248 2,497 Avg. Annual AIF (MGD) 11372 1,255 2,627 1,289 1,349 2,638 1,248 1,248 2,497 2,491 1,248 1,248 2,497 2,497 1,277 1,191 2,468 2,321 1,463 611 2,074 2,312 1,463 1,463 2,926 2,923 1,463 1,463 2,926 2,926 1,463 1,463 2,926 2,926 1,463 1,463 2,926 2,926 1,123 1,463 2,586 2,513 383 1,463 1,846 2,341 1,019 1,382 2,401 2,574 1,248 1,248 2,497 2,497 1,239 1,309 2,548 2,604 Table 5-3. Low Level Intake Service Water (RN) Actual Withdrawal Rates (MGD) from January 2015 through December 2017 January February March April May June July August September October November December Avg. Annual AIF (MGD) Station Unit Station Unit Station Aver nit 1 Unit 2 Total 1 Unit 2 Total 1 Unit 2 Total 13 14 27 13 13 26 13 14 27 27 15 13 28 14 14 28 14 17 31 29 14 14 28 15 14 29 12 16 28 28 14 14 28 16 15 31 12 16 28 29 14 15 29 14 14 28 12 14 26 28 14 15 29 13 13 26 12 13 25 27 15 15 29 13 12 25 13 13 26 27 13 15 28 12 12 25 13 12 25 26 15 17 32 13 13 26 14 13 27 28 14 16 30 13 14 27 14 13 27 28 12 12 25 13 13 26 14 13 27 26 12 13 25 13 13 26 13 13 26 26 14 14 28 13 13 27 13 14 27 27 Duke Energy 1 50 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal Cooling Water System Data [§122.21(r)(5)] Table 5-4 provides the days per month from January 2015 to December 2017 that the Main Intake was in service. Since McGuire is a base load generating station, the Main Intake RC pumps operate unless the associated unit is in an outage. The RN pumps typically operate every day, even during outages. Table 5-4. Days in Service for the RC Water Withdrawal from the Main Intake from January 2015 through December 2017 I Unit 1 I Unit 2 I Unit 1 I Unit 2 I Unit 1 I Unit January 31 31 31 31 31 31 February 28 28 29 29 28 28 March 31 31 19* 31 31 30* April 30 30 24* 30 30 16* May 31 31 31 31 31 31 June 30 30 30 30 30 30 July 31 31 31 31 31 31 August 31 31 31 31 31 31 September 30 12* 30 30 23* 30 October 31 22* 31 31 13* 31 November 30 30 30 30 24 30 December 31 31 31 31 30 31 Total 365 338 348 366 333 350 Asterisk (*) indicates refueling unit outage. Based on average monthly withdrawal rates (Table 5-5) and days of operation (Table 5-6), the LLI pumps were operated on average approximately 5 percent of the year (Table 5-7) typically one to five weeks of operation occurring between June and September. Most often, LLI operations occur in August when Lake Norman is most stratified. During this time, minimal DO is available, creating hypoxic conditions in the vicinity of the LLI structure. The timing of the LLI pump operation and the location of the LLI structure minimize potential impingement and entrainment impacts. Duke Energy 1 51 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Cooling Water System Data [§122.21(r)(5)] r Table 5-5. Monthly Average LLI Pump Withdrawal Rates (MGD) from January 2015 through December 2017 January 0 0 0 0 February 0 0 0 I 0 March 0 0 0 0 April 0 0 0 I 0 May 0 0 0 0 June 0.67 1.23 2.16 I 1.35 July 0 67.1 0 22.4 August 183 333 123 216 September 0 67.5 0 22.5 October ■ 0 0 0 0 November 0 0 0 0 December ■ 0 0 0 0 Table 5-6. Monthly LLI Pump Operation (days) from January 2015 through December 2017 January 0 0 0 February 0 0 0 March 0 0 0 April 0 0 0 May 0 0 0 June 1 3 1 July 0 6 0 August 17 20 9 September 0 5 0 October 0 0 0 November 0 0 0 December 0 0 0 Note: The number of days the LLI pumps operated was calculated based on any pump operation in a single day and does not necessarily correlate to 24-hour operation of the pumps. Duke Energy 1 52 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Cooling Water System Data [§122.21(r)(5)] r Table 5-7. Percent of Time the LLI Pumps were in Operation from January 2015 through December 2017 0 96% 92% 98% 95% <0.1% <0.1% <0.1% <0.1% 2 3.6% 5.9% 2.3% 4.0% 3 0% 2.2% <0.1% 0.8% Note: Percent of time based on hours of operation. 5.2.1 Seasonal Operations When the facility operates at near 100 percent capacity and intake water temperatures are greater than 62°F, all four RC pumps per unit are used. During cooler months when intake water temperatures are less than 62°F, three RC pumps per unit may be used (a reduction of 25 percent) (Duke Energy 2014b). As mentioned in Section 4.5, during times of high surface water temperatures in the lake, the LLI pumps withdraw cooler water from the hypolimnion of Lake Norman to cool the warmer water in the Main Intake (Duke Energy 2009). In recent times, the LLI pumps have typically been operated one to five weeks per year for thermal compliance (generally June through September). When operated, typically only two of the three LLI cooling water pumps are used (HDR 2015). Table 5-6 shows the monthly rates of water routed from the hypolimnion to the Main Intake from 2015 to 2017. Duke Energy has an agreement with the NCWRC to coordinate LLI pump operation with fish habitat conditions in the lake (i.e., temperature and DO). If suitable habitat is present, the LLI pumps can only be used to meet McGuire's NPDES permit thermal limits. When suitable habitat is no longer available, the LLI pumps may be used to achieve higher thermal efficiency. 5.2.2 Proportion of Design Flow Used in the Cooling Water System The DIF at McGuire's Main Intake is 2,969 MGD, and approximately 2,926 MGD or 98.5 percent of the design flow is used for non -contact cooling water purposes. The remaining water (43 MGD) is used for service water (Table 5-1). 5.2.3 Distribution of Water Reuse and use of Grey Water McGuire does not reuse water. There are no reclaimed25 water sources of sufficient volume or quantity within a five -mile radius that could be used for cooling purposes. 25 Grey water is untreated wastewater from showers and kitchens and should not be used for cooling because of the potential to impact health and safety of McGuire staff. Reclaimed water is treated wastewater. Duke Energy 1 53 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal Cooling Water System Data [§122.21(r)(5)] 5.2.4 Reductions in Total Water Withdrawals As discussed in Section 10, one RC pump per unit can be turned off when the intake water temperature drops below 62°F. RC pumps are typically shut down during associated unit outages, which occur approximately every 18 months and last approximately 30 days. From January 2015 through December 2017, the RN AIF / DIF ratio (i.e., water withdrawn from the LLI) was 63 percent (27 MGD / 43 MGD); or a reduction of 37 percent from the maximum RN pumping capacity. (Because water pumped using the LLI cooling water pumps is included in the Main Intake RC withdrawal rates, LLI cooling water pumps are not included in the flow reduction estimates). 5.2.5 Water Used in Manufacturing Processes McGuire is not a manufacturing facility; therefore, this sub -section is not applicable. 5.2.6 Proportion of Source Waterbody Withdrawn The amount of water withdrawn from Lake Norman to support station operations is dependent upon environmental conditions (i.e., intake water temperatures) and generation demand. The percentage of source waterbody withdrawn for cooling purposes is calculated differently for riverine and lacustrine source waterbodies. For riverine source waterbodies, the calculation is a straightforward comparison of two volumetric flow rates with shared units: Percent of source waterbody withdrawn (%) = AIF (MGD) Mean annual river flow rate (MGD) Eq. 5-1 Mean annual river flow rate is typically measured in cubic feet per second, and can be converted to MGD. For lacustrine source waterbodies, the same comparison cannot be made because the cooling water is a volumetric rate while the source waterbody is a volume. For these facilities, rather than calculate the percent of source waterbody withdrawn, which would require an arbitrary time step for the calculation (e.g., minute, day, week, etc.), the value to be estimated is cooling water residence time (CWRT). The CWRT is a theoretical estimate of the time required for cooling water that exits the discharge to be withdrawn by the intake in the recirculation process and is calculated as: CWRT (days) = Lake Volume (million gallons) Eq. 5-2 AIF(MGD) Lake Norman, which was created to provide cooling water for both McGuire and Marshall, has a volume of approximately 356,374 million gallons. The combined AIF for McGuire's Main Intake and LLI is 2,631 MGD. The CWRT of Lake Norman is therefore approximately 135 days, and is calculated as follows: Lake Norman CWRT (days) = 356,374 (MG) Eq. 5-3 (2,631 MGD) Duke Energy 1 54 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Cooling Water System Data [§122.21(r)(5)] r 5.3 Design and Engineering Calculations TSVs have been calculated for the Main Intake and LLI and are included in Appendix 5-A. For the Main Intake, at the FERC-authorized maximum (non -emergency) drawdown water elevation for Lake Norman of 751 ft msl, the TSV at the Main Intake is approximately 1.3 fps. At normal pond elevation (756 ft msl), TSV is approximately 1.2 fps. At full pond elevation (760 ft msl), TSV is approximately 1.0 fps. These estimates assume that the screens are clean; otherwise, the TSV would increase26. The LLI withdraws water from a depth between 654 ft msl and 670 ft msl and is fully submerged within Lake Norman (Duke Energy 2001). The LLI has a total screen area of approximately 1,680.9 square feet (Duke Energy 2008). The TSV at the LLI has been calculated assuming clean screens and various pump scenarios. The TSV is approximately 0.84 fps with three LLI pumps and the RN pumps operating, 0.58 fps with two LLI pumps and the RN pumps operating, and 0.32 fps with one LLI pump and the RN pumps operating. With only the RN pumps operating, the TSV is estimated at 0.06 fps. 5.4 Existing Impingement and Entrainment Reduction Measures Duke Energy employs operational measures to reduce impingement and entrainment at McGuire. These include: • The facility provides seasonal flow reductions, which result in proportional reductions in numbers impinged and entrained. Duke Energy has an agreement with the NCWRC to coordinate LLI pump operation with fish habitat conditions in the lake (i.e., temperature and DO). These pumps are used only when suitable operational conditions are available (i.e., hypoxic conditions exist near the LLI such that suitable habitat conditions are unavailable). Such coordination directly aids in minimizing or eliminating impingement and entrainment by an estimated 95 percent or greater. 26 Screen components such as side seals, boot seals, and basket frames are assumed to have minimal affect on the traveling water screen effective open area. Duke Energy 1 55 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Chosen Method(s) of Compliance with Impingement Mortality Standard [§122.21(r)(6)] r 6 Chosen Method(s) of Compliance with Impingement Mortality Standard [§ 12 2.21 (r) (6)] The information required to be submitted per §122.21(r)(6), Chosen Method(s) of Compliance with Impingement Mortality Standard, is outlined as follows: The owner or operator of the facility must identify the chosen compliance method for the entire facility; alternatively, the applicant must identify the chosen compliance method for each cooling water intake structure at its facility. The applicant must identify any intake structure for which a BTA determination for Impingement Mortality under 40 CFR §125.94 (c)(11) or (12) is requested. The Rule at §125.94(c) requires that existing facilities employ one of seven IM BTA options (IM Options) or alternatives27: 1. Operate a closed -cycle recirculating system as defined by the Rule (this includes cooling towers and certain impoundments). 2. Operate a cooling water intake structure that has a maximum design through screen velocity of 0.5 fps or less. 3. Operate a cooling water intake structure that has a maximum actual through screen velocity of 0.5 fps or less. 4. Operate an existing offshore velocity cap that is a minimum of 800-ft offshore and has bar screens or otherwise excludes marine mammals, sea turtles, and other large aquatic organisms. 5. Operate a modified traveling screen system such as modified Ristroph screens with a fish handling and return system, dual flow screens with smooth mesh, or rotary screens with fish returns. Demonstrate that the technology is or will be optimized to minimize impingement mortality of all non -fragile species. 6. Operate any combination of technologies, management practices, and operational measures that the Director determines is BTA for reducing impingement. As appropriate to the system of protective measures implemented, demonstrate the system of technologies has been optimized to minimize impingement mortality of all non -fragile species. 7. Achieve a 12-month performance standard of no more than 24 percent mortality including latent mortality for all non -fragile species. IM Options 1, 2, and 4 are essentially pre -approved technologies that require minimal additional monitoring after their installation and proper operation. IM Options 3, 5, and 6 require that more detailed information be submitted to the Director before they can be specified as the BTA to reduce impingement mortality. Options 5, 6, and 7 require demonstrations with field studies that the technologies have been optimized to minimize impingement mortality of non -fragile species. The 27 Or under specific circumstances, one of nine alternatives, which includes §125.94(c)(11) and (12) in addition to §125.94(c)(1)-(7). Duke Energy 1 56 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal Chosen Method(s) of Compliance with Impingement Mortality Standard [§122.21(r)(6)] remaining options for which the Director may consider little or no additional controls for IM compliance apply under very specific circumstances: De minimis rate of impingement — if the rates of impingement at a facility are so low that additional impingement controls may not be justified (Section 125.94(c)(11)); and ii. Low Capacity utilization of generating units — if the annual average capacity utilization rate of a 24-month contiguous period is less than 8 percent (Section 125.94(c)(12)). The information presented in the following sections is provided to support a request for a BTA determination for IM BTA under 40 CFR §125.94 (c)(11). Based on existing data at the Main Intake and operational data at the LLI, Duke Energy is seeking a determination of de minimis rate of impingement as the IM BTA for McGuire, as discussed in the following sections. A comparative evaluation of IM reduction options (i.e., technologies and operational scenarios) was performed for McGuire's Main Intake and LLI based on Rule requirements for existing facilities. The potential compliance options were evaluated based on technology efficacy, site -specific applicability, regulatory acceptability, order of magnitude costs, operational experience at similar facilities, and anticipated station downtime, to identify those technologies or operational scenarios that are feasible and practicable. Three technologies were advanced for further consideration: (1) obtaining a regulatory determination of de minimis rate of impingement, (2) installation of a barrier net, and (2) installation of modified-Ristroph screens with coarse mesh and an aquatic organism return system. Based on the results of this evaluation, de minimis rate of impingement was identified as the target compliance approach for the two intakes at McGuire. The following information addresses the option of de minimis rate of impingement at McGuire. The additional technologies and operational measures evaluated (including barrier net and FMS options) are summarized in Appendix 6-A. 6.1 Main Intake - Regulatory Determination of de Minimis Rate of Impingement At §125.94(c)(11), the Rule recognizes that in limited circumstances where rates of impingement at a facility are low, additional impingement controls may not be justified. This determination would be made by the Director based on the review of site -specific data submitted under §122.21(r)(4) and (r)(6). Under this compliance approach, McGuire would not be required to implement an impingement reduction technology, but would be required to evaluate impingement and provide a justification of de minimis rate of impingement to the Director. The preamble to the Rule provides examples of the information that may be considered by the Director in making a de minimis rate of impingement determination; such as, low numbers of organisms or age 1 equivalents or facility withdrawal rates in relation to the mean annual flow of the river or source waterbody. As discussed in Section 11 of this document, impingement sampling in 2016 and 2017 indicated that approximately 2,175 and 2,113 fish per year, respectively, are impinged at McGuire's Main Intake. However, fragile clupeid species comprised over half of the total annual impingement estimated in 2016 and 2017. Excluding the fragile species, total annual impingement at McGuire was estimated at 826 and 797 fish per year, respectively, or approximately 2.3 and 2.2 fish per day (Table 6-1). The Rule acknowledges and defines fragile species (i.e., those with less than 30 percent on -screen impingement survival), as they are often highly sensitive species that have demonstrated poor survival under a variety of technologies and operational conditions. To address this concern, Duke Energy 1 57 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Chosen Method(s) of Compliance with Impingement Mortality Standard [§122.21(r)(6)] r impingement technology performance optimization studies (which are required by the Rule under certain impingement compliance options, as detailed above) must demonstrate technology optimization for minimizing impingement mortality for all non -fragile species. Table 6-1. Summary of Estimated Impingement Mortality under Actual Water Withdrawals Excluding Fragile Species at McGuire Nuclear Station 2016 2,175 1,349 (62.0%) 826 2.3 2017 2,113 1,316 (62.3%) 797 2.2 As such, the Rule acknowledges that facilities, like McGuire, with impingement driven by large numbers of fragile species would be at a disadvantage when trying to design and demonstrate optimization of IM reduction technologies. This factor is the strongest supporting factor for the de minimis rate of impingement determination at McGuire (also see Section 11.2.1.2); however, additional factors (i.e., cooling water withdrawal from a reservoir originally constructed for cooling purposes, a managed fishery subject to state -managed stocking program, the absence of threatened or endangered aquatic species, water quality that is fully attaining aquatic life use designations) provide further support for a de minimis determination. 6.2 Low Level Intake - Regulatory Determination of de Minimis Rate of Impingement McGuire's LLI pumps currently operate based on the results of periodic water quality sampling and hydroacoustic monitoring (multi -beam sonar), as described in Section 4.10.2. Water quality sampling begins in mid -June each year to determine when conditions near the LLI structure become hypoxic, thus limiting fish movement into this area. Hydroacoustic monitoring is performed at the same time as water quality sampling to track location and density of fish near the LLI structure. Field monitoring continues until fish with potential to be susceptible to impingement are no longer observed in the vicinity of the LLI structure, thus indicating that the LLI pumps may be operated to pump cooler water from near the bottom of Lake Norman up to the Main Intake structure. This typically occurs by mid - August each year, but can be earlier or later depending on site -specific conditions. Per §1 25.94(c)(1 1), McGuire's current operations and monitoring for presence/absence of fish that would be susceptible to impingement at the LLI should be considered BTA for a de minimis rate of impingement based on the following: • The LLI cooling water pumps are operated less than five percent of the time; typically one to five weeks per year based on operating data from 2015 — 2017 (Table 5-5). • LLI pumps are typically operated during warmer months (i.e., June — September) when Lake Norman is thermally stratified with low to zero DO concentrations in the LLI AOI (i.e., approximately the bottom 16 feet of the lake and nearly 100 feet below the lake's surface). • Duke Energy monitors water quality and presence/absence of fish in the vicinity of the LLI starting in mid -June each year and the LLI cooling water pumps are not operated unless conditions exist that would minimize impingement at the LLI structure. Duke Energy 1 58 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal Chosen Method(s) of Compliance with Impingement Mortality Standard [§122.21(r)(6)] While the TSV is slightly higher than 0.5 fps when all three LLI pumps are in operation28, the potential for impingement at the LLI is minimized based on the current monitoring and surveillance program and operating protocols described above. 28 As described in Section 5.3, the TSV at the LLI structure is 0.84 fps when both RN pumps and all three LLI cooling water pumps are in operation. Duke Energy 1 59 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal Entrainment Performance Studies [§122.21(r)(7)] 7 Entrainment Performance Studies [§ 122.21 (r)(7)] The information required to be submitted per §122.21(r)(7), Entrainment Performance Studies, is as follows: The owner or operator of an existing facility must submit any previously conducted studies or studies obtained from other facilities addressing technology efficacy, through -facility entrainment survival, and other entrainment studies. Any such submittals must include a description of each study, together with underlying data, and a summary of any conclusions or results. Any studies conducted at other locations must include an explanation as to why the data from other locations are relevant and representative of conditions at your facility. In the case of studies more than 10 years old, the applicant must explain why the data are still relevant and representative of conditions at the facility and explain how the data should be interpreted using the definition of entrainment at 40 CFR 125.92(h). Each of these requirements is addressed in the following subsections. 7.1 Site -Specific Studies No site -specific entrainment performance studies (i.e., studies evaluating biological efficacy of specific entrainment reducing technologies) have been completed at McGuire in the past five years. To evaluate potential entrainment performance at McGuire, and as part of the Benefits Valuation Study (§122.21 (r)(1 1)), incremental losses and technology benefits were modeled assuming the installation of entrainment reducing technologies. These technologies included a scenario modeling the installation of closed -cycle MDCTs and a scenario modeling the installation of FMS with modified-Ristroph traveling water screens and an aquatic organism return system. The MDCT scenario assumed a flow reduction estimate based on site -specific information and operations (see Section 10), resulting in an equivalent percent reduction in entrainment mortality. The Rule defines entrainment mortality as those organisms passed through a facility and killed due to thermal, physical, or chemical stressors, and also includes "the death of those fish and shellfish that may occur on fine mesh screens" (79 FR 158, 48330). As such, performance under the FMS scenario was defined as the reduction of ichthyoplankton passing through the screens based on morphological measurements. Early life stage organisms are inherently fragile due to limited development of scales and body musculature (EPRI 2010b), therefore, to more accurately represent mortality of ichthyoplankton converted from entrainment to impingement on the FMS, historical on- screen survival data (compiled and summarized in Appendix 11-C were used to adjust the performance estimates for the FMS scenario. Details on model development, assumptions, best professional judgment (BPJ) decisions associated with the assessment, and estimated entrainment performance (and the McGuire Benefits Valuation Study) are presented in Section 11. Duke Energy 160 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal Entrainment Performance Studies [§122.21(r)(7)] 7.2 Studies Conducted at Other Locations In addition to entrainment performance studies, the potential for through -plant survival of entrained organisms at McGuire's Main Intake structure was considered. The Rule assumes 100 percent of entrained organisms suffer mortality" (79 FR 158, 48318). However, through -plant entrainment survival studies demonstrate some survival can occur, depending on site -specific design, operations, and the species and life stages entrained at the facility (EPRI 2018). Through -plant survival has not been assessed at McGuire. However, entrainment survival studies have been performed at other electric utilities and recent research indicates that results of those studies may be transferable to other facilities under certain conditions (EPRI 2018). Entrainment survival is mainly dependent on three stressors: thermal, chemical, and physical. Thermal stressors are variable due to generating load, pumping rate, ambient temperature, and thermal tolerance of organisms entrained. Chemical stressors are principally attributable to periodic biocide applications used to control biofouling within the cooling system. Therefore, thermal and chemical stressors are often intermittent, although have the potential to cause 100 percent mortality if conditions are severe (very high temperatures or recent/present application of biocides). Physical stress of entrainment is consistent for entrained organisms and can include many sources, the greatest of which is likely the circulating water pumps. Physical stressors can impose some mortality; however effects can be variable depending on species and life stages. Depending on the seasonal influence of temperature, periodic biocide treatments, and facility equipment (particularly circulating water pumps), some through -plant survival at McGuire could occur. However, the degree of survival possible depends on site and seasonal -specific conditions. As such, the baseline entrainment values presented for McGuire have not been adjusted for potential through -plant survival and should be viewed as a conservative estimate of existing conditions. 7.3 Summary The determination of entrainment BTA is made by comparing the costs and benefits, based on estimated performance of alternative entrainment reduction technologies, to the costs and benefits of the existing facility technologies. The assumption of 100 percent through -plant mortality results in a negative bias to this comparison, assuming greater entrainment losses than may actually occur under existing conditions, and can result in an overestimation of the benefits of the entrainment technologies (FMS and MDCTs) and bias the analysis toward the FMS or MDCTs. The combination of these biases can cause the benefits analysis to be biased toward the FMS (EPRI 2018). This bias has the potential to result in increased entrainment losses if FMS result in higher organism mortality compared with potential through -plant survival. Therefore, while not eliminating the bias entirely from these assumptions, the incorporation of impingement mortality from those organisms converted from entrainment to impingement under the FMS scenario provides a more accurate estimate of entrainment mortality and reduces the bias associated with a comparison to the MDCT scenario or to existing or baseline conditions. Duke Energy 161 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal �� Operational Status [§122.21(r)(8)] 8 Operational Status [§122.21(r)(8)] The information required to be submitted per §122.21(r)(8), Operational Status, is outlined as follows: (i) For power production or steam generation, descriptions of individual unit operating status including age of each unit, capacity utilization rate (or equivalent) for the previous 5 years, including any extended or unusual outages that significantly affect current data for flow, impingement, entrainment, or other factors, including identification of any operating unit with a capacity utilization rate of less than 8 percent averaged over a 24-month block contiguous period, and any major upgrades completed within the last 15 years, including but not limited to boiler replacement, condenser replacement, turbine replacement, or changes to fuel type; (ii) Descriptions of completed, approved, or scheduled uprates and Nuclear Regulatory Commission relicensing status of each unit at nuclear facilities; (iii) For process units at your facility that use cooling water other than for power production or steam generation, if you intend to use reductions in flow or changes in operations to meet the requirements of 40 CFR 125.94(c), descriptions of individual production processes and product lines, operating status including age of each line, seasonal operation, including any extended or unusual outages that significantly affect current data for flow, impingement, entrainment, or other factors, any major upgrades completed within the last 15 years, and plans or schedules for decommissioning or replacement of process units or production processes and product lines; (iv) For all manufacturing facilities, descriptions of current and future production schedules; and, (v) Descriptions of plans or schedules for any new units planned within the next 5 years. Each of these requirements is addressed in the following subsections. 8.1 Description of Operating Status McGuire Unit 1 began commercial operation in 1981 and Unit 2 began operation in 1984 (Duke Energy 2016a). At the time of this submittal in 2019, Unit 1 and Unit 2 are 38 and 35 years old, respectively. The current USNRC licenses expire in 2041 (Unit 1) and 2043 (Unit 2) (USNRC 2017a, b). In 2019, Units 1 and 2 have 22 and 24 years remaining, respectively. Duke Energy 162 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal �� Operational Status [§122.21(r)(8)] 8.2 Utilization for Previous 5 Years McGuire Units 1 and 2 have a gross generating capacity of 2,38629 megawatts (MW) (Duke Energy 2017a). Each unit's capacity (for winter only) is provided in Table 8-1. Gross monthly generation at McGuire is presented in Table 8-2 for January 2013 through December 2017. Table 8-1. McGuire Nuclear Station Winter Gross Generating Capacity (Duke Energy 2017a) Unit 1 1,199.0 Unit 2 1,187.2 Total 2,386.2 Table 8-2. Monthly Gross Generation (MW) for McGuire Nuclear Station for the 5-Year Period30 January 2013 through December 2017 (Duke Energy 2018) January 1,728,606 1,747,943 1,776,992 1,774,577 1,832,422 1,772,108 February 1,438,284 1,579,338 1,401,591 1,663,224 1,503,075 1,517,102 March 1,241,516 1,460,371 1,773,678 1,396,671 1,403,958 1,455,239 April 1,025,423 989,409 1,717,625 1,221,969 1,101,356 1,211,156 May 1,727,494 1,742,802 1,770,606 1,769,044 1,826,424 1,767,274 June 1,607,266 1,669,569 1,696,529 1,694,452 1,758,811 1,685,325 July 1,710,990 1,711,576 1,683,689 1,727,341 1,796,255 1,725,970 August 1,706,712 1,710,630 1,655,699 1,722,675 1,795,234 1,718,190 September 1,649,316 1,165,268 1,130,952 1,676,758 1,496,122 1,423,683 October 1,718,134 881,616 728,370 1,750,810 1,342,278 1,284,242 November 1,604,795 1,210,887 427,546 1,713,224 1,780,380 1,347,366 December 1,750,795 1,726,969 155,384 1,773,544 1,839,781 1,449,295 Annual Total 18,909,331 17,596,378 15,918,661 19,884,289 19,4776,09 18,356,951 29 This is the 2017 winter gross generating capacity. Generating capacity is higher in the winter than in the summer. 30 Under §122.21(r)(8)(i), an owner must provide a description of individual unit operating status including capacity utilization rates (or equivalent) for the previous 5 years, including any extended or unusual outages that significantly affect flow data, entrainment or impingement, or other factors. Duke Energy 163 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal �� Operational Status [§122.21(r)(8)] Capacity utilization factor is the ratio of gross generation to total generating capacity for a given period of time. The average monthly capacity factor at McGuire for the five-year period from January 2013 through December 2017 was generated using the total winter gross generating capacity value of 2,386.2 MW and is provided in Table 8-3. Table 8-3. Average Monthly Capacity Utilization Factors', Expressed as a Percent, for McGuire Nuclear Station for the 5-Year Period from January 2013 through December 2017 (Duke Energy 2018) January 97 98 100 100 103 100 February 90 98 JM` 100 " 94 '_ March 70 82 100 79 79 82 April 60 58 10N 71 64 W May 97 98 100 100 103 100 June 94 97 99 102 98 • July 96 96 95 97 101 97 August 96 96 93 97 101 97 September 96 68 66 98 87 83 October 97 50 41 99 76 72 November 93 70 25 100 104 78 December 99 97 9 100 104 82 Average Annual Capacity 90 84 76 95 93 88 Factor (Percentage) USNRC approved McGuire's application for measurement uncertainty power uprates for both units on May 16, 2013 (USNRC 2017c); this document is included in Appendix 8-A. 2 Unit 2 had an outage near the end of 2015 which resulted in a lower capacity utilization factor. 8.3 Major Upgrades in Last 15 Years McGuire Units 1 and 2 underwent measurement uncertainty recapture uprates in 2013, which increased the generating capacity by approximately 1.7 percent. The cooling water system was not expanded or upgraded due to the increased generating capacity. 8.4 Descriptions of Consultation with Nuclear Regulatory Commission The original operating licenses were issued on May 27, 1981 and May 27, 1983 for Units 1 and 2, respectively (USNRC 2017a, b), which authorized the operation of each unit for 40 years. On December 5, 2003, USNRC issued a renewed license for the operation of Units 1 and 2 at McGuire Duke Energy 164 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal �� Operational Status [§122.21(r)(8)] for an additional 20 years, extending the anticipated life of Units 1 and 2 to 2041 and 2043, respectively. On May 16, 2013, USNRC approved McGuire's application for measurement uncertainty power uprates for both units (USNRC 2017c). 8.5 Other Cooling Water Uses for Process Units McGuire does not have other process units; therefore, this section is not applicable. 8.6 Current and Future Production Schedules at Manufacturing Facilities McGuire is not a manufacturing facility. Current electricity generation rates are shown in Table 8-2 and average monthly capacity factors are shown in Table 8-3. These rates are anticipated to be representative of future generation. 8.7 Plans or Schedules for New Units Planned within 5 years There are no new units planned at McGuire within the next 5 years. Duke Energy 165 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal Entrainment Characterization Study [§122.21(r)(9)] 9 Entrainment Characterization Study [§ 122.21 (r)(9)] The information required to be submitted per §122.21(r)(9), Entrainment Characterization Study, is outlined as follows: (i) Entrainment Data Collection Method — The study should identify and document the data collection period and frequency. The study should identify and document organisms collected to the lowest taxon possible of all life stages of fish and shellfish that are in the vicinity of the cooling water intake structure(s) and are susceptible to entrainment, including any organisms identified by the Director, and any species protected under Federal, State, or Tribal law, including threatened or endangered species with a habitat range that includes waters in the vicinity of the cooling water intake structure. Biological data collection must be representative of the entrainment at the intakes subject to this provision. The owner or operator of the facility must identify and document how the location of the cooling water intake structure in the waterbody and the water column are accounted for by the data collection locations. (ii) Biological Entrainment Characterization — Characterization of all life stages of fish, shellfish, and any species protected under Federal, State, or Tribal law (including threatened or endangered species), including a description of their abundance and their temporal and spatial characteristics in the vicinity of the cooling water intake structure(s), based on sufficient data to characterize annual, seasonal, and diel variations in entrainment, including but not limited to variations related to climate and weather differences, spawning, feeding, and water column migration. This characterization may include historical data that are representative of the current operation of the facility and of biological conditions at the site. Identification of all life stages of fish and shellfish must include identification of any surrogate species used, and identification of data representing both motile and non -motile life -stages of organisms. (iii) Analysis and Supporting Documentation — Documentation of the current entrainment of all life stages of fish, shellfish, and any species protected under Federal, State, or Tribal law (including threatened or endangered species). The documentation may include historical data that are representative of the current operation of the facility and of biological conditions at the site. Entrainment data to support the facility's calculations must be collected during periods of representative operational flows for the cooling water intake structure, and the flows associated with the data collection must be documented. The method used to determine latent mortality along with data for specific organism mortality or survival that is applied to other life -stages or species must be identified. The owner or operator of the facility must identify and document all assumptions and calculations used to determine the total entrainment for that facility together with all methods and quality assurance/quality control procedures for data collection Duke Energy 1 66 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Entrainment Characterization Study [§122.21(r)(9)] r and data analysis. The proposed data collection and data analysis methods must be appropriate for a quantitative survey. Although the Rule permits the use of recent (within past 10 years) historical entrainment data in support of compliance with §122.21(r)(9), historical entrainment studies have not been performed at McGuire. As such, a two-year Study was performed at McGuire with the goal of characterizing entrainment at the shoreline -situated, surface -level Main Intake. Data presented in the Study are used to support development of three additional reports required by the Rule at §122.21(r)(10) - (r)(12): (1) Comprehensive Technical Feasibility and Cost Evaluation Study, (2) Benefits Valuation Study, and (3) Non -water Quality and Other Environmental Impacts Study. Since McGuire does not currently employ entrainment reduction technologies, the information presented in these studies will be used by the Director to make a site -specific BTA determination for compliance with the entrainment reduction requirements of the Rule. The USEPA considers the entrainment of ichthyoplankton through a CWIS to result in 100 percent mortality; therefore, latent mortality was not addressed in this Study. Each of these requirements is addressed in the following subsections. 9.1 Entrainment Data Collection Methods Ichthyoplankton sampling was performed by Normandeau Associates, Inc. twice per month from March 1 through October 31 in 2016 and 2017 (16 sampling events per year). Samples were collected at the entrance to the Main Intake structure, upstream of the bar racks, using a pumped sampling technique. Based on life history data of species likely to be entrained at McGuire, the Study design (frequency and duration of sampling) allowed for collection of a representative sample of entrainable-sized organisms (i.e., ichthyoplankton) present in Lake Norman. Based on these data, the sampling window provided the greatest likelihood of capturing the start and end of the spawning season each year, while also minimizing sampling effort and costs. The sampling period selected was also consistent with data collected at other regional reservoirs in the southeastern U.S. supporting a shortened sampling season (EPRI 2011). Field sampling was coordinated with plant operations personnel to ensure circulating pumps were scheduled to operate during the specified sampling intervals. 9.1.1 Sampling Gear and Collection Protocol 9.1.1.1 Sampling Gear Ichthyoplankton samples were collected upstream of the bar racks at the CWIS using a pump sampling design due to intake configuration and safety considerations. There were three primary components to the sample collection system employed at McGuire; (1) the in -water sampler (Figure 9-1), (2) the pump, and (3) the collection tank and plankton net with 3.3-ft-diameter opening (Figure 9-2). Duke Energy 1 67 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal Entrainment Characterization Study [§122.21(r)(9)] Quick -connect couplings and flexible hosing were used to attach the in -water sampler, at deck level, to the pump and sample collection tank to allow the system to be partially dismantled between sampling events. The in -water sampler consisted of a rigid pipe deployed and secured in the forebay of the McGuire CWIS, approximately five feet upstream of the bar racks near the centerline of Unit 2 (Figure 9-3). A second sampling location is shown in Figure 9-3 indicating the sampling location in front of Unit 1 that was used during a scheduled Unit 2 outage that occurred during the Study. The in -water sampling pipe consisted of a 3-inch-diameter Schedule 80 PVC pipe with three orifices designed to collect a depth -integrated sample. The orifices allowed for the simultaneous withdrawal of water from just below the bottom of the bulkhead (approximately 750 ft msl), near the bottom of the CWIS (approximately 720 ft ni and a point mid -way between the other two orifices (approximately 735 ft msl). Deck Height L7 Elev.: 770 ft S Surface Buoy Surface Buoys HWL Eiev: 760 ft Sub -surface Buoy NWL Elev__ 756 ft 1 — Foam Filled Bulkhead — 3-in. Schedule 80 PVC or ABS Pipe Aluminum Sirongback Sample Intake Ports (3) Elev.: 745 0 1 I 1 �Z' FLOW Float `�I 4° Flex Hose To Shore 150 lb Pyramid Anchor 75 lb Anchors Elev.: 715 ft 1 Bottom Elev. 710 - 712 ft V CONCEPTUAL VIEW - NOTTO SCALE Figure 9-1. Schematic of Flotation and Anchoring System for In -Water Sampler Deployment at McGuire Nuclear Station Duke Energy 1 68 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal Entrainment Characterization Study [§122.21(r)(9)] Figure 9-2. Gas -powered Pump and 100-gallon Collection Tank System used for Ichthyoplankton Sampling at McGuire Nuclear Station Figure 9-3. Location for Collection Tank and Pump and Associated Piping for the Sampling Location Upstream of Unit 2 Duke Energy 1 69 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� Entrainment Characterization Study [§122.21(r)(9)] r 9.1.1.2 Sample Collection Protocol The twice -monthly Study consisted of samples collected at a sufficient duration and frequency to capture seasonal patterns in entrainment, as specified by the Rule for existing facilities. During each of the twice -monthly sampling events, ichthyoplankton sample collection targeted the following discrete 6-hour time intervals31: 2100-0300 hours (night), 0300-0900 hours (morning), 0900-1500 hours (day) and 1500-2100 hours (evening), for a total of four diel samples over 24 hours. During daylight saving time, sample start and end times were adjusted to maintain their representativeness of the target diel period (i.e., crepuscular versus night).To accurately capture crepuscular periods throughout the sampling season, the sampling start time was adjusted for each event based on the estimated time of sunrise/sunset. Sampling for the crepuscular periods was then initiated approximately one hour before sunrise/sunset and completed approximately one hour after sunrise/sunset. A combined total of 128 ichthyoplankton samples were collected in 16 sample events from the March to October, 2016 and 2017. The sampling protocol is summarized in Table 9-1. Additional details of the sampling protocol are in the 2016-2017 Study report as well as Section 6 of the Study plan (HDR 2016) as provided in Appendices 9-A and 9-13. One depth -integrated sample, with a target volume of 100 m3, was collected during each 6-hour diel period. The target sample volume was measured using an in -line flowmeter attached to sample collection tank system. Depending upon pump flow rates, each sample required approximately two hours to collect. Table 9-1. Ichthyoplankton Sampling Details Sample Location Five feet upstream of the bar racks and near the centerline of the unit being sampled. The majority of samples were collected at Unit 2, however Unit 1 was sampled during a Unit 2 outage period. Sampling Events Thirty-two (32) sampling events; twice per month; between March 1 and October 31, 2016 (Days) and between March 1 and October 31, 2017 Daily Collection Samples collected within four, 6-hour diel periods within each 24-hour sample event; on Schedule average, pumped for 2 hours per 6-hour period' Targeted Organisms Fish eggs, larvae, and juveniles Depths Depth -integrated sample using selective withdrawal from near -surface, mid -depth, and near -bottom. Sample Duration Approximate 100-m3 samples collected within each 6-hour sampling interval. Total Number of Sixteen (16) sampling events/year x 4 samples/sampling event (days) x 2 years = 128 Samples samples 31 During summer months, sunrise occurs earlier and sunset occurs later in the day. As a result, sample start and end times were shifted accordingly. For example, sample collection for events in June and July (2016 and 2017) was initiated between 1900 and 1930 and completed between 2150 and 2209, ending outside of the target evening diel period. During these months, the target 6-hour diel time intervals were shifted to accommodate this change, such that subsequent diel samples were also started at a later time, to avoid overlapping diel samples within each 24- hour sampling event. Duke Energy 170 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Entrainment Characterization Study [§122.21(r)(9)] r During daylight saving time, sample start and end times were adjusted to maintain their representativeness of the target diel period (i.e., crepuscular versus night). Sample water was filtered through a 330-micron ([gym) plankton net suspended in a water -filled tank to reduce velocity and turbulence and prevent extrusion of larvae through the mesh. The mouth of the plankton net was placed at the tank opening with the plankton net suspended inside the tank above the water line to prevent loss of organisms in the event of tank overflow. To minimize organism damage, the net was rinsed at least twice during each 100-m3 pumped sample collection. Net rinses were combined in the field to provide a single concentrated 100-m3 sample. More frequent net rinses were conducted if debris buildup caused net clogging. The net and collection cup were carefully rinsed into sample jars with preprinted labels (internal and external) and preserved in 5-10 percent formalin solution. Total sample volume and total sample duration (time in minutes) were recorded on pre-printed field data sheets. Samples were transported back to the laboratory for analysis under a required chain -of - custody. 9.1.1.3 Water Quality At the beginning of each sample period, water quality parameters including intake water temperature (°C), DO ( mg/L), pH (standard units) and specific conductance (micro Siemens per centimeter [pS/cm]) were collected from the sample tank using a calibrated water quality meter. Data were recorded on a field data sheet. 9.1.2 Laboratory Sample Processing Samples were processed by the biological laboratory following the data quality objectives outlined in the Quality Assurance Plan and Standard Operating Procedures for Entrainment Sampling at McGuire Nuclear Station (NAI 2017), provided in Appendix 9-B. Samples that were estimated to contain more than 400 fish eggs and larvae (all taxa combined) were split with a plankton splitter to a subsample quota of approximately 200 eggs and larvae combined prior to analysis. Ichthyoplankton from each sample were placed in individually labeled vials and preserved in 5 to 10 percent formalin prior to taxonomic analysis. Fish eggs, larvae, and juveniles were identified to the lowest practical taxonomic level using current references and taxonomic keys (e.g., Auer 1982; Wallus et al. 1990; Kay et al. 1994; Simon and Wallus 2004; EPRI 2016). Samples were assigned a life stage category based on the following definitions: • Eggs: Required to be whole, show signs of fertilization, and live (i.e., no fungus present). • Yolk -sac larvae: Transition stage from hatching through development of complete, functioning digestive system. • Post yolk -sac larvae: Transition stage from completely developed digestive system through the transition to the juvenile form. • Young -of -year: Stage from complete transformation to Age 1 (fin rays identical to adult stage). • Age 1+: Yearling and older. • Unidentified larvae: Specimens unidentifiable as yolk- or post yolk -sac larvae due to organism damage. Duke Energy 171 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Entrainment Characterization Study [§122.21(r)(9)] r Species -specific size distributions were assessed through the collection of morphometric data. Only whole organisms were selected for measurements. For each diel sample, the following morphometric data were collected: • Up to 10 yolk -sac, post yolk -sac and "larvae" of each fish species were measured for total length, greatest soft tissue body depth, and head capsule depth to the nearest 0.1 mm. Among dorso-ventrally compressed organisms whose body or head capsule width exceeds the body or head capsule depth, soft tissue body and head capsule width were also measured to the nearest 0.1 mm. Up to 10 eggs of each taxon were measured for minimum and maximum diameter to the nearest 0.1 mm. If more than 10 eggs or larvae were present, a randomly selected subset of each species and life stage was measured. 9.1.3 Data Analysis Upon receipt of sample data from the laboratory, a thorough QC review was completed to confirm species identifications were consistent with regional taxa, and to confirm parity between laboratory - provided data and the field data sheets. Data were then imported to a project -specific Microsoft Access® database. 9.1.3.1 Exclusion Calculation Because the orifices of the sample pipes were larger than the maximum opening of 0.56 inches or 0.53 inches allowed by the USEPA in discerning between impingement and entrainment32, impingeable-size organisms were collected in the ichthyoplankton samples. Therefore, an exclusion calculation was developed to separate organisms of an impingeable size and exclude them from the density calculations. Fish with a body depth greater than 13.5 mm (0.53 inches) were classified as impingeable and removed ("excluded") from the ichthyoplankton density calculations. The young -of -year Gizzard Shad collected in the Study were of sufficient size to be excluded by a 3/8-inch mesh screen and were therefore excluded from monthly and annual entrainment estimates. 9.1.3.2 Density Calculations Egg and larval fish sample densities (post -exclusion), expressed as number per 100 m3, were used to calculate diel and sample event (i.e., including all samples collected within a 24-hour period) densities for each taxon and life stage. Interpolated daily densities were used to calculated mean monthly and mean annual densities for each taxon and life stage. Detailed descriptions and formulas for each calculation performed on the raw sample data (diel sample density, sample event density, interpolated daily density, average daily density of ichthyoplankton by month, screen exclusion for existing 3/8-inch mesh size, monthly and diel density with 3/8-inch mesh exclusion, and annual 32 In the Rule, USEPA allows facilities to differentiate between entrainment and impingement based on passage of organisms through a 12- by 'V4-inch screen (0.56-inch diagonal opening) or a 3/8-inch screen (0.53-inch diagonal opening). Duke Energy 172 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� Entrainment Characterization Study [§122.21(r)(9)] r entrainment with 3/8-inch mesh exclusion under actual and maximum water withdrawals are provided in Appendix 9-C (Entrainment and Impingement Calculations). 9.2 Results - Entrainment Characterization 9.2.1 Species Composition No extreme variations in water quality parameters were observed in either year that may have adversely affected the quality of the ichthyoplankton samples (Appendix 9-A). The two-year Study collected 2,568 ichthyoplankton from eight taxonomic families (Table 9-2). Three of the eight families occurred only in 2016 samples (Ictaluridae, Cyprinidae, and Atherinopsidae) and one of the eight families occurred only in 2017 (Catostomidae). The 2016 sampling effort resulted in the collection of 1,327 ichthyoplankton representing seven families. The dominant families collected based on relative abundance in 2016 were Atherinopsidae (50.3 percent) and Clupeidae (43.6 percent), for a combined relative abundance of 93.9 percent. The 2017 sampling effort resulted in the collection of 1,241 ichthyoplankton representing five families. The dominant families in 2017 samples were Clupeidae (82.8 percent) and Moronidae (16.1 percent), which together represented 98.9 percent of total ichthyoplankton collected. Table 9-2. Summary of Ichthyoplankton by Family Collected during the Entrainment Characterization Study at McGuire Nuclear Station, 2016-2017 Mar-OctiMar-Oct Taxa Richness Total No. Total No. Collected Collected Clupeidae 3 578 43.6 1,028 82.8 1,606 62.5 Atherinopsidae 1 668 50.3 -- -- 668 26.0 Moronidae 1 23 1.7 200 16.1 223 8.7 Centrarchidae 3 30 2.3 8 1.0 38 1.5 Unidentified Fish 1 18 1.4 2 0.2 20 0.8 Percidae 1 7 0.5 1 0.1 8 0.3 Cyprinidae 1 2 0.2 -- -- 2 0.1 Catostomidae 1 -- -- 2 0.0 2 0.0 Ictaluridae 1 1 0.1 -- -- 1 0.0 Totals 1,327 100 1,241 100 2,568 100 (--) represents no ichthyoplankton within that family were collected. *606 of the Atherinopsidae were collected during a single sampling event A total of 12 distinct taxa were collected during the two-year Study, with 10 distinct taxa in 2016 ichthyoplankton samples and 8 distinct taxa collected from the 2017 samples (Table 9-3). Inland Silverside (Menidia beryllina) dominated (50.3 percent) the total sample catch in 2016, followed by two groups of clupeids, Alewife/Gizzard Shad/Threadfin Shad (Alosa pseudoharengus/Dorosoma cepedianum/D. petenense; 26 percent) and Gizzard Shad/Threadfin Shad (15.5 percent). The Inland Silverside is not native to Lake Norman and has not previously been collected in fisheries surveys Duke Energy 173 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� Entrainment Characterization Study [§122.21(r)(9)] r performed by Duke Energy or the NCWRC. Since Inland Silverside were not previously collected at Lake Norman, voucher specimens were collected and deposited with the North Carolina Museum of Natural History. All remaining taxa accounted for less than two percent of the total sample catch in 2016. The taxa group of Alewife/Gizzard Shad/Threadfin Shad also dominated samples collected in 2017, consisting of 81.1 percent of the total collection. White Perch (Morone americana; 16.1 percent) was the only other taxa that accounted for greater than two percent of the total sample collection in 2017. Table 9-3. Composition and Relative Abundance of Taxa Collected in the Entrainment Characterization Study at McGuire Nuclear Station, March to October 2016 and 2017 Common Name Scientific Name Total No. Collected Inland Silverside Menidia beryllina 668 50.3 -- -- Alewife/Gizzard Shad/ Alosa pseudoharengus/Dorosoma 342 25.8 1,007 81.1 Threadfin Shad cepedianum/D. petenense Gizzard Shad/Threadfin Dorosoma cepedianum/D. 206 15.5 11 0.9 Shad petenense Common Sunfish Lepomis spp. 25 1.9 5 0.4 White Perch Morone americana 23 1.7 200 16.1 Unidentified Fish Unidentified Osteichthyes 18 1.4 2 0.2 Gizzard Shad Dorosoma cepedianum 14 1.1 2 0.2 Alewife Alose pseudoharengus 11 0.8 8 0.6 Threadfin Shad Dorosoma petenense 5 0.4 -- -- Darter Species Etheostoma spp. 4 0.3 1 0.1 Common Sunfish/Crappie Species Lepomis spp.lPomoxis spp. 4 0.3 -- -- Swamp Darter Etheostoma fusiforme 3 0.2 -- -- Black Bass Micropterus spp. 1 0.1 2 0.2 Carp and Minnow Family Cyprinidae 1 0.1 -- -- Channel Catfish Ictalurus punctatus 1 0.1 -- -- Common Carp Cyprinus carpio 1 0.1 -- -- Sucker Family Catostomidae -- -- 2 0.2 Black Crappie Pomoxis nigromaculatus -- -- 1 0.1 Total 1,327 100.0 1,241 100.0 Total Number of Distinct Taxa Collected 10 -- 8 -- represents no ichthyoplankton within that taxa were collected. Duke Energy 174 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Entrainment Characterization Study [§122.21(r)(9)] r Samples collected in 2016 predominantly consisted of young -of -year (50.5 percent) and post yolk - sac larvae (47.6 percent) life stages (Table 9-4). Few egg or yolk -sac larvae were collected in 2016, with each of the life stages consisting of no more than one percent of the total collected. Post yolk - sac larvae accounted for nearly the entire (98 percent) 2017 ichthyoplankton totals, followed by yolk - sac larvae (2 percent). Few egg or young -of -year were collected in 2017, with each comprising no more than one percent of the collection. Table 9-4. Total Number Collected by Life Stage during the Entrainment Characterization Study performed at McGuire Nuclear Station, March to October 2016 and 2017 TotalLife Stage Total No. Total No. Percent Collected Collected Egg 12 <1 4 <1 Yolk -sac larvae or 1 <1 19 1.5 Post yolk -sac larvae 632 47.6 1,212 97.7 Young -of -year 670 50.5 2 <1 Unidentified larval stage 12 <1 4 <1 Grand Total 1,327 100 1,241 100 Species belonging to the Clupeidae family are broadcast spawners, which release eggs and sperm into the water column over structure or substrate and do not provide parental care. Because eggs are not laid in nests and/or guarded like that of centrarchids, they are more susceptible to dispersal by water current prior to sinking. Eggs of clupeids, depending on the species, develop into larvae after two to six days (EPRI 2012). Some eggs may still be suspended in the water column at the time of development from egg to larvae. Most clupeids collected at McGuire were larvae. Clupeids remain in the larval form for approximately 27 days for Threadfin and Gizzard Shad and 53 days for Alewife (EPRI 2012). 9.2.2 Size Distribution The minimum, median, and maximum of egg width, larvae body depth, head depth, and total length of each taxon collected during the two years of ichthyoplankton sampling, as well as length - frequency distribution plots are presented in the Study report (Appendix 9-A). During the two years of sampling, body depths ranged from a minimum of 0.2 mm for post yolk -sac larvae of various clupeid groups to a maximum of 16.1 mm for Gizzard Shad young -of -year. Total lengths ranged from a minimum of 2.8 mm for White Perch yolk -sac larvae to a maximum 63 mm Gizzard Shad young -of - year. Gizzard Shad young -of -year is the only taxon that was excluded from entrainment estimates due to their size. 9.2.3 Temporal and Spatial Patterns in Abundance 9.2.3.1 Average Daily Density by Month Based on monthly ichthyoplankton densities for the Study, the primary period of ichthyoplankton entrainment at the McGuire CWIS occurs during late spring to early summer, from March through June (see Appendix 9-A). The period of entrainment observed in this study is consistent with the time period and data collected at other southeastern U.S. reservoirs (EPRI 2011). It is also Duke Energy 175 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� Entrainment Characterization Study [§122.21(r)(9)] r consistent with documented life history information for the species entrained at McGuire (summarized in Appendix 4-A). Average ichthyoplankton density in March 2016 was 3.87 organisms/100 m3 and consisted of post yolk -sac larvae of shads (Dorosoma spp.) and darters (Etheostoma spp.). However, based on species -specific totals for both March 2016 sampling events (Appendix 9-A, Table Al), no ichthyoplankton were collected in the first March 2016 sampling event. This indicates that the Study successfully captured the initiation of spring spawning activity in 2016. The average density for organisms collected in March 2017 was 15.95 organisms/100 m3 and consisted of egg, yolk -sac, and post yolk -sac larval life stages of the Clupeidae, Moronidae, and Catostomidae families. Eight post yolk -sac larval Alewife/Threadfin/Gizzard Shad group were collected in the first March 2017 sampling event (Appendix 9-A, Table Al). Based on the occurrence of post yolk -sac larvae during the first sampling event in March, it is possible that spawning for this species initiated at the end of February or first of March in 2017. Earlier spawning may be due to warm temperatures occurring earlier and more frequently in the spring of 2017. Average monthly ichthyoplankton densities were highest in May (56.78 organisms/100 m3) and June (51.47 organisms/100 m3) during 2016 sampling, which was dominated by Inland Silverside young - of -year (Appendix 9-A). A minor peak in April (34.67 organisms/100 m3) was dominated by Alewife/Gizzard Shad/Threadfin Shad post yolk -sac larvae. Peak ichthyoplankton densities occurred in April (98.11 organisms/100 m3) 2017, with samples dominated by post yolk -sac larvae of the Alewife/Gizzard Shad/Threadfin Shad species group. A smaller secondary peak in May 2017 (23.83 organisms/100 m3) was also dominated by post yolk - sac Alewife/Gizzard Shad/Threadfin Shad. White Perch post yolk -sac larvae also contributed to the April and May ichthyoplankton densities from both, 2016 and 2017. Average monthly densities were low for the remaining months, with less than 3 organisms/100 m3 in July, August, and September of both years and no organisms entrained in October of either sample year. Considering both years of data, peak ichthyoplankton densities occurred in the months of April, May, and June. Peak ichthyoplankton densities occurred in April and May for both years if the collection of Inland Silverside is discounted. The duration and frequency of ichthyoplankton sampling successfully captured the beginning and end of the spawning season, as evidenced by zero catch in the first sample event of 2016 followed by zero catch from mid -September through the end of October 2016 (Appendix 9-A, Table Al). In 2017, eight post yolk -sac larvae of the Alewife/Gizzard Shad/Threadfin Shad group were collected during the first March sampling event, which accounted for less than 8 percent of the total post yolk - sac larvae collected for this species group throughout 2017. All other taxa collected in 2017 sampling efforts appear to have initiated and concluded spawning within the Study sampling window, with only one entrainable-size young -of -year Alewife collected during the first August sampling event and no organisms collected thereafter. Duke Energy 176 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� Entrainment Characterization Study [§122.21(r)(9)] r 9.2.3.2 Diel Densities Diel vertical migration has been documented for pelagic freshwater fish (e.g., clupeids) and patterns of occurrence tend to be species -specific (Mehner 2012). Diel vertical migration is typically triggered by change in light intensity, although temperature, pressure, zooplankton resources, and predator presence have also been implicated as drivers of migration. As light intensity decreases at dusk, ichthyoplankton ascend within the water column where they remain until light intensity begins to increase near dawn, triggering fish to descend back toward the bottom of the water column (Mehner 2012). Ichthyoplankton densities were highest during night and morning hours in 2016 (Figure 9-4). During 2017, ichthyoplankton densities were also highest at night, followed by lower densities during the evening and morning hours. Densities were lowest during the daytime diel period for both years of the Study. The diel patterns observed in the 2016 and 2017 ichthyoplankton densities are consistent with observations by Mehner (2012). These data demonstrate that ichthyoplankton in the vicinity of the Main Intake are vulnerable to entrainment throughout a 24-hour diel period, however, ichthyoplankton densities tend to increase during night and morning hours while light intensity is still low and ichthyoplankton are moving in the water column. 300 0 250 v z 200 a ❑ 150 a 100 m m 50 0 2016 Morning Daytime Evening Night 2017 Diel Period Figure 9-4. Total Average Ichthyoplankton Densities (No./100 m3) by Diel Period Collected during the Entrainment Characterization Study performed at McGuire Nuclear Station, March to October 2016 and 2017 (Note: bars are standard error bars) 9.2.4 Monthly and Annual Entrainment Estimates 9.2.4.1 Cooling Water Intake Flows Maximum cooling water withdrawal volumes were calculated using the daily design pump capacity of the CCW pumps and assumed that all cooling water pumps would be operated at maximum capacity year-round. Actual cooling water intake flows were measured at pipe locations on the plant side or downstream side of the pumps and were provided to HDR (Duke Energy 2018). These values were summarized on a monthly basis and are presented as maximum and actual cooling water withdrawal Duke Energy 177 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Entrainment Characterization Study [§122.21(r)(9)] r volumes (m3) for 2016 and 2017 (Table 9-5). To calculate the annual estimated entrainment under actual withdrawal volumes, daily interpolated ichthyoplankton density data were averaged by month and then extrapolated by the total monthly cooling water volume. Fluctuations in actual withdrawal volumes are dependent upon facility operations and are affected primarily by energy demand and intake water temperatures. Table 9-5. Total Monthly Volume (m3) Withdrawn at Design Pump Capacity and Based on Actual Operations (January 2016 through December 2017) and the Percent Reduction in Withdrawal Volume at McGuire Nuclear Station, 2016-2017 January 343,368,787 343,368,787 293,012,538 293,012,538 14.7 14.7 February 321,215,962 310,139,550 274,108,503 264,656,486 14.7 14.7 March 343,368,787 343,368,787 234,072,796 289,819,166 31.8 15.6 April 332,292,375 332,292,375 258,160,041 235,329,249 22.3 29.2 May 343,368,787 343,368,787 343,368,787 343,368,787 0.0 0.0 June 332,292,375 332,292,375 332,292,375 332,292,375 0.0 0.0 July 343,368,787 343,368,787 343,368,787 343,368,787 0.0 0.0 August 343,368,787 343,368,787 343,368,787 343,368,787 0.0 0.0 September 332,292,375 332,292,375 332,292,375 293,952,607 0.0 11.5 October 343,368,787 343,368,787 324,045,253 216,624,403 5.6 36.9 November 332,292,375 332,292,375 284,258,929 272,469,118 14.5 18.0 December 343,368,787 343,368,787 293,012,538 293,012,538 14.7 14.7 9.2.4.2 Estimates of Annual Numbers Entrained Based on Design Flows The total annual estimates presented under the design flow scenario represent the maximum entrainment values at the McGuire CWIS if all pumps were operated at maximum capacity for one year. An estimated total of 506.7 million ichthyoplankton were entrained at McGuire during 2016 based on maximum water withdrawals at this facility (Appendix 9-A, Table 9-A3). The percent contributions of each taxon to the total abundance remains consistent with the ichthyoplankton sample densities, but the total abundance values change in response to the larger design flow volumes used to calculate total number entrained. Therefore, Inland Silverside was the most abundant taxon entrained with more than 252.3 million organisms, followed by 131.6 million Alewife/Gizzard Shad/Threadfin Shad and 79.6 million Gizzard Shad/Threadfin Shad. All remaining taxa combined contributed approximately 43 million organisms to the estimated annual total number entrained under DIF. For 2017, the estimated total entrained based on maximum water withdrawals was 478.4 million ichthyoplankton. The most abundant taxon in 2017 samples was Alewife/Gizzard Shad/Threadfin Shad with an estimated 386.7 million entrained, followed by almost 77.5 million White Perch and 4.5 million Gizzard Shad/Threadfin Shad. Collectively as families, species belonging to the Clupeidae Duke Energy 178 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Entrainment Characterization Study [§122.21(r)(9)] r family dominated 2017 entrainment estimates at 395.3 million, followed by Moronidae (White Perch) at 77.5 million and Centrarchidae (common sunfish, crappie, and black bass) at 3.5 million. Remaining families combined contributed approximately 2.2 million organisms to the estimated annual total entrained at DIF. 9.2.4.3 Estimated Annual Entrainment Based on Actual Flows An estimated total 476.8 million ichthyoplankton were entrained at McGuire during 2016 based on actual water withdrawals (Appendix 9-A). Inland Silverside accounted for 252.3 million organisms, or 53 percent of the estimated annual total entrainment. Taxa and species groups belonging to the family Clupeidae contributed 194.3 million organisms to the total annual estimate, or 41 percent. The remaining species combined for a total of 30.1 million organisms. Total annual entrainment during 2016 based on actual water withdrawals represents a reduction in entrainment of 5.9 percent from estimates based on maximum water withdrawals. An estimated 374.7 million ichthyoplankton were entrained at McGuire during 2017 based on actual water withdrawals (Appendix 9-A). Taxa and species groups belonging to the Clupeidae family dominated the 2017 entrainment estimates at 307.2 million organisms, followed by White Perch (Moronidae) at 61.8 million organisms. The combined total for the remaining species collected in 2017 includes 5.6 million organisms, or 1.5 percent of the annual total entrainment. Total annual entrainment during 2017 based on actual water withdrawals represents a reduction in entrainment of 21.7 percent from estimates based on maximum water withdrawals. The majority of organisms entrained at McGuire belong to the Clupeidae family comprising Alewife, Gizzard Shad, and Threadfin Shad. These species are prolific, broadcast spawners. Gizzard Shad, for example, on average may spawn 300,000 eggs per spawning event; and Alewife and Threadfin Shad may spawn up to 21,000-22,000 eggs per female (Etnier and Starnes 1993; Hendrickson et al. 2015). Additional spawning, nesting, and fecundity information for clupeid species frequently collected in Lake Norman is included in Appendix 4-A. Given the high fecundity and high natural mortality of these species, the estimated level of annual entrainment documented for McGuire is not anticipated to have an impact on population viability for these forage species. Recreational species, such as White Perch, sunfish (Lepomis spp.), crappie (Pomoxis spp.), Channel Catfish (Ictalurus punctatus), or black bass (Micropterus spp.) represent a small portion of the annual entrainment estimates for both years. The estimated annual entrainment for recreational species in 2016 was 20.2 million, representing 4.2 percent of the total estimated annual entrainment for 2016. Excluding the impact of Inland Silverside collections in 2016, recreational species represented 9.0 percent of the total estimated annual entrainment in 2016. The proportion of the annual entrainment estimate comprised of recreational species increased in 2017, with recreational species representing 17.4 percent of the annual entrainment estimate. The increase in recreational species was primarily due to increased entrainment estimates for White Perch (estimated annual entrainment of 7.8 million for 2016 versus 61.8 million in 2017). 9.3 Summary A total of 2,568 ichthyoplankton representing 12 distinct taxa from 8 families were collected during the two-year Study. The ichthyoplankton samples were dominated by species in the Clupeidae family (Alewife, Gizzard Shad, and Threadfin Shad), Inland Silverside (2016 only), and White Perch. Duke Energy 179 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Entrainment Characterization Study [§122.21(r)(9)] r The single event collection of a relatively large number of young -of -year Inland Silverside is an anomaly, and represents the first documented occurrence of this species in Lake Norman. No endangered or threatened species are known to exist in Lake Norman and none were collected during the two-year Study. Ichthyoplankton samples largely consisted of post yolk -sac larvae, with fewer eggs or yolk -sac larvae collected. The 2016 ichthyoplankton samples were dominated by young -of -year (50.5 percent) and post yolk -sac larvae (48 percent); however, the young -of -year density in 2016 was primarily the result of the collection of Inland Silverside in a single sample collection event. Eggs and yolk -sac larvae comprised no more than one percent of the collection. The 2017 ichthyoplankton samples were dominated by post yolk -sac larvae, which accounted for over 98 percent of entrained organisms, followed by yolk -sac larvae (2 percent). Eggs and young -of -year comprised no more than one percent of the collection. Ichthyoplankton were collected during all four diel periods with the highest densities occurring at night and morning periods, and the lowest densities during daytime samples for both years of sampling. These patterns are consistent with prior studies (Mehner 2012) that documented similar patterns, attributing them to diel vertical migration in response to changes in light intensity, temperature, pressure, food resources, or predators. The primary period of entrainment in both years occurred from March to August, with peak densities in 2016 occurring in May and June (April and May when excluding Inland Silverside), and with 2017 peak densities occurring in April and May. Ichthyoplankton samples were generally dominated by post yolk -sac larvae of clupeid species (with the exception of Inland Silverside young -of -year in 2016). White Perch post yolk -sac larvae also contributed to peak densities during April and May. Average monthly ichthyoplankton densities were low for the remaining months in both years, with few organisms collected from July to September, and no organisms collected in October. At the maximum potential cooling water intake withdrawal volumes (based on design pump capacities), the estimated total annual entrainment varied from 506.7 million ichthyoplankton in 2016 to 478.4 million ichthyoplankton in 2017. The annual entrainment estimates based on 2016 and 2017 actual water withdrawals varied from 476.7 million ichthyoplankton in 2016 to 374.7 million ichthyoplankton in 2017. The period of peak entrainment at the McGuire CWIS is primarily from April to May, which is followed by a sharp decline through August and drops to near -zero in September and October. The two -to -three-month spring period of entrainment observed in Lake Norman is typical of reservoirs located in the southeastern U.S. (EPRI 2011). Based on the results of this Study, post yolk -sac larvae of White Perch and species of the Clupeidae family are most susceptible to entrainment at the McGuire CWIS. Other than White Perch, few recreational species were entrained. Clupeids are prolific broadcast spawners, which results in eggs and larvae more susceptible to entrainment as compared to species that build and guard nests, such as centrarchids (USEPA 2001, Stone 2008; Rohde et al. 2009). Because of the high fecundity of clupeid species and more suitable spawning habitat outside of the influence of the intake structure, losses do not have measurable effect on clupeid standing stocks. Data from ongoing annual monitoring of Lake Norman demonstrates a healthy forage fish base supportive of predatory species such as temperate and warm water basses (Duke Energy 2017). Duke Energy 180 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� Comprehensive Technical Feasibility and Cost Evaluation Study [§122.21(r)(10)] r 10 Comprehensive Technical Feasibility and Cost Evaluation Study [§122.21(r)(10)] The information required to be submitted per §122.21(r)(10), Comprehensive Technical Feasibility and Cost Evaluation Study, is outlined as follows: The owner or operator of an existing facility that withdraws greater than 125 MGD AIF must develop for submission to the Director an engineering study of the technical feasibility and incremental costs of candidate entrainment control technologies. &122.21(r)(10)(i): Technical feasibility. An evaluation of the technical feasibility of closed -cycle recirculating systems as defined at 40 CFR §125.92(c), fine -mesh screens with a mesh size of 2 millimeters or smaller, and water reuse or alternate sources of cooling water. In addition, this study must include: (A) A description of all technologies and operational measures considered (including alternative designs of closed -cycle recirculating systems such as natural draft cooling towers, mechanical draft cooling towers, hybrid designs, and compact or multi -cell arrangements); (8) A discussion of land availability, including an evaluation of adjacent land and acres potentially available due to generating unit retirements, production unit retirements, other buildings and equipment retirements, and potential for repurposing of areas devoted to ponds, coal piles, rail yards, transmission yards, and parking lots; (C) A discussion of available sources of process water, grey water, waste water, reclaimed water, or other waters of appropriate quantity and quality for use as some or all of the cooling water needs of the facility; and (D) Documentation of factors other than cost that may make a candidate technology impractical or infeasible for further evaluation. 122.21(r)(10)(ii): Other entrainment control technologies. An evaluation of additional technologies for reducing entrainment may be required by the Director. 122.21 NO 0)(iii): Cost evaluations. The study must include engineering cost estimates of all technologies considered in paragraphs (r)(10)(i) and (ii) of this section. Facility costs must also be adjusted to estimate social costs. All costs must be presented as the net present value (NPV) and the corresponding annual value. Costs must be clearly labeled as compliance costs or social costs. The applicant must separately discuss facility level compliance costs and social costs, and provide documentation as follows: (A) Compliance costs are calculated as after-tax, while social costs are calculated as pre-tax. Compliance costs include the facility's administrative costs, including costs of permit application, while the social cost adjustment includes the Director's administrative costs. Any outages, Duke Energy 181 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� Comprehensive Technical Feasibility and Cost Evaluation Study [§122.21(r)(10)] r downtime, or other impacts to facility net revenue, are included in compliance costs, while only that portion of lost net revenue that does not accrue to other producers can be included in social costs. Social costs must also be discounted using social discount rates of 3 percent and 7 percent. Assumptions regarding depreciation schedules, tax rates, interest rates, discount rates and related assumptions must be identified, (B) Costs and explanation of any additional facility modifications necessary to support construction and operation of technologies considered in paragraphs (r)(10)(i) and (ii) of this section, including but not limited to relocation of existing buildings or equipment, reinforcement or upgrading of existing equipment, and additional construction and operating permits. Assumptions regarding depreciation schedules, interest rates, discount rates, useful life of the technology considered, and any related assumptions must be identified, and (C) Costs and explanation for addressing any non -water quality environmental and other impacts identified in paragraph (r)(12) of this section. The cost evaluation must include a discussion of all reasonable attempts to mitigate each of these impacts. Each of these requirements is addressed in the following subsections. 10.1 Approach to Feasibility and Cost Evaluation 10.1.1 Approach for Feasibility Evaluation An evaluation of potential entrainment reduction technologies for McGuire was performed to identify those that are feasible and practicable to address requirements of §122.21(r)(10). The evaluation included the potential siting location for reduction technologies with the goal of identifying locations that would pose a minimal impact on station operations and the community surrounding the station. The evaluations have attempted to specify a system for each technology that: (1) does not impact nuclear safety; (2) overcomes clear operational problems (e.g., does not result in unacceptable intake velocities; does not exceed the pressure specification of the condensers; accounts for obvious constraints on discharge of cooling tower blowdown); (3) minimizes the facility -level costs to the extent practicable; and (4) minimizes impact to McGuire's operational reliability. 10.1.2 Assumptions and Cost Basis This technology and cost evaluation was performed to meet the requirements of §122.21(r)(10) of the Rule, with costs based on a 10 to 15 percent design to enable an Association for the Advancement of Cost Engineering (AACE) Class 4 estimate to facilitate a BTA determination. As such, a detailed design has not been developed and is not required for any of the entrainment reduction technologies evaluated for feasibility and cost at McGuire. A conceptual configuration and location was identified for each of the entrainment reduction technologies for use in developing approximate costs of installation and operation, as well as identifying constraints on installation and operation that would affect estimated costs and feasibility. While the assumptions and approach for this evaluation is appropriate for addressing compliance requirements of §122.21(r)(10) of the Rule, Duke Energy 182 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� Comprehensive Technical Feasibility and Cost Evaluation Study [§122.21(r)(10)] r the potential exists for extenuating or exigent circumstances (e.g., subsurface problems during construction activities) that have not been identified by this process. A more complete design process could result in higher facility costs and/or identify constraints resulting in lower feasibility Further, a detailed design process would be required before the installation of any one of the potential technologies or measures described in this evaluation. Retrofitting a nuclear station presents different challenges than constructing a new facility. Maintaining safe plant conditions is paramount during a retrofit. The Rule (§125.94[f]) states that if compliance with the Rule conflicts with the safety requirements established by the USNRC, the Director must make a site -specific determination that would resolve the conflict with such safety requirements. The retrofit therefore attempts to avoid interfering with or modifying the station's nuclear safety system or modifying the nuclear safety water intake structure. Modifications to the station would need to be approved by the USNRC. Tie-ins to the station or other modifications to the cooling system invariably increase downtime and associated costs. Therefore, this evaluation considers scenarios where much of the hypothetical construction work would be carried out without disrupting McGuire operations to the extent practicable and, after the majority of the new construction is complete, perform the tie-ins and invasive construction steps. This tradeoff is considered in the following subsections. 10.1.2.1 Facility Cost Estimation The engineering evaluation presented herein aims to develop a Class 4 cost estimate as defined by AACE and illustrated in Table 10-1. A Class 4 estimate suggests between 1 and 15 percent design of the system and is meant to assess the feasibility of a project (which is also the goal of the §122.21(r)(10) engineering evaluation). A Class 4 estimate does not need to assess all costs in detail; parametric estimates that apply to the system are acceptable. Such an estimate is expected to be accurate to between -15 and -30 percent on the lower end to between 20 and 50 percent on the upper end. Additional information about cost estimating accuracy may be found at AACE (2016). Duke Energy 183 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� Comprehensive Technical Feasibility and Cost Evaluation Study [§122.21(r)(10)] r Table 10-1. AACE Costing Categories (AACE 2016) Primary Characteristic Secondary Characteristic LEVEL OF EXPECTED PREPARATION PROJECT DEFINITION ENO USAGE METHODOLOGY ACCURACY RANGE EFFORT Typical degree of ESTIMATE Expressed as % of Typical purpose of Typical estimating Typical variation in effort relative to least CLASS complete definition estimate method low and high cost index of 1 ranges Capacity Factored, Parametric Models, L: -20% to -50% Class 5 0%to 2% Concept Screening Judgment, or H: +30% to+100% 1 Analogy Equipment Factored or L: -15% to-30% Class 4 1 % to 15% Study or Feasibility Parametric Models H: +20% to+50% 2 to 4 Budget, Semi -Detailed Unit Authorization, or Costs with L: -10% to-20% Class 3 10% to 40% Control Assembly Level H: +10% to +30% 3 to 10 Line Items Detailed Unit Cost Control or Bid/ with Forced L: -5% to -15% Class 2 30% to 70% Tender Detailed Take -Off H: +5% to+20% 4 to 20 Detailed Unit Cost Check Estimate or with Detailed Take- L: -3% to-10% Class 1 50% to 100% Bid/Tender off H: +3% to+15% 5 to 100 Duke Energy 184 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� Comprehensive Technical Feasibility and Cost Evaluation Study [§122.21(r)(10)] r 10.1.2.2 Components Included in Technology Cost Estimates The engineering cost estimate for each feasible/practical entrainment reduction technology includes the following cost elements: (i) Capital and operation and maintenance (O&M) costs"; (ii) Owner's administrative costs; (iii) Facility downtime costs; and (iv) Mitigation costs associated with non -water quality impacts (discussed in Section 12). Capital Costs include (as applicable): 1. Key components based on site -specific conditions such as: • Equipment; • Installation; • Foundation costs, including piles (depending on subsurface conditions); • Key electrical equipment; and • Earth moving (assuming non -hazardous). 2. Parametric estimates for: • Pumps; • Pipelines; and • Conduits and pipes. 3. Lump sum placeholders for: • Permits; • Valves; • Signage; • Costs for modifying, restoring, or relocating infrastructure impacted by the installation of the entrainment reduction technology (e.g., parking lots); O&M costs include (as applicable): • Labor; • Electricity34; • Chemicals; • Maintenance and repair costs; and • Solids removal. 33 The Rule requires that additional taxes that may be paid by the owner be included in the owner's costs. Duke Energy is exempt from paying sales tax on equipment and services. The Duke Energy Power System Model incorporates asset depreciation and potential tax savings that Duke Energy could gain. Therefore, taxes are not explicitly incorporated into this evaluation. 34 This evaluation assesses the increase or decrease in energy usage but does not assign the cost of electricity, which the Duke Energy Power System Model estimates. This evaluation assigns costs for other O&M categories (where applicable). Duke Energy 185 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� Comprehensive Technical Feasibility and Cost Evaluation Study [§122.21(r)(10)] r Owner's Administrative Costs: Owner's administrative costs include effort to plan and manage the project; the cost to prepare a design change package and assess consistency with the existing station design; coordination with regulators and contractors, etc. This evaluation assumed that the Owner's administrative costs would be approximately 10 percent of the total project costs, distributed proportional to each year's project spending. Facility Downtime Costs: This engineering evaluation estimates the potential downtime associated with each technology implementation. Associated costs were developed by the Duke Energy Power Systems Model; therefore, this evaluation does not include downtime -related costs. Mitigation Costs Associated with Non -Water Quality: Potential mitigation measures are presented in Section 12 of this document, and are quantified where appropriate and feasible. 10.1.2.3 Remaining Life of the Station The remaining life of each generating unit and technology impacts O&M costs, potential future technology repair costs (if the life of the unit is longer than the anticipated life of the technology), and the benefits. Operating licenses for both McGuire units are due to expire in June 2041 for Unit 1 and in March 2043 for Unit 2 (USNRC 2002). A potential second license renewal could extend the station's life by another 20 years, but for the purposes of this evaluation, McGuire generating units are assumed to operate through June 2041 and March 2043. If the original entrainment reduction technology is in good operating order at that time, it is assumed that the technology would be retired (no salvage value has been evaluated). If the anticipated life of the technology is shorter than the anticipated life of the units, this evaluation assumes that the technology would be repaired or rebuilt and made available to service the generating units through June 2041 and March 2043, respectively, for Unit 1 and Unit 2. 10.2 Technical Feasibility 10.2.1 Technologies and Operational Measures Considered The objective of this evaluation is to assess and describe measures that may reduce entrainment rates at the McGuire CWIS. The Rule requires that three technologies be considered at each relevant facility and these include; (1) retrofitting the existing once -through system to closed -cycle cooling, (2) installing and operating FMS, and (3) reusing water and/or securing alternative water supplies. In addition to these three technologies, the Rule at §122.21(r)(10)(ii) indicates that the Director may require consideration of additional technologies to reduce entrainment. A cursory assessment of aquatic filter barriers35, porous dikes, and variable speed pumps36 indicated that 35 The small pore sizes associated with filter barriers and porous dikes would necessitate a long barrier which would enclose a large portion of the Lake. This would lead to entrapment. 36 McGuire is a base load nuclear station, therefore generation does not fluctuate to allow load -following and flow reduction. During cooler months one or more pumps are turned off. Duke Energy 186 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Comprehensive Technical Feasibility and Cost Evaluation Study [§122.21(r)(10)] r these technologies are infeasible and impractical at McGuire; therefore, they are not discussed or evaluated in this document. Measures and technologies that are focused exclusively on impingement mortality reduction are addressed in Section 6 of this document. 10.3 Closed -cycle Recirculating Systems The Rule requires that the CCRS evaluation consider the retrofit of the non -contact cooling water system with various types of cooling towers. The suitability of a specific cooling tower type depends on a station's condenser design, local atmospheric conditions, site topography, site layout, operating constraints, and a host of other site -specific criteria. Additionally, different cooling towers have different operating criteria. The evaluation, therefore, needs to match the operating criteria and constraints with conditions at the site. This section begins by describing site conditions and constraints, the existing cooling water system, and how it may or may not be retrofitted. The remainder of Section 10.3 describes cooling tower principles, constraints associated with various cooling tower types, compares the suitability of each cooling tower type to site conditions, and selects the cooling tower type that may be suitable (or least unsuitable) to be used for the remainder of the evaluation. The cost evaluation presented here and the impacts evaluation under §122.21(r)(12), provided in Section 12, are based on that selection. 10.3.1 Description of Existing Cooling System The existing cooling water structure and cooling water system at McGuire are described in detail in Section 3 and Section 5 of this document, respectively. Relevant portions of the cooling water system with respect to CCRS are described herein. McGuire is bounded by residential development to the east, NC Highway 73 to the south, the Catawba River and Cowans Ford Dam to the west, and Lake Norman to the north. The station's SNSWP is located southeast of the station and north of NC Highway 73. The area of the SNSWP is approximately 34.9 acres and in the unlikely event that Lake Norman becomes unavailable, the SNSWP is designed to provide cooling water for the safe shutdown of McGuire (Duke Energy 2014a). All water for McGuire is withdrawn from Lake Norman through a dual intake system (i.e., Main Intake and LLI). These two systems supply water to the Main Condenser Cooling Water (RC), Conventional Low -Pressure Service Water (RL), Nuclear Service Water (RN), Fire Protection System (RF/RY), and Containment Ventilation Cooling Water System (RV) (Duke Energy 2009). 10.3.1.1 The Main Intake The Main Intake provides water to McGuire's electric power generating units with four RC pumps per unit. Each pump has a design rating of 254,000 gallons per minute (gpm) per pump at 23 feet (ft) of total head. The pumps are located approximately 16.7 ft downstream of the traveling water screen in the Main Intake. See Section 10.4.1 for additional information about the CWIS. 10.3.1.2 The Low Level Intake The LLI was originally built with six LLI pumps, each with a capacity of 150,000 gpm, and is located along the downstream slope of the embankment between Cowans Ford Dam and McGuire (Duke Energy 2009). The Unit 2 LLI pumps have been retired; therefore, only three LLI pumps are currently operational for Unit 1 and the SNSWP (Duke Energy 2014a). Duke Energy 187 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� Comprehensive Technical Feasibility and Cost Evaluation Study [§122.21(r)(10)] r During times of high surface water temperatures in the lake, the LLI pumps can pump cooler water from the hypolimnion37 of Lake Norman to cool the warmer water in the Main Intake (Duke Energy 2009). In recent times, the LLI pumps have typically been operated one to five weeks per year for thermal compliance (usually in the summer: June, July, August, and September). When operated, typically only two of the three pumps are used (see Section 5.2). LLI water is piped to the surface and discharged between the trash racks and traveling screens of the Main Intake (i.e., there is no direct piping connection between the LLI pumps and the RC pumps) (HDR 2015). In addition to the 150,000 gpm LLI pumps, four RN pumps, each at 17,500 gpm capacity, withdraw water from the LLI. Under normal operating conditions, two RN pumps are typically used which pipe water from the LLI to McGuire for filtration and use within the station. RN water may also be withdrawn from the SNSWP. The piping configuration also allows for the LLI to provide water to the SNSWP either through gravity alignment or use of the RN pumps (Duke Energy 2019). Considering that (1) the LLI pumps are operated infrequently, (2) the RN pumps primarily withdraw water from the LLI with a TSV of less than 0.5 fps, (3) the depth of the structure is between approximately 90 ft to 110 ft below the normal water elevation, and (4) the LLI structure is close to the Cowans Ford Dam making technology retrofits difficult, this evaluation does not attempt to modify the LLI or convert flows associated with the LLI to closed -cycle mode. 10.3.1.3 DIF and AIF As discussed under §122.21(r)(5), the McGuire DIF is 2,969 MGD and AIF is 2,708 MGD. 10.3.1.4 Flow Rates used in the Evaluation The two McGuire condensers are identical. Each condenser is rated for 959,602 gpm or 1,382 MGD. The hypothetical cooling tower evaluation uses the condenser flow rate, while the screen evaluation in Section 10.4 uses DIF. 10.3.2 Cooling Tower Principles The primary method used to dissipate waste heat rejected from a closed -cycle cooling water system is through a cooling tower. Once -through cooling systems can hypothetically be retrofitted with a variety of cooling tower designs. The designs are grouped based on factors influencing the type of design, including: • Method of heat transfer — wet, dry, or combination wet and dry heat transfer; • Method of air flow — natural draft, mechanical forced draft, mechanical induced draft; • Direction of air flow — counter -flow or cross -flow; and • Shape and Arrangement — rectilinear (i.e., in -line or back-to-back) or round. These factors have the greatest impact on the cooling tower size and operation, which subsequently influence environmental and social impacts. The method of heat transfer is perhaps the most 37 In a thermally -stratified lake, the hypolimnion layer is the dense layer below the surface epilimnion. Duke Energy 188 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Comprehensive Technical Feasibility and Cost Evaluation Study [§122.21(r)(10)] r important factor in determining the type of cooling tower. The different types of cooling towers are described in Section 10.3.4. 10.3.2.1 Method of Heat Transfer The cooling tower acts as a mechanism to transfer the waste heat38 from the water to the atmosphere. Heat transfer to the atmosphere can be carried out through one of three methods: • Latent heat transfer, which is associated with the phase changes of water, such as evaporation; • Sensible heat transfer, which is associated with the incremental change in temperature of a medium, such as air in the atmosphere; or • A combination of both latent heat transfer and sensible heat transfer. Cooling towers that employ a combination of sensible and latent heat transfers are evaporative -type towers and are typically referred to as wet cooling towers. Cooling towers that employ only sensible heat transfer utilize a dry -surface, finned -tube heat exchanger that transfers heat to the atmosphere; these towers are typically referred to as dry towers. Similar to wet cooling towers, once -through cooling systems typically employ a combination of both heat transfer methods; heated water from the once -through system is discharged to a receiving waterbody, which is heated through sensible heat transfer. Latent heat transfer then drives evaporation of a small portion of the waterbody to the atmosphere for further cooling. Sensible heat transfer also occurs from the waterbody to the air but the cooling provided by sensible heat transfer is smaller than the cooling provided by latent heat transfer. 10.3.2.2 Method of Air Flow Air flow through the cooling tower is critical to facilitate both latent and sensible heat transfer. In the absence of air exchange, if hot water continues to be introduced, natural drafting will still occur and the tower will cool the range, albeit at a very high approach. The method of air flow can be either natural draft, mechanical forced draft, or mechanical induced draft. With respect to natural draft cooling towers (NDCT), the hyperboloid shape has been shown to improve performance; the density differential between the heated, less dense air inside the cooling tower and the cooler, denser air outside the cooling tower produces air flow through the tower (SPX 2009). Mechanical, forced draft cooling towers have a fan located on the ambient air intake and blow air through the tower. Forced draft towers typically have high entrance velocities and low exhaust velocities; therefore, they are susceptible to recirculation (SPX 2009). Recirculation occurs when the exhaust is drawn back into the intake, increasing the ambient air wet -bulb temperature and decreasing the performance of the cooling tower (SPX 2009). 38 Heat energy is utilized in the generation of electricity; heat energy that is not converted to electricity is removed to cooling water within the condensers. Duke Energy 189 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� Comprehensive Technical Feasibility and Cost Evaluation Study [§122.21(r)(10)] r Mechanical, induced draft cooling towers have a fan located on the exhaust side and draw air in through the tower. Induced draft towers can have an exhaust velocity of three to four times the entrance velocity, meaning there is little tendency for self -initiating recirculation (SPX 2009). 10.3.2.3 Direction of Air Flow Air flow through the towers can be either counter -flow or cross -flow. In counter -flow towers, air moves vertically through the tower fi1139, counter to the downward cascade of water (SPX 2009). In a cross -flow tower, the fill's configuration is such that the air flows horizontally across the downward cascading water (SPX 2009). In all types, the ambient air enters from the side and is exhausted through the top of the tower; the portion of water that evaporates into the air stream cools the remainder of the water (EPRI 2011). 10.3.2.4 Shape and Arrangement Cooling towers can also be characterized by their shape and arrangement. While all NDCTs are round, a mechanical draft cooling tower (MDCT) is usually comprised of multiple rectangular cells; however, the cells can be arranged in a rectilinear or round fashion. In a rectilinear arrangement, the cells can be aligned in a single row (i.e., in -line) or in a double row (i.e., back-to-back) (EPRI 2011). In a rectilinear arrangement, evaporative cooling towers should be arranged parallel to prevailing wind patterns (SPX 2009). The cells can also be arranged in a round configuration, where they are clustered as closely as possible to the center point of the tower. There is also an alternate version of round towers where the cells are arranged in an octagonal arrangement, allowing for larger heat loads that impact less area, compared to rectilinear towers (SPX 2009). 10.3.3 Cooling Tower Terminology Cooling towers are chosen based on factors that affect their performance. The atmosphere has various psychrometric properties40 and cooling towers react thermally or physically to each property (SPX 2009). Similarly, properties of the power plant and cooling towers also affect cooling tower performance and sizing. Some properties, such as heat load, are more significant than others. The following is a discussion of some key terms with an emphasis on those relevant to evaporative MDCTs. 10.3.3.1 Heat Load Heat load is the total amount of heat removed from the circulating water by the cooling tower and is a function of the mass flow rate of water entering the cooling tower and the cooling tower range (EPRI 2011; SPX 2009). The heat load is designed to dissipate heat from condensation of steam generated in the steam cycle. The heat load can be related to the approach and range. 39 Fill is an important component of cooling towers because it aids in performance of the tower through maximizing contact surface and contact time between air and water while providing the least amount of restriction of air flow (SPX 2009). 40 Psychrometrics is the study of physical and thermodynamic properties of gas -vapor mixtures. Typical psychrometric parameters include dry-bulb, wet -bulb, and dew point temperatures. Duke Energy 190 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Comprehensive Technical Feasibility and Cost Evaluation Study [§122.21(r)(10)] r 10.3.3.2 Range The range is the difference between the hot water temperature entering the cooling tower and the cold water temperature exiting the cooling tower. The cooling tower range is equivalent to the temperature rise across the station's condensers, commonly referred to as the delta T (AT) or temperature differential. The size and subsequent cost of a cooling tower is proportional to the heat load and the cooling tower range (SPX 2009). The range is shown graphically on Figure 10-1. Condenser Cooling Tower Hot water Hot Water Condenser Temperature Rise u 3 4 l Cool Ing Tower Range r Catd WaWr TernperMe Cold Water T Cooling rower Approach Ambient wet bulb temperature Figure 10-1. Condenser and Cooling Tower Water Temperature Relationship 10.3.3.3 Approach Another factor that is part of the basis for thermal design and performance of a wet cooling tower is the approach. The approach is the difference between the cold water temperature exiting the cooling tower and the ambient air wet -bulb temperature41 entering the tower. Cooling tower performance and size are inversely proportional to the approach. When varying cooling tower size, the approach starts to become asymptotic near 5°F. Approach temperatures of less than 5°F are typically not guaranteed, because errors in measurement of performance are significant (SPX 2009). An approach temperature of 10°F was selected at McGuire because this value represents a high performance cooling tower system, and is common in preliminary cooling tower design. 10.3.3.4 Drift A portion of the circulating water in the cooling tower is lost42 due to drift, evaporation, and blowdown. Drift occurs when circulating water is lost from the tower as liquid droplets are entrained in the exhaust air stream (EPRI 2011). In order to reduce the amount of water lost, drift eliminators 41 Wet -bulb temperature is the temperature of air if it were cooled to 100 percent relative humidity (i.e., saturation) by evaporation of water into it through latent heat transfer. 42 Basin leaks and overflows can also result in water lost from the system when the towers are not properly operated. Duke Energy 191 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� Comprehensive Technical Feasibility and Cost Evaluation Study [§122.21(r)(10)] r can control the loss of water to as low as 0.0005 percent of the circulating water flow rate and are always installed in wet cooling towers (EPRI 2011). 10.3.3.5 Evaporation Water is also lost due to evaporation, which is the primary method of removing the waste heat from the circulating water. Cooling towers operate on the principle of transferring heat from a large quantity of water to a small quantity of water. The portion of water absorbing heat evaporates; the evaporation of a small amount of the circulating water cools the remainder. 10.3.3.6 Blowdown A portion of the water that circulates between condensers and cooling towers is removed from the system to prevent the build-up of solids and minerals to concentrations high enough to cause corrosion and scaling of various cooling system components. This is called blowdown. The higher the cycle of concentration (COC), the lower the blowdown rate — see the following discussion of cycles of concentration. Blowdown discharged to a receiving waterbody that is classified as WOTUS is permitted by the station's NPDES permit. Operating at high levels of total dissolved solids (TDS) with the continued evaporation of water can cause the impurities to reach saturation levels which may produce scale and precipitate, lead to corrosion problems, and can increase operation and maintenance costs (USDOE 2016; USEPA 2014). 10.3.3.7 Cycles of Concentration As water is evaporated from the tower, dissolved solids remain in the circulating water, and the concentration of dissolved solids continues to increase as the process continues (USDOE 2016). Cooling towers are designed to operate within a particular COC, which is defined by the United States Environmental Protection Agency (USEPA)43 as "the ratio of dissolved solids in the recirculated water versus that in the make-up water" (USEPA 2014). The COC is controlled through the intentional discharge of water from the system, referred to as blowdown. The USEPA notes that the Rule does not establish fixed requirements for COCs, because it recognizes that unavoidable circumstances could exist where an established COC might not be achievable; one such instance could be that "site -specific circumstances could include situations where water quality -based discharge limits might limit the concentration of a pollutant that is not readily treatable in the cooling tower blowdown..." Water quality parameters whose discharge would be constrained by the NPDES permit due to limitations in the receiving waters should be considered prior to COC determination. 10.3.3.8 Make -Up Water Circulating water that is lost from the system due to evaporation, drift, and blowdown is replaced with make-up water. Make-up water is typically withdrawn from the source waterbody through the CWIS. 43 The USEPA also indicates that, when data is available, COC can be estimated as the "ratio of the measured parameter for the cooling tower water such as conductivity, calcium, chlorides, or phosphate, to the measured parameter for the make-up water" (USEPA 2014). Duke Energy 192 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� Comprehensive Technical Feasibility and Cost Evaluation Study [§122.21(r)(10)] r 10.3.4 Review of Candidate Approaches Based on an initial evaluation of standard MDCTs, NDCTs, cooling towers with plume -abatement (i.e., hybrid cooling systems), and dry cooling systems, as described below, standard MDCTs were selected for more detailed evaluations in subsequent sections. NDCTs and dry cooling systems were found to be incompatible with the station. These two types of cooling systems would also result in higher facility costs that would very likely result in higher social costs compared to MDCTs. The following sections provide greater detail on the various cooling tower types considered, the applicability of each at McGuire, and why standard MDCTs are the preferred alternative. 10.3.4.1 Mechanical Draft Cooling Towers Description MDCTs are comprised of multiple rectangular cells, arranged in a rectilinear or round fashion. MDCTs either induce or force air through the tower, and can be susceptible to recirculation and interference from other towers (SPX 2009). MDCTs are more fully discussed later in this section. Feasibility The feasibility of MDCTs depends on design and siting, environmental, and overall station impacts. The footprint of an MDCT can be larger or smaller than other towers, but in most cases, the footprint will require a relatively flat, rectangular area. MDCTs and NDCTs have similar cooling performance (SPX 2016a). MDCTs use fans to move air through the towers, so they do not rely on a density differential that NDCTs rely on for cooling. MDCTs can be significantly shorter than NDCTs (up to 10 times), and because their air flow is mechanically forced, they can be designed with a lower cooling tower approach temperature than NDCTs. General environmental impacts include particulate matter (PM) emissions, increased water consumption, and increased residual waste generation. MDCTs produce noise from the use of fans and related appurtenances in addition to the noise from cascading water. Because of the lower height of the towers, there is a higher potential for local fogging and icing due to the plume. MDCTs tend to have the lowest capital costs of all cooling tower types, but the operating costs can be greater than other tower types. Nuclear power stations are base load generators typically with long lifespans. The smaller capital and larger operating costs of MDCTs tend to be more expensive over the life of the station compared to NDCTs, when they are feasible. A hypothetical design and the feasibility of installing MDCTs are discussed in later sections. 10.3.4.2 Natural Draft Cooling Towers Description NDCTs are wet cooling towers and typically have a hyperboloid shape. The hyperboloid shape has been found to improve performance (EPRI 2011). Similar to MDCTs, water flows downward through fill material contacting air in either a counter -flow or cross -flow pattern. The advantage of a natural Duke Energy 193 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� Comprehensive Technical Feasibility and Cost Evaluation Study [§122.21(r)(10)] r draft unit is that the power required for fans is eliminated44. Because these are very tall structures (up to 600 ft in height) ice and fogging impacts (if any) are not generally experienced within the immediate surroundings; however, these impacts are dependent upon the meteorological conditions of the site (CTI 2003). Feasibility The feasibility of NDCT technology depends on design and siting, environmental, and station impacts. With respect to design and siting, compared to MDCTs, the footprint area of NDCTs can be larger or smaller, but in all cases, the footprint will require a relatively flat and extensive land area. The hyperboloid towers are the highest of all tower types and can be greater than 10-times the height of MDCTs; therefore, they could pose potential adverse aesthetic impacts on the viewscape. NDCTs are similar to MDCTs regarding cooling performance; however, NDCTs are only suitable when high cooling tower ranges and approach temperatures are consistent with the existing condenser(s) (SPX 2016a). NDCTs do not have fans to force/move air through them, instead the density differential induced by the temperature differential causes air to move upward. When the cooling tower range is large, the density differential is easily induced. When the cooling tower range is small, a taller cooling tower is needed to help induce an adequate density differential to cause air to move up through the tower. Additionally, the performance of evaporative cooling towers is dependent on the ambient wet bulb temperature. The approach is the difference between cold water temperature and the ambient wet bulb temperature. Environmental impacts are generally similar between MDCTs and NDCTs for PM emissions, water consumption, and residual waste. While there is no fan noise related to NDCTs, the water noise due to cascading water can be significant. Due to the height of the tower, there is a higher visible plume; however, the fogging and icing issues are reduced compared to MDCTs. While operating costs for NDCTs are usually lower than MDCTs, capital costs for NDCTs can be significantly greater, with approximate capital costs ranging from one -and -a -half to two times the cost of MDCTs. Due to the combination of the small cooling tower approach of 10°F and cooling tower range of 16°F (see 10.3.6.1 for more information), SPX Cooling Technologies, Inc. (SPX) (SPX 2016c) determined that the height of NDCTs needed at McGuire would be taller than the maximum height (of 600 ft) typically designed/constructed and that NDCTs are infeasible from technical perspective at McGuire. While a condenser retrofit in tandem with an NDCT retrofit could reduce the size of the cooling tower, a condenser retrofit has been found to be infeasible. The feasibility of a condenser replacement is discussed later in this section (Section 10.3.4.6). 44 per SPX (2016b), the wet deck (or top of fill) of a NDCT is at approximately the same height as for MDCTs; therefore, the energy requirements with respect to pumps is assumed to be similar. Duke Energy 194 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Comprehensive Technical Feasibility and Cost Evaluation Study [§122.21(r)(10)] r 10.3.4.3 Plume -Abated Cooling Towers Description Plume -abatement can be grouped into two major groups: those that add heat to the plume above the wet deck of the cooling tower and those that do not add heat. Cooling towers with plume -abatement that adds heat above the wet section of the cooling tower are called hybrid towers. The wet portion of a hybrid tower can be similar to a MDCT or NDCT (assuming the system meets the necessary criteria for that type of tower) (SPX 2009). A set of coils or finned -tubes are located above the wet portion to add heat/warmth to the near -saturated air leaving the tower to help reduce/eliminate the visible plume. In the mechanical hybrid tower, the dry portion is typically installed below the fan (like the configuration shown on Figure 10-2) and is called a Parallel Path Wet/Dry Cooling Tower (CTI 2010). Figure 10-2. Cross -Section Schematic of a Parallel Path Wet/Dry Cooling Tower (CTI 2010) Cooling towers with plume -abatement technology installed do not need to be operated in plume - abated mode at all times. They may be operated in plume -abated mode when needed (typically during cooler months when the visible plume is more likely), and operated in wet -only mode during other times of the year to save energy. For hybrid towers, the hot water from the condenser may be used as the heat source. When operated in the hybrid mode with hot water from condensers as the heat source for the dry portion, water enters the tower at the top of the dry portion where sensible heat transfer lowers the Duke Energy 195 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� Comprehensive Technical Feasibility and Cost Evaluation Study [§122.21(r)(10)] r temperature of the circulating water while raising the temperature of the air leaving the tower (thereby eliminating the visible plume); the slightly cooled circulating water then cascades down to the evaporative portion of the cooling tower where water is further cooled through latent heat transfer (EPRI 2011). No contact is made between the air and water in the dry portion of the tower; however, there is contact between air and water in the lower, wet portion of the tower (EPRI 2011). Feasibility Cooling towers with plume -abatement technology are typically used in areas where the plume may have an adverse impact on the area, including safety -concerns owing to fogging or icing or for areas where long-range visibility is needed, such as near airports. Plume -abated towers have a larger base (compared to non -plume -abated towers) and a height of approximately one -and -a -half times that of standard MDCTs. Hybrid towers have lower performance, a lower summer output, and a higher energy penalty compared to standard MDCTs (SPX 2016a). With the exception of fan noise and a plume, most environmental impacts associated with plume - abated towers are similar to non -plume -abated towers. Plume -abated towers can be operated in plume -abated mode by actuating the air cooled portion of the tower, and when operated as such, there is usually a minimal to no visible plume. There is greater fan noise with the use of hybrid towers. Cooling towers with plume -abatement are technically feasible at McGuire, but are not advanced further in this assessment for several reasons. The capital cost of a tower with plume -abatement is greater due to the increased footprint, height, and auxiliary equipment (EPRI 2011). Operating costs are also greater because plume -abated towers have a larger power loss due to lower performance and greater auxiliary energy requirements. Given the space constraints and topography at the McGuire site, it would be even more challenging to locate and construct a larger tower (compared to a non -plume -abated tower). And, plume -abatement technology is likely not necessary as McGuire is not situated adjacent to a major roadway or airport. 10.3.4.4 Dry Cooling Description There are two key dry cooling methods: direct dry cooling and indirect dry cooling. Dry cooling uses only sensible heat transfer and can use ambient air directly or indirectly. With direct dry cooling systems (e.g., air-cooled condensers [ACCs]), a dry -surface, finned -tube heat exchanger provides for the non -evaporative transfer of heat to the atmosphere (SPX 2009). Steam from the turbine is sent directly to the ACC where the steam is condensed inside air-cooled finned tubes; there is no steam surface condenser and there is no contact between the ambient air and the steam and condensate. An ACC can be up to two to three -times the height of MDCTs. Figure 10-3 provides an aerial photograph of an ACC. Duke Energy 196 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� Comprehensive Technical Feasibility and Cost Evaluation Study [§122.21(r)(10)] r Figure 10-3. Aerial Photograph of an Air-cooled Condenser (Direct Dry Cooling) (Enexio 2016) Indirect dry cooling systems use a combination of a dry cooling tower (natural or mechanical draft) with a steam surface condenser. In these cooling towers, the heated water is pumped to heat exchangers arranged vertically around what looks like a standard wet cooling tower. But as shown in Figure 10-4, no water cascades down through the tower; instead, water flows through the bundles of tubes placed around the tower. Air flow through the tower cools the water within the bundles of tubes (SPX 2016c). There is no contact between air and the circulating water (EPRI 2011). Natural Draft Tower i _ f __ _ Cooling Delta with louvers Source: SPX 2016c Source: Enexio 2016 Figure 10-4. Schematic of an Indirect Dry Cooling Tower Duke Energy 197 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� Comprehensive Technical Feasibility and Cost Evaluation Study [§122.21(r)(10)] r Feasibility When designing and siting a dry cooling system, a considerable area of land is required. Dry cooling systems require the largest area of land of all cooling systems because they use only sensible heat transfer .45 Dry cooling systems have the lowest cooling performance and lowest summer output of all cooling systems, which results in the greatest energy penalty (EPRI 2011). Dry cooling systems have a considerable energy requirement to operate the fans. Dry cooling is limited by the dry-bulb temperature, rather than the wet -bulb temperature. Because the dry-bulb temperature is always greater than or equal to the wet -bulb temperature, the resulting cold water temperature is higher compared to wet cooling tower water temperatures. Therefore, the energy penalty with dry cooling is significantly higher than with wet cooling towers. Because dry cooling uses sensible heat transfer, there is no visible plume or related PM emissions, cascading water noise, water consumption, scale, sediment, or sludge accumulation. Dry cooling systems result in the greatest reduction in water use of all systems. However, they result in the highest fan noise and in the largest land footprint, including potential land use impacts. Capital and operating costs for dry cooling systems, especially ACCs, are the highest of all systems. Capital costs can be up to four to six times that of MDCTs. Dry cooling systems are generally not compatible with existing condensers due to unacceptable turbine backpressure (EPRI 2007). For this reason, installation of a dry cooling system typically requires significant redesign and reconstruction of condensers, facility buildings, equipment, and piping. Due to the large energy penalty, a dry cooling system may have impacts on the reliability of the facility and electric transmission distribution system. As a result, a dry cooling system is not technically feasible at McGuire as a retrofit option. 10.3.4.5 Condenser Replacement The previous discussion of cooling tower types (NDCT, MDCT, plume -abated towers, and dry cooling) was based on reuse of the condenser. Such a hypothetical closed -cycle cooling tower retrofit would need to accommodate the existing condenser characteristics such as its pressure rating, backpressure impacts, water flow rate, and temperature rise. A power plant's condensers and cooling towers need to complement each other; that is, all heat added at the condenser needs to be removed by the cooling tower. The design process for new power plants would include an evaluation of the cooling tower and condenser in tandem to achieve optimal performance of the system based on site conditions. 45 Wet cooling towers utilize sensible and latent heat to transfer heat from water to air. The latent heat of vaporization for water is 970.3 British thermal units (Btu) per pound mass (Ibm) (Lindeburg 2003). The specific heat of water is 1 Btu/Ibm-°F. That is, it takes 970.3 Btu to evaporate a pound of water, and it takes only 1 Btu to raise the temperature of one pound of water by 1 °F. Wet cooling towers operate by evaporating a small quantify of water and cooling the remaining large quantity of water. The portion that evaporates absorbs energy from the remaining hot water, which then cools. Cooling through evaporation of water using latent heat transfer is more effective than using sensible heat transfer. Duke Energy 198 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� Comprehensive Technical Feasibility and Cost Evaluation Study [§122.21(r)(10)] r However, when retrofitting a power plant with cooling towers, the existing condensers are used as -is to the extent practicable (EPRI 2007). Certain reinforcements to the condenser tubes or waterboxes can facilitate continued use of the existing condensers; however, the design, construction, and age of the existing condensers may not always allow for conversion of an existing once -through system to closed -cycle. Replacing the condensers with new condensers would eliminate those constraints. However, a condenser replacement would result in significant reconstruction at the station, increased outage time (resulting in lower grid reliability), higher cost, and greater disturbance to site and surroundings resulting in greater adverse impacts. Owing to the longer construction outage and greater adverse impacts that would result from condenser replacement to accommodate different types of cooling towers, this option is considered inferior to the MDCT option discussed above and will not be evaluated further. Instead, the current evaluation assumes that the existing condensers would remain in place and that the cooling tower retrofit would conform to the constraints of the condensers. 10.3.4.6 Selected Cooling Tower Type Based on the types of cooling towers discussed in this section, as well as McGuire's condenser design, cooling water piping design, and other site considerations (discussed in Sections 10.3.6 through 10.3.10), NDCTs and dry cooling systems were deemed infeasible and impractical at McGuire and eliminated from further evaluation. Site constraints at McGuire eliminate potential siting locations for plume -abated cooling towers, thus these towers were also deemed impractical and infeasible. MDCTs were selected for further evaluation. The following matrix (Table 10-2) provides a summary comparison of the various cooling tower types using MDCTs as the base case. Duke Energy 199 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal F�� Comprehensive Technical Feasibility and Cost Evaluation Study [§122.21(r)(10)] r Table 10-2. Comparison Matrix of Cooling Tower Types (EPRI 2011, CTI 2003, Maulbetsch and Stallings 2012, EPRI 2002) Footprint Area Height Performance Energy Penalty Compare . IVIDCT Design and Siting Impacts • MDCT cells can be • If NDCTs were feasible at arranged in a modular McGuire, they may have fashion to meet on -site resulted in a smaller footprint space constraints (with than base case limitations) • Large, circular areas required • Base case • Tallest of all towers • Approximately 600 ft-tall towers may be needed to induce the necessary draft • Base case • Similar to base case • Base case Lower than base case with respect to fan requirements • Largest area required, approximately 2 to 4 times the area required for the base case • Taller than base case • Lowest cooling system performance • Lowest summer output • Highest energy consumption; large energy requirement for fans • Cooling limited by dry-bulb temperature rather than wet - bulb temperature; dry-bulb temperature always higher than wet -bulb temperature. Therefore, dry cooling systems have warmest cold water temperature and greatest backpressure energy penalty. • Larger footprint than base case • Rectilinear tracts of flat land required, ideally oriented with prevailing winds • Taller than base case • Less efficient than base case • Higher than base case Duke Energy 1 100 Visible Plume46 • Potential for local fogging or icing PM Emissions • Dependent upon source water total dissolved solids, cycles of concentration, and drift eliminator efficiency Noise Emissions • Fan noise • Cascading water Water Consumption • Significantly reduced water withdrawal rate, but larger evaporation rate, compared to once - through cooling Residual Waste . Dependent upon water and air quality, basin sizing, and use of chemical additives Capital Costs • Base case Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� Comprehensive Technical Feasibility and Cost Evaluation Study [§122.21(r)(10)] r Environmental Impacts • Visible plume at higher elevation • Reduced likelihood for ground level fogging or icing due to height of plume emission • Similar to base case • No fan noise • Greater water noise • Similar to base case • Similar to base case • No visible plume • No fogging or icing • No PM emissions • Greatest fan noise • No water noise • No water consumption • Greatest reduction in water use of alternatives • No scale, sediment, sludge accumulation Station Impacts • Approximately 1.5 to 2 times Highest capital costs, the base case approximately 4 to 6 times 46 Plume abatement technologies available for MDCTs; hybrid cooling towers are typically always plume -abated. • Minimal to no visible plume • Minimal fogging or icing • Potentially reduced PM emissions, dependent upon rate of use of dry portion of tower • Significant fan noise • Similar to base case • Similar to base case • Higher than base case Duke Energy 1 101 Operating Costs • Base case Site -Specific • Challenging due to Applicability limited suitable space availability • Major reconstruction of existing station equipment, buildings, and parking lots • Proximity to Cowans Ford Dam, related dikes, and site topography makes siting of towers difficult Feasibility • Feasible from an engineering perspective • Least expensive cooling alternative Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� Comprehensive Technical Feasibility and Cost Evaluation Study [§122.21(r)(10)] r • Lower than base case • Highest operating costs • Infeasible due to condenser temperature rise and approach temperatures • Large towers may have an adverse visual impact on area • Infeasible due to condenser incompatibility. Range and approach temperatures are smaller than required to facilitate the natural draft in a NDCT • Infeasible • Incompatible with existing condensers • Insufficient suitable space • Impact plant and regional reliability • Infeasible due to real estate requirements and incompatibility with existing condensers • Higher than base case • Similar to base case, except costlier and greater space constraints • May be feasible from an engineering perspective — needs further evaluation • More challenging space requirements • Greater cost and power consumption I Duke Energy 1 102 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� Comprehensive Technical Feasibility and Cost Evaluation Study [§122.21(r)(10)] r 10.3.5 Existing Condensers Steam electric power generation facilities use turbines and condensers to generate electricity. Turbines typically consist of a rotor assembly, which is a shaft or drum with blades attached; steam is generated and moves through the turbine turning the blades and shaft. The rotational energy from the rotor assembly is converted into usable energy to produce electricity47. The exhaust steam from the turbine is then condensed to liquid water for recirculation through the system by use of a condenser, which is a type of heat exchanger. Condensers typically consist of multiple tubes encased in a shell, hence the terminology "shell and tube". Steam flows through the shell and is condensed when passed across tubes, which contain cold water. Tubes may be in a single -pass or multiple -pass arrangement, depending on the design requirements of the condenser. The condensate is then collected where it is reheated to steam and recirculated through the system. A waterbox is located on both sides of the condenser. On the inlet side, the cold water enters and is directed with uniform distribution towards the tube sheet. The tube sheet is a metal sheet with perforations that allow for entry of water into the condenser tubes. On the discharge side, the warmed water is collected in the outlet waterbox and removed from the condenser. In a once - through system, the warmed water is discharged to a receiving waterbody, and in a closed -cycle recirculating cooling system, the warmed water is directed to the cooling towers to be cooled and reused. If a facility is retrofitted to closed -cycle cooling, the waterboxes and condenser would be reconstructed to form a closed -loop circulating system. Reuse of an existing system in closed -cycle system must accommodate the constraints of the existing system. Each main condenser at McGuire serves a six -flow, single -reheat type turbine operating at 1,800 revolutions per minute (rpm) with primary steam conditions of 975 pounds per square inch of absolute pressure (psia) and 541.5°F (Duke Power Company 1971 b). Each unit has a three- shell, parallel flow, single pass condenser with a heat duty rated at 7,676,815.6 x 103 British thermal units (BTU)/hour (Duke Power Company 1971 b). Condenser performance specification is based on a cleanliness factor of 95 percent and they are mechanically cleaned with an Amertap system48 (Duke Power Company 1971 b). 47 The rotor assembly operates in conjunction with an electrical generator. 48 The Amertap system utilizes specially -designed cleaning balls that are injected in the inlet waterbox, move through and clean the condenser tubes, and then are collected in the outlet waterbox or discharge channel. Duke Energy 1 103 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Comprehensive Technical Feasibility and Cost Evaluation Study [§122.21(r)(10)] r The condensers are designed with a circulating water flow rate of 959,602 gpm49 (1,382 MGD) and an inlet design temperature of 60OF (Duke Power Company 1971 b). The water flows through the condenser tubes at approximately 7.0 ft per second (fps) (Duke Power Company 1971 b). The design parameters of the condensers pertinent to the cooling tower feasibility evaluation are summarized in Table 10-3. According to Duke Power Company (1971 b), the various parts of the condensers are welded; these welds are designed to safely hold a maximum pressure differential of 15 pounds per square inch50 (psi) externally or 15 psi internally (steam pressure measured at the centerline of the shell). The condensers can also withstand indefinite successive temperature changes between 32°F and 240°F. Similarly, the waterboxes are designed for 15 psi external pressure and 30 psi internal pressure. Each waterbox is divided into two sections; one section can operate while the other is out -of -service. The waterboxes have 84-inch internal diameter (ID) inlet and outlet cooling water pipe connections (Duke Power Company 1971 b). The intake and discharge cooling water pipes are steel, and different sections of cooling water pipes are rated for internal pressures between 10 and 40 psi and external pressures between 12 and 26.4 psi (Duke Power Company 1971 a). The intake pipes are rated for a temperature variation between 40°F and 79°F, and the discharge pipes are rated for a maximum temperature of 103°F (Duke Power Company 1971 a). The Main Intake piping begins with four 108-inch ID pipes per unit; the 108-inch ID pipes increase to 112-inch ID pipes, which then join to form a 222-inch ID pipe (Duke Power Company 1971 a). This pipe is then reduced to three 132-inch ID pipes, each of which is further reduced to two 84-inch ID pipes (for a total of six 84-inch ID pipes) that are welded to each unit's condenser inlet valves (Duke Power Company 1971 a; Duke Energy 2015a). The discharge pipes from the condensers begin with six 84-inch ID pipes per unit, which then converge into three 132-inch ID pipes per unit, leading to the discharge structures on Lake Norman (Duke Power Company 1971 a; Duke Energy 2015b). The LLI intake pipes begin with three 126-inch ID pipes that each reduce to two 84-inch ID pipes at the low level pump structure (Duke Power Company 1971 a). The discharge outlet of the LLI pumps utilize six 84-inch ID pipes which form two 132-inch ID pipes; each of these pipes is subsequently reduced to eight 66-inch ID pipes in the Main Intake (Duke Power Company 1971 a; Duke Energy 2012a). 49 The cooling tower retrofit evaluation for McGuire assumes that only the condenser cooling water flow needs to be recirculated and that service water flow (even if there is a heat load associated with it) would not be recirculated. Because of the significantly smaller flow rate, the heat load associated with service water flows is low but the temperature differential of certain service water uses may be high. If cooling towers would be selected as BTA, this may need to be reviewed in greater detail. The hypothetical CCRS retrofit assumes a new forebay would be constructed in front of the existing Main Intake. All water in the forebay would be from the cooling towers or from the make-up water pumps. Nuclear Service Water is withdrawn from the Main Intake and the LLI. When withdrawn from the Main Intake, much of it would be recirculated water. The evaluation assumes that Nuclear Service Water would not be returned to the cooling towers. When Nuclear Service Water is withdrawn from the Main Intake, it is assumed that the make-up pumps would compensate by supplying additional water to the forebay. 50 1 psi is approximately 2.3 ft of water (depth). Duke Energy 1 104 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal �� Comprehensive Technical Feasibility and Cost Evaluation Study [§122.21(r)(10)] Table 10-3. Pertinent Design Parameters from the Existing Condenser Specification Turbine Primary Steam Pressure to Turbine 975 psia Primary Steam Temperature to Turbine 541.5 °F Revolutions per Minute 1,800 rpm Condenser Condenser Duty 7,676,815.6 x 103 Btu/hr Effective Tube Length 44.75 ft Number of Shells Three - Design Flow 959,602 gpm Design Inlet Temperature 60 °F Temperature Differential (i.e., Delta T) 16 °F Guaranteed Backpressure5l 1.46 Inches HgA52 Tubes Number of Tubes 62,826 - Effective Surface Area 736,041 square ft Cleanliness Factor 95 % Number of Passes One - Circulating Water Velocity Through Tubes 7.0 fps Outer Diameter of Tubes 1 inch Tube Material 304 stainless steel - Waterboxes Number per Condenser Three, One per Shell - Non -Divided or Divided Horizontally Divided - Inlet and Outlet Us 84 inch Source: Duke Power Company 1971 b 51 The McGuire system is a vacuum system; a vacuum system is used to remove air and other gases to maintain the design heat transfer. 52 Inches of Mercury, absolute pressure Duke Energy 1 105 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� Comprehensive Technical Feasibility and Cost Evaluation Study [§122.21(r)(10)] r 10.3.6 Description of Selected CCRS Technology 10.3.6.1 MDCT Design Assumptions Several design conditions have been assumed with the selection of MDCTs. These assumptions are described in the following sections. Flow The once -through cooling water flow rate used in the condensers is approximately 959,602 gpm per unit53. This flow is assumed to be equivalent to the recirculating flow required for the cooling towers of each unit because the same amount of water would be required for the condensers in once - through and closed -cycle cooling systems. This evaluation assumes that service water will remain in a once -through flow configuration. Some service water uses have an associated heat load, but it is significantly smaller than the heat load in condenser cooling water. The temperature differential (AT) of service water uses vary, and is often different from the condenser AT. When service water is withdrawn from the Main Intake, it is assumed that the make-up water pumps would compensate by supplying additional water to the forebay. Water evaporation rate in the cooling towers necessary to dissipate the required heat has been estimated and is listed in Table 10-4. The evaporation rate is estimated at approximately 24,566 gpm for the station (12,283 gpm per unit) using a cooling tower range of 16°F and a cooling tower flow rate equal to the current condenser flow rate of 959,602 gpm. The blowdown rate is a function of source water quality and NPDES permit discharge quality requirements. Because Lake Norman is freshwater, the TDS levels range from approximately 33 to 120 parts per million (ppm) (Duke Energy 2015d); therefore, the COC could be up to around five COCs54. This evaluation assumes that the hypothetical cooling towers would employ the most efficient drift eliminators presently on the market with a 0.0005 percent efficiency. Drift from the towers would be 0.0005 percent of the circulating water flow or approximately 4.8 gpm per unit. These values are discussed in more detail in Section 12 of this document. Engineering estimates of evaporation, drift, blowdown and make-up are provided in Appendix 10-A. 53 Water withdrawal rate at the Main Intake is 1,016,000 gpm per unit and includes service water. 54 Cooling towers would increase the concentration of parameters in the discharge from the ambient concentration in the source waterbody. The design and actual COC may vary during operation due to changes in water quality. For the purposes of this evaluation, site -specific TDS values have been used to estimate the COC; however, if cooling towers are determined to be BTA, the quality of the discharge may need to be evaluated prior to a detailed design or construction of a hypothetical cooling tower to further refine the COC. Duke Energy 1 106 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� Comprehensive Technical Feasibility and Cost Evaluation Study [§122.21(r)(10)] r Table 10-4. Estimated Water Use in Cooling Towers Circulating water flow rate gpm 959,602 959,602 1,919,204 Evaporation rate gpm 12,283 12,283 24,566 Drift flow rate gpm 4.8 4.8 9.6 Blowdown rate gpm 3,066 3,066 6,132 Make-up rate55 gpm 15,354 15,354 30,707 Reduction in the circulating water o 98.4 98.4 �� 98.4 withdrawal rate Reduction in the total water % 92.9 92.9 withdrawal rate" 92.9 Temperatures Because MDCTs are wet cooling towers, the ambient wet -bulb temperature that is exceeded during 1 percent of the record at Charlotte, NC (76°F) has been used for the basis of the design (WMO 2016). The design also incorporates a potential for plume recirculation and interference, which increases the wet -bulb temperature for MDCTs by 2°F to the design value of 78°F (SPX 2016b). The cooling tower approach temperature is assumed to be 10°F57, meaning that during the warmest and most humid periods, the cold recirculating water temperature leaving the cooling towers would be approximately 88°F. The cooling tower range, which is equivalent to the AT across the condensers, is approximately 16°F. The AT was calculated using the condenser design parameters in Table 10-4 and Table 10-5 with a cooling tower range of 16°F, the hot water temperature entering the cooling tower is assumed to be equal to approximately 104°F (i.e., the addition of cold water temperature and AT). Cycles of Concentration This evaluation used TDS in Lake Norman to assess the potential COC under which the hypothetical cooling towers at McGuire could operate. Based on between 33 and 120 ppm of TDS (Duke Energy 2015d), five COCs were selected for this evaluation. TDS is not an indicator of whether parameters of concern should be concentrated. If cooling towers were determined to be BTA, Duke Energy would need to evaluate the impact of ambient water quality constituents on COC, water quality standards, and toxicity of the blowdown stream and assess the distribution of suspended vs. dissolved components, how the suspended component may be treated, how the sludge or reject may be disposed of, and their associated costs. Even though 55 This estimate assumes that there are no other leaks in the system. Make up rate equals the sum of evaporation, drift, and blowdown. 56 Including service water flows. 57 This is the practical minimum approach temperature. Duke Energy 1 107 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� Comprehensive Technical Feasibility and Cost Evaluation Study [§122.21(r)(10)] r the flow rate of the discharge is expected to be reduced, the concentration of the constituents in the blowdown will increase based on the COCs. This increase could cause issues with meeting NPDES permit limits as well as toxicity requirements in the blowdown stream. Duke Energy may need to test potential treatment techniques to assess its treatability and costs prior to the cooling tower design. Based on a thorough evaluation of parameters of concern, the cooling tower may need to be operated at a lower COC than 5. All these additional tasks and operating measures would increase the costs beyond what has been estimated in this evaluation. 10.3.6.2 Sizing Based on the design inputs described in 10.3.6.1, hypothetical MDCTs were sized by SPX for the cooling water system at McGuire. Vendor sizing information for both Units 1 and 2 is provided in Table 10-5. Table 10-5. Cooling Tower Sizing In Description TowerType Number of Cells Number of Towers Cells per Tower Cell size (I x w x h) Arrangement CT Basin Size (I x w x d) Motor Input Power for Fans Motor Output Power for Fans Total Fan Motor Input Power Total Lift Pump Head Condenser Water Flow Rate Condenser Temperature Differential Design Wet Bulb Temperature Wet Bulb Temperature Exceedance Percentile Recirculation/Interference Assumption Prevailing Wind Direction Minimum Distance Between Towers 58 Brake horsepower. formation for Unit 1 and Unit 2 (Source: SPX 2016b) cells towers cells/tower ft ft hp bhp58 hp ft gpm °F °F °F ft MDCT 56 4 14 60x60x50 (4) x 14-cell Back -to - Back (4) 428 x 128 x 6 250 235 14,000 43 959,602 16 76 1 2 SW 428 MDCT 56 4 14 60x60x50 (4) x 14-cell Back -to - Back (4) 428 x 128 x 6 250 235 14,000 43 959,602 16 76 1 2 SW 428 Duke Energy 1 108 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Comprehensive Technical Feasibility and Cost Evaluation Study [§122.21(r)(10)] r 10.3.6.3 Nuclear Safety and Ultimate Heat Sink Per the existing design, the Main Intake and the LLI withdraw water from Lake Norman. The Main Intake can be used to supply the SNSWP, but that is not its primary function. The 42-inch water supply line for the SNSWP begins at the Station and extends to the SNSWP; there are cross connects with the LLI. The nuclear safety is of utmost importance as acknowledged in §125.94(f) of the Rule. Compliance with the Rule should not impact safety features. This evaluation attempts to avoid downtime or disruption to this supply line. 10.3.6.4 Existing Conditions Based on geotechnical investigations and on -site boring logs, partially weathered bedrock is at a depth of approximately 50 ft near McGuire (AMEC 2013). This evaluation assumes that cooling tower basins would be pile -supported and that the hypothetical pilings would be driven to a depth of 50 ft. 10.3.6.5 Potential Locations for the MDCTs (§122.21 (r)(1 0)(i)(B)) Lake Norman is a man-made impoundment. The same topographic features that made this location suitable for impoundment create challenges for extensive site construction. Figure 10-5 shows the topography of the area around McGuire. Except for the section of the property where the nuclear reactors are located, there is an approximate 70-ft59 elevation difference for every 1,000 ft of linear distance. Topography is steeper around the berm of the reservoir. The following aspects were considered when identifying potential locations for cooling tower placement; one potential location was then selected for use in the remainder of the feasibility evaluation: Must not impact nuclear safety or security at the plant — Nuclear safety is paramount and the evaluation attempted to locate the hypothetical cooling towers such that they would not impact nuclear service water, the SNSWP, or its water supply, as such an impact could trigger a significantly longer outage. The evaluation also attempted to avoid interference with the security line of sight or the plant's other safety features. 2. Must have space for construction — The footprint of the cooling tower basins, booster pumphouse, construction access, excavation space, and space to setup equipment were considered under this category. This evaluation attempted to locate cooling towers for each unit in the same general area. Additionally, the topography of the site should be amenable to construction, or the site should be amenable to re -grading. 3. Must have space for cooling tower operation — Good air circulation is needed for the cooling towers to operate efficiently. 4. Must facilitate minimizing retrofit -related plant downtime to the extent practicable — Plant downtime is costly and affects the reliability of the electric grid. es Each story of a commercial building is approximately 10 ft high. Therefore, 70 ft corresponds to approximately a 7- story building. Duke Energy 1 109 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� Comprehensive Technical Feasibility and Cost Evaluation Study [§122.21(r)(10)] r 5. Must facilitate minimization of O&M costs — To the extent practicable, the evaluation attempted to locate cooling towers and other related new equipment to minimize fuel, labor, and other maintenance costs. 6. Located close to existing condensers — Long distances between condensers and cooling towers increase the cost of construction, and increases headloss through the system that would need to be compensated with larger pumps (which would in turn result in higher auxiliary energy requirements). Therefore, the distances between condensers and cooling towers were minimized to the extent practicable during the assessment. 7. Located close to the existing CWIS and discharge — Much of the cooling water pipe network is buried under the plant and intertwined with other utilities. This evaluation attempted to minimize disturbance to the plant by using existing pipes. Locating one set of hypothetical cooling towers close to the discharge canal facilitated its utilization to the maximum extent possible, reduced disruption to plant operations, and reduced disturbances to the site. 8. Must have pipe or channel routes available between the condensers and cooling towers and between cooling towers and condensers — Power plants have extensive above -ground and underground infrastructure. Pipe routes that avoid crossing transmission corridors and other densely utilized areas of the site are preferable. Cooling tower locations that allow for practical hot and cold water pipeline routes are also preferred. The evaluation also attempted to avoid cooling water pipe crossings. 9. Must facilitate minimal construction -related disturbance to the extent practicable — Restoring a construction site is costly. This evaluation attempts to locate and sequence work to minimize disturbance. 10. Must have space for equipment laydown — It is convenient and cost-effective for contractors to have Iaydown space readily available near construction activities. When there is not sufficient space, equipment needs to be hauled to the construction site as -needed. This evaluation attempted to identify Iaydown space to the extent practicable, but available space is insufficient for the extent of work needed. There is limited work space at McGuire. Providing Iaydown space for each of the construction areas would help with efficient progression of work; however sufficient Iaydown space is not available owing to topography. There are no locations on the McGuire property (or adjacent to the property) that meet all of the above criteria for cooling tower placement. This evaluation therefore tried to identify spaces that met most of the requirements. Duke Energy 1 110 Figure 10-5. Topography in the Vicinity of McGuire Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal Comprehensive Technical Feasibility and Cost Evaluation Study [§122.21(r)(10)] ! `� Duke Energy 1 111 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� Comprehensive Technical Feasibility and Cost Evaluation Study [§122.21(r)(10)] r 10.3.6.6 Conceptual Approach to Hypothetical Closed -cycle Cooling This concept assumes that the Unit 1 hot water would be intercepted at the discharge structure and routed to a bank of MDCTs located on the contractor parking lot. Cold water would be piped across the discharge canal, through the peninsula between the intake and discharge, to a newly constructed forebay in front of the existing Main Intake. The Unit 2 hot water would be intercepted immediately to the east of the Unit 2 turbine building (taking care not to interrupt the SNSWP supply line) and routed south and then eastward over the main parking lot (which would be restored later), to the vegetated section west of the main station. A bank of MDCTs would be located between the station and the Catawba River over the Conventional Wastewater Treatment System (which would be relocated). To avoid disruption of or new construction over the SNSWP supply line, cold water from the Unit 2 MDCTs would be routed to the LLI pump structure60 (which would no longer be needed if the station were retrofitted to be closed - cycle) and use the pipes for Unit 2 (and portions of existing pipe for Unit 1) to route cold water from the LLI pumps to the newly constructed forebay in front of the Unit 2 intake bays. Figure 10-6 shows schematics of the cooling water system before and after the cooling tower retrofit. The design, sizing, siting, feasibility, and costing of MDCT technologies are described in subsequent sections. Existing system After hypothetical retrofit Wnhar;r canal Lake Norman I oischarse svurwre J Lake Norman •� ��d�� Y 6lowdown Apo ofschar;e Canal -- ___ ___ SNSWP 1 _ ilnitI Unit y iTurhine Turhlne Makeup I I Unit 1 I Eli & ]Iding NIldia; +Hater I , MDCr I I a i I L.r•R � i I I_J oiuhar;c strurn,rr �,r 1, li _______ ________________________ SRSWP -rr-••-- _ �7 wit un It2 I 1 Turbo," Turbine 111 Bulldina Buildln; , I,,,Iyyy��• � 4r I_J' 131 Figure 10-6. Schematic Showing Cooling System Components and Piping before and after Hypothetical Cooling Tower Retrofit 60 The existing LLI pumps would be replaced with new ones to accommodate the Unit 2 flow rate. Duke Energy 1 112 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Comprehensive Technical Feasibility and Cost Evaluation Study [§122.21(r)(10)] r Orientation of the Cooling Towers Wind speed and direction significantly influence cooling tower performance as well as the potential effects of facility emissions. While moderate wind speeds are critical for transporting the saturated plume away from the tower and increasing cooling tower performance, excessive wind speeds can diminish cooling tower performance by restricting the plume from rising up and out of the tower. A cooling tower array performs best when its primary (long) axis is oriented parallel to the predominant wind direction, because this orientation minimizes the potential for saturated air recirculation. When space and other physical conditions allow, MDCTs are oriented parallel to the dominant wind direction that coincides with design wet bulb temperature. Meteorological data from the World Meteorological Organization (WMO Station Number 723140) for Charlotte, NC was used for this evaluation. Wind roses61, which depict prevailing wind direction and percent frequency of observed wind speeds, for Charlotte NC for the different months of the year are shown on Figure 10-7. Recirculation occurs when the saturated air leaving the cooling tower is introduced back into the tower's air inlets (SPX 2009). Interference is similar to recirculation, with the exception that the saturated air leaving the cooling tower is introduced into a nearby cooling tower's air inlet (SPX 2009). When multiple cooling towers are utilized in a side -by -side fashion, a minimum distance62 between the towers must be maintained to minimize interference63. Minimum separation distance between towers is provided in Table 10-5. The winter (December, January, and February) wind rose shows that the majority of prevailing winds are from the south to southwest direction and from the north to northeast direction. Wind from the south to southwest occurs around 23 percent of the time and occurs around 24 percent of the time from the north to northeast direction (Figure 10-7). Wind speeds are commonly between 6 and 14 knots64 (approximately 7 and 16 miles per hour [MPH]). 61 A wind rose is a graphical representation of how prevailing wind direction and percent frequency of wind speed are distributed at a specific location for a given period of record of data. The wind rose is plotted in a circular format. Straight lines directed towards the center represent the prevailing wind direction; the concentric circles (or dashes on the straight lines) represent the percent frequencies of wind speed, which increase in percent frequency from the center of the wind rose (NRCS 2016). The percent of time the wind speed is observed as calm is typically provided as a note to the wind rose. Wind speeds may be provided in units of either miles per hour or in knots. 62 The minimum distance is typically a function of the length of the cooling tower and the offset between the side -by - side towers. When the site does not allow for this minimum separation between towers or does not allow for the appropriate orientation of towers, the inefficiencies may be overcome by using more powerful fans or adding a few extra cooling tower cells. 63 Recirculation is minimized by limiting the size of any tower. For example, if a plant needs 48 cooling tower cells, the design can minimize recirculation by utilizing four 12-cell towers instead of a single 48-cell tower. 64 A knot is a measure of velocity in nautical miles per hour, where one nautical mile is equivalent to 1,852 meters, or approximately 6,076 ft. To convert from knots to MPH, the value in knots should be multiplied by 6,076 ft per hour per knot and then divided by 5,280 ft per mile. Duke Energy 1 113 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� Comprehensive Technical Feasibility and Cost Evaluation Study [§122.21(r)(10)] r The spring (March, April, and May) wind rose shows that the majority of prevailing winds is from the south and southwest directions and occurs approximately 29 percent of the time. During the remaining time, wind occurs between 4 and 7 percent from each of the other directions (Figure 10-7). Wind speeds are commonly between 6 and 14 knots (approximately 7 and 16 MPH). December, January and February March, April and May N NNW 11 ' NNE. NNW 12 NNE to NW NE NW $ NE WNW ENE WNW ENE W E W E WSW ESE WSW ESE SW SE SW SE SSW SSE SSE S S Percent Calm: 8.90 Percent Calm: 6.70 June, July and August September, October and November N N-NAV 1` NNE NNW 16 ti�E 10 NW 8 NE NW NE G WNW ENE WNW INE W E W E WSW ESE WSW ESE SW SE SW SE SSW SSE SSNV SSE S S Percent Calm: 7.71 Percent Calm: 13.18 -34 knots 25-34 knots ■ 15-24 knots ■ 6-14 knots ■ 1-5 k7iots Figure 10-7. Wind Rose Summary for Charlotte, NC (WMO 2016) Duke Energy 1 114 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� Comprehensive Technical Feasibility and Cost Evaluation Study [§122.21(r)(10)] r The summer (June, July, and August) wind rose shows that the majority of prevailing winds are from the south to southwest. Wind occurs from the southwest approximately 28 percent of the time. Wind speeds are commonly between 6 and 14 knots (approximately 7 and 16 MPH). The autumn (September, October, and November) wind rose shows that the majority of the prevailing winds are from the north to east-northeast directions, occurring approximately 35 percent of the time between 6 and 14 knots (approximately 7 and 16 MPH). The predominant wind during the highest wet bulb temperature conditions (i.e., the summer months) is from the southwest; therefore, the main axis of the cooling towers would be oriented in the southwest to northeast direction. The direction and speed of winter winds have a greater influence on ice and safety impacts arising from station activities; however, PM impacts may be experienced all year. Several on -site locations were initially considered prior to selecting two areas for the two sets of cooling towers. Location A — MDCT for Unit 2 The concept for Location A includes placing four cooling towers associated with Unit 2 immediately to the west of the main plant and south of the LLI pump structure. This would involve routing hot water, via a series of new pipelines, from Unit 2 from outside the Unit 2 turbine building (see Figure 10-8) to newly -constructed wet wells that would be located at the base of each cooling tower. Booster pumps installed in the wet wells would withdraw water from the respective wet wells and pump the hot water up to the wet deck of the cooling towers. The cold water from the cooling tower basins would be routed to a newly constructed forebay in front of the Unit 2 intake screens using a combination of new pipelines, new pumps installed at the LLI pumps structure, and existing LLI pipes (Figure 10-9). The Unit 2 circulating water pumps would remain in -place, and as such, the Unit 2 condensers would not experience a change in flow rate or water pressure. A new make-up water pump would be installed immediately outside the new forebay to pump make-up water from Lake Norman to a location downstream of the trash racks on the Main Intake. Blowdown pumps would withdraw from the forebay and route it to the existing discharge canal. While this is not an ideal location for siting cooling towers, other potential locations considered were less suitable. To the north of this location is Lake Norman, to the west is the Catawba River, to the south is the Wastewater Collection Basin, and to the far south and southeast are the main transmission corridors. Duke Energy 1 115 r' Unit 1 discharge pipes I a would connect directly to a pipe or channel that would P route hot water to wet wells located at the base of each r ceol ing tower. 1RCFA0051 IRCFAa05� 1RCFAa07— 1RDFM37 T"T 1 Unit 1 LLI pips to e t11.9 be modified . 0 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal �� Comprehensive Technical Feasibility and Cost Evaluation Study [§122.21(r)(10)] iQn •S ris✓<s srr_sxnot�• I I �i �J. T 2RCFAM7 2RCFA005 2RCFAM I These segments of - '/ ^:i •I � 1,( •i the e2 pipes he \� r '1 �'� • /� �,//f ; , severeFed d, filled. and c5 f Ad �• Yd � iabandoned in -place s' M� Existing cooling 6, � t^ water pipes toI.�' %(fi ywr ao.s]� remain unchanged : 1RCFA010 2RCFAees S 1RCFAeea 1RCFA001 ' iRCFAarAB �2RCFA00 l0 L _ IRCFA002 1RCFA603 ;`r1l ,1, Cp14 ,\ � 1 rjI - •t�[1RCFA01 �� 1RCFR013 urr -7 _ i_5le 5Cs opf ••T•'� 1 � .` • , 'L , IRCFAa t r -�. I 2RCFaa 12 `• ,` '' N�—F - - �� ' 2RCFA0l l `:��. it II 1RCFA014 i � \\ _ pL l •4 g •!Cs' _ !r!4FF9 R1�6 iyI Y'y l- �•, ram.-s.:re ao-.,w.dfy � � l I I I tl �'��' � � -FA0I5 i II C' n Ri a 16 Unil 2 pipes to be p�. L ! e• . severed and hot a a .ma• r9a• ! aIa• 'Hater rerouled to SRCFaa26 J .0 � rrkn .r. o' r av u P 1RCFA021 R �, Y" I- now Unit 2 cooling ' 1RCFA022 LfRCFAp lB m y 2RCFA017 SRCFMV 2RCFA020 y k'I 2F1CFR018 t4W9r 2RCFAa JACFAa}}$ �t e..do,.e. 2RCFRB21 � W 2RLFld 19B �tCv.wer.� \ , ,22RCFA2023 `.L 4irisian :� 2RCFA922 & S Diririon F Figure 10-8. Existing Cooling Water Piping (Duke Energy 2012b) Duke Energy 1 116 Figure 10-9. Hypothetical Cooling Tower Locations Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� Comprehensive Technical Feasibility and Cost Evaluation Study [§122.21(r)(10)] r Duke Energy 1 117 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� Comprehensive Technical Feasibility and Cost Evaluation Study [§122.21(r)(10)] r Siting cooling towers at Location A would require repurposing or relocating the following key existing infrastructure: 1. McGuire main station's ground surface is approximately at the same elevation as Lake Norman (760 feet above mean sea level [ft msl]) and man-made berms protect the plant. Location A slopes downward towards the section of the Catawba River that is immediately south of the Cowans Ford Dam from approximately 730 ft msl to approximately 665 ft msl. To allow for appropriate water flow (instead of using multiple booster pumps in series) and to facilitate proper air flow and cooling tower operation, this evaluation assumes that Location A would be filled in and leveled up to an elevation of 750 ft msl. An approximately one-half mile tiered retaining wall would need to be constructed trending in a north -south direction, from approximately 500 ft north of the Highway 73 bridge to south of the Cowans Ford Dam, to allow building up a total height of 85 ft65 to create the space needed for the Unit 2 cooling towers. The volume of soil needed to fill this area is estimated to exceed 1.5 million cubic yards. This evaluation assumes that the site would be filled in gradually as construction of the cooling tower basins and hot and cold water pipes progresses. The hot and cold water pipes shown on Figure 10-10 will be buried or covered. 2. The Conventional Wastewater Treatment System (Settling Pond A, Settling Pond B, Chemical Mixing and Storage Building, Final Holdup Pond, Recirculation Pump House, WC Main Valve Pit, and all associated piping) would be relocated to the south of the Wastewater Collection Basin. The supply pipe from the Initial Holdup Pond would need to be extended from the current Conventional Wastewater Treatment System to the new location (see Figure 10-10). 3. A section of the LLI pipes would be repurposed to route water from the Unit 2 cooling towers to the newly constructed Unit 2 forebay. The Unit 2 LLI pumps have already been retired. Unit 1 LLI pumps are used for a few days (approximately one to five weeks) of the year to pump colder water from the hypolimnion to the front of the Main Intake screens. A closed - cycle retrofit meant to minimize water withdrawal from Lake Norman would eliminate the use of the LLI system for cooling purposes. This evaluation therefore assumes that cold water from the cooling tower basins would be routed via three pipes to the LLI pumps, which would be used to route water to the new forebay in front of the Unit 2 intake bays. The section of Unit 1 LLI pipe shown on Figure 10-11 would be severed, filled with flowable fill, and abandoned in -place. The remaining segment of the Unit 1 LLI pipe would be routed under the Unit 2 LLI pipe to the Unit 2 forebay. The LLI system that routes hypolimnetic water to the Main Intake has a total capacity of 1,296 MGD. The Unit 2 cooling water flow rate is 1,381.8 MGD. The evaluation assumes that the pipe would be able to route the additional seven percent of water if provided sufficient hydraulic head, and that the LLI pumps at the LLI pump structure would be replaced with new pumps that can develop the necessary hydraulic head. 4. Repurposing the LLI pipes provides several advantages; the most important being that it avoids construction near the 42-inch diameter pipe (highlighted yellow on Figure 10-11) that routes water from the LLI to the SNSWP. Taking this pipe out of service or having to replace 65 The equivalent of 8.5 stories. Duke Energy 1 118 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Comprehensive Technical Feasibility and Cost Evaluation Study [§122.21(r)(10)] r it may trigger a significantly longer plant outage as well as potential concerns regarding the availability of the SNSWP. The existing pumps would be replaced with slightly higher capacity pumps. f ,141 wtia�te wnTer syetem lanJ 4mrer,- X G•EEMICAL • ' �Ii1f11,jQ d 51�712 t y TOAPOVARY r } , -7 15 RAIN GALE 7560 DEL. IT INITIAL HOLDUP POND -�T; rr''-EL 75110 E7' 7 I rT CCNVENT110NAL WASTE WATER TREATMENT SYSTEM T'ON PUSS t xj 439� eWCB(L:10)G PH CONTROL 7488NOTE-'WC MAIN VALVE PIT WATER TREATMENT BLDG 7490 Figure 10-10. Existing Conventional Wastewater Treatment System to be Relocated (Duke Energy 2014b) Duke Energy 1 119 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal �� Comprehensive Technical Feasibility and Cost Evaluation Study [§122.21(r)(10)] Exisling LLI Pump Structure r I- W LEVEL MP yT R. � Unit �ofd water pipes Rerouting Unit t LLI Pipe /P. Severe, fill and abandon section of ' Unit 1 LLI Pipe Ar"2r i ice, I ice+ J J • J � r \ \•" REAC yYATE 1 % INTPKF \•Ii E Uhl• "2—� PAINT $ GAS Figure 10-11. Schematic of Repurposing the LLI Pump Structure (Duke Energy 2014b) ■o The yellow line in Figure 10-11 is nuclear safety related piping, the pink dotted line is the LLI piping for Unit 1, and the green line is the rerouted Unit 1 LLI piping. The green arrows show the cold water pipes from the hypothetical cooling towers. Location B — MDCT for Unit 1 The concept for Location B identified in Figure 10-9 includes siting four cooling towers that would be associated with Unit 1 on the Construction Parking Lot. This would involve routing hot water from the Unit 1 discharge structure via a newly constructed series of pipes that would serve each of the Unit 1 wet wells, which in turn would route water to the cooling towers via booster pumps. The cold water from the cooling tower basins would again be routed via newly constructed cold water pipes to a new forebay that would be constructed in front of the Unit 1 intake bays. The cold water pipes would therefore need to traverse through the existing discharge canal and cross the Cowans Ford Dam Road and the peninsula. The new concrete forebay would hydraulically separate the existing intake from Lake Norman. The cold water pipes would discharge into the new forebay. The hot water chamber outside the discharge structure would hydraulically separate the station's cooling water system on the hot water side. Duke Energy 1 120 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� Comprehensive Technical Feasibility and Cost Evaluation Study [§122.21(r)(10)] r The existing Unit 1 circulating water pumps would remain in -place, and as such, the Unit 1 condensers would not experience an increase in flow rate or a change in pressure. A new make-up water pump would be installed immediately outside the new forebay to pump make-up water from Lake Norman to a location downstream of the trash racks in the Main Intake. Blowdown pumps would take from the Unit 1 MDCTs would be routed to the current discharge canal. This site is located within one -mile of Southlake Christian Academy (a local school). The potential impacts to the outdoor activities from a hypothetical cooling tower are addressed in Section 12 of this document. The contractor laydown area and parking to the northeast of the main plant was selected for the Unit 1 cooling towers because this section is already developed, is flat, is close to the discharge structure, and provides adequate air circulation and construction access.66 This location minimizes construction activities within the Protected Area, which is a high -security area enclosed by physical barriers. This location has several drawbacks as well. During the fall and winter months, for about a third of the time, the winds are from the northeast (refer to Figure 10-7); therefore the plume from the cooling towers could potentially impact security line of sight. Per USNRC Regulations at 10 CFR Part 73.55(e)(8)(ii): Penetrations through the protected area barrier must be secured and monitored in a manner that prevents or delays, and detects the exploitation of any penetration. These regulations are further explained in the USNRC's Regulatory Guide 5.44, Perimeter Intrusion Alarm Systems, which describes the areas and types of alarm systems required to monitor and detect unauthorized penetration or activities at a nuclear power plant. A cooling tower plume that impacts the line of sight of authorized security personnel or perimeter intrusion alarm systems could impact the safety and security of the public, the station and station's personnel, and the surrounding area. Location B would require relocation of the following existing infrastructure: The Construction Parking Lot located between the discharge structure and McGuire Nuclear Station Road would need to be relocated to the northwest corner of Highway 73 and McGuire Nuclear Station Road.67 2. The Site Services Warehouse at the end of Hagers Ferry Road would need to be relocated to the lot that is to the east of McGuire Nuclear Station Road and immediately south of the discharge canal. Vegetation must be cleared to allow for the relocation. 66 The laydown area is currently managed by McGuire's EnergyExplorium, an energy education center. The laydown area is located where public events occur (e.g., concerts, movies, public tours, fishing). This area would be utilized during the construction period and would be reopened to the public once construction is completed and the area is restored. 67 Highway 73 in the vicinity of McGuire Nuclear Station Road may be undergoing a widening and relocation project which could impact the relocation of the Construction Parking Lot. See the Uncertainties section for additional information. Duke Energy 1 121 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� Comprehensive Technical Feasibility and Cost Evaluation Study [§122.21(r)(10)] r 3. The peninsula and section of Cowans Ford Dam Road between the intake and the Energy Emporium would need to be drilled under or excavated to route cold water tunnels. The hypothetical Unit 1 tie-ins would be performed after the Unit 2 tie-ins, which would eliminate Unit 2 hot water discharge to the discharge structure. To minimize downtime, the hypothetical wet wells and cooling towers would be constructed while the station is online. The final tie-in of the hot water pipes would involve connecting the existing discharge pipes to the new hot water pipes. Newly constructed pipes on the northeast side of these cooling towers would gather cold water from the cooling tower basins and route the water through the existing discharge canal to the head of the intake. Several segments of cold water pipes may be constructed while the plant is operating, however, Unit 1 would need to be taken out of service to complete construction of the cold water pipes. Hot and cold water pipes would be similarly sized, and would conform to Duke Energy piping specifications. A concrete forebay would enclose the Unit 1 intake bays and the cold water pipes would discharge into this forebay. The hypothetical retrofit would eliminate the hydraulic connectivity between the McGuire cooling water system and Lake Norman. For Unit 1, the existing discharge pipes would be reutilized; the condenser discharge would flow to the existing discharge structure, which would be connected to new pipe. The water would then flow through a hot-water supply line to the respective wet wel168 for each tower to be pumped to the hypothetical Unit 1 cooling towers. The cold water from the hypothetical towers would then be routed to the new Unit 1 concrete forebay. Similarly, for the hypothetical Unit 2 cooling towers, a hot-water pipeline would tie into the existing Unit 2 condenser, where the water will flow to the respective Unit 2 wet wells. Once through the cooling towers, the water would flow to the LLI pump structure, where the water would be rerouted to discharge into the new concrete forebay for Unit 2 using the new LLI pumps. The following subsections summarize alternative cooling tower locations that were considered and reasons for their dismissal. 10.3.7 Alternate Cooling Tower Locations Other locations were considered for placement of MDCTs both on -site and off -site. 10.3.7.1 On -site Location C Location C is the area immediately to the south of the main plant and encompasses the main parking lots and grassy area (Figure 10-12). Its closeness to turbine buildings and cooling water pipes and relatively level space are advantageous, however, the station's main transmission lines traverse over this space. Relocating transmission lines would be costly and impractical. It would also likely result in substantial facility down time. 68 The wet wells would be designed to hold a volume of water approximately equal to a five minute retention time. Duke Energy 1 122 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal Comprehensive Technical Feasibility and Cost Evaluation Study [§122.21(r)(10)] ! `� Potential Cooling Tower —J Location yYv ��i sa.n� ri, PRO�EC1t�GVNE ENERGYg1a0JA�81Efl CCNTMCIVACGuiRE NMLERR BTpTCNM%WrtRpRx flCVRE>I_N11 Oa]BCGGLMC �CK£R MxG - UdER: EKCCH - MTE: E 4016 Figure 10-12. Alternate Cooling Tower Locations Duke Energy 1 123 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Comprehensive Technical Feasibility and Cost Evaluation Study [§122.21(r)(10)] r 10.3.7.2 Off -Site Location D Location D is on the lot that is bound by Hagers Ferry Road, Cowans Ford Dam Road, and Highway 73 (Figure 10-12) and is closer to residential properties than to the station itself. Additionally, it is adjacent to the Southlake Christian Academy. A bank of cooling towers near a school and several residential properties would be poorly received by the public. 10.3.7.3 Repurposing Existing Infrastructure McGuire has no existing infrastructure that is unused or underused and whose footprint may be repurposed for cooling towers. 10.3.8 Construction Sequence and Outage 10.3.8.1 Construction Sequence This type of project may be sequenced and implemented in different ways. The following construction sequence was assumed for this evaluation. Several of these tasks would overlap and be implemented using several crews. • Construct new parking areas —temporary and permanent; • Prepare laydown areas; • Construct retaining wall; • Construct new wastewater treatment plant (WWTP); • Demolish existing Conventional Wastewater Treatment System and fill in construction site for Unit 2; • Drive pilings for cooling tower basins and wet well foundations; • Drive pilings for cold water pipelines; • Drive pilings for hot water pipelines; • Drive pilings for forebay and make-up water intake structure; • Construct cooling tower basins; • Construct wet wells (to supply booster pumps); • Refurbish LLI pump structure and LLI pipes; • Construct portions of forebay inside a coffer dam, allowing cooling water to enter the Main Intake; • Install blowdown pipelines; • Construct hot water pipelines, but allowing hot water to discharge via intake; • Install make-up water pipeline; Duke Energy 1 124 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Comprehensive Technical Feasibility and Cost Evaluation Study [§122.21(r)(10)] r • Construct cold water pipeline; • Erect cooling towers; • Complete the construction of the forebay inside an expanded coffer dam, cutting off water from the Main Intake (requires both units to be offline); • Construct make-up water intake structure (requires both units to be offline); • Install screens for make-up water pumps; • Install booster pumps, LLI pumps at the LLI pump structure, and make-up water pumps; • Tie-in the new Unit 1 hot water pipe to the Unit 1 hot water discharge structure (requires Unit 1 to be offline); • Tie-in the new Unit 2 hot water pipe to the Unit 2 hot water pipelines outside the turbine building (requires Unit 2 to be offline); • Testing and commissioning, with units coming online; and • Restore construction areas, parking lots, etc. 10.3.8.2 Construction -Related Outage Based on the above hypothetical construction sequence, this evaluation estimated that an approximately 12-month concurrent outage would be needed to tie-in closed -cycle systems associated with both units. There may be other construction sequences that would allow one unit at a time to be in outage. In this construction sequence, the construction of the forebay would drive the outage duration. 10.3.9 Feasibility Discussion The feasibility of construction, operation, and retrofitting MDCTs at McGuire is discussed below. 10.3.9.1 Retrofit Feasibility The existing McGuire condenser waterboxes are rated for 30 psi of pressure (or approximately 69 ft of water). The various segments of the cooling water pipes are rated for between 10 and 40 psi internal pressure (or between 23 and 92 ft of water), and between 12 and 26.4 psi external load. If the cooling water system was retrofitted with a single set of pumps that could route water through the condensers, the hot water pipes, up the cooling towers, and back to the pump, such pumps would need to develop approximately 122 ft of head69, which the condensers or cooling water pipes would not be able to withstand. Additionally, this site has significant topographic relief. Except for the section of the site where the reactors and main station are located, there is approximately a 70-ft elevation difference for every 1,000 ft of linear distance. It is this feature that made the site for suitable for inundation and creation of Lake Norman. The topographic relief creates challenges for a closed -cycle conversion due to additional pumping requirements; increased pumping increases 69 This does not account for the margin of safety (approximately 2 or more times the operating pressure). Duke Energy 1 125 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� Comprehensive Technical Feasibility and Cost Evaluation Study [§122.21(r)(10)] r auxiliary energy requirements. Large pumps needed to move water through this system would develop significant head, which existing infrastructure cannot withstand. To address the issue of system pressures directly caused by a retrofit would require the condensers to be replaced and the cooling water pipes to be reinforced or replaced. The replaced condensers would be designed to work in tandem with a cooling tower. However, this would involve work on infrastructure that is in and under the turbine building and other key station infrastructure. In addition to the prohibitive capital cost, the cost associated with the long unit outages, likely longer than one year per unit70, would make the retrofit impractical. This evaluation, therefore, assumed that two sets of pumps for Unit 1 and three sets of pumps for Unit 2 would be used to circulate water between condensers and cooling towers. 1. Sixteen new booster pumps per unit or four booster pumps per cooling tower (32 total) would be used to pump hot water to the cooling tower wet decks. Each booster pump would be rated at approximately 59,975 gpm and could capable approximately 96 ft of head. 2. To reduce the potential impact on the water line that supplies water to the SNSWP, the LLI pump structure would be retrofitted with new pumps. 3. Cold water would be routed to the condensers using four existing circulating pumps (eight total). In this way, the existing once -through system (e.g., pumps, condensers, water boxes) would be used under their current pressures and would not need to be retrofitted. Engineering estimates for pump and pipe selections are provided in Appendix 10-B. 10.3.9.2 Construction Feasibility It is estimated that the station may require up to eight towers, four per unit. Each tower would have 14 cells in back-to-back arrangement, for a total of 56 cells per unit, or 112 cells total for the station While having a back-to-back arrangement reduces the overall length of the cooling tower footprint, the MDCTs will still require long, rectilinear tracts of relatively flat land. McGuire has limited suitable space available for the construction of MDCTs; therefore, major reconstruction of existing station facilities, buildings, and equipment would be required. In addition, the topographic relief makes siting the towers difficult. Because McGuire is located adjacent to the Cowans Ford Dam and related dikes, any and all demolition of existing buildings, land preparation, and construction of new equipment would need further evaluation to ensure the activities would have no adverse impacts on the safety, stability, and reliability of the dam and dikes. Relocated infrastructure (e.g., the wastewater treatment facility) would be difficult to re -position on the site due to the same constraints. The McGuire cooling tower retrofit requires construction within the discharge canal and construction in front of the existing Main Intake, both of which would require several federal and state permits and 70 Replacing the stations' condensers would likely extend the cooling tower retrofit outage by 6 months (i.e., from 12 months to 18 months) and would result in additional energy impacts to the system. Extending the outage duration by 6 months could increase the Power System cost estimate (see Table 10-17) by as much as 50 percent. Duke Energy 1 126 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� Comprehensive Technical Feasibility and Cost Evaluation Study [§122.21(r)(10)] r approvals, including from the U.S. Army Corps of Engineers (USACE). Boring and pipe construction under the peninsula would require approvals from the North Carolina Department of Transportation. This evaluation assumed that coal tar epoxy -coated steel pipe would route hot and cold water between condensers, cooling towers, and intake forebay. The pipes would be buried at least 7 ft below grade. Routing a series of pipelines under the existing station would be impractical. The key construction -related challenges associated with the hypothetical cooling tower retrofit include: Lack of parking space. Construction and modifications will require over 250 MDCT project - related contractors to be on -site. Because contractor parking would be allocated to the Unit 1 MDCT, some other parking or transportation method would need to be provided for these contractors. Refueling outages typically bring a few hundred contractors to the site. When refueling outages coincide with the MDCT-related work, the numbers of contractors on -site would be challenging to accommodate — from parking, to food, accommodations, security clearances, and sanitation. 2. Lack of laydown space. This evaluation assumes that there would be approximately four construction areas to support this hypothetical project: the WWTP area, the Unit 1 MDCT area, the Unit 2 MDCT area, and the CWIS/forebay area. Laydown space for the hypothetical WWTP area may be created by clearing undeveloped areas. The other three project areas do not have sufficient laydown space. 3. Routing cold water pipelines from the Unit 1 cooling towers via the existing discharge canal, under the peninsula, and to the new forebay that would need to be constructed in front of the Unit 1 cooling water intake structure would require an extended unit outage. Reconfiguration of the Unit 1 discharge would also require a Unit 1 outage. 4. Relocating the Conventional Wastewater Treatment System to site the Unit 2 cooling towers, building up the site by as much as 85 ft due to restrictive space, and holding back the earth with two retaining walls constructed along the Catawba River would be a tremendously costly and challenging endeavor. The newly built-up section would need to meet seismic stability criteria required at a nuclear station. The constructability of this section of the site requires additional evaluation. 5. Finding a location for the Conventional Wastewater Treatment System. This system was preliminarily relocated to a site immediately south of its current location. Its suitability requires additional evaluation. 6. The western portion of Location A is within the 100-year floodplain limits (Amec Foster Wheeler 2014). The southwestern portion of Location A has wetlands features (Amec Foster Wheeler 2015); therefore, permitting this site and preparing it for construction would be challenging. Permits may take several years for approval. 7. Avoiding impacts to the McGuire safety water system by routing cold water from the cooling towers to the new Unit 2 forebay using the existing LLI pipes. 8. Rerouting the Unit 2 pipes away from the discharge structure and towards the Unit 2 cooling towers presents the greatest amount of difficulty. A large and deep construction pit would need to be shored and excavated immediately to the east of the Unit 2 turbine building. The Duke Energy 1 127 Duke Energy Corporation 1 McGuire Nuclear Station CWA §316(b) Compliance Submittal L� Comprehensive Technical Feasibility and Cost Evaluation Study [§122.21(r)(10)] r excavation would need to be nearly flush with the eastern wall of the Unit 2 turbine building with stable shoring to avoid structural instability of the building. Construction work would need to be performed without impacting the SNSWP water supply, whose pipeline runs immediately to the north of the hypothetical construction pit. See Figure 10-13 for the hot water tie-in location. 9. Isolating the intakes and outfalls of both units from Lake Norman to achieve a closed- cycle would involve in -water construction of dikes that is both costly and would trigger extensive review by the USACE and the Federal Energy Regulatory Commission (FERC), potentially including review under the National Environmental Policy Act (NEPA). 10. Several, if not all, of the hypothetical activities have the potential to affect nuclear safety and would need to be reviewed by the USNRC. -. 7?� W � Cokdrnr�r j �irixr'a�r �� i Unit 2 condensers I.S6 5' iq I 1 I F 7. _ y ti ilit 2 pes to sev;ed and *t wat r r route to new Uhit 2 cooling - - -- - -, . tDW Figure 10-13. Unit 2 Takeoff Location (Duke Energy 2012b) Prior to construction, a constraints analysis and a refined concept of the site plan would need to be prepared. The constraints analysis would review potential constraints due to regulatory, zoning, or siting requirements. Once constraints are identified, the original site plan would need to be refined to account for identified constraints. Duke Energy 1 128 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� Comprehensive Technical Feasibility and Cost Evaluation Study [§122.21(r)(10)] r After construction, the site would need to be regraded/recontoured and reseeding and replanting would be necessary in some areas, as appropriate. Based on the challenges described, the construction of cooling towers and rerouting of cooling water pipes is not practical. 10.3.9.3 Technology Operational Feasibility The operation of MDCTs involves the addition of pumps, fans, and related equipment, which consume energy. These auxiliary energy requirements would subsequently reduce the station's electricity supply to the grid. Due to the relatively low height of the MDCTs, there would be potential for fogging and icing of the surrounding area. In addition, there would be PM emissions from the MDCTs, which are not present in the existing system. Additional noise would be generated due to operation of the fans and the cascading of water inside the towers. Water consumption would increase due to the larger evaporation rate of MDCTs compared to once - through cooling. Because Duke Energy controls the water level in Lake Norman, this evaluation assumes that Duke Energy would be able to release additional water to compensate for the increased evaporation and avoid potential shoreline impacts associated with evaporation. This evaluation also assumes that circulating water would be treated with a dispersant, mild steel corrosion inhibitor, chlorine, sulfuric acid, anti -foaming agent, and flocculent. Residual waste generated by cooling towers, such as scale, sediment, and sludge, will be increased compared to the existing cooling water system. The type and extent of waste would depend upon the quality of the source waterbody, the air quality, and the use of chemical additives in the circulating water. These effects are discussed further in Section 12. 10.3.9.4 Facility Operational Feasibility Due to Technology Retrofit The intake pipes are rated for a temperature variation between 40°F and 79°F, and the discharge pipes are rated for a maximum temperature of 103°F (Duke Power Company 1971a). During the warmest periods of the year, cold water from cooling towers would be as warm as 88°F and hot water from condensers would be as warm as 104°F, which are greater than the pipe ratings. If cooling towers are determined to be BTA for McGuire, additional evaluations would be needed to assess if existing pipes could withstand the greater temperatures. If the existing pipes cannot withstand the higher temperatures, then they would need to be replaced at significantly higher costs, or the station would need to reduce its power production rate as ambient temperatures rise, also at significant cost. Both of these outcomes would make cooling towers impractical. McGuire cooling water is withdrawn from Lake Norman, which is approximately 40 ft deep immediately in front of the CWIS. This depth of the water column allows relatively cool water to enter the system. For a few days each year, McGuire uses water from the LLI; currently for Unit 1 only. McGuire would lose the temperature advantage (1-2°F) if it would be retrofitted from once -through cooling to closed -cycle and would suffer a loss in turbine generation efficiency (this is discussed in greater detail in Section 12). Duke Energy 1 129 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Comprehensive Technical Feasibility and Cost Evaluation Study [§122.21(r)(10)] r 10.3.9.5 Feasibility of Cooling Towers (§122.21 (r)(1 0)(i)(D)) Based on the current analysis, retrofitting McGuire with cooling towers is impractical for the following reasons; The existing facility is not conducive to a cooling tower retrofit. A potential cooling tower retrofit at McGuire needs to be designed to a lower approach (assumed to be 10OF for this evaluation) to help reduce, to the extent practical, extended summertime power -reduced operations, and regular high backpressure energy penalty. However, the small approach temperature increases the tower costs. 2. The existing condensers have a 16°F AT, which means that the cooling towers need to be designed for a 160F range. SPX (2016b) determined that an NDCT is infeasible with 10°F approach and 160F range. As discussed in Section 10.3.4, hybrid towers and dry cooling systems are also infeasible at this site; as such, the only potentially feasible cooling tower type for this site is the MDCT. 3. MDCTs have a relatively high auxiliary energy requirements due to pump and fan operations; therefore, large nuclear stations such as McGuire typically use NDCTs. Additionally, MDCTs cause local and on -site fogging and icing, which, at a nuclear station, could interfere with site safety and security. 4. The topography and terrain that made this site suitable for inundation to create Lake Norman also make additional construction challenging. This evaluation assumed that the site would be built-up, up to 85 ft in some sections, to allow for construction. Having level terrain is important, not only for construction, but also for the proper operation of cooling towers. Other buildings or site topography should not interfere in air circulation. The earthwork required at this station is extensive and includes tree clearing, relocation of wetlands, destruction of tributaries, and over 1.5 million cubic yards of earth placement. See Section 10.3.12 for detailed information. 5. The site is crisscrossed with high voltage transmission lines and there is limited space for additional construction. The evaluation assumes that hypothetical construction activities would take appropriate safety precautions, however, if this technology were found to be BTA, additional extensive evaluations would need to be performed to assess safety and constructability. 6. Construction of the pipelines would result in significant disturbances to McGuire's existing infrastructure and extended disruptions to the station's operations. It is assumed that the existing contractor parking lot would be used for the Unit 1 cooling towers. Staff parking would need to be temporarily moved elsewhere for the period of construction (estimated to be approximately 3 years). 7. The complexity of the retrofit, along with work in WOTUS, would necessitate approvals from USNRC, USACE, and FERC and also would likely require a NEPA review. See Section 10.3.10 for additional details. Given the significant challenges outlined above, and considering that Lake Norman already meets the regulatory definition of CCRS (see Section 5), a closed -cycle cooling tower retrofit is not recommended at McGuire. Duke Energy 1 130 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� Comprehensive Technical Feasibility and Cost Evaluation Study [§122.21(r)(10)] r 10.3.10 Permitting Requirements Construction and operation of cooling towers at McGuire would trigger several additional federal, state, and local permitting efforts. These triggers and approvals include: 1. USNRC's nuclear safety evaluations and major modifications to a nuclear power plant; 2. FERC permitting for work within Lake Norman; 3. NCDEQ air quality permit under the Prevention of Significant Deterioration Program due to cooling tower emissions (see Section 12); 4. NCDEQ NPDES permit modification to account for cooling water system modifications (e.g., lower discharge flow with higher concentration of constituents, cooling tower blowdown, cooling tower chemical usage); 5. North Carolina water withdrawal registration updates"; 6. NCDEQ and USACE permits to fill and construct within wetlands and waterways; 7. Application for review under the NEPA; and 8. Local and state permits (e.g., construction and modified industrial stormwater). 10.3.11 Anticipated Schedule A potential implementation schedule of the hypothetical MDCTs is provided in Table 10-6. 71 Per North Carolina General Statutes, Chapter 143, Article 21 (G.S. 143-215.22H) Duke Energy 1 131 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Comprehensive Technical Feasibility and Cost Evaluation Study [§122.21(r)(10)] r Table 10-6. Hypothetical MDCT Implementation Schedule Sep-19 0 Submit NPDES renewal application and §316(b) information Feb-20 0.5 NPDES permit expiration Aug-20 1 Final BTA determination Feb-21 1.5 Engineering contract Aug-21 2 30 percent design Feb-22 2.5 Aug-22 3 Site investigations (geotechnical borings, topographical survey) Feb-23 3.5 Permit applications (see Section 10.3.10) Aug-23 4 Feb-24 4.5 Aug-24 5 Permitting (2-3 years )12 Feb-25 5.5 Aug-25 6 Feb-26 6.5 60 percent design Aug-26 7 Procurement contracts Feb-27 7.5 95 percent design Aug-27 8 Bid construction; select contractor Feb-28 8.5 General conditions; local permits Aug-28 9 Feb-29 9.5 Aug-29 10 Construction; both units would need to be in outage during the Feb-30 10.5 last 12 months of construction Aug-30 11 Feb-31 11.5 Aug-31 12 Commissioning Aug-32 13 In-service 72 FERC application can be submitted only after all other permits are obtained. Duke Energy 1 132 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� Comprehensive Technical Feasibility and Cost Evaluation Study [§122.21(r)(10)] r 10.3.12 Costs 10.3.12.1 Capital Costs Based on the conditions and assumptions stated herein, as well as a conceptual -level design, the AACE Class 4 estimates were developed for the hypothetical cooling tower retrofit at McGuire. The construction cost estimates utilize union wage rates specific to the Charlotte, NC metropolitan area, budgetary equipment pricing obtained from major equipment suppliers, and construction standard pricing (using RSMeans® data for construction costs in 2017). Capital costs are presented in 2017 U.S. dollars. The Class 4 estimate for the capital costs for outside labor and materials for the implementation of the hypothetical MDCTs at McGuire would be approximately $1.5 billion dollars (B) if all work were implemented in 2017, and includes the following components, which are also listed in Table 10-7: • Equipment costs (MDCT costs from SPX); • Existing infrastructure demolition costs; • Equipment costs, including cooling tower structural components and fill, circulating water pumps, booster pumps, replacement LLI pumps, make-up water pumps, and blowdown pumps; • Cooling tower basin construction; • Earth moving and civil work; • Piping and electrical work; • Lump sum allocations for underground utility identification and relocation; • Lump sum allocations for relocation and reconstruction of the Conventional Wastewater Treatment System; • Lump sum allocations for relocation of staff and contractor parking lots; • Construction of retaining walls; • Construction of the forebay in front of the existing intake; • Construction of hot and cold water pipelines and wet wells; • Engineering design; • Permitting the cooling towers, and intake and discharge modifications; • Non -water quality environmental and other impacts mitigation; • Owner's costs at 10 percent of total construction cost; and • Contingency at 25 percent of total construction cost. Duke Energy 1 133 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� Comprehensive Technical Feasibility and Cost Evaluation Study [§122.21(r)(10)] r Table 10-7. Hypothetical MDCT Capital Costs Construction Direct Costs Demolition $2.4 Civil/Site work $458.9 Mechanical $226.4 Structural $0.4 Architectural $12.0 Electrical and I&C $17.2 Subtotal Construction Direct Costs $717.2 Construction Indirect Costs Contractor Site Supervision $3.5 General Conditions $113.5 General Admin & Profit $125.1 Subtotal Construction Indirect Costs $242.1 Total Construction Cost $959.4 Design Engineering $86.1 Permitting $1.5 Project Management (Engineering) $35.9 Owners Costs $108.3 Contingency $297.4 TOTAL CAPITAL COST $1,488.5 10.3.12.2 O&M Costs O&M costs for the hypothetical MDCTs are estimated at approximately $6.4M based on actual O&M costs from nearby Catawba Nuclear Station per year (if incurred in 2017), and includes labor, chemicals73, solids removal, and parts replacement for mechanical components (pumps and fans). It is assumed that electricity consumption would be considered a net reduction in McGuire's power production and therefore would not be counted as an additional cost when estimating net present value (NPV). 73 This evaluation assumes that chlorine would be added as 12 percent sodium hypochlorite (NaCIO) one to three days per week for biofouling control. During chlorination, the blowdown would be dechlorinated. A dispersant and a corrosion/scale inhibitor would be added continuously at a low dose. Duke Energy 1 134 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Comprehensive Technical Feasibility and Cost Evaluation Study [§122.21(r)(10)] r Electricity consumption by fans and pumps is estimated at approximately 583 gigawatt-hours per year. 10.3.12.3 Environmental Mitigation Costs (from §122.21(r)(12)) The design incorporates potentially feasible impact mitigation measures listed below. No additional environmental mitigation efforts or costs are anticipated because additional measures are not expected to be technically feasible. Use of plume -abated MDCTs would have reduced the potential impact of ground -level fogging and icing; however, the increase in land required due to larger hypothetical plume - abated towers is not available on -site. • The following environmental mitigation measures have already been incorporated into the base design described above: o Reduce additional energy consumption by assuming the implementation of the most energy efficient equipment; and o Safety features by way of allowing separation distance between the station and the tower that would reduce ground level ice in the main station. 10.3.12.4 Facility -Level Compliance Costs (Annual and NPV) The NPV of this option is approximately $1,742M, with approximately $963M from capital costs and the rest from O&M costs (excluding electricity costs). The evaluation assumes that the hypothetical cooling towers would operate continuously using water of acceptable quality for the cooling tower fill; therefore the fill would not need to be replaced for remainder of the station's life. Per the schedule presented in Section 10.3.11, the cooling towers would be operational in early 2031. Table 10-8 overlays capital costs on the anticipated implementation schedule. O&M costs are presented in Table 10-9. Duke Energy 1 135 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal Comprehensive Technical Feasibility and Cost Evaluation Study [§122.21(r)(10)] Table 10-8. Hypothetical MDCT Capital Cost Outlay74 Sep-19 2019 0 Submit NPDES renewal application $0 $0 $0 and §316(b) information Feb-20 2020 0.5 NPDES permit expiration $0 $0 $0 Aug-20 2020 1 Final BTA determination $0 $0 $0 Feb-21 2021 1.5 Engineering Contract $2.2 $2.5 $1.9 Aug-21 2021 2 $31.8 $35.8 $27.6 30 percent design Feb-22 2022 2.5 $17.0 $19.7 $14.3 Aug-22 2022 3 Site investigations (geotechnical $17.0 $19.7 $14.3 borings, topographical survey) Feb-23 2023 3.5 Permit applications (see Section $3.3 $3.9 $2.6 Aug-23 2023 4 10.3.10) $3.3 $3.9 $2.6 Feb-24 2024 4.5 $2.2 $2.8 $1.8 Aug-24 2024 5 $2.2 $2.8 $1.8 Permitting Feb-25 2025 5.5 $2.2 $2.8 $1.7 Aug-25 2025 6 $2.2 $2.8 $1.7 Feb-26 2026 6.5 60 percent design $17.0 $22.2 $12.4 Aug-26 2026 7 Procurement contracts $17.0 $22.2 $12.4 Feb-27 2027 7.5 95 percent design $17.0 $22.9 $12.0 Aug-27 2027 8 Bid construction; select contractor $17.0 $22.9 $12.0 Feb-28 2028 8.5 General conditions; local permits $86.1 $119.2 $58.4 Aug-28 2028 9 $41.1 $56.9 $27.9 Feb-29 2029 9.5 $164.0 $233.8 $107.4 Aug-29 2029 10 Construction; both units would need $164.2 $234.1 $107.5 to be in outage during the last 12 Feb-30 2030 10.5 months of construction $328.1 $481.8 $207.4 Aug-30 2030 11 $339.7 $498.8 $214.7 Feb-31 2031 11.5 $175.8 $265.9 $107.2 Aug-31 2031 12 Commissioning $37.8 $57.2 $23.1 74 Capital costs are presented in 2017 U.S. dollars. Inflation escalation rate is assumed to be three percent per year. Duke Energy 1 136 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� Comprehensive Technical Feasibility and Cost Evaluation Study [§122.21(r)(10)] r Table 10-9. Hypothetical MDCT Annual O&M Cost Outlay (Excluding Electricity)75 I Unit 1 Unit 2 I Unit 1 I Unit 2 I Unit 1 I Unit 2031 3.2 3.2 4.8 4.8 2.0 2.0 2032 3.2 3.2 5.0 ` 5.0 1.9 1.9 2033 3.2 3.2 5.1 5.1 1.8 1.8 2034 3.2 3.2 5.3 5.3 1.8 1.8 2035 3.2 3.2 5.4 5.4 1.7 1.7 2036 3.2 3.2 5.6 5.6 1.6 1.6 2037 3.2 3.2 5.8 5.8 1.6 1.6 2038 3.2 3.2 6.0 6.0 1.5 1.5 2039 3.2 3.2 6.1 6.1 1.5 1.5 2040 3.2 3.2 6.3 6.3 1.4 1.4 2041 1.6 3.2 3.3 6.5 0.7 1.4 2042 -- 3.2 -- 6.7 -- 1.3 2043 -- 0.8 -- 1.7 -- 0.3 75 O&M costs are presented in 2017 U.S. dollars. Inflation escalation rate is assumed to be three percent per year. Duke Energy 1 137 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� Comprehensive Technical Feasibility and Cost Evaluation Study [§122.21(r)(10)] r 10.3.13 Uncertainty Key uncertainties associated with the CCRS evaluation are: • USNRC approval, permit issuances, and utility commission approval, if required, are assumed; • The hypothetical cooling tower locations are assumed to be available; • The Unit 2 towers are assumed to be built on a space that would be filled -in, and earth held back with two retaining walls. A detailed evaluation of its viability was not performed; • Clean fill needed to build up the Unit 2 cooling tower space is assumed to be readily available locally; • Construction of the two sets of cooling towers assumes a crew size of approximately 250 people. This many people are assumed to be manageable on -site when the station is operating. The potential interaction of regular maintenance outage staff and cooling tower project construction staff was not evaluated. Contractor parking allocated to the project is assumed to be sufficient. Sufficient numbers of necessary staff are assumed to be readily available; • Cooling tower COCs were based on Lake Norman TDS concentration. If lower than five COCs were required by a parameter of concern, larger blowdown and make-up systems may be needed; • Costs of hot and cold water pipelines are based measurements taken from aerial images, and site -specific geotechnical evaluation or pipeline alignment has not be performed for this project; • McGuire capacity factor would remain unchanged after the cooling tower retrofit; • McGuire operations and condenser performance are assumed to be consistent with the existing condensers; • No hazardous materials would be encountered; and • Figure 10-14 shows the preliminary new alignment for Highway 73 from Beatties Ford Road to Plant Access Road (MUMPO 2011). If Highway 73 is, in fact, modified, the alternate access routes and new parking lot costs may be different than presented here. Duke Energy 1 138 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Comprehensive Technical Feasibility and Cost Evaluation Study [§122.21(r)(10)] r Figure 10-14. Preliminary Study Corridor of New Alignment of Highway 73 Widening and Relocation Project (MUMPO 2011) Duke Energy 1 139 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� Comprehensive Technical Feasibility and Cost Evaluation Study [§122.21(r)(10)] r 10.4 Fine -Mesh and Fine -Slot Screen Retrofit [§122.21(r)(10)(i)] The regulations at §122.21(r)(10)(i) require an evaluation of the technical feasibility of FMS with a mesh size of 2.0 mm or smaller. FMS are designed to reduce entrainment compared to coarse -mesh screens76, which are currently installed on the traveling water screens of the Main Intake at McGuire. 10.4.1 Existing CWIS and Screens Relevant portions of the Main Intake with respect to FMS are described herein; detailed descriptions and drawings are provided Sections 3 and 5 of this document. The 246.58-ft-wide Main Intake withdraws water from between elevation 715 ft msl and 745 ft msl (Duke Energy 2001). Water moves from Lake Norman through 16 intake bays, eight per unit, with trash racks and traveling water screens. The intake bays then combine in sets of two to form eight, 26.0-ft wide bays (four bays per unit) with one circulating water pump per bay. The Main Intake houses eight circulating water pumps, four per unit. The invert of the screen -house structure is at 715 ft msl. The operating deck is at 770 ft msl. The invert of the CWIS rises from 716 ft msl after the traveling water screens to 722 ft msl at the end of the intake bay. The bell mouth inlets of the circulating water pumps are at 725.8 ft msl. The discharge pipes from the pumps have a centerline elevation of 760.5 ft msl (Duke Power Company 1974). The 11.2-ft-wide traveling water screens are located 23 ft downstream of the trash racks. The screens are backwashed with untreated lake water once -per -week per screen unless more cleanings are required during periods of high debris loading. The traveling water screens have 10-ft wide baskets and 3/8-inch stainless steel mesh panels; the spray wash pumps are rated to clean two screens at one time using a high pressure spray (HDR 2015). The debris is washed into a debris sluice and discharged into trash baskets on either side of the intake, and the screenwash water is returned to Lake Norman. The calculated velocity approaching the traveling water screens of both units is the same, since both units have identical flow through the traveling water screens. The FERC-authorized maximum (non - emergency) drawdown water elevation for Lake Norman is 751 ft msl. At this elevation, the design through -screen velocity (TSV) at the Main Intake is approximately 1.3 fps. At normal pond elevation (756 ft msl), the calculated TSV velocity is 1.2 fps. At full pond elevation (760 ft msl), the calculated TSV is approximately 1.0 fps. These estimates assume that the screens are clean, otherwise, TSV would increase. Engineering estimates of TSV are provided in Appendix 10-D. The LLI is used to supplement the water from the Main Intake. The LLI is located near the base of the dam and withdraws water from 127-inch ID pipes with a centerline elevation of 715.92 ft msl (Duke Power Company 1974; Duke Power Company 1971 a). The LLI intake pipes withdraw water 76 Coarse mesh usually screens out larger organisms (e.g., juvenile and adult finfish) and debris and does not exclude smaller organisms (e.g., egg and larval finfish). Duke Energy 1 140 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� Comprehensive Technical Feasibility and Cost Evaluation Study [§122.21(r)(10)] r from a depth between 654 ft msl and 670 ft msl (Duke Energy 2001). The LLI structure is composed of upper and lower sections. The lower section is composed of flat screen panels; the upper section includes box screens extending from the face of the LLI structure. The LLI has a total screen area of approximately 1,680.9 square feet (Duke Energy 2008). The LLI is inspected and cleaned annually by divers. The TSV has been estimated to be approximately 0.84 fps with three LLI pumps operating, 0.58 fps with two LLI pumps operating, and 0.32 fps with one LLI pump operating. 10.4.2 Typical Screen Types FMS fall into two main groups: fine -mesh traveling water screens and fine -slot wedgewire screens. The suitability of these screen types depends on the source waterbody (e.g., depth near the intake, silt and debris loading, biological activity, extent of navigation) and the type and extent of water withdrawal (e.g., the withdrawal rate, screen operating patterns). Both types of screens are meant to reduce the amount of debris and aquatic organisms that enter the cooling water system, but their design and operational characteristics are different. Traveling screens are metallic or polymer -based, and are approximately 10 ft wide and approximately 40 ft deep" (with about 15-20 ft submerged) and rotate along a continuous belt. These are rotated and cleaned based on a timer or pressure differential (Figure 10-15).The screens may have several speeds of rotation, which can be changed depending on the debris loading. Traveling water screens are typically installed in through -flow or dual -flow alignment. Through -flow screens are oriented parallel to the face of the CWIS, whereas dual -flow screens are oriented perpendicular to the face of the CWIS. Through -flow screens utilize the front of the screens to accept incoming flow, whereas dual -flow screens use two sides of mesh to accept incoming flow. As such, dual -flow screens typically have more available screen area than through -flow screens, which can comparatively reduce TSV and headloss. However, the installation of dual -flow screens is often more difficult than the installation of through -flow screens and can require extensive CWIS modification, especially when considering a retrofit of dual -flow screens at a CWIS where through - flow screens are already in use. Extensive CWIS modification could impact station reliability and nuclear safety at McGuire. For the purposes of this evaluation, fine -mesh through -flow traveling water screens are under consideration at McGuire. Fine -mesh dual -flow traveling water screens are not being considered at McGuire due to the likelihood of increased retrofit complexity, extensive CWIS modification, and increased costs. 7' The width and depth of traveling screens are typically dependent on station -specific needs and site conditions. Duke Energy 1 141 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� Comprehensive Technical Feasibility and Cost Evaluation Study [§122.21(r)(10)] r LP Fish S ra r' zo LP Fis S Fish Return =0 HP Debris pr Debris Return Figure 10-15. Schematic of a Through -flow Traveling Water Screen (left) and Close -Up View of Fish Buckets, Fish Return, and Debris Return (right) (courtesy of Evoqua Water Technologies 2016) Wedgewire screens are stationary passive screens that are typically designed to maintain through - slot velocity of 0.5 fps or lower. These are metallic screens that are typically cylindrical in shape, although several other shapes are also now available as discussed below (see Figure 10-16). Figure 10-16. Wedgewire Screens out of Water (Image Courtesy of ISI 2016) Both traveling screens and wedgewire screens can be coarse mesh (>2.0-mm) or fine mesh (:52.0- mm). The Rule requires the evaluation of FMS. Section 10.4.3 evaluates the feasibility of utilizing fine -mesh traveling screens at McGuire. Section 10.4.4 evaluates the feasibility of utilizing fine -slot wedgewire screens. Duke Energy 1 142 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� Comprehensive Technical Feasibility and Cost Evaluation Study [§122.21(r)(10)] r 10.4.3 Fine -mesh Traveling Water Screens Traveling water screens span the entire water column and extend above the high water elevation of the waterbody to avoid overtopping of the screen. On traditional traveling screens, screen panels are attached to the rotating belts and travel in a loop. The screens travel upward on the upstream side and travel downward on the downstream side. As the screen panels breach the water surface at the top of the structure, a pressure wash system sprays water against the screens to remove the debris (Figure 10-15). Typical systems include a high-pressure spray18. The debris is typically deposited into a debris trough for disposal. Conventional traveling screens whose main goal is debris removal are typically operated either on a timer or are set up with a pressure differential monitoring system, which actuates the screens when the pressure differential across the screens reaches a set threshold level. The screens are operated on an intermittent basis to avoid wear and tear and to reduce maintenance costs (USEPA 2014). Conventional traveling screens are cleaned with a high-pressure wash system. However, the USEPA states that modified traveling screens must have continuous or near -continuous rotation of screens to recover impinged fish as soon as practical (USEPA 2014). Traveling screens with fish protection features have low- and high-pressure wash spray headers on the descending side of the screen. The low pressure spray wash is used prior to the high pressure spray to improve survival of organisms. Low pressure spray wash systems and fish -friendly screen mesh79 help reduce fish mortality. Fish -friendly baskets hold water to prevent air exposure to fish, and they include a lip on the bucket to reduce turbulence. Studies using fish friendly traveling water screens with coarse -mesh have documented improvements in the survival of impinged fish compared to stationary coarse mesh screens. But studies and literature on the efficacy of fish friendly traveling water screens with FMS is sparse. Available literature and experience indicate that the efficacy of FMS is site and screen -specific. 10.4.3.1 Fine -Mesh Screen Selection The Rule requires the evaluation of engineering feasibility and costs for entrainment reducing technologies including "fine -mesh screens with a mesh size of 2 millimeters or smaller" at §122.21(r)(10). While screen technologies with 2.0-mm and smaller openings may be considered, commercially available technologies are generally limited to Ristroph modified traveling screens, wedgewire screens (cylindrical and flat panel), and perforated plate (typically flat panel). The following approach was developed to assess entrainment at McGuire to determine which mesh size(s) should be evaluated as a part of the analyses required in §122.21(r)(10)-(12): 1. Engage screen vendors to confirm commercially available FMS mesh/slot sizes and associated percent open areas to facilitate TSV calculations. 78 Screens designed for fish -protection also include low-pressure sprays, which remove impinged organisms into a fish return trough prior to the high-pressure spray wash removes debris into the debris trough. 79 The fish -friendly mesh is typically constructed of smooth, flat wire to prevent descaling of fish. Duke Energy 1 143 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Comprehensive Technical Feasibility and Cost Evaluation Study [§122.21(r)(10)] r 2. Evaluate technical feasibility of each mesh relative to headloss, operational constraints, and other site -specific engineering factors. 3. Evaluate site -specific entrainment as discussed in Appendix 10-E. 4. Finally, after consideration of the above, use Best Professional Judgment to select a mesh size or sizes for advancement in evaluations conducted in §122.21(r)(10)-(12). Based on discussions with screen manufacturers including ISI, Bilfinger, Ovivo, and Evoqua, wedgewire screens can be sourced in virtually any slot size requested, while traveling screens are generally limited to mesh sizes of 0.5, 0.75, 1.0 and 2.0-mm. 10.4.3.2 Mesh Size As discussed in Appendix 10-E, based on biological and engineering input, screens with 2.0-mm mesh sizes have been selected for further evaluation at McGuire because they appear to be potentially feasible based on the following factors, however, additional evaluations would be needed prior to their implementation: • Through -screen velocity; • Headloss; • Site -specific debris loading conditions; and • Biological efficacy. The TSV for all FMS options evaluated exceeded 3 fps for the scenario that assumed 50 percent screen clogging and the FERC-maximum drawdown elevation. The likelihood of this scenario occurring would need to be evaluated further if the FMS were considered for implementation at McGuire. 10.4.3.3 Through -Screen Velocity Fine -mesh screens use higher gauge (thinner) wire. Typically, finer mesh sizes have thinner wire; therefore fine mesh is not as strong as coarse mesh and a reinforced backing (approximately 1-inch square) is typically used. Some facilities overlay fine mesh on the existing coarse mesh. Either way, as the mesh size gets smaller, the open area available for water flow also gets smaller, and the resulting TSV increases unless the intake structure is expanded with additional intake bays to maintain a lower TSV. In the absence of an intake expansion, replacing existing coarse mesh with fine mesh impacts screen performance and efficacy in two key ways: 1. It increases the TSV, and thereby the velocity that larvae and juveniles need to swim away from, or for those that cannot swim away, the velocity with which organisms collide with the mesh. Exclusion and TSV both impact survival, therefore the selection of fine -mesh size needs to strike a balance between the rate of exclusion and increased mortality due to higher TSV. 2. It increases the headloss across the screens. Screens are designed for a pre -determined maximum headloss for normal operation (typically between 2 and 5 ft) and a maximum headloss at the start of screen operation (typically between 5 and 10 ft). If the water level difference across the screen increases beyond the rated headloss, the screen can collapse. If the screen does not collapse under increased headloss conditions, the reduction in water Duke Energy 1 144 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Comprehensive Technical Feasibility and Cost Evaluation Study [§122.21(r)(10)] r level can lead to pump cavitation and potentially lead to pump failure. Additional evaluation of pump submergence and hydraulics would be required if FMS were considered for implementation at McGuire. This evaluation assesses screen headloss under various mesh size and fouling conditions. Using TSV and headloss data from Figure 10-17, Table 10-10 presents estimated headloss for 2.0- mm mesh and presents estimated headloss under various clogging and water depth scenarios. Through -Screen Velocity vs. Headloss Curves for various Screen Cleanliness Values 120 +HL{3{$) y= 0.2877xr-0.0002x+ 8.9236 R2=1 fHL{.25x_Sj 133 x �l� H L{.125x. z5j yj!—HL{3mmx3mmj tHL{2mmx2mm] tHL{lmmxlmmj 80 0.2072xz + 0.0032x + 4.0799 40 20 Y 1x+.1v 1 y = 0.0996x2 - 0.0051m + 1.0656 RZ=1 y = 0.0545xr+ 0.0051x + 0.458 R2 = 1 y = 0.048W + 0.0007x + 0.3439 R2=1 y = 0.0457x2 - 0.0413x + 0.2966 0 R =1 0 2 4 6 8 10 12 14 16 18 Through -Screen Velocity (fps) Figure 10-17. Through -Screen Velocity and Headloss Curves (US Filter 2016) Duke Energy 1 145 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal �� Comprehensive Technical Feasibility and Cost Evaluation Study [§122.21(r)(10)] Table 10-10. Through -Screen Velocity and Headloss for 2.0-mm and 3/8-inch Mesh 0 51 1.7 4.7 1.5 4.6 1.4 4.5 2.0-mm x 2.0- 1-inch 15 44 2.0 4.9 1.8 4.8 1.6 4.6 mm 50 26 3.5 6.6 3.0 6.0 2.8 5.7 3/8-inch None 0 68 1.3 0.4 1.2 0.4 1.0 0.3 Engineering estimates of fine -mesh through -screen velocities are provided in Appendix 10-F. 10.4.3.4 Impact of Headloss As described in Section 10.4.1, the pump bell is at elevation 725.8 ft and the FERC-authorized maximum (non -emergency) drawdown water elevation for Lake Norman is 751 ft; a difference of 25.2 ft that is potentially available for pump drawdown and total headloss between the lake and the pumps. Even if the screens are designed to withstand 5 to 10 ft of headloss across the screens at startup, the existing McGuire system cannot accommodate 10 ft of headloss. The maximum water level difference available is 9.2 ft. If the water level would drop by more than 9.2 ft, pumps would not be able to take suction. If FMS were selected as BTA at McGuire, pumps would need to be evaluated to understand the drawdown that they impose on the water surface and assess the minimum water level needed behind the screens to provide necessary net positive suction head. 10.4.3.5 Potential Retrofit Options (§122.21(r)(10)(i)(A)) A coarse -mesh to fine -mesh retrofit may be implemented in several ways. The two typical methods include80: • Replacing the coarse -mesh screens with FMS. • Installing fine -mesh overlays on the coarse -mesh baskets, on a permanent or seasonal basis. Each of these options is discussed below, including their applicability at McGuire. Replace Existing Coarse -Mesh Screens with FMS The screens at McGuire have coarse mesh (i.e., 3/8-inch). This option assumes that the coarse - mesh screen panels will be permanently replaced with FMS panels. Survival of aquatic organisms 80 While expanding the intake may be an option at certain facilities, given the size and space within the embayment (Section 10.4.1), intake expansion is not an available option at McGuire therefore is not discussed further. Duke Energy 1 146 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� Comprehensive Technical Feasibility and Cost Evaluation Study [§122.21(r)(10)] r require each panel to include a fish bucket that holds water, and for the screens to be rotated continuously or near -continuously. Water -filled buckets increase the weight of the screens. Continuous rotation of heavier screens requires more powerful motors and a more robust chain. Screens that provide fish protection require two sets of screen spray wash nozzles: the low-pressure wash system to gently wash aquatic organisms into the fish trough, and the high-pressure wash system to clean the screen of debris. The current intake is configured to wash two screens at a time. The increased water use per screen and continuous rotation and washing require additional water at the intake. Owing to the heavier screens, continuous rotation and washing, this option requires that the screens be replaced. Merely replacing the screen panels while keeping the same chain, frame, screen motors, rotors, gaskets, belts, and pumps is considered impractical. Two vertical guide slots that extend from the intake deck elevation to the intake floor elevation hold each traveling water screen in place. If the screens are lifted out of water regularly (approximately once per year) then there may be only minor corrosion in the guide slots. Under that scenario, lifting screens out of water would be relatively easy; the older screen may be lifted out and the new screen lowered to its position within a single day after the crane is setup. Reconnecting electrical and water connections would also require additional time. Alternatively, if the screens are not lifted out of water regularly, and the screen guide is corroded within the slot, the screen well would need to be dewatered and sections of screens may need to be cut out and removed from the screen well. This can take a week or longer per screen. Installing a cofferdam and dewatering would also require additional time. Most screen replacement efforts require the screens to be hydraulically isolated from the pump to protect the field personnel and to protect the pumps. The screen replacement may be performed while the intake bay is wet (but pumps are turned off) with divers setting the boot seal. Seasonal Fine -Mesh Overlay Another potential option is to use fine -mesh overlays. In this option, fine -mesh panels would be bolted on over the coarse -mesh panels, and the coarse -mesh would function as the necessary back- up mesh. The fine -mesh panels may be bolted on permanently or seasonally. Seasonal overlays would be bolted on prior to the entrainment season and removed after the entrainment season (see Appendix 10-E for additional information). Overlays have greater TSV impacts because the velocity through the composite mesh is greater than the velocity through the fine mesh only. With the seasonal overlay option, the screens would need to be modified with fish buckets (that hold water during screen ascent). As discussed previously, the entire screen would ultimately need to be replaced because the chain, motors, screenwash headers, and location of the headers would all require modification. Some facilities bolt on fine -mesh panels on a seasonal basis, but the screen frame needs to be amenable to such a seasonal retrofit. In addition to the fish buckets, a fish return trough would also be required. Bolting and unbolting screen panels on and off before and after the entrainment period is time- consuming and labor-intensive, and would require coordination to ensure that the fine -mesh panels were in place prior to the start of the peak entrainment period. Duke Energy 1 147 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� Comprehensive Technical Feasibility and Cost Evaluation Study [§122.21(r)(10)] r The conventional traveling screens at McGuire are 0.75 horsepower (hp) screens (Link -Belt Company 2006). Screens that would provide fish protection at McGuire would require 2.0 hp low pressure screen wash pumps (Evoqua 2017). Therefore, the existing McGuire screens cannot be repurposed as FMS for seasonal or year-round use. This option is not evaluated further. Aquatic Organism Return System An aquatic organism return system is integral to the operation of a fine -mesh aquatic organism protection system. The spray headers for each screen would require 484 gpm of water and each of two aquatic organism return troughs (one for each unit) would need another 192 gpm as trough make-up water$'. In total, approximately 4,400 gpm of water would be required for the hypothetical FMS aquatic organism return system82. The 4,400 gpm would be conveyed via two aquatic organism return troughs, for a flow of 2,200 gpm per trough. Each aquatic organism return trough would be constructed of smooth high -density polyethylene 18-inch half pipe with 12-inch vertical walls. The system would maintain approximately 4 fps water velocity in the troughs. The terminus would be located beyond the peninsula, as shown on Figure 10-18 to avoid re -impingement. The aquatic organism return system would be pile -supported. Potential Fine -mesh Retrofit of the LLI The LLI supplies nuclear safety water, and per Section 125.94(f) of the Rule, would not be modified. Additionally, the LLI withdraws water from the hypolimnion where the ichthyoplankton density is anticipated to be lower (based on fish habitat use by life stage); therefore, retrofitting the LLI would not be needed since ichthyoplankton densities are expected to be relatively low in the hypolimnion. 81 Per Evoqua (2017), each screen would require 238 gpm of wash water at 80 psi for the debris header, 176 gpm of wash water at 15 psi for the dual aquatic organism return system header, and 70 gpm of wash water at 7 psi for the auxiliary aquatic organism return system header. Another 192 gpm of water per trough would be needed to maintain flowing water in the troughs. This trough make-up water flow is common to all screens that discharge to the troughs. 82 This assumes that half of the water from the aquatic organism return system headers and auxiliary aquatic organism return system headers would be routed to the troughs, with the additional half of the water spilling into the screen wells. The additional 192 gpm (per trough) of trough make-up water would continuously feed the troughs. Duke Energy 1 148 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� Comprehensive Technical Feasibility and Cost Evaluation Study [§122.21(r)(10)] r Figure 10-18. Aquatic Organism Return System for the Hypothetical FMS Retrofit Duke Energy 1 149 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� Comprehensive Technical Feasibility and Cost Evaluation Study [§122.21(r)(10)] r 10.4.3.6 Feasibility Discussion Construction Feasibility Replacing the existing coarse -mesh screens with fine- mesh screens appears feasible but would result in increased, yet operationally acceptable, TSV. While bolting fine -mesh baskets onto the existing coarse -mesh baskets may be feasible from a construction standpoint, this effort would be labor intensive and time consuming and result in possible screen damage; therefore, it is deemed impractical. Technology Operational Feasibility Because fine mesh incorporates a smaller open area than the coarse -mesh currently installed at McGuire, fouling and clogging of the screens would likely increase considerably. For improved fish protection83, and to reduce fouling and clogging, this evaluation assumes that the screens would be operated continuously. Continuous rotation increases wear and tear of the screens. Fine -mesh fabric is prone to tearing. As such, converting from the existing coarse -mesh traveling screens with intermittent rotation to FMS with continuous rotation would increase the maintenance burden on the station. Facility Operational Feasibility Installation of FMS would increase the headloss across the screens, which would reduce the operator margin on pumps. Potential cavitation of pumps due to a drop in water level could impact safe and proper operation of the cooling water system, if FMS were determined to be BTA, extensive pump tests would need to be performed to assess the allowable drop in water level behind the screens for reliable pump operation. Practicality and Feasibility of Fine -Mesh Screens With respect to retrofit feasibility, construction feasibility, and operational feasibility, this evaluation deems FMS implementation as inconclusive. Additional extensive evaluations would be required to confirm feasibility at McGuire, particularly relative to debris and fouling. Considering the high level of uncertainty and the potential impacts to TSV, increased operations burden, and maintenance due to fouling and clogging, FMS are deemed impracticable. However, pursuant to requirements of the Rule, the following sections will evaluate permitting requirements, construction schedule, cost to Duke Energy and cost to society of replacing the existing coarse -mesh screens with FMS. Potential additional evaluations needed include: The drawdown caused by pumps, and the minimum water surface elevation allowable behind the screens. 83 As discussed under Section 122.21(r)(9), the density of impingeable and entrainable organisms in Lake Norman near McGuire is low. Duke Energy 1 150 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� Comprehensive Technical Feasibility and Cost Evaluation Study [§122.21(r)(10)] r 2. Debris loading study to understand extent of short-term impacts. 3. Fish survival and technology optimization study. 10.4.3.7 Permitting Requirements Installation and operation of fine -mesh traveling screens would likely trigger additional federal, state, and local permitting efforts. These triggers and approvals include: 1. USNRC's nuclear safety evaluations; 2. NCDEQ NPDES permit modification prior to commissioning new equipment; 3. USACE and FERC approval to drive piles to support the aquatic organism return system; and 4. Local and state construction permits 10.4.3.8 Anticipated Schedule An implementation schedule of the hypothetical FMS retrofit is provided in Table 10-11. Table 10-11. Hypothetical Fine -mesh Modified-Ristroph Screen Implementation Schedule Submit NPDES renewal application and §316(b) Sep-2019 0 information Feb-2020 „ 0.5 NPDES permit expiration Aug-2020 1 Final BTA determination Feb-2021 1.5 Pump evaluation and debris loading evaluation Aug-2021 2 Feb-2022 2.5 Engineering contract, site investigations Aug-2022 3 Design and permit applications Feb-2023 3.5 Aug-2023 4 Procure screens, permits, bid construction work, select Feb-2024 4.5 contractor Mar-2025 5 Install aquatic organism return system Apr-2025 5.5 Unit 1 - four screens Apr-2026 6 Unit 2 - four screens Oct-2026 6.5 Unit 1 - four screens Oct-2027 7 Unit 2 - four screens 84 The schedule has been adjusted so that the screen replacements would coincide with McGuire maintenance outages. Duke Energy 1 151 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� Comprehensive Technical Feasibility and Cost Evaluation Study [§122.21(r)(10)] r 10.4.3.9 Costs (§122.21(r)(10)(iii)) Costs associated with replacing the coarse -mesh traveling screens with FMS and installing an aquatic organism return system are presented below. Capital Costs The initial cost of implementing modified-Ristroph fine -mesh traveling screens at McGuire, based on an AACE Class 4 estimate, would be approximately $34M if the design, permitting, evaluations, procurement, and installation, were performed in 2017 (Table 10-12). This includes the following installed components: • Eight modified-Ristroph traveling water screens per unit (Evoqua 2017); • Two 860-ft long aquatic organism return system to return fish, larvae, and eggs to Lake Norman; • New screenwash pumps as suggested by Evoqua (2017); • One year of pump evaluations and debris loading evaluations; • Fish survival and technology optimization study; • Allowances for engineering, permitting, construction management; • Owner's costs at 10 percent of project costs; and • Contingency at 25 percent of project costs. Duke Energy 1 152 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� Comprehensive Technical Feasibility and Cost Evaluation Study [§122.21(r)(10)] r Table 10-12. Hypothetical Fine -mesh Modified-Ristroph Screen Capital Costs Construction Direct Costs Cost of screens _■ Cost of installing screens $2.62 Aquatic organism return system . Installed screenwash pumps $0.14 Electrical and I&C $0.59= Subtotal Construction Direct Costs $13.29 Construction Indirect Costs Contractor Site Supervision $0.76 General Conditions85 $7.04 General Admin & Profit $1.99 Subtotal Construction Indirect Costs $9.80 Total Construction Cost $23.09 Design Engineering $0.80 Permitting $0.40 Project Management $0.27 Pump Evaluation and Debris Loading Evaluation $0.25 Fish Survival and Technology Optimization Study $0.25 Owners Costs $2.51 Contingency $6.89 TOTAL CAPITAL COST $34.45 85 The General Conditions estimated cost includes: mobilization/demobilization (11 percent of direct costs given four installation events); performance bond (2.5 percent of direct costs); insurance (1.5 percent of direct costs); and metal work (5 percent of direct costs). Duke Energy 1 153 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� Comprehensive Technical Feasibility and Cost Evaluation Study [§122.21(r)(10)] r O&M Costs Annual O&M costs are estimated to be approximately $2.42M assuming that: On average, 4 full-time equivalent staff would provide maintenance for the modified-Ristroph fine -mesh traveling screens, organism return system and associated pumps. • Continuous rotation of screens results in additional wear and tear, therefore annual parts repair and replacement would be approximately 6 percent of capital costs. • No additional chemicals would be required. Key cost O&M components are provided in Table 10-13. Table 10-13. Hypothetical Fine -mesh Modified-Ristroph Screen Annual O&M Costs Labor Parts Replacement and Maintenance $0.54 $1.88 Total $2.42 Each screen would also consume approximately 20 megawatt -hours (MWhr) per year more energy than the existing coarse -mesh screens that are intermittently rotated. In addition, continuous screen washing would consume approximately 84 MWhr per year per screen. These increases in energy costs are not included in Table 10-13 because they are accounted for in the Power Systems cost (see Table 10-17). Environmental Mitigation Costs (§122.21(r)(12)) There are no significant environmental mitigation measures associated with this technology. Facility -Level Compliance Cost (Annual and NP10 The NPV of this option is approximately $67M, with approximately $45M from capital costs and the rest from O&M costs (including electricity costs). The evaluation assumes that the screens would be replaced once per 8 years through Operating License expiration in 2041 and 2043 for Units 1 and 2, respectively. Therefore, the NPV estimate assumes that each screen would be replaced once. Per the schedule presented herein (Anticipated Schedule), this evaluation assumes that four Unit 1 screens and the aquatic organism return system would be operational in 2025; that four Unit 2 screens would be available in 2026; that the remaining Unit 1 screens would also be available in 2026; and the last four screens for Unit 2 would be available in 2027. The screen replacements attempt to coincide with unit maintenance schedules so that the screens may be replaced without an outage. Table 10-14 overlays capital costs associated with FMS on the tentative schedule; Table 10-15 gives O&M costs during operations period. Duke Energy 1 154 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal �� Comprehensive Technical Feasibility and Cost Evaluation Study [§122.21(r)(10)] Table 10-14. Hypothetical Fine -mesh Modified-Ristroph Screen Capital Cost Outlay" Submit NPDES renewal Sep-19 2019 application and §316(b) $0 $0 $0 information Feb-20 2020 Permit expiration $0 $0 $0 Aug-20 2020 Final BTA determination $0 $0 $0 Feb-21 2021 Pump evaluation and debris $0.3 $0.4 $0.3 Aug-21 2021 loading evaluation $0.3 $0.4 $0.3 Feb-22 2022 Engineering Contract, site $0.4 $0.4 $0.6 investigations Aug-22 2022 $0.7 $0.8 $0.6 Design and permit applications Feb-23 2023 $0.9 $1.1 $0.7 Aug-23 2023 Procure screens, permits, bid $3.1 $3.7 $2.5 construction work, select Feb-24 2024 contractor $3.7 $4.6 $2.9 Mar-25 2025 Install aquatic organism return $7.5 $9.5 $5.7 system Apr-25 2025 Unit 1 - install four FMS87 $6.8 $8.7 $5.2 Apr-26 2026 Unit 2 - install four FMS $3.5 $4.6 $2.6 Oct-26 2026 Unit 1 - install four FMS $3.5 $4.6 $2.6 Oct-27 2027 Unit 2 - install four FMS $3.5 $4.7 $2.5 2033 Unit 1 - replace four screens $3.5 $5.6 $2.0 2034 Unit 2 - replace four screens $3.5 $5.8 $1.9 2034 Unit 1 - replace four screens $3.5 $5.8 $1.9 2035 Unit 2 - replace four screens $3.5 $6.0 $1.9 86 Capital costs are presented in 2017 U.S. dollars. Inflation escalation rate is assumed to be three percent per year. 87 For the purposes of cost projections, it is assumed that the first screen installation would have associated mechanical, electrical, instrumentation, and controls costs that the remaining installations would not have. Duke Energy 1 155 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal �� Comprehensive Technical Feasibility and Cost Evaluation Study [§122.21 (r)(1 0)] Table 10-15. Hypothetical Fine -mesh Modified-Ristroph Screen Annual O&M Cost Outlay" 2017 •: •: D. 2025 $0.6 $0 � $0.8 $0' $0.5 $0 2026 $1.3 $1.3 $1.6 $1.6 $0.9 $0.9 2027 $1.3 $1.3 .� $1.7 $1.7 $0.9 $0.9 2028 $1.3 $1.3 $1.7 $1.7 $0.9 $0.9 2029 $1.3 $1.3 $1.8 $1.8 $0.8 $0.8 2030 $1.3 $1.3 $1.8 $1.8 $0.8 $0.8 2031 $1.3 $1.3 $1.9 $1.9 $0.8 $0.8 2032 $1.3 $1.3 $2.0 $2.0 $0.7 $0.7 2033 $1.3 $1.3 $2.0 $2.0 $0.7 $0.7 2034 $1.3 $1.3 $2.1 $2.1 $0.7 $0.7 2035 $1.3 $1.3 $2.1 $2.1 $0.7 $0.7 2036 $1.3 $1.3 $2.2 $2.2 $0.6 $0.6 2037 $1.3 $1.3 $2.3 $2.3 $0.6 $0.6 2038 $1.3 $1.3 $2.3 $2.3 $0.6 $0.6 2039 $1.3 $1.3 $2.4 $2.4 $0.6 $0.6 2040 $1.3 $1.3 $2.5 $2.5 $0.6 $0.6 2041 $1.3 $1.3 $2.6 $2.6 $0.5 $0.5 2042 $0 $1.3 $0 $2.6 $0 $0.5 2043 $0 $0.3 $0 $0.7 $0 $0.1 10.4.3.10 Uncertainty Key uncertainties associated with replacing the conventional traveling screens with fine- mesh modified-Ristroph traveling screens include: • This evaluation assumed that screens would be replaced during regular maintenance outages, and would not require an outage specifically for screen replacement. An outage specifically for screen replacement would increase the technology implementation costs. • Replacement cost of screens. This evaluation assumes that the existing screens may be lifted out of its well using a crane. If the screens are rusted in their slots or the existing 88 O&M costs are presented in 2017 U.S. dollars. Inflation escalation rate is assumed to be three percent per year. Duke Energy 1 156 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� Comprehensive Technical Feasibility and Cost Evaluation Study [§122.21(r)(10)] r concrete wells require repairs, cutting and replacing the screens would be a greater effort than estimated herein. 10.4.4 Fine -Slot Wedgewire Screens 10.4.4.1 Description of Technology A wedgewire screen is a passive intake in that the screen is designed so that the circulating water pumps do not withdraw water from the waterbody; instead, the hydraulic head differential between the waterbody and a wet well causes water to flow into the wet well from which the pumps take suction. While other shapes may be available, cylindrical wedgewire tee -screens are reviewed in this evaluation89. While mesh openings for conventional traveling water screens are usually square and punched into the screen face or woven using metal wire, a wedgewire screen is constructed with wedge-shaped, or "V" shaped, wires welded onto an internal, cylindrical frame. The screens are fabricated using a single continuous wire wrapped around an array of internal support rods in a spiral fashion, producing a strong cage -like structure with relatively high percentage of open area for water flow. The spaces between the wires, referred to as slots, are long openings that run lengthwise along the screen or form a spiral along its axis. They provide for low TSV and smaller openings than typical coarse -mesh screens. The maximum distance between the adjacent wires is referred to as the slot size (USEPA 2014). Wedgewire screens often have a debris deflector on the upstream side of the structure and are typically placed in parallel with the direction of the current (USEPA 2014). The entire screening structure (i.e., screen and associated piping) is typically submerged in the waterbody (USEPA 2014). In installations for large water withdrawals, multiple screens may be utilized in an intake system, which would require the screens be attached to a manifold. Wedgewire screens are typically located within the water column to avoid damage from ice and debris at the surface and potential scour and impact to the waterbody bed. Depending on site specific conditions, wedgewire screens may be located right at the water surface or almost at the bottom of the waterbody (by constructing a concrete slab). Submerged structures, such as wedgewire screens, would need to be properly delineated and permitted to minimize potential impacts to recreational uses of Lake Norman. Screens can be produced with various slot widths and in various cylinder diameters and lengths to accommodate flow needs. Wedgewire screens are installed in the source waterbody such that debris and fish are not collected or directly handled or transported by the technology and the screens are engineered to have low TSV (typically less than 0.5 fps after accounting for some loss of open area associated with debris). These characteristics result in potentially high survival rates for fish that contact the screens. 89 Other wedgewire screen shapes include conical, pyramidal, tee and box screens; these shapes are often designed for unique site requirements, such as shallow water depths or for existing sump retrofits. Duke Energy 1 157 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� Comprehensive Technical Feasibility and Cost Evaluation Study [§122.21(r)(10)] r 10.4.4.2 Screen Cleaning and Maintenance Due to the potential for debris accumulation and plugging, manual maintenance cleanings of the wedgewire screens would be required at a minimum; however, wedgewire screens are often installed with an automated cleaning system. Manual cleanings typically involve deploying a dive team to clean the screens by hand using coarse brushes or other cleaning tools. Manual cleanings may be carried out in combination with automated cleaning systems running at a low frequency to ensure that screens remain clean and operating at their design specifications. Occasional cross -flow may need to be induced at the screens with pumps; however, this would need further evaluation prior to selection of this technology. The two most common automated wedgewire screen cleaning systems are airburst and mechanical brush. The airburst cleaning system includes a compressor, an accumulator (also known as a receiver), controls, a distributor, and air piping that directs a burst of air from within each screen. The percussive force produced by the air burst system dislodges accumulated debris, which then drifts away from the screen unit in the sweeping velocity (see 10.4.4.4). The mechanical brush system cleans the screens while the cylindrical screens are rotated. During a screen rotation, a fixed position external brush cleans the outer surface, while an internal rotating brush prevents biofouling90 on the internal wedgewire surface. A water jet system may also be incorporated into the screen unit to facilitate additional removal of organisms and debris. In automated cleanings, the system would be set to actuate with a pressure differential system or on a timer91. In a pressure differential system, the pressure drop across the screen is monitored and cleaning would start when the when the drop increases to a predetermined threshold. 10.4.4.3 Wedgewire Screen Material Wedgewire screens, intake pipes, and related manifolds are typically constructed of stainless steel. Other metals and alloys may be utilized depending on site specific requirements, such as nickel and copper alloys for use in discouraging biofouling (USEPA 2014). 10.4.4.4 Sweeping Velocity Regardless of the cleaning method employed (i.e., airburst, mechanical brush, manual), the flow of water in a source waterbody helps to carry debris away from the screens. The velocity component of this flow is referred to as the sweeping velocity, which should be roughly parallel to the screen face. The sweeping velocity should not be confused with the through -screen or approach velocities. To maximize debris removal, the sweeping velocity should be greater than the through -screen and approach velocities. 90 Biofouling is the gradual growth or accumulation of organisms (e.g., microorganisms, plants, algae, or animals) on underwater equipment. 91 Improvements in the air burst system have largely reduced the use of timed cleaning cycles in favor of pressure differential monitoring systems (USEPA 2014). Duke Energy 1 158 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Comprehensive Technical Feasibility and Cost Evaluation Study [§122.21(r)(10)] r The sweeping flow has an important impact on the efficacy of screens. If sweeping flow velocity is greater than through -screen and approach velocities, then drifting organisms would also be moved away from the screens (along with debris). 10.4.4.5 Percent Open Area Because a portion of the screened area is covered by the wire and other structural elements, the percent open area refers to the percentage of open area of the slot to the total screened area. Fine - slot openings typically result in a relatively small open area, indicating that several screens must be utilized to maintain the design maximum 0.5 fps TSV. 10.4.4.6 Slot Size and Number of Screens Per the Regulations at §122.21(r)(10)(i), the slot size of potential wedgewire screens must be evaluated at a maximum of 2.0-mm openings. The fine -mesh slot size excludes small organisms, including larvae and eggs, which reduces entrainment (USEPA 2014). The slot size is typically chosen in conjunction with site specific data that will physically exclude to prevent the entrainment of the smallest target taxa or life stage (USEPA 2014). As discussed in Appendix 10-E, 2.0-mm opening size was selected for McGuire. The number of screens required for a particular flow rate is indirectly proportional to the slot size, assuming a similar diameter and length. That is, as the slot size decreases, the open area decreases, meaning that water is withdrawn through a reduced open area. Wedgewire screens are designed to maintain a TSV of less than 0.5 fps. The 0.5 fps TSV would be BTA for impingement compliance; and a lower TSV will improve post -exclusion survival as well. Based on a slot size of 2.0-mm and in conjunction with the design flow and several assumptions, the required number of screens for each unit has been estimated. The design criteria used to estimate the number of screens is provided in Table 10-16. Table 10-16. Wedgewire Screen Design Criteria for 2.0-mm Slots Pump Flow per Units 1,016,00 gpm Target Through -slot Velocity 0.35 fps Maximum Through -slot Velocity 0.5 fps Percent Open Area 67 - Required Open Area 6,468 square ft Slot Size 2.0 mm Wire Width 1.0 mm Diameter of Screen 7 ft Total Length of Screen 28 ft Length of Screen Available to Withdraw Water 19 ft Duke Energy 1 159 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� Comprehensive Technical Feasibility and Cost Evaluation Study [§122.21(r)(10)] r Using the information in Table 10-16, 46 wedgewire screens (23 per unit) are required to maintain a TSV of less than a maximum target of 0.5 fps for impingement compliance. A target TSV of 0.35 fps has been used to estimate the number of screens, which will eliminate the need for redundant screens. Additionally, the target velocity allows for operator margin in case of screen clogging, maintenance -related availability, or periods of low water. A typical wedgewire screen illustrating an optional flange to connect to an airburst cleaning system is shown on Figure 10-19. Due to the location of the screens in the embayment, a debris deflector will not likely be required for the screens. 28-ft Length 7-ft Diameter 2.0-mm Slot Size 1.0-mm wire Width Airburst Cleaning System Flange (Optional) Outlet Connection Flange Plan View Section View (not to scale) wedgewire Screen Dimensions Unit 1 Flow- 1,016,000 GPM (23 Screens Duke Energy Unit 2 Flow- 1.016,000 GPM (23 Screens) KR McGuire Nuclear Station Flow per Screen: 44.174 GPM Figure 10-19. Wedgewire Screen Dimensions for 2.0-mm Slots Duke Energy 1 160 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Comprehensive Technical Feasibility and Cost Evaluation Study [§122.21(r)(10)] r 10.4.4.7 Potential Wedgewire Screen Locations During a potential wedgewire screen retrofit, an access pathway would be constructed with earthen fill and concrete walls extending from the shoreline west of the Main Intake into the embayment about 550 ft, and back to the shoreline east of the Main Intake; this is shown on Figure 10-20. p IF careens OW /�/ er Vertical ical Column Three Screens per Vertical Column -ft Diameter, 28-ft Length � � ✓ .0-mm Slot Width '�I 3 Screens per Unit Concrete Wall 790 Unit 2 Figure 10-20. Wedgewire Screen Intake Structure Four Screens per Vertical Column Three Screens per Vertical Column — + EW.-M n tnw! Access Pathway-400 w 0 ! �+- Unit 1 The access pathway will be built to withstand vehicular and pedestrian access and will create a new intake bay between the pathway and the Main Intake. The new intake bay will be separated into two portions with a concrete wall, with each unit having a dedicated section. The concrete wall will have sluice gates to cross -connect the two sections as necessary. In addition, each section will have a bypass that will allow for an alternate route for water to enter the intake in the event the screens are out of service. The location of the screens and access pathway extend a considerable amount into the embayment to have the depth required for the number and diameter of wedgewire screens.92 Due to a normal water surface of 756 ft msl and an estimated 7-ft diameter screen, areas of the embayment with a water depth of less than 10 ft are assumed to be infeasible for screen installation. The bathymetry of the embayment is shown on Figure 10-20. The screens, oriented horizontally, would be `stacked' to form vertical columns, with four screens in the deeper portions of the embayment and three screens in the shallower portions of the 92 Extending the screens and walls into the embayment poses potential entrapment in the newly created intake bay. This would need to be evaluated further during detailed design and permitting. Duke Energy 1 161 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� Comprehensive Technical Feasibility and Cost Evaluation Study [§122.21(r)(10)] r embayment. A section view showing the arrangement of the screens is included on Figure 10-21. The columns of screens would be in sets of two, with space between each set of columns. The space would be required for access and maintenance of the screens. Due to the potential depth of screens in Lake Norman, water may be withdrawn from the hypolimnion layer of the waterbody. If water is withdrawn from this layer of the waterbody, it is possible they may have the same operating restrictions as the LLI system. That is, the use of the screens may need to be coordinated with the use of the LLI system and Marshall, since they would all be accessing the same layer of cold water from the lake. This would also require coordination with the NCWRC regarding fish habitat. Four Screens Access Fabricated 4_ Pier Manifold Normal Lake Water Surface El. 756.0-ft ............... ............ ... Typ- Wedgewire Screens La (not to scale) Slide Gate Three Screens Access Fabricated �� Pier Manifold Normal Lake Water Surface El. 756.0-ft Typ- Wedgewire Screens} Lake Bottom El. Varies Slide Gate (not to scale) Wedgewire Screen Section View I Unit 1 Flow- 1,016,000 GPM (23 Screens) Duke Energy Unit Flow: 1;016.000 G P A (23 Screens) McGuire Nuclear Station Flow per Screen: 44;174 GPM Figure 10-21. Wedgewire Screen Section View Feasibility Discussion Construction Feasibility The wedgewire screen system requires extensive construction within Lake Norman and much of the construction would need to be performed in a dry setting, within coffer dams. To accommodate continued use of the Main Intake, a phased installation of the wedgewire screens would be required. The intake system would include a southwest arm, southeast arm, and a separation wall; the southeast and southwest arms would also function as the access pathways. The compressors for Duke Energy 1 162 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Comprehensive Technical Feasibility and Cost Evaluation Study [§122.21(r)(10)] r backwashing would be mounted on the access pathway to avoid long air headers that would lose pressure. The southwest and southeast arms of this structure would need to build into the existing dike. Demolition and reconstruction of the dike could potentially destabilize the dike surrounding the station, and the dam. While many different permutations of phases may be possible, one sequence is to build the system as follows: Install a coffer dam that would enclose approximately 75 percent of the southwest arm of the concrete structure, construct a portion of the southwest arm, remove the coffer dam, and open the three gates. This step may be performed without a plant/unit outage. 2. Install a second coffer dam that would enclose approximately 75 percent of the southeast arm of the concrete structure, construct that portion of the southeast arm, remove that cofferdam, and then open the three gates. This step also may be performed without a plant/unit outage. 3. Install a coffer dam that would enclose approximately 20 percent of the separation wall that is closest to the intake structure, construct that portion of the wall and remove the coffer dam. This coffer dam would cut off water to the middle three to four intake bays. This step may be constructed during winter months when fewer pumps are used, or during a plant outage. 4. Construct the remainder of the separation wall within a coffer dam. There are paths to access construction; therefore the coffer dam does not need to extend to the shorelines. 5. Construct the remainder of the two arms within a coffer dam. Construction access through paths. This evaluation assumes that the mud bottom within the enclosure would remain as such, and would not be finished with concrete. The access path would have appropriate lighting, signage, and security. Technology Operational Feasibility The embayment in which the intake is located provides for insufficient space to provide for redundant screens in the event that one or more screens is damaged or otherwise made unavailable to water supply. But because the target TSV is 0.35 fps, the system can continue to operate with fewer screens and still meet the velocity criterion of less than 0.5 fps. Each arm of the access path would incorporate three `bridge' sections with 10 ft high by 10 ft wide gates installed on the outer (lake side) wall. These gates would be designed to actuate automatically so that one gate at a time would open if the water surface elevation difference inside and outside the structure was more than two ft for longer than a minute. The gates would allow water to bypass the wedgewire screens as necessary. To provide reliable water, this design maintains the existing traveling water screens in place even when the wedgewire screens are deployed. If water needs to bypass the wedgewire screens, water would flow directly into the new concrete enclosure bay and to the trash racks and traveling water Duke Energy 1 163 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Comprehensive Technical Feasibility and Cost Evaluation Study [§122.21(r)(10)] r screens (similar to current operations). This measure would allow the screen -house and wedgewire screens to operate reliably. A key challenge to reliable operation of this system is preventing the bypass gates from rusting in place. To minimize potential issues, this evaluation assumes that the gates would be exercised once per month. Such exercising also means that aquatic organisms from Lake Norman would be allowed to enter the new concrete enclosure, and potentially thrive within the enclosure. If gate exercising does not introduce aquatic organisms, wind, overtopping during storms, and bird droppings might; therefore, maintaining the coarse -mesh traveling screens is imperative for debris and fouling control for downstream pumps, waterboxes, and condensers. FMS will physically exclude organisms to reduce entrainment; however, it will also physically exclude other debris, which has the potential to clog the screens at a higher rate than with coarse -mesh screens. Due to the location of the wedgewire screens within the embayment, there will be little sweeping velocity to carry away debris; therefore, the screens must rely heavily on the cleaning system to remove debris from the screens. Little to no sweeping velocity can also reduce the biological efficacy of the screens; organisms that cannot swim would not be flushed away but would remain near the screens and potentially be drawn towards it. The cleaning system of the wedgewire screens may be required to operate more frequently and possibly designed to be more robust to handle a relatively high debris loading. Operating wedgewire screens involves the addition of a cleaning system and related appurtenances, which consume energy (e.g., through a compressor or through the mechanical brushes and related motors), as well as additional lighting along the access pathway. These additional items would result in an energy penalty through auxiliary energy requirements. Additional noise will be generated due to the frequent operation of air compressors for the cleaning systems. Operation of compressors could impact boaters near the Main Intake. The low design TSV of less than 0.5 fps of a potential wedgewire screen retrofit would not have a scour effect on the lake bottom; therefore, a bathymetric survey would need to be performed in front of and near the current Main Intake system to evaluate existing conditions. After installation, routine maintenance dredging would likely be required to minimize the buildup of sediment near the intake. This design assumes that five wedgewire screens would be installed in the deepest sections. Each screen would be 7 ft in diameter. Assuming a 1-ft vertical separation between screens, these screens would withdraw water from a 39-ft column of water. Assuming an elevation of 740 ft msl for the top of the topmost screen, there would still be 11 ft of water covering the screen at the maximum (non -emergency) drawdown of 751 ft msl. The bottom of the bottommost screen would be at 701 ft msl. At least two screens would routinely withdraw water from the same depth as the LLI. The LLI withdraws water between elevations 710 and 721.2; these depths are within the hypolimnion. McGuire presently restricts the use of hypolimnetic water so as not to impact operations. The use of a wedgewire screen system that would routinely withdraw from the hypolimnion would violate this restriction regularly. The LLI pump operation with respect to fish habitat is discussed in more detail in Section 10.3.1. Duke Energy 1 164 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Comprehensive Technical Feasibility and Cost Evaluation Study [§122.21(r)(10)] r Facility Operational Feasibility Due to Technology Retrofit With respect to retrofit feasibility, construction feasibility, and operational feasibility, this evaluation deems fine -slot wedgewire screen implementation as impractical and potentially infeasible. Additional extensive evaluations would be required to be performed to confirm feasibility at McGuire, particularly relative to materials testing, screen fouling from lack of sweeping flow, and water use restrictions due to impact on the hypolimnion. Practicality and Feasibility of Fine -Slot Wedgewire Screens With respect to retrofit, construction, and operational feasibilities, this evaluation deems a wedgewire screen retrofit as impractical and potentially infeasible owing to the following key reasons: 1. The two arms of the structure would need to build into the dike. Construction and disturbance could potentially impact the stability of the dike and the dam. 2. The need for sweeping flow/velocity93 for a wedgewire screen installation needs to be evaluated in detail on a site -specific basis. Such an evaluation has not been performed for Lake Norman and McGuire. 3. The system requires 46 screens, some of which would be installed within the hypolimnion. 4. Extensive in -water construction and disruption to the station and extensive damage to the lake bed. 5. High maintenance burden on the station. As such, wedgewire screens are not evaluated further, and their costs, efficacy, and impacts are not assessed further. 10.5 Summary of Social Costs The first step in estimating social costs is to determine whether the entrainment reducing technology costs will result in the plant becoming economically unfeasible to operate. A premature shutdown of the plant would have social costs related to loss of jobs, loss of income and expenditures, loss of tax base, increased electricity costs due to generation being dispatched at a higher price from less efficient plants, and increased infrastructure costs to maintain grid reliability. Installing entrainment reducing technologies at McGuire to comply with the Rule represents an additional cost of operations that would most likely be passed onto Duke Energy's electric customers in the form of higher rates. These costs will need to be recovered in future rate case filings. The significance of McGuire in Duke Energy's nuclear generating portfolio along with the current operating license not expiring before 2041 suggests that only an extraordinarily expensive conversion requirement would lead to premature closure. Therefore, this analysis assumes Duke Energy will incur the entrainment reducing compliance costs and continue to operate McGuire. The social costs of installing entrainment reduction technologies are estimated by determining the design, construction, and installation costs of the evaluated technologies along with the O&M, power 93 It is not practical to induce a sweeping velocity at a facility with such a large intake rate. Duke Energy 1 165 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� Comprehensive Technical Feasibility and Cost Evaluation Study [§122.21(r)(10)] r system, externality, and permitting costs. The analysis assumes that all compliance costs would be passed on to Duke Energy's electric customers. Table 10-17 summarizes the results of this evaluation and its implication for social costs. Following the requirements of the Rule, Table 10-17 evaluates social costs under two discount rates: 3 and 7 percent (USEPA 2014). As the first column of Table 10-17 shows, the top half of the table presents the present value of social costs discounted at 3 percent, and the bottom half presents the social costs discounted at 7 percent. The next column of the table presents each of the feasible technologies evaluated at McGuire. The third and fourth columns present the compliance costs estimated for each feasible technology. The third column presents the estimated design, construction, and installation costs, and the fourth column presents the annual O&M costs for each feasible technology. The remaining columns in the table present the individual categories of social costs developed for this analysis: electricity price increases from compliance and power system costs, externality costs, and government regulatory costs. The analysis discounts the future stream of each of these social costs at the relevant discount rate and sums them over the years they are specified to occur to develop the Total Social Cost estimate presented in the last column. Table 10-17 concludes by presenting the Annual Social Cost estimate for each technology. The annual estimate divides the Total Social Cost by the years the analysis is conducted over. Duke Energy 1 166 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� Comprehensive Technical Feasibility and Cost Evaluation Study [§122.21(r)(10)] r Table 10-17. Total Enaineerina and Social Costs of Feasible Technoloav Options at McGuire Total Design, Annual Compliance Power Externality Government Total Annual Construction, & O&M Costs System Costs b Regulatory Social Social Installation Costs Costs Costs Costs Costs Costs Closed -Cycle $1.49B $6.4M $1.85B $557.1M $14.21M $0.21M $1.47B $113.21M Cooling Retrofit 2.0-mm Fine - Mesh Ristroph $34.45M $2.42M $50.53M $0.63M $OM $4.21K $51.2M $2.69M Traveling Screens Closed -Cycle $1.4913 $6.41M $922.10M $277.1 M $8.1 M $0.1 M $733.61M $56AM Cooling Retrofit 2.0-mm Fine - Mesh Ristroph $34.45M $2.42M $29.01 M $0.36M $OM $2.81K $29AM $1.55M Traveling Screens a Compliance costs are undiscounted and in 2017 dollars. The social costs associated with each technology are discounted at 3 and 7 percent using the specifications outlined in Table 10-18. b Externality costs include decreases in social wellbeing resulting from property value, water consumption (i.e., lost hydroelectric generation), and winter fishery (i.e., recreation) impacts. Duke Energy 1 167 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Comprehensive Technical Feasibility and Cost Evaluation Study [§122.21(r)(10)] r Compliance costs are specified as occurring over a 13-year period for a cooling tower retrofit and over the remaining life of the station (a 19-year period) for FMS, as discussed in Section 10.2.2 and summarized in Table 10-18 below. Power system costs are specified to occur during construction, based on outage impacts, and during operation, based on efficiency and auxiliary load impacts. Regulatory documents will be submitted in 2019 and the timing for activities related to installation is dependent on the technology being installed. Table 10-18 reflects the timing specifications for each of the alternatives evaluated. As Table 10-17 shows, the social costs of each technology include the expected electricity price increases associated with each technology, the additional power system costs that would be incurred with each technology, the externality costs of each technology, and the governmental regulatory costs. As previously noted, the analysis specifies that all compliance costs are passed on to Duke Energy's rate payers resulting in increased electricity prices. To develop the electricity price increases, the design, construction, and installation costs are allocated over the specified construction and installation time -periods presented in Table 10-18. Operation and maintenance costs are then added for each year the technology is operational, and the future stream of those costs are discounted by 3 and 7 percent to develop the present value estimate for each discount rate. Power system costs represent the additional power needed to operate the new technologies and the additional fuel needed from running less efficient units during installation construction outages. The power system costs are developed from evaluating backpressure and auxiliary load effects, capacity losses from each of the technologies with estimated outage times, and electricity consumption associated with each technology. Externality costs represent the environmental impacts associated with the installation and operation of entrainment reducing technologies. Operation of a closed -cycle cooling system would create a visible plume from the MDCTs and would result in water consumption impacts, namely increased evaporation. The visible plume from the towers has the potential to negatively affect property values of the surrounding area and increased water consumption would negatively impact hydroelectric generation. Operation of a closed -cycle cooling system would also negatively impact recreation on Lake Norman due to the elimination of the winter fishery, which depends on the warm water discharge from McGuire. Each of these negative impacts is briefly described below. A more detailed evaluation is provided in Appendix 10-C. Property Value Effects The viewshed near McGuire could be affected by a visible plume. EPRI (2011) applied results from a study that evaluated the effect that an industrial site with a vapor plume had on nearby property Duke Energy 1 168 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� Comprehensive Technical Feasibility and Cost Evaluation Study [§122.21(r)(10)] r values. EPRI (2011) used the results of that study to infer that plumes from a closed -cycle -cooling retrofit are likely to have a 0.4 percent reduction in affected property values. The height of the hypothetical MDCTs is estimated at 50 ft and the tower plume could extend several hundred feet above the towers. Based on the EPRI (2011) study, a 6-mile radius around McGuire was assumed to have potential viewshed impacts. The residential properties associated with the census tracts within the 6-mile radius are collectively valued at approximately $4.613. Applying, a 0.4 percent reduction to the $4.613 in properties within six miles of McGuire results in a negative property value impact of $18.4M. Water Consumption Effects The hypothetical closed -cycle MDCTs used in this evaluation rely on evaporation to cool water and evaporative losses would be made up though withdrawals from Lake Norman. This would result in reduced water levels in Lake Norman, thereby affecting the availability of water for other uses. The estimated net increase in water consumption resulting from operation of the MDCTs at McGuire is approximately 3,416 million gallons per year (MGY). The estimated annual lost system hydroelectric generation resulting from the loss of this water ranges from $927,000 (7 percent discount rate) to $1.9M (3 percent discount rate). Winter Fishery Effects Heated water discharged into Lake Norman from McGuire creates favorable habitat conditions during colder winter months by forming a warm water refuge which supports a substantial winter fishery for recreational anglers. Under closed -cycle cooling operation, there would be a social cost related to loss of these positive recreational effects. A site -choice simulation model was developed to evaluate the effects that thermal discharges from McGuire have on the recreational fisheries in Lake Norman. Within the model, winter catch estimates were modified to represent recreational catch rates and values if the thermal discharge was eliminated. The site -choice model considered potential impacts to anglers located in ZIP codes within a 50-mile radius of McGuire. The model was applied from 2031 (the year the MDCTs would be operational, thus eliminating the heated discharge) to 2043 (the assumed retirement of McGuire). Over this 13-yr period, the present value estimate of the social cost ranges from a loss of approximately $82,000 (7 percent discount rate) to approximately $172,000 (3 percent discount rate). Governmental regulatory costs include the total costs associated with permitting, monitoring, administering, and enforcing the technology selection and installation. Costs are incurred by the government as the permitting and review process is undertaken. These vary with the type of technology, as certain technologies require substantially more permitting. Those with more significant environmental effects would have higher permitting costs. These costs are initially borne by the government, but ultimately paid by taxpayers. Further information can be found in the Veritas Economic Consulting (Veritas) (2018a) report: Social Costs of Purchasing and Installing Entrainment Reduction Technologies: McGuire Nuclear Station (see Appendix 10-C). Duke Energy 1 169 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal �� Comprehensive Technical Feasibility and Cost Evaluation Study [§122.21 (r)(1 0)] 10.6 Alternate Cooling Water Sources [§122.21(r)(10)(i)(C)] Alternate water sources, including groundwater and grey water sources, have been evaluated for potential use as some or all of the cooling water needs at McGuire. These sources are evaluated by first comparing the distance and flow rate of the alternate water source to the location of the station, and then by determining its practicability as a source of cooling water for McGuire. Table 10-19 is used to compare the flow rate of potential alternate water sources within a specified distance of the station to McGuire's DIF (i.e., 2,969 MGD). Due to permitting challenges such as stream and wetlands crossings, numerous rights -of -way required over private properties94, and prohibitive construction costs, alternate water sources greater than a distance of 5 miles from the station are not considered to be practicable. For alternate water sources within a distance of between 0 to 5 miles from the station, a value was chosen to represent the minimum percent of the station's DIF that a potential alternate water source would need to provide in order for the source to be considered practicable. Challenges of attaining an alternate water source would increase with increased distance from the station; therefore, this methodology assumes that a greater distance from the station would require a greater percent of the station's DIF be provided as an alternate water source. If the alternate water source flow rate, as a percent of the station's DIF, was considered to be practicable, the water source was retained for further evaluation. Table 10-19. Alternate Water Source Evaluation Criteria On -site 0- to 1-mile 1- to 2-mile 2- to 3-mile 3- to 4-mile 4- to 5-mile McGuire's DIF = 2,969 MGD Any Any 5% 149 MGD 10% 297 MGD 15% 445 MGD 20% 594 MGD 25% 742 MGD Next, the potential alternate water source would undergo further evaluation to understand the practicability of utilizing the water source. The evaluation would include an approximate pipeline alignment from the alternate source to the station. Additional aspects of the water source that would be evaluated are dependent on the type of water source used. Reclaimed sources with sufficient capacity would be further evaluated for the following: reliability of supply, water quality compatibility, additional necessary treatment, cost of conveying from the 94 While eminent domain may provide an alternate mechanism for acquiring rights -of -way over private properties, the lengthy legal proceedings would not allow availability of alternate water sources from long distances in a timely manner. Duke Energy 1 170 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Comprehensive Technical Feasibility and Cost Evaluation Study [§122.21(r)(10)] r source, the relative effort to negotiate rights -of -way, and the impact of discharge, including permitting issues. In addition, groundwater sources with sufficient well yields to serve as a viable source would be further evaluated for the following: water quality compatibility with equipment; groundwater and surface water compatibility; groundwater discharge options and the potential impacts of comingling ground and surface waters; potential need for additional chemical use; cursory evaluation of the impact of groundwater on the biota in the receiving waterbody; and the impact of groundwater extraction on the aquifer, other wells, and other groundwater uses. 10.6.1 Description of Water Uses within the Facility Water use on -site is withdrawn primarily from Lake Norman and largely consists of circulating water and service water; however, there are other purposes for water withdrawal, such as for intake screen backwash and for nuclear safety -related uses. Per the Updated Final Safety Analysis Report, the nearest major user of groundwater for public use is in the town of Cornelius, located approximately six miles northeast of McGuire. The nearest industrial user of surface water for human consumption is located approximately 18 river miles downstream of McGuire. The Charlotte Municipal Water Intake is located approximately 11 river miles downstream of McGuire (Duke Energy 2015c). 10.6.2 Description of Alternate Water Sources 10.6.2.1 On -Site Water Reuse On -site water use primarily consists of circulating water, service water, screen backwash water, and nuclear safety -related uses. Water reuse on site would include reusing water from existing station uses in support of the condenser cooling water. Intake screen backwash water is not suitable for reuse, as it is intended to remove debris from the screens and convey that debris back to Lake Norman. Nuclear safety -related water uses are not typically operated on a continuous basis. The safety -related systems must be kept available for immediate use in the unlikely event of an accident Service water is the only potentially viable source of water reuse on the site. As shown in Table 5-3, the average service water usage from January 2015 through December 2017 was 27 MGD (approximately one percent of the station's DIF). Used service water exits the plant and is routed through a series of wastewater treatment ponds prior to being discharged to Mountain Island Reservoir via Outfall OOX. Re-routing this effluent back to the Main Intake would require installation of pumps, piping, and associated electrical supply. Due to the small percentage of available flow relative to DIF, and the amount of infrastructure involved in rerouting used service water back to the Main Intake, reusing service water is not considered a candidate for further evaluation. 10.6.2.2 Grey Water Sources Several WWTPs have been identified within the 5-mile radius of the station and are presented on Figure 10-22. These WWTPs represent a potential supply of reclaimed wastewater that could be used to reduce the amount of water that McGuire withdraws, thereby also reducing potential entrainment. Duke Energy 1 171 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� Comprehensive Technical Feasibility and Cost Evaluation Study [§122.21(r)(10)] r The evaluation of these WWTPs compared to the station's DIF is detailed in Table 10-20. Of the facilities found, none are considered a candidate for further evaluation based on the relatively low design flow from the wastewater treatment plants95. Table 10-20. Grey Water Alternate Water Source Evaluation CandidateDistance Design Percent of L: ter Source From Flow Station DIF for Further References Station Evaluation Forney Creek Wastewater Treatment Plant 3- to 4-Mile 0 MGD 0% No (USEPA 2016a) Permit No.: NCO074012 Killian Creek Wastewater Treatment Plant 4- to 5-Mile 1.68 MGD <0.1 % No (Lincoln County Permit No.: NCO088722 2016) McDowell Creek Wastewater (USEPA 2016b; Treatment Plant 3- to 4-Mile 12 MGD 0.4% No Charlotte Observer Permit No.: NCO036277 2015) *The Forney Creek Wastewater Treatment Plant has recently closed with wastewater being routed to the Killian Creek Wastewater Treatment Plant (Lincoln County 2012) 95 If a wastewater treatment plant's design capacity is significantly lower than the minimum target flow rate for further evaluation listed in Table 10-19, then the wastewater treatment plant's reliable capacity that may potentially be available as an alternate water source would be still lower, often less than one-half of the design. Duke Energy 1 172 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal �� Comprehensive Technical Feasibility and Cost Evaluation Study [§122.21(r)(10)] Figure 10-22. Groundwater Wells and WWTPs within a 5-mile Radius of McGuire (Source: USEPA 2013; NCREDC 2000; NCDEQ 2015) Duke Energy 1 173 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� Comprehensive Technical Feasibility and Cost Evaluation Study [§122.21(r)(10)] r 10.6.2.3 Groundwater Sources Groundwater in the area is derived entirely from local precipitation, and the water table varies from ground surface elevation in valleys to more than 100 ft below the surface on topographic highs (Duke Energy 2015c). Groundwater at the station is primarily controlled by the water level in Lake Norman, and the majority of groundwater flow96 is governed by the local topography (Duke Energy 2015c). The only current and foreseeable use of groundwater in the area is as a domestic water supply in the area immediately surrounding the site (Duke Energy 2015c). Groundwater wells within the 5-mile radius have been identified and plotted on Figure 10-22. Due to the number of wells located, these have been grouped with the largest yield well compared to McGuire's DIF (see Table 10-21). Of the groundwater wells identified, none have a sufficient well yield to be considered for further evaluation. Table 10-21. Groundwater Alternate Water Source Evaluation 0- to 1-Mile 0 - - - 1-to2-Mile 1 0(104 GD <0.01% No 2- to 3-Mile 4 0.07 <0.01% No gpm) 3- to 4-Mile 6 0.03 <0.01% No gpm) 0.170 8 MGD 4- to 5-Mile 7 <0.01% No Source: NCDEQ 2015 Based on findings presented here, alternate water sources will not be evaluated further. 10.7 Summary of Findings — Technical Feasibility 10.7.1 Summary of Evaluation Findings and Reasoning This evaluation included the following technologies as potential entrainment reduction measures at McGuire to comply with the Rule: • Closed -cycle recirculating cooling; • Fine -mesh screens; and • Alternate water sources and water reuse options. Evaluation findings are summarized in Table 10-22. 96 The only groundwater recharge areas within the influence of McGuire are adjacent to the Standby Nuclear Service Water Pond and the Waste Water Collection Basin (Duke Energy 2015c). Duke Energy 1 174 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Comprehensive Technical Feasibility and Cost Evaluation Study [§122.21(r)(10)] r Technology Table 10-22. Summary of Evaluation Findings Closed -cycle Cooling Natural Draft Cooling Infeasible Approach and range of cooling tower needed at McGuire too small for Towers this type of tower. Technology technically feasible. The retrofit would involve reconstruction and relocation of existing equipment and facilities. There Mechanical Draft Feasible, but are space constraints associated with Cowans Ford Dam and related Cooling Towers impractical dikes and would result in significant changes to land topography and viewshed from Lake Norman, Catawba River and surrounding community. The retrofit would involve a significant capital investment, large energy penalty, and power loss. Plume -abated Given the larger site requirements of plume -abated towers, there is Mechanical Draft Infeasible insufficient space to locate inline towers at this facility. Cooling Towers Technology's design characteristics incompatible with McGuire Dry Cooling System Infeasible condensers. Installation would require redesign and reconstruction of existing equipment and facilities. Fine -mesh Screens Permanent Replacement of This technology is deemed impractical due to the potential impacts to Existing Coarse- TSV, reduction in operating margin of circulating pumps during low mesh Traveling Inconclusive; water level conditions, increased operations burden, additional Screens with 2.0-mm impractical maintenance due to fouling and clogging. Additional extensive Fine -mesh Modified- evaluations would be required to be performed in order to confirm Ristroph Screens feasibility at McGuire, particularly relative to debris and fouling. Need to with Fish -Return assess net positive suction head required/available. System Overlaying Existing The higher TSV and higher headloss across the screens during a high - Coarse -mesh Likely infeasible; intensity low -duration debris loading event could exceed screen Baskets with Fine- impractical reliability rating. Labor intensive installation would make this technology mesh, and adding a impractical. Fish -Return System Expanding the intake and to Maintain Existing TSV with Insufficient space within the embayment for intake expansion. 2.0-mm Mesh Expansion of intake requires extensive civil and earthwork construction, Screens, Replace Infeasible which would result in significant disturbance to shoreline and dike Existing Screens with system, as well as plant outage. The potential instability of an EMS, and adding a expansion of the Main Intake makes this option infeasible. Fish -Return System Duke Energy 1 175 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Comprehensive Technical Feasibility and Cost Evaluation Study [§122.21(r)(10)] r Rebuild Existing Intake which has Traveling Water Screens to Utilize 2.0-mm Wedgewire Screens Reuse Existing Water Sources Replace Existing Surface Water Source, at least in part, with Alternate Water Sources The intake would need an access pathway to be built into the embayment in Lake Norman. This would require extensive construction within the waterbody and construction into the dike which would impact Impractical; likely infeasible stability of Cowans Ford Dam. In addition, there would be minimal sweeping flow to carry debris away from screens when cleaned. The wedgewire screens would withdraw water from the hypolimnion layer of the waterbody, which requires coordination with the NCWRC. Alternate Water Sources Infeasible Only reusable water source is service water, which is already used for certain cooling needs. Insufficient quantity. Insufficient quantities. Evaluated wastewater treatment plant and groundwater sources within 5 miles of station. Even if those sources Infeasible were available, and transfers were allowable, the quantities available would be insufficient to supplement even a portion of McGuire's usage rate meaningfully. 10.7.2 Technologies Retained for Biological Efficacy and Cost Evaluations Based on the summary in Table 10-22, technologies retained for further evaluation are listed in Table 10-23. Table 10-23. Technologies Retained for Further Evaluation Natural Draft Cooling Towers No Mechanical Draft Cooling Towers ' Yes Plume -abated Mechanical Draft Cooling Towers No Dry Cooling System No Permanent Replacement of Existing Coarse -mesh Traveling Screens with 2.0-mm Fine- Yes mesh Modified-Ristroph Screens with Fish -Return System Overlaying Existing Coarse -mesh Baskets with Fine -mesh, and adding a Fish -Return No System Expanding the intake to Maintain a Reasonable TSV with 2.0-mm Mesh Screens, No Replace Existing Screens with Fine -Mesh Screens, and adding a Fish -Return System Reuse Existing Water Sources No Replace Existing Surface Water Source, at least in part, with Alternate Water Sources No Duke Energy 1 176 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� Benefits Valuation Study [§122.21 (r)(1 1)] r 11 Benefits Valuation Study [§122.21 (r)(1 1)] 1.1 Introduction and Background The information required to be submitted per §122.21(r)(11), Benefits Valuation Study, is outlined as follows: (i) Incremental changes in the numbers of individual species and life stages of fish and shellfish97 lost due to impingement mortality (IM) and entrainment as defined at §125.92; (ii) Description of basis for any estimates of changes in the stock sizes or harvest levels of commercial and recreational fish or shellfish species, or forage fish species; (iii) Description of basis for any monetized values assigned to changes in the stock size or harvest levels of commercial and recreational fish or shellfish species, forage fish, and to any other ecosystem or nonuse benefits; (iv) A discussion of mitigation efforts completed prior to October 14, 2014, including length of implementation and level of effect on fish abundance and ecosystem viability in the CWIS area of influence; (v) Discussion, with quantification and monetization where possible, of any other benefits expected to accrue to the environment and local communities, including but not limited to improvements for mammals, birds, and other organisms and aquatic habitats; and (vi) Discussion, with quantification and monetization where possible, of benefits expected to result from any reductions in thermal discharges from entrainment technologies. Under §122.21(r)(11) of the Rule, "the owner or operator of the facility must submit a detailed discussion of the benefits of the candidate entrainment reduction technologies evaluated in § 122.21(r)(10) and using data in the Entrainment Characterization Study in § 122.21(r)(9). Each category of benefits should be described narratively, and when possible benefits should be quantified in physical or biological units and monetized using appropriate economic valuation methods." Each of these requirements is addressed in the following subsections. 11.2 Review of Model Development and Valuation Methods This Benefits Valuation Study provides a summary of the ecological and monetary benefits of select entrainment reduction technologies and operational measures evaluated for McGuire per the requirements at §122.21(r)(10) (see Section 10). The benefits of reductions in entrainment and 97 The Rule requires a characterization of the annual impingement mortality and entrainment for fish and shellfish. Shellfish were not collected in the two-year Study or historical impingement study; therefore impacts to shellfish are assumed to be zero and are not addressed further in this document. Duke Energy 1 177 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Benefits Valuation Study [§122.21 (r)(1 1)] r impingement losses of early life stage fish are best evaluated by translating losses to an ecological or human -use context, and assessing differences in total losses among compliance technology scenarios discussed in Section 10. The estimation of benefits was accomplished using a multistep process: 1. Calculate incremental losses of entrained and impinged organisms annually. 2. Convert losses using commonly applied and accepted methods including the equivalent adults (EA), production foregone (PF), and equivalent yield (EY) models. Calculate the harvest yield foregone by incorporating trophic transfer of PF biomass and fishing pressure to commercial/recreationa198 taxa. 4. Monetize the changes in harvest yield resulting from implementation of candidate technologies and subsequent reductions in entrainment at McGuire. This process was followed to calculate the baseline losses as well as reductions in entrainment and relevant changes in IM for the two feasible technologies identified in Section 10: Conversion to closed -cycle cooling (i.e., MDCT); and Installation of a fish -friendly FMS with 2.0-mm mesh and an aquatic organism return. As noted in Section 10, alternative water supplies were determined to be infeasible and were not carried forward to the estimation of benefits. 11.2.1 Baseline Losses of Fish and Shellfish Site -specific entrainment data from the recent Study (Section 9) and data from a historical impingement study (Duke Power 2003), discussed in Section 4, were extrapolated to annual entrainment and impingement loss estimates using actual water withdrawals reported for McGuire in 2016 and 2017. 11.2.1.1 Entrainment Loss Estimates Ichthyoplankton were sampled at McGuire over the spawning season (i.e., March to October) in 2016 and 2017 (as presented in Section 9), and then extrapolated based on flows to estimate the total annual entrainment at McGuire based on actual water withdrawals in 2016 (Table 11-1) and 2017 (Table 11-2). An estimated 476.8 million and 374.7 million ichthyoplankton were entrained in 2016 and 2017, respectively. In 2016, 52.9 percent of the total density of ichthyoplankton collected consisted of Inland Silverside, a forage species not previously documented in Lake Norman. The 98 None of the taxa collected in entrainment or impingement studies were classified as commercially harvestable; therefore, for the purposes of this report, all species are referred to as `recreational". Duke Energy 1 178 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Benefits Valuation Study [§122.21 (r)(1 1)] r Inland Silverside collected in the study consisted of post yolk -sac larvae and juveniles from two diel periods on a single collection event; no Inland Silverside were collected in 2017 sampling efforts. Table 11-1. Species and Life Stage -Specific Annual Entrainment Loss Estimates for 2016 based on Actual Water Withdrawals at McGuire Nuclear Station Inland Menidia 758,495 251,613,383 252,371,878 Forage Robust Silverside beryllina Shad and Clupeidae -- 114,497,612 - 114,497,612 Forage Fragile Herring Family Shad Species Dorosoma spp. 1,066,162 68,508,054 - 69,574,216 Forage Fragile Sunfish Species Lepomisspp. -- 10,141,792 - 10,141,792 Recreational Robust White Perch Morone 1,063,718 6,772,906 - 7,836,624 Recreational Robust americans Unidentified Unidentified -- 6,620,757 - 6,620,757 Forage3 Robust Fish Osteichthyes Alosa Alewife 2,843,411 pseudoharengus 1,601,655 - 4,445,066 Forage Fragile Gizzard Shad Dorosoma 3,826,455 - 3,826,455 Forage Fragile cepedianum Threadfin Shad Dorosoma 1,998,006 - 1,998,006 Forage Fragile petenense Sunfish/ Crappie Lepomis/ 1,516,041 - 1,516,041 Recreational Robust Species Pomoxis spp. Darter Species Etheostoma 1,242,739 - 1,242,739 Forage Robust spp. Etheostoma Swamp Darter fusiforme 735,316 376,087 1,111,403 Forage Robust Common Carp Cyprinus carpio -- 474,041 - 474,041 Forage Robust Carp and Cyprinidae -- 378,895 - 378,895 Forage Robust Minnow Family Channel Ictalurus Catfish punctatus 376,087 376,087 Recreational Robust Black Bass' Micropterus 354,573 - 354,573 Recreational Robust spp. Total 4,973,291 219,427,338 252,365,557 476,766,186 -- -- None collected 'Species Total is the sum of life stages rounded to the nearest whole number. 2Classifications include Forage, Recreational, or Commercial. No specimens collected in entrainment or impingement studies were classified as commercially harvestable. As such, all specimens collected at McGuire were recreational or forage only. 313ased on months of occurrence, expected to be Dorosoma and/or Inland Silverside, therefore, Unidentified Fish were mapped Duke Energy 1 179 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Benefits Valuation Study [§122.21 (r)(1 1)] r to Gizzard Shad as a conservative measure (larger forage species). 4Due to hybridization in Lake Norman, black bass (Micropterus spp.) includes Largemouth Bass (M. salmoides) and Alabama Bass (M. henshalli). Table 11-2. Species and Life Stage -Specific Annual Entrainment Loss Estimates for 2017 based on Actual Water Withdrawals at McGuire Nuclear Station Shad and Clupeidae - 299,678,462 - 299,678,462 Forage Fragile Herring Family White Perch Morone _ 61,829,106 - 61,829,106 Recreational Robust americans Shad Species Dorosoma 1,270,032 2,715,764 - 3,985,796 Forage Fragile spp. Alewife Alosa _ 2,448,130 721,061 3,169,191 Forage Fragile pseudoharengus Sunfish Species Lepomis spp. - 2,363,843 -- 2,363,843 Recreational Robust Unidentified Fish Unidentified _ 948,137 -- 948,137 Forage3 Robust Osteichthyes Gizzard Shad Dorosoma _ 683,839 - 683,839 Forage Fragile cepedianum Black Basso Micropterus _ 683,839 - 683,839 Recreational Robust spp. Sucker Family Catostomidae - 634,855 634,855 Forage Robust Darter Species Etheostoma _ 474,041 -- 474,041 Forage Robust spp. Black Crappie Pomoxis _ 270,316 - 270,316 Recreational Robust nigromaculatus Total 1,270,032 372,730,332 721,061 374,721,425 -- - None collected 'Species Total is the sum of life stages rounded to the nearest whole number. 2Classifications include Forage, Recreational, or Commercial. No specimens collected in entrainment or impingement studies were classified as commercially harvestable. As such, all specimens collected at McGuire were recreational or forage only. 'Based on months of occurrence, expected to be Dorosoma and/or Inland Silverside, therefore, Unidentified Fish were mapped to Gizzard Shad as a conservative measure (larger forage species). 4Due to hybridization in Lake Norman, black bass (Micropterus spp.) includes Largemouth Bass (M. salmoides) and Alabama Bass (M. henshalli). The collection of Inland Silverside likely represents an anomalous collection event of an introduced species (possibly introduced into the waterbody by anglers); expert biological peer reviewers concur with this conclusion. The anomalous collection event could indicate that this species may not be collected again in future sampling efforts. Alternatively, the collection may represent the first documented occurrence of this introduced species in Lake Norman (see Section 4). Although annual monitoring activities by Duke Energy have not collected Inland Silverside, the species has the potential to persist in Lake Norman and provide an additional forage species to the system. Therefore, Inland Silverside species were conservatively included in the EA and PF model output and subsequent monetization of benefits under each of the candidate entrainment compliance technology scenarios. Due to the uncertainty surrounding the potential longevity of this species in Duke Energy 1 180 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� Benefits Valuation Study [§122.21 (r)(1 1)] r Lake Norman, a sensitivity analysis of the EA and PF model results was performed to evaluate the impact of inclusion of Inland Silverside in the benefits valuation (Appendix 11-A). Excluding Inland Silverside (2016 only), fragile species (e.g., Alewife, Gizzard and Threadfin Shad) were the most abundant species (194.3 million ichthyoplankton) representing 40.8 percent and 82.1 percent of entrainment in 2016 and 2017, respectively. Recreational species, such as perch, bass, sunfish, crappie, and catfish were entrained less frequently, representing 4.2 and 17.4 percent of estimated annual entrainment for 2016 and 2017, respectively. Despite their low relative abundance in samples and minimal impact on annual entrainment estimates during 2016, juvenile Channel Catfish equate to a large number of equivalent adults due to reduced natural mortality of the juvenile life stage. Channel Catfish was the only recreational species collected during 2016 and the implications regarding this collection are discussed in Section 11.5. 11.2.1.2 Impingement Mortality Loss Estimates Based on the Duke Power (2003) impingement study summarized in Section 4 and actual water withdrawals at McGuire (from 2016 and 2017), annual IM was estimated at 2,175 fish in 2016 (Table 11-3) and 2,113 fish in 2017 (Table 11-4), for an estimated two-year average of 2,144 fish. Table 11-3. Species and Life Stage -Specific Estimated Annual Impingement Loss Estimates for 2016 based on Actual Water Withdrawals at McGuire Nuclear Station Dorosoma Threadfin Shad 257 633 890 Forage Fragile petenense Alosa Alewife 318 18 336 Forage Fragile pseudoharengus White Perch Morone americans 43 103 146 Recreational Robust Lepomis Bluegill 103 40 143 Recreational Robust macrochirus White Bass Morone chrysops 21 56 77 Recreational Robust Striped Bass Morone saxatilis -- 77 77 Recreational Robust Channel Catfish Ictalurus punctatus 30 33 63 Recreational Robust Dorosoma Gizzard Shad 22 35 56 Forage Fragile cepedianum Unidentified Fish Unidentified 26 28 54 Forage' Robust Osteichthyes Flathead Catfish Pylodictis olivaris 40 2 42 Recreational Robust Redbreast Lepomis auritus 26 15 41 Recreational Robust Sunfish Notemigonus Golden Shiner 23 17 41 Forage Robust crysoleucas White Crappie Pomoxis annularis 23 -- 23 Recreational Robust Blue Catfish Ictalurus furcatus 22 -- 22 Recreational Robust Yellow Perch Perca flavescens 22 -- 22 Recreational Robust Warmouth Lepomis gulosus 20 -- 20 Recreational Robust Duke Energy 1 181 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� Benefits Valuation Study [§122.21 (r)(1 1)] r Redear Sunfish Largemouth Basso Catfish Species Black Crappie Herring Species Spotted Bass5 Sunfish Species Temperate Bass Species Hybrid Sunfish Common Carp Eastern Silvery Minnow Quillback Lepomis microlophus Micropterus salmoides Ictaluridae Pomoxis nigromaculatus Alosa spp. Micropterus punctulatus Lepomis spp. Morone spp. Lepomis spp. Cyprinus carpio Hybognathus regius Carpiodes cyprinus Total 18 7 7 12 7 7 4 4 6 2 1,072 Species z ie 1 Total' Classification Vulnerabilit -_. '.. 11 18 Recreational Robust 8 15 Recreational Robust 3 15 Recreational Robust 6 13 Forage Fragile 4 11 Recreational Robust 5 9 Recreational Robust 4 8 Recreational Robust -- 6 Recreational Robust 4 4 Forage Robust -- 2 Forage Robust 1 1 Forage Robust 1,103 2,175 - -- None collected 'Species Total is the sum of life stages rounded to the nearest whole number. 2Impingement data were collected in 2000- 2002; Actual water withdrawals from 2016 were used to estimate losses to impingement. 'Based on the high abundance of forage species (versus recreational), Unidentified Fish were considered forage species (see Section 11.4.1.2). 4Largemouth Bass have largely been replaced by Alabama Bass (or hybridized) since the initial collection of Alabama Bass in Lake Norman in 2000 (Duke Energy 2017). 'Since the time that this study was performed, this species has been confirmed as Alabama Bass (NCWRC 2017). Table 11-4. Species and Life Stage -Specific Estimated Annual Impingement Loss Estimates for 2017 based on Actual Water Withdrawals at McGuire Nuclear Station Common Name Scientific Name ®® Threadfin Shad Dorosoma petenense 253 633 886 Forage Fragile Alewife Alosa pseudoharengus 296 16 313 Forage Fragile Bluegill Lepomis macrochirus 101 37 138 Recreational Robust White Perch Morone americana 42 92 134 Recreational Robust White Bass Morone chrysops 21 54 75 Recreational Robust Striped Bass Morone saxatilis -- 72 72 Recreational Robust Channel Catfish Ictalurus punctatus 29 31 60 Recreational Robust Unidentified Fish Unidentified Osteichthyes 26 28 54 Forage Robust Gizzard Shad Dorosoma cepedianum 21 32 53 Forage Fragile Duke Energy 1 182 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal �� Benefits Valuation Study [§122.21 (r)(1 1)] Redbreast Sunfish Lepomis auritus Flathead Catfish Pylodictis olivaris Golden Shiner Notemigonus crysoleucas White Crappie Pomoxis annularis Yellow Perch Perca flavescens Blue Catfish Ictalurus furcatus Warmouth Lepomis gulosus Redear Sunfish Lepomis microlophus Largemouth Basso Micropterus salmoides Black Crappie Pomoxis nigromaculatus Catfish Species Ictaluridae Herring Species Alosa spp. Spotted Bass5 Micropterus punctulatus Sunfish Species Lepomis spp. Temperate Bass Morone spp. Species Hybrid Sunfish Lepomis spp. Common Carp Cyprinus carpio Eastern Silvery Hybognathus regius Minnow Quillback Carpiodes cyprinus Total MW ,. . 26 15 41 Recreational Robust 39 2 41 Recreational Robust 23 17 40 Forage Robust 24 -- 24 Recreational Robust 22 -- 22 Recreational Robust 22 -- 22 Recreational Robust 20 -- 20 Recreational Robust 18 2 20 Recreational Robust 7 11 18 Recreational Robust 13 3 16 Recreational Robust 7 8 15 Recreational Robust 6 5 11 Forage Fragile 6 4 10 Recreational Robust 4 5 9 Recreational Robust 4 4 8 Recreational Robust 6 -- 6 Recreational Robust -- 4 4 Forage Robust 2 -- 2 Forage Robust -- 1 1 Forage Robust 1,040 1,073 2,113 -- None collected 'Species Total is the sum of life stages rounded to the nearest whole number. 2Impingement data were collected in 2000- 2002; Actual water withdrawals from 2017 were used to estimate losses to impingement. 'Based on the high abundance of forage species (versus recreational), Unidentified Fish were considered forage fishes (see Section 11.4.1.2). °Largemouth Bass have largely been replaced by Alabama Bass (or hybridized) since the initial collection of Alabama Bass in Lake Norman in 2000 (Duke Energy 2017). 'Since the time that this study was performed, this species has been confirmed as Alabama Bass (NCWRC 2017). Discounting the fragile species from the annual IM estimates resulted in revised annual estimates of 826 and 797 fish for 2016 and 2017, respectively, or a loss of approximately 2.3 and 2.2 fish per day (Table 11-5). Duke Energy 1 183 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal �� Benefits Valuation Study [§122.21 (r)(1 1)] Table 11-5. Summary of Estimated Impingement Mortality under Existing Conditions Excluding Fragile Species at McGuire Nuclear Station 2016 2,175 1,349 (62.0%) 826 2.3 2017 2,113 1,316 (62.3%) 797 2.2 Although the impingement study data are over 10 years old, withdrawal rates and screen operations at McGuire have remained fairly consistent over time (see Sections 3 and 5) and are therefore representative of current conditions. Based on Duke Energy's annual MMP data, the biological community of Lake Norman has remained generally consistent over the past twenty years, with some annual variation observed in the abundance of specific clupeid species (Duke Energy 2017). As such, these data indicate that the impingement data collected during the 2000-2002 study performed at McGuire are representative of existing conditions at the Main Intake and the fish community in Lake Norman is not significantly impacted by operations at McGuire. 11.3 Candidate Entrainment Reduction Technology Scenarios Modeled for McGuire Several facility configurations and operational scenarios were evaluated as potential retrofit compliance options at McGuire (Section 10) and a select set of candidate compliance technologies was retained for further evaluation. The EA and PF models were used to estimate entrainment losses and potential entrainment reduction benefits under each of these candidate compliance technologies, as summarized in Table 11-6 and described in the following sections. . =Description . . . Scenario onfiguration and Operation Compliance Applicability Assumption Entrainment Impingement Without- Complete elimination Current configuration with actual Entrainment of entrainment at the water withdrawals (existing Yes Yes (100% Reduction) Main Intake condition) FMS and Aquatic Fine -Mesh screens 2.0-mm fine -mesh Ristroph screens with a an aquatic Organisms Return (FMS) at actual Yes Yes System water withdrawals organism return system at actual water withdrawals Mechanical Draft MDCT at actual water MDCT Cooling Towers at withdrawals based on preliminary Yes Yes actual water withdrawals design presented in Section 10 IFMS is intended to address entrainment but would also satisfy the impingement criteria (with appropriate measures such as an aquatic organism return, entrapment prevention, etc.). Duke Energy 1 184 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� Benefits Valuation Study [§122.21 (r)(1 1)] r 11.3.1 Determining Losses under Without -Entrainment Scenario To evaluate the benefits associated with a Without -Entrainment scenario (i.e., 100 percent reduction in entrainment), the losses under this compliance alternative equal the estimated annual losses based on the current configuration (3/8-inch coarse -mesh traveling water screens without an aquatic organism return system) at actual water withdrawals. This compliance alternative assumes the complete removal of entrainment at McGuire. 11.3.2 Determining Losses under Fine -Mesh Screens and an Aquatic Organism Return System Scenario Data were modeled under the FMS technology scenario assuming the installation of 2.0-mm fine - mesh Ristroph traveling water screens with an aquatic organism return system. An aquatic organism return system includes continuously rotating traveling water screens with fish -friendly buckets designed to minimize turbulence, a guard rail/barrier to prevent organisms from escaping the collection bucket, and smooth, woven or synthetic mesh (79 FIR 158, 48337). The system would use a low-pressure wash to remove aquatic organisms from the screens to a transfer trough designed to avoid avian and animal predation (79 FIR 158, 48346). Organisms would be returned to the source waterbody at a location a sufficient distance from the Main Intake to reduce risk of repeated impingement on the FMS. Installation of traveling water screens with a mesh size smaller than the current configuration inherently results in an increase in the impingement of organisms. Ichthyoplankton with head depths equal to or greater than 2.0 mm, which would have otherwise been entrained through 3/8-inch coarse -mesh screens, would be impinged on the 2.0-mm FMS (i.e., "converted" from entrainment to impingement). Due to the fragility of early life stage organisms (attributable to limited development of scales and body musculature [EPRI 2010a]), not all ichthyoplankton may survive impingement on a FMS. Therefore, converted organisms were also adjusted for on -screen survival using values identified from multiple historical survival studies and meta -analyses (EPRI 2003, 2004b, 2006, 2010b, 2013). Additional losses were calculated by applying on -screen survival rates to determine the number of convert losses due to impingement on the FMS; the convert losses were then added to the entrainment mortality loss estimates (79 FIR 158, 48330). Applied on -screen survival values are discussed further in Section 11.4.1. Because convert mortalities are accounted for under entrainment estimates, IM is estimated based on the life stages collected during the historic impingement study (i.e., juveniles and adults). Similar to the converted early life stage organisms, on -screen survival data were used to model the effects of impingement mortality under this scenario. 11.3.3 Determining Losses under Mechanical Draft Cooling Towers Scenario Closed -cycle cooling system retrofits typically result in a significant reduction to the total volume of cooling water withdrawn by the facility. In Section 10, a site -specific hypothetical retrofit with MDCTs was designed for McGuire that is conservatively estimated to reduce cooling water withdrawals by as much as 98.4 percent. This value was used to reduce the actual water withdrawal volumes reported for 2016 and 2017, which were then used to determine the incremental entrainment losses Duke Energy 1 185 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� Benefits Valuation Study [§122.21 (r)(1 1)] r under the MDCT compliance alternative scenario. Since MDCTs are considered closed -cycle cooling systems, they also qualify as impingement BTA and provide a corresponding reduction in IM losses. 11.3.4 Summary of Incremental Losses under Entrainment and Impingement Reduction Scenarios Since no entrainment or IM-reducing controls are currently implemented at McGuire, the existing configuration and conditions (coarse -mesh traveling water screens and no aquatic organism return system) present the highest total estimated losses for entrainment and IM (Table 11-7 and Table 11-8). The installation of FMS with a fish return system may reduce entrainment losses by 0.1 to 28.9 percent (compared to existing conditions). The wide range estimated for FMS reductions is attributable to the anomalous collection of Inland Silverside, which comprised 99.1 percent of 115.5 million convert mortalities (or 114.5 million organisms) in 2016 (Appendix 11-13). In the absence of this species (or a similar collection) in 2017, the number of convert mortalities decreased by 98.5 percent to 1.7 million converts, of which 79.3 percent were fragile clupeids. Fragile species also comprised 46.4 percent of converts in 2016 with the exclusion of Inland Silverside. A sensitivity analysis demonstrating the effect of the Inland Silverside collection on the incremental losses and model outputs for each entrainment reduction technology is provided in Appendix 11-A. Table 11-7. Summary of Incremental Losses due to Entrainment by Compliance Technology Scenario for 2016 and 2017 Total .Reduction Baseline2 476,766,186 -- 374,721,425 -- FMS3 338,983,699 28.9 374,238,514 0.1 MDCT 7,628,259 98.4 5,995,543 98.4 'Total No. Lost were rounded to the nearest whole number. 2Baseline condition represents the current configuration of 3/8- inch coarse -mesh traveling water screens and no organism return system. This technology represents the losses that would be eliminated under the "Without -Entrainment' scenario. 3Total FMS losses include convert mortalities. Table 11-8. Summary of Incremental Losses due to Impingement by Compliance Technology Scenario for 2016 and 2017 Baseline2 2,175 -- 2,113 -- FMS 1,593 26.8 1,554 26.5 M DCT 35 98.4 34 98.4 'Total No. Lost were rounded to the nearest whole number. 2Baseline condition represents the current configuration of 3/8- inch coarse -mesh traveling water screens and no organism return system. This technology represents the losses that would be eliminated under the "Without -Entrainment' scenario. Duke Energy 1 186 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� Benefits Valuation Study [§122.21 (r)(1 1)] r The FMS compliance alternative would provide a reduction in IM of approximately 27 percent (Table 11-8), however, similar to the entrainment analysis, fragile species also comprise a large portion of incremental losses estimated for this technology (approximately 82 percent). Because fragile species comprise a large portion of both, the early life stage organisms and the juvenile/adult fish impinged and entrained at McGuire, the installation of fish -friendly Ristroph screens with an aquatic organism return system may not be as effective as compared to other waterbodies where entrainment and impingement losses include a larger portion of robust species. Apart from the complete elimination of entrainment and IM at McGuire, installation of MDCTs would result in the greatest reduction in entrainment and IM (Table 11-7 and Table 11-8). While a proportional reduction of 98.4 percent through flow decrease was used (79 FIR 158, 48331), it is possible that an even greater reduction in IM would be achieved under this scenario due to a lower TSV. However, for the purposes of this analysis, a reduction of 98.4 percent was applied to the total losses from the existing condition and these values were incorporated to the modeling efforts. Incremental losses by species and life stage are provided in Appendix 11-B. The degree of interannual variation in incremental loss estimates documented in Table 11-7 demonstrates the potential annual variation in entrainment reduction benefits that can be anticipated for fishery stocks in Lake Norman and near the McGuire Main Intake under a specific entrainment reduction technology. Furthermore, given similar operating conditions across the two years, these data demonstrate how non -operational factors (e.g., year class strength, annual precipitation and temperature patterns and fluctuations) can influence fishery stocks and annual entrainment estimates. Therefore, it is important to note that annual entrainment estimates and potential entrainment reduction benefits presented in this section are intend to be generally representative of potential conditions at McGuire and are not intended to represent minimum or maximum scenarios. 11.4 Basis for Estimates of Changes in Stock Size or Harvest Levels To quantify the benefits of a technology, the annual incremental entrainment losses of recreational taxa were extrapolated using EA and PF models. EA losses are the number of fish (and biomass) that would have survived to some future age (based on age of equivalence), but were removed from the harvestable population due to entrainment or impingement (EPRI 2004a). The EA model used for McGuire was the Forward Projection approach (EPRI 2012), as described in the McGuire Entrainment and Impingement Calculations appendix (Appendix 9-C). This model approach uses taxa-specific life history information (e.g., growth and survival rates, weights -at -age) to estimate the number and biomass of individuals surviving to the age of equivalence. For recreational taxa, the age of equivalence was defined for each species/life history table as the age of 100 percent vulnerability to the fishery (summarized in Appendix 11-C). To account for forage species (non -recreational taxa), the Rago approach (EPRI 2012) was used to extrapolate prey and non -game (i.e., forage) biomass losses (i.e., production foregone) to an age of equivalence. This model includes the expected future growth of forage species prior to their consumption by predators. Because the PF model quantifies the forage biomass lost to entrainment and impingement, forage species were excluded from the EA model to avoid redundancy. The age Duke Energy 1 187 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� Benefits Valuation Study [§122.21 (r)(1 1)] r of equivalence for forage species in the PF model was the age of reproductive maturity of female taxa (summarized in Appendix 11-C). Assumptions and BPJ decisions employed during the development of the EA and PF models are described below and are summarized in Appendix 11-C. 11.4.1 Model Development 11.4.1.1 Life History Table Development Parameters used in the modeling effort include life stage duration, stage -specific weights, natural mortality, fishing mortality and vulnerability (for harvestable species), and fecundity. Data were obtained from numerous resources (see Appendix 11-C); however the majority of information was drawn from the following documents: • EPRI Final Report 1008471 "Extrapolating Impingement and Entrainment Losses to Equivalent Adults and Production Foregone" (EPRI 2004a); EPRI Technical Report 1023103 "Fish Life History Parameter Values for Equivalent Adult and Production Foregone Models: Comprehensive Update" (EPRI 2012); and • USEPA-821-R-04-007 "Regional benefits Analysis for the Final Section 316(b) Phase II Existing Facilities Rule" (USEPA 2006). Modeling fish survival into the future through the EA and PF models warrants the incorporation of natural mortality into the analyses. Early life stage fish experience high natural mortality rates, which can be the result of starvation, competition, predation, disease, natural senescence, or other factors (Fuiman and Werner 2009). Therefore, it is important to consider natural mortality in estimated losses given the vast majority of eggs and larvae would not have survived to adulthood in the natural environment, even without entrainment and/or impingement effects. In addition to natural mortality, fishing mortality is also applied in calculations of EY for recreational taxa, as categorized in Appendix 11-C. Life history tables were adjusted to achieve approximately zero net growth per generation to assume that all populations are stable throughout the model projections (EPRI 2004a). This adjustment was referred to as life history table "balancing" and was applied to all species life history tables. Natural and fishing mortality, stage -specific maturity, population gender ratio, and fecundity were used for the balancing process, where natural mortality rates were adjusted to result in zero cumulative egg production over the life of the fish. This approach limits the magnitude of the biases that can occur in model projections when parameters are compiled from different studies that were performed at different times using various methods for different life stages and populations (EPRI 2004a). 11.4.1.2 Best Professional Judgment Decisions Life History Information Life history information (e.g., life stage duration, weight -at -death, natural mortality rates, fishing mortality rates) has not been developed for all species and life stages potentially entrained or impinged for all waterbodies in the U.S. Information on stock status (e.g., spawning stock biomass, Duke Energy 1 188 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� Benefits Valuation Study [§122.21 (r)(1 1)] r standardized catch -per -unit -effort, recruitment) is generally only available for harvested species, which represent a minor fraction of impingement and entrainment losses (USEPA 2006). In fact, only 23 percent of U.S. managed fish stocks have been fully assessed (U.S. Ocean Commission 2002). Therefore, site -specific, region -specific, or species -specific data were not readily available for each of the species and life stages collected at McGuire and reported in this benefits valuation analysis (i.e., all species collected during the entrainment and impingement studies). Life history information previously developed by EPRI (2004a, 2012) and the USEPA (2006) was used. When species -specific life history data were unavailable, information from a surrogate species was applied. Surrogate species were ideally a species from the same genus or family exhibiting the greatest similarity in body size and growth -rate. The process of substituting life history data from a surrogate species is referred to as "mapping" the collected species to the life history information of a surrogate species. For example, no existing life history table or sufficient site -specific fishing mortality information was available for the Redbreast Sunfish. Therefore, Bluegill was selected as a surrogate species for Redbreast Sunfish, which was then "mapped" to the existing life history table for Bluegill. Both species are members of the Lepomis genus and exhibit similar life history characteristics and ecosystem functions, and are likely to experience comparable fishing pressure in Lake Norman. A summary of life history table mapping selections and BPJ mapping decisions is provided in Appendix 11-C. Not all organisms were identified to species level; therefore, some BPJ decisions were based on data that were collected during previous entrainment or impingement studies (e.g., periodicity, morphometrics) or data collected during the Duke Energy MMP (species composition and abundance within the vicinity of McGuire). In instances where species identification was only to the genus level (i.e., Dorosoma spp. or Alosa spp.lDorosoma spp.) and there was potential for selecting from more than one existing life history table, a BPJ decision was made based on morphometrics, periodicity of occurrence, or relative abundance. For example, larvae identified as a shad (Dorosoma spp.) was "mapped" to either Threadfin Shad (D. petenense) or Gizzard Shad (D. cepedianum) based on larvae length and month of occurrence (i.e., spawning season). In the event that there was no clear decision of which life history table to use, the species was mapped to the life history table of the species with the greater likelihood of occurrence in samples collected at McGuire based on a comparison of sample densities of the two possible species. Some parameters of the life history tables did not include all of the necessary data required to develop EA and PF models. These data were developed based on BPJ decisions following EPRI guidelines. Parameter -specific BPJ decisions made during life history table development are summarized in Appendix 11-C. For example, where median weight data were unavailable, the midpoint (i.e., average) between starting weights of successive life stages was calculated using formulas provided in EPRI 2004a. On -screen Survival On -screen survival data from multiple historical survival studies were compiled and summarized by species, life stages, and screen mesh types, sizes, and configurations (EPRI 2003, 2004b, 2006, 2010b, 2013). Due to limitations on availability of species -specific information, the compiled data were grouped based on three life stages (larvae, juvenile, and adult) and species vulnerability (fragile vs. robust). On -screen survival data were used to adjust the entrainment and impingement losses estimated under the FMS with aquatic organism return scenario. Duke Energy 1 189 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� Benefits Valuation Study [§122.21 (r)(1 1)] r Fragile species are defined as those with an impingement survival rate of less than 30 percent. For this facility, fragile species consisted of taxa within the Clupeidae family99. Robust species were considered non -fragile species, or species with an impingement survival rate of greater than 30 percent. Based on the accepted IM standard acknowledged by the USEPA (2014), a 76 percent survival rate was applied for robust (Age 1+) fish species. The minimum, median, and maximum on- screen survival rates by life stage and species vulnerability based on data identified in the literature are presented in Appendix 11-C. 11.4.1.3 Changes in Stock or Harvest Levels under Compliance Scenarios To analyze the benefit of each feasible technology, the total entrainment losses that would still be incurred under each With -Entrainment scenario (FMS and MDCT) were converted to net benefits and compared to the baseline (existing) conditions. The With -Entrainment scenarios were calculated as the total additional recreational taxa that would occur with the technology -specific reduction in entrainment at McGuire. For comparison purposes, an additional scenario (Without -Entrainment) was calculated as the total additional recreational taxa that would occur with the complete elimination of entrainment at the Main Intake, and was calculated using the assumption of 100 percent reduction based on baseline entrainment data at actual water withdrawals documented at McGuire. Benefits of entrainment --reducing technologies were analyzed by creating age -structured transition (i.e., Leslie) matrices (Leslie 1945, 1948; Caswell 2001). These dynamic matrix models were developed incorporating survival rates and biomass by age, simulated through the remaining useful plant life to identify changes in forage, commercial, or recreational fish stocks for each evaluated compliance technology. Trophic Transfer Monetizing impacts to forage species is accomplished by converting them to an equivalent number and biomass of recreational and commercial species via the "trophic-transfer" method (EPRI 2004a). Although a trophic transfer efficiency of 10 percent is widely referenced and utilized in the ecological community (including the Regional Benefits Analysis for the Final Section 316(b) Phase III Existing Facilities Rule by the USEPA [2006]), it is also generally acknowledged that this value is an oversimplification of the complex ecosystems and food web relationships within a given waterbody (Burns 1989; USEPA 2006). Therefore, trophic transfer efficiencies were developed for the benefits analysis based on the species collected during the two-year Study at McGuire to better represent the predator -prey relationships in the vicinity of the Main Intake and the potential benefits of entrainment reduction via prey biomass transfer to economically valuable (recreational) species. The percentage of biomass transferred (trophic transfer efficiency) was developed using a matrix with species -specific trophic levels and species relationships and trophic levels were obtained from FishBase (Froese and Pauly 2018). Trophic transfer efficiency was dependent upon the percent 99 Section §125.92(m) of the Rule (USEPA 2014) includes Alewife and Gizzard Shad on the list of fragile species; however, Threadfin Shad also exhibit similar characteristics and are a member of the same family (Clupeidae). Thus, for this analysis, Threadfin Shad were considered a fragile species. For additional information, see Section 4.11) Duke Energy 1 190 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Benefits Valuation Study [§122.21 (r)(1 1)] r allocation of the harvestable species (equally distributed [USEPA 2006]) and the trophic level relationship between harvestable and forage/non-game species (paired). While the trophic-transfer method provides a means for "accounting for" all entrained species, it lacks a way to consider complex food web dynamics (Burns 1989). It also does not incorporate the effects of entrainment reductions on species not included in the analysis, i.e., species within the vicinity of McGuire that were not entrained. Assumptions Like all model approaches, there are assumptions inherent to the EA and PF models used to develop the comparative scenario outputs. These models do not assume density -dependent effects in the unaffected populations, such as faster growth rates and/or greater survival of fish not entrained or impinged due to reduced competition or predation. Additionally, both models assume that "losses" are equivalent to complete removal of the biomass from the system (total carbon removal and no longer available as an energy resource). Equivalent adult models also assume stock equilibrium, i.e., that an adult female fish will produce enough eggs during her lifetime to replace herself and one male (Goodyear 1978). As such, these models are intrinsically conservative in loss and benefit valuations. Quality Assurance/Quality Control Procedures The life history table development and modeling process included quality control (QC) and documentation to ensure the quality of model inputs and outputs. A general overview of the quality QC procedures implemented through the biological modeling process is summarized in Table 11-9. Table 11-9. QC Procedures for the McGuire Benefits Valuation Biological Modeling Process • Data converted from PDF to Excel where possible General . Data copied and pasted as values preferred over manual data entry • All BPJ decisions documented Species mapping decisions . Reviewed by a Senior Fish Biologist Data compilation • Data inputs reviewed for integrity (sources), applicability (e.g., regional -specific data, surrogate species, etc.), and calculation or transcription errors Life history table balancing • Data inputs reviewed for data integrity, applicability, and transcription errors • Review of formula accuracies and balancing methodology On -screen survival . Review of species selections, data analyses, and value finalization • Formulas reviewed for accuracy, trends in survival, growth rates, etc. evaluated for consistency Modeling • Modeling process described by EPRI (2004a, 2012) was replicated to ensure model accuracy • Checksums performed on time series modeling for data accuracy Trophic transfer matrix • Step -wise matrix building reviewed for accuracy of trophic level values and formulas for trophic transfer efficiencies Duke Energy 1 191 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal �� Benefits Valuation Study [§122.21 (r)(1 1)] 11.4.2 Basis for Monetized Values Assigned to Changes in Stock Size and Harvest Levels Estimates of projected changes in fish stocks (calculated and provided by HDR) were used to develop the Entrainment Reduction Benefits Valuation Study for McGuire (Veritas 2018) (provided in Appendix 11-D). This study included modeling the facility in its current condition ("With - Entrainment"), with the complete elimination of entrainment ("Without -Entrainment"), as well as two entrainment -reducing technologies (FMS and MDCTs). The With- and Without -Entrainment scenarios and the entrainment -reducing technologies were modeled based on the anticipated plant retirement date100 (or based on the end of useful plant life). 11.4.2.1 Interpreting Benefits Valuation Figures Figure 11-1 and associated text in this section provides an example output from the benefits valuation process with notes on interpreting the subsequent figures. The figure shows the estimated difference between With -Entrainment (baseline) and Without -Entrainment conditions. This difference shows how much greater recreational yield would be under Without -Entrainment conditions (i.e., with a technology installed) than under baseline conditions101 The change in recreational yield is shown for a technology that becomes operational in 2024 (illustrated by the first arrow) and remains operational until the plant is scheduled to shut down under baseline conditions (2043 as indicated by the second arrow). Over this time period, Figure 11-1 shows the general pattern of increasing recreational yield change that would occur under Without -Entrainment conditions and then cease to occur once the plant is scheduled to shut down under baseline conditions. ioo The operating license expiration is 2041 and 2043 for Units 1 and 2, respectively. 101 For expositional purposes, Figure 11-1 presents the metric of recreational yield. The concepts described in the text accompanying Figure 11-1 can also be applied to the additional metrics presented throughout this section including number of recreational adults, forage species biomass, change in expected catch, change in number of trips, and welfare difference. Duke Energy 1 192 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� Benefits Valuation Study [§122.21 (r)(1 1)] r 80 3 70 Q C i4 60 7 3 �� W_ m C 40 l6 t U 30 Baseline Plant d Technology r R 20 0 m 10 V d a v 2015 2020 2025 2030 2035 2040 2046 2060 2066 Time (years) Recreational Species Species A — Species B Change in Recreational Yield VERITAS Eepani[Ceritl0 Installed 2024 Closure 2043 Figure 11-1. Change in Recreational Yield with Technology Installation (Example) The example on Figure 11-1 depicts the recreational yield changes for two species. Species A is recruited to the fishery quickly and has a relatively short lifespan—approximately six years. Species B is recruited to the fishery more slowly and has a longer lifespan—approximately 25 years. For both species, although entrainment is reduced in 2024, the juveniles that are spared are not yet eligible to be caught in 2024; therefore, there is no increase in yield. • In 2025, the juveniles of Species A that were not entrained in 2024 become vulnerable to fishing gear and there is an increase in yield of 32 fish for Species A. • In 2026, additional juveniles of Species A become vulnerable to fishing gear. However, the change in yield for Species A does not double from 2025 to 2026 because the fish caught in 2025 and those that died naturally are removed from the fishery. Thus, the yield of Species A increases to 43, consisting of: o 32 one -year -olds that were not entrained in 2025; and 0 11 two -year -olds that were not entrained in 2024. • In 2027, the yield of Species A increases by a total of 47, consisting of: 0 32 one -year -olds that were not entrained in 2026; 0 11 two -year -olds that were not entrained in 2025; and 0 4three-year-olds that were not entrained in 2024. As the fishery evolves, the yield of Species A reaches a steady state around 2030 when the fish not entrained in 2024 have either been caught or have died naturally and are no longer part of the Duke Energy 1 193 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� Benefits Valuation Study [§122.21 (r)(1 1)] r fishery. This steady state continues one year past the scheduled baseline plant closure in 2043. After 2043, there is no difference between With- and Without -Entrainment Conditions because the plant is scheduled to cease operations. The 32 recruits to the fishery that would not have been entrained in 2044 with the technology in operation are no longer included in the analysis because the plant is no longer operating; therefore, the increase in recreational yield change starts to decline (15 caught fish in 2045). In 2046, only fish spared before 2043 are caught (i.e., age three and older), reducing the change in recreational yield further (five fish in 2046). This decline in the recreational yield change continues until there are no more fish in the fishery that have a maximum lifespan of six years and would have otherwise been entrained in 2043. Yield changes for Species B are similar; however, the curve has a slightly different position because Species B takes two years longer to be recruited to the fishery and lives longer. As a result, Species B yield changes begin in 2026, do not begin to drop off until 2047, and take longer to dissipate than Species A. The results in Figure 11-1 are presented for one year of entrainment data. The following figures presented throughout this section depict results using two years of entrainment data (2016 and 2017) at McGuire. The simulated model results using each year are presented individually so the effects that interannual variation have on each component of the benefit estimation process are transparent. The results are also depicted for the complete elimination of entrainment. This is done for simplicity and clarity in presenting the results. Presenting the results for a combination of multiple technologies adds additional complexity to the figures and makes them difficult to interpret; therefore, the results of the estimated benefits of each technology are presented in a table at the end of this section. 11.4.2.2 Estimated Benefits Estimating the benefits of entrainment reduction requires an assessment of the relationship between entrainment, fish stock changes, and the impact that fish stock changes may have on people. For instance, this includes understanding how entrainment at McGuire affects recreational fishing catch rates, and consequently, how that affects angler well-being. To evaluate these relationships, a site -choice simulation is used to evaluate the effects that entrainment losses have on recreational fisheries. The analysis modifies site catch estimates to generate recreational catch that could occur with entrainment reductions, and then estimates the economic value of catch rates by linking them to models of recreational angling demand presented in Bingham et al. (2011). Age -structured changes in stock using survival parameters were developed and linked to the site - choice simulation model through fishery -specific catch and effort rates. This forms a bio-economic equilibrium (i.e., yield, trips, and expected catch are integrated) for the With -Entrainment representation of the Lake Norman fishery expected to be affected by entrainment at McGuire's Main Intake. The integrated partial equilibrium models are used to simulate conditions under With - Entrainment (baseline) and Without -Entrainment conditions, and the monetized welfare differences between these two conditions determine the benefits of entrainment reductions. As described in USEPA's Guidelines for Preparing Economic Analysis, equilibrium modeling using the With- and Duke Energy 1 194 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� Benefits Valuation Study [§122.21 (r)(1 1)] r Without -Impact approach is central to all sound benefit estimation processes and regulatory impact analysis (USEPA 2010). The analysis also considers the benefits that would result from the entrainment reduction technologies that have been evaluated at McGuire. Taking into account the additional time needed for permitting, design, and construction of the entrainment -reducing technologies, the timing specified for the models is presented in Table 11-10 below. The study results are summarized in this section, while Appendix 11-D provides a detailed description of the assumptions, methodologies, and results of the study. Table 11-10. Timing Specified for Feasible Technologies at McGuire Mechanical Draft Cooling Towers (MDCT) 2019 2021-2031 2031 13 2.0-mm Fine -Mesh Ristroph Screens 2019 2021-2025 2025 19 (FMS) with a Fish Return System a Timelines are from Duke Energy's PROSYM model 11.4.2.3 Non -Recreational Benefits (Forage Species) Monetizing impacts to forage species is accomplished by converting them to an equivalent number and biomass of recreational species via the trophic-transfer method. As typically applied, this approach multiplies adult equivalent forage biomass (i.e., production foregone) by a conversion factor to identify changes in higher trophic level species that are recreationally and commercially valuable. 11.4.2.4 Recreational Benefits Changes in yield (which impact anglers) could occur at recreational sites throughout Lake Norman. A site -choice simulation of recreational angling demand was developed to evaluate how changes in yield due to entrainment reductions may occur at Lake Norman. As described in the McGuire Entrainment Reduction Benefits Valuation Study (Veritas 2018) (Appendix 11-D), these sites were aggregated to a single affected site. Substitute sites were also considered, which were defined as sites where anglers could fish but that were not used to estimate the angling population most likely to be affected by changes in entrainment at McGuire. Substitute sites were generally within 100-200 miles of the affected site. The number of anglers were estimated, by ZIP Code, within a 50-radius of McGuire (see Figure 11-2). Changes in the expected catch per unit effort (i.e., catch per trip) of each recreationally harvested species at Lake Norman is presented in Figure 11-3. Duke Energy 1 195 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� Benefits Valuation Study [§122.21 (r)(1 1)] r F-1 1 D K Inge p ort Cherokee Q N abon al 1.1inson City Forest ■ F� , I t l l ■■ q A:.lie•� tll� Lake Norman McGuire Nuclear Station ■ ■ ■ J ■ �alsl ill ■ 1, l ■ *eensboro a em o p Durham a ai I E) M C N L Q .� ■rrNORTH A ie CAR al. II I�d ■ ■ Surnt$r ■ Columbia Naban id Fae st SOUTH CAROLINA N Augusta 35 miles F ayette ■ ■ o Lumb ee Sd tsa ■ ■ Saf�ry a ■ Legend i Affected Site _ -= —• A Substitute Sites ' Number of Anglers Residing in Each ZIP Code " w 1-1,000Anglers M _ 1,001-2, 000 Anglers 2.001-3.000 Anglers 3.001-4.000 Anglers Area Enlarged Above i 4,000+ Anglers Angling Population, Affected and Substitute V E R I TAS Sites Near McGuire Nuclear Station Economic Consulting Figure 11-2. Location of Sites with Affected Catch Rates, Location of Substitute Sites, and the Concentration of Anglers (Source: Veritas 2018) Duke Energy 1 196 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Benefits Valuation Study [§122.21 (r)(1 1)] r Panel A: 2016 a14ao — a12oo a 1= n 0.1000 m w 0.0000 m U a m 0.0600 K W c 0.0400 m w L U 0.0200 0.0000 2015 2020 2026 2030 20a5 2040 2046 2050 2056 2060 2065 Time (years) Recreational Species • Channel Catfish t Whke Perch Black bass - Suntleh — Black Crappie Panel B: 2017 0.0100 0.0090 n 0.0080 r a 0.0070 a L 0.0060 V m 0.0060 n m n 0.0040 W G 0.0030 01 C 0.0020 0.0010 0.0000 1' 201S 2020 2026 2030 2035 2040 2046 2060 2056 2080 2065 Time (years} Recreational Species — ChannelCatfish + Whft&Perch — Black bass - Sunfish — BlackCrappfe V E R I T A S Expected Catch Economic Consulting Figure 11-3. Change in Expected Catch per Trip by Species at Lake Norman (Source: Veritas 2018) Duke Energy 1 197 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Benefits Valuation Study [§122.21 (r)(1 1)] r Channel Catfish and White Perch exhibit the largest increase in the number of fish per trip in 2016 and 2017, respectively. However, the magnitude of change was much greater for Channel Catfish in 2016 (approximately 13.5 times higher compared to White Perch, black bass, sunfish, and Black Crappie) than for White Perch in 2017 (approximately 7.2 times higher compared to black bass, sunfish, and Black Crappie). Based on these expected catch changes, equations from welfare economics were used to identify annual changes in trips and economic benefits (based on changes in expected catch for all affected species). The metric used for economic benefits was changes in consumer surplus that arise from changes in site demand. This methodology is consistent with economic theory and adheres to Rule discussion with respect to considering the "the availability of alternative competing water resources for recreational usage [alternative substitute sites], and the resulting estimated change in demand for use and value of the affected water resources" (79 FR 158, 48371). Figure 11-4 depicts the total change in trips to Lake Norman where catch changes are specified to occur based on the complete elimination of McGuire's entrainment losses. Figure 11-5 depicts the annual change in dollar -valued welfare associated with the estimated trip changes from a complete reduction in McGuire's entrainment losses. 1,2DD J- 1,000 1 m 800 U a F 60D H m nr m 400 `a 200 o 2015 2020 2025 2030 2035 2D40 2045 2050 2055 2060 2065 Time (years) Entrainment Year ' 2016 — 2017 V E R 1 TA S Affected Sites Change in Trips Economic Consulting Figure 11-4. Estimated Trip Change with Elimination of Entrainment at McGuire (Source: Veritas 2018) Duke Energy 1 198 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal Benefits Valuation Study [§122.21 (r)(1 1)] 50 K 45K 40K..----'--------------------------- 35 K w_ m = 30K gd L 25K `w 20K m 15K 10K 5000 0 2015 2020 2025 2050 2035 2040 2045 2050 2455 2060 2065 Time (years) Entrainment Year — 2016 —2017 Welfare Difference in US Dollars V E R ITA S Economic Consulting Figure 11-5. Change in Welfare with Elimination of Entrainment at McGuire (Veritas 2018) The expected change in number of fishing trips to Lake Norman based on entrainment loss estimates in 2016 shows a peak of approximately 1,500 trips in 2043, at the end of the station's useful life (retirement date). The magnitude of difference observed between the number of trips expected in 2016 compared to 2017, as illustrated in Figure 11-4, is driven by the density of juvenile Channel Catfish collected in 2016 (with zero collected in 2017). Juvenile Channel Catfish are not susceptible to fishing pressure and typically exhibit increased survival in comparison to eggs and larvae, thus their estimated entrainment losses result in larger EY values and an increase in the expected number of fishing trips. The increased number of fishing trips based on 2016 entrainment data results in a substantially higher welfare value, peaking at approximately $50,000 in 2043, as illustrated in Figure 11-5 Similarly, in 2017 the increased number of fishing trips is due to the estimated entrainment losses of post yolk -sac larvae White Perch, which resulted in a larger EY compared to other species collected in 2017. Based on the larger EY value (Figure 11-5), the estimated annual welfare difference peaks at just under $5,000 in 2043. 11.4.2.5 Nonuse Benefits The final category of benefits that could be monetized is nonuse benefits. Krutilla (1967) presented the original philosophical underpinning for nonuse values, arguing that individuals do not have to be consumers of unique, irreplaceable resources to derive value from the continuing existence of such resources. He wrote: Duke Energy 1 199 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Benefits Valuation Study [§122.21 (r)(1 1)] r "when the existence of a grand scenic wonder or a unique and fragile ecosystem is involved, its preservation and continued availability are a significant part of the real income of many individuals" (Krutilla 1967, p. 779). Important components of Krutilla's original concept are that nonuse values are related to the continuing existence of unique resources. Under this framework, common resources suffering from limited injury do not generate significant nonuse values. The economic literature emphasizes the relationship between nonuse values and both the uniqueness of the resource in question and the irreversibility of the loss or injury (Freeman 2003; Freeman et al. 2014). Freeman (2003) summarizes this relationship as follows: "...economists have suggested that there are important nonuse values in ...preventing the global or local extinction of species and the destruction of unique ecological communities. In contrast, resources such as ordinary streams and lakes or a subpopulation of a widely dispersed wildlife species are not likely to generate significant nonuse values because of the availability of close substitutes" (Freeman 2003, p. 162). As Freeman's text indicates, common resources (i.e., resources that are not unique) that do not experience irreversible losses are not likely to generate significant nonuse value. The effects of McGuire's operation have occurred for decades. Although changes have occurred in the Lake Norman ecosystem, these do not appear related to entrainment. Moreover, entrainment sampling does not indicate federally protected species are being entrained at McGuire. As compared to Krutilla's "grand scenic wonder" these resources and impacts also exhibit low levels of awareness by the public. This was demonstrated in the 2012 Environmental Impacts Awareness Study (Veritas 2012). Thus although some of the described quantified outcomes (e.g. changes in entrainment, changes in stock) could conceivably be associated with nonuse benefits (e.g. changes in entrainment, changes in stock), the magnitude of nonuse values for entrainment reductions at McGuire has not been quantitatively evaluated as part of this effort. However, based on the precepts of nonuse values, the nonuse benefits of reducing entrainment at McGuire are anticipated to be low. Specifically, given estimated entrainment reduction costs and benefits, correctly measured nonuse benefits would not impact a BTA determination that considers benefits and costs based on historically applied criteria. 11.4.3 Discussion of Mitigation Efforts Made Prior to the Rule No previous entrainment mitigation activities have been implemented at McGuire. 11.5 Technology -Specific Findings 11.5.1 Estimated Stock and Harvest Losses under Each Compliance Scenario The estimated stock and harvest losses and the potential impact to the fishery under existing conditions and evaluated entrainment- and impingement -reducing technologies are summarized in Table 11-11 and Table 11-12. Technology -specific details of these results are presented in the following sections. Additionally, the results of the analysis of model sensitivity (EA, PF, and EY Duke Energy 1200 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Benefits Valuation Study [§122.21 (r)(1 1)] r model estimates) to the inclusion of the anomalous Inland Silverside collection event on the model predicted loss estimates under each technology -specific scenario is presented in Appendix 11-A. The model -derived entrainment and impingement losses by species and life stage, and their estimated impacts to stock and harvest of the Lake Norman fishery are provided in Appendix 11-13. Table 11-11. Annual Entrainment Loss Estimates by Compliance Scenario for 2016 and 2017 at McGuire Nuclear Station 2016 Baseline' 42,946 2,958 674,086 16,682 FMS2 21,210 1,898 332,793 7,655 MDCT 687 47 10,785 267 2017 Baseline' 19,119 7,446 65,065 542 FMS2 18,830 7,265 65,022 420 MDCT 306 119 1,041 9 'Baseline condition represents the current configuration of 3/8-inch coarse -mesh traveling water screens and no organism return system at actual water withdrawal volumes. This table presents the estimated entrainment losses that would occur under each compliance scenario in 2016 and 2017. 2Total FMS losses include convert mortalities. Table 11-12. Annual Impingement Loss Estimates by Compliance Scenario for 2016 and 2017 at McGuire Nuclear Station 2016 Baseline' 121 163 118 120 FMS 32 40 77 30 MDCT 2 2 2 2 2017 Baseline' 115 154 116 113 FMS 30 38 75 28 MDCT 2 2 2 2 'Baseline condition represents the current configuration of 3/8-inch coarse -mesh traveling water screens and no organism return system. This table presents the estimated impingement losses that would occur under each compliance scenario in 2016 and 2017. Duke Energy 1201 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal Benefits Valuation Study [§122.21 (r)(1 1)] 11.5.1.1 Without -Entrainment Condition Entrainment Based on the Without -Entrainment Scenario (100-percent elimination of entrainment) under existing conditions, the changes in recreational and forage fish stocks would vary annually between an additional 19,119 (7,446 Ibs) and 42,946 (2,958 Ibs) EA returned to the fishery (Table 11-11). Recovered forage biomass would return between 65,065 Ibs and 674,086 Ibs of PF to the forage fish stocks. The total potential impact to the recreational fishery by eliminating entrainment at the Main Intake is between 542 and 16,682 Ibs of EY. The disparity of EA, PF, and EY between years is largely driven by Channel Catfish (for EA and EY) and Inland Silverside (for PF) (Appendix 11-B). Channel Catfish in 2016, alone, consisted of 92 and 99 percent of EA and EY losses, respectively. The effect of Inland Silverside presence is also apparent: assuming the Inland Silverside collection was an anomalous event, excluding this species from the analysis would reduce total PF by 93 percent, to 49,989 lbs. The large difference in total EY losses between 2016 and 2017 is due to the differences in species composition between the two years. The EY in 2016 is influenced by the estimated losses of juvenile Channel Catfish (99 percent), while EY in 2017 is influenced by estimated entrainment losses of post yolk -sac black bass and White Perch (90 percent) (Appendix 11-B). Channel Catfish are considered a robust, recreational species with a lower natural mortality rate at the juvenile life stage in comparison to egg or larval stages. Thus their collection in entrainment samples contributed greatly to the EA and EY estimates for 2016. Particularly for EY, the relatively -high age of equivalence for White Perch results in a greater EY estimate for this species, even with collections at a post yolk -sac larval life stage. Benefits of estimated changes in fish stocks expected for recreational species in Lake Norman (such as Channel Catfish, Black Crappie, black bass, sunfish, and White Perch), that would occur with the complete elimination of entrainment at the Main Intake, is depicted in Figure 11-6. The changes in fish stock are substantially higher in 2016 than in 2017, which are driven by the Channel Catfish. While White Perch has the greatest change in 2017, the difference between this species and the other recreational species (black bass, sunfish, and crappie) is on a much smaller scale (a difference of approximately 21,000 recreational adults). Comparing this to 2016, Channel Catfish has a much greater maximum (of approximately 85,000 recreational adults) compared to the other recreational species in 2016. Figure 11-7 depicts the adult equivalent biomass for the forage species entrained at the Main Intake. Similar to the disparity between years and species for recreational species, the large y-axis scale differences are driven by a collection of Inland Silversides in 2016, which resulted in an increase of forage species biomass a magnitude greater than the highest biomass seen in 2017 (Alewife/Gizzard Shad/Threadfin Shad). Incorporation of this forage biomass via the trophic-transfer method and resulting changes to predator stock is depicted in Figure 11-8. Again, the difference between 2016 and 2017 is substantial (maximum transferred forage biomass of greater than 13,000 Ibs in 2016, versus just over 1,600 Ibs in 2017) and is driven by the Inland Silverside collection, which consisted of over 93 percent of the total forage biomass transferred. Duke Energy 1202 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Benefits Valuation Study [§122.21 (r)(1 1)] r Panel A: 2016 90K S0K 70K N a SOIL a N c SOIL a m m C d01i 0 s 30K E 2 20K SOK 0 2016 2020 2025 2030 2636 2010 20" 2060 246 2660 2065 Time (Ye" Recreational Species - Ch a n nel Catfish t White Perch Black bass sunfish Black Crappie Panel B: 2017 22.5K 20K 17.6K n 16K Q t t 2.5K Ix 1OK 0 s 7600 E 2 5000 2500 I v. 2015 2020 2025 2030 2035 2040 20" 2060 2055 2060 2065 Tim& Iyears] Recreational Species Chan—ICatrrsh t White Perch glaCk hays Sunfish - @lack Crappie VE R 1 T A S Recreational Species Economic Consulting Figure 11-6. Direct Changes in Recreational Fish Stocks as Equivalent Adults with Elimination of Entrainment at McGuire Nuclear Station (Source: Veritas 2018) Duke Energy 1203 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal �� Benefits Valuation Study 1§122.21(r)(11)] Panel A: 2016 10DK v 600K r 7 e 5UDK w E❑ 400K in m 30DK R n 0. rn 200K m ' a K 0 900K LL 0 2015 2020 202S 2030 2035 2040 204S 2050 205S 2060 2D65 Time (years) Forage Species Aiewlfe Glx and shad Threadfin shad t A]ewlfe16it2ard shaWThreadfln Shad Gizzard Shad7Thraadfrn Shad Unidentified fish Carp and Minnow Family — Golden shiner + Unidentified herring Common carp er Wand Silverside Unidentified Oste ichthyes — Darter Species Qulllback Eastern siivery minnow Swamp Darter Panel B: 2017 60K N 50K a o 40K E 0 30K m o a 20K fA d 0 10K LL 2015 2020 2025 2030 2035 2M 2045 20SO 2055 2060 2065 Time (years} Forage Species ••• Alewife [Guard shad Threadrin shad + AlewlfelGivard ShadlThreadfin Shad Gizzard ShadlThreadfln Shad Unidentified fish Carp and Minnow Family — Golden shiner Unidemified herring • common Carp Inland Silverside UnlderdifiSd OSIsichthyO — Darter Species Quillback Eastern silvery minnow Swamp Darter V E R I TA S Forage Species Economic Consulting Figure 11-7. Direct Changes in Forage Fish Stocks as Biomass (lbs) with Elimination of Entrainment at McGuire Nuclear Station (Source: Veritas 2018) Duke Energy 1204 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Benefits Valuation Study [§122.21 (r)(1 1)] r Panel A: 2016 14K 12K 3 n 10K N d a 8000 N LL 6000 E 0 N 4000 E 0 m 200a 0 — 2015 2020 2025 2030 2035 2040 2045 2050 2055 2060 2065 Time (years) Recreational Species ° Channel Catfish White Perch Black bass Sunfish Black Crappie Panel B: 2017 ,aoo ,boa I c 1400 a a w 1200 7000 uqi m `0 800 0 E c 600 m 0 400 m 200 0 - 11 = - - ��- . - 2015 2020 2025 203a 2035 2040 2045 2050 2055 2a60 2065 Time (years) Recreational Species .. Channel Catfish + White Perch Black bass Sunfish Black Crappie V E R I T A 5 Biomass from Forage Species Economic Consulting Figure 11-8. Trophic Transfer -Based Changes in Pounds of Biomass with Elimination of Entrainment at McGuire Nuclear Station (Source: Veritas 2018) Duke Energy 1205 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal Benefits Valuation Study [§122.21 (r)(1 1)] To identify the recreational yield changes associated with changes in stocks, harvest rates were applied to stock changes. When possible, these harvest rates are based on fishery stock assessments of the source waterbody. However, stock -specific recreational harvest rates were not available and were developed based on species -specific harvest rates provided in the literature (EPRI 2004a; USEPA 2006; EPRI 2012) with adjustments based on BPJ. However, empirical and anecdotal evidence (based on angler reports) indicate that Lake Norman is a superior recreational fishery with anglers reporting that the freshwater fishing in Lake Norman may be the best in the state (Turnage 2009). Figure 11-9 depicts the estimated recreational yield changes for the sportfish species entrained at McGuire. As observed with the direct changes in recreational (Figure 11-6) and forage (Figure 11-7) fish stocks, the difference between years is attributable to two primary species: Channel Catfish and Inland Silverside. Because the collection of these species in 2016 may have caused inflated estimates, it may be assumed that 2017 results represent more typical conditions at McGuire. With the total elimination of entrainment at the Main Intake, recreational yield in Lake Norman could potentially increase by a maximum of approximately 1,300 White Perch and between 100 to 225 fish of each, sunfish, Black Crappie, and black bass (Figure 11-9). Duke Energy 1206 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Benefits Valuation Study [§122.21 (r)(1 1)] r Panel A: 2016 20K 16K 16K n m 14K E Z 12K m C i 10K V E 0 $000 a C 80DD a m m 4000 a 2000 0 2016 2020 2026 2030 2D35 2040 2046 2060 2066 2060 2055 Time [ysxsj Recreational Species • Channel Catfish t White Perch + Stock bees = Sunfish — B4ek Crapple Panel B: 2017 1400 1200 1000 g i coo 'a 600 Y 40D u 200 T - 8 .15 2020 2625 2630 2635 2040 2045 2060 2055 2060 2085 Time (years) Recrea[lonal Species . Channel Catfish - Whits Perch Slack bass Sunfish -- Black Crappie V E R I T A S Recreational Yield Economic Consulting Figure 11-9. Total (Direct and Indirect) Changes in Recreational Yield with Elimination of Entrainment at McGuire Nuclear Station (Source: Veritas 2018) Duke Energy 1207 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal Benefits Valuation Study [§122.21 (r)(1 1)] Impingement Under baseline (existing) conditions, the changes in harvestable and forage fish stocks would vary annually between an additional 121 (163 Ibs) and 115 (154 Ibs) EA returned to the fishery (Table 11 12). Recovered forage biomass would be between 129 Ibs and 130 Ibs of PF returned to the fishery. The total potential impact to the recreational fishery by eliminating IM at McGuire is approximately 128 Ibs of EY (estimated for both years). Because annual IM estimates were made based monthly average densities and extrapolated based on actual water withdrawals for 2016 and 2017, variation between years in individual species estimates were minor given that intake volumes were similar across years (Appendix 11-B). Fragile clupeids represented approximately 62 percent of total losses and 55 percent of the foregone production biomass (Table 11-5). Common Carp, a non-native species introduced from Asia known to cause ecosystem impacts in some areas (Nico et al. 2019), comprised another 36 to 37 percent of PF biomass (Appendix 11-B). The dominance of fragile species in the impingement samples was likely driven by their intolerance for cold temperatures, as indicated by increased impingement rates during winter months (EPRI 2010b). As fragile species, they inherently have a low impingement survival rate; therefore, it is unlikely that these species would survive impingement and handling through a fish return system, particularly if already stressed by cool temperatures. Additional information regarding Threadfin Shad, Alewife, and Gizzard Shad low temperature intolerances can be found in Section 4.5.1. 11.5.1.2 Estimated Changes under with Fine -Mesh Screens and an Aquatic Organism Return System Scenario Entrainment The installation of FMS would reduce the total losses to the fishery to 18,830 (7,265 Ibs) to 21,210 (1,898 Ibs) adults (Table 11-7). Forage biomass lost would be reduced to 65,022 to 332,793 Ibs of PF. The total potential impact to the recreational fishery through reducing entrainment by installation of FMS is estimated to be between 420 and 7,655 Ibs of EY lost to the fishery. Incorporation of on -screen survival to include mortality of converted organisms was an important element of the FMS scenario analysis, as demonstrated in the changes of EA, PF, and EY for 2016 (Table 11-13). The convert mortalities in 2016 consisted mainly of Channel Catfish juveniles. All Channel Catfish would be excluded by the 2.0-mm FMS, however, 171,120 juveniles (equating to 18,022 EA) would suffer mortality due to impingement on the FMS. Overall, convert mortalities comprised 86 percent of total numbers of EA (48 percent of EA biomass), 86 percent of PF, and 99 percent of EY in 2016. The addition of convert mortalities in 2017 had a marginal effect for EA and PF (one to three percent). However, converts comprised over 32 percent of the total EY biomass, primarily due to the collection of black bass post yolk -sac larvae (Appendix 11-B). Duke Energy 1208 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Benefits Valuation Study [§122.21 (r)(1 1)] r Table 11-13. Estimated Entrainment Losses with Fine Mesh Screens at McGuire Nuclear Station 2016 1.0-mm FMS 3,021 987 47,828 101 Convert Mortalities 18,189 911 284,965 7,554 FMS Total Mortalities 21,210 1,898 332,793 7,655 2017 1.0-mm FMS 18,508 7,063 64,438 284 Convert Mortalities 322 202 584 136 FMS Total Mortalities 18,830 7,265 65,022 420 Impingement Based on the installation of fish -friendly fine -mesh Ristroph traveling water screens and an organism return system, the reduced losses in recreational and forage fish stocks would total 30 (40 Ibs) to 32 (38 Ibs) adults (Table 11-12). Forage species biomass losses would be reduced to 75 to 77 Ibs of PF. The reduced impact to the recreational fishery by the addition of an organism return system at McGuire is between 28 and 30 Ibs of EY lost to the fishery. Although Channel Catfish contributed approximately 21 percent of the total EA numbers lost, Striped Bass and White Bass comprised the majority of EA (87 to 92 percent) and EY (75 to 81 percent) biomass losses. Forty-four to 73 percent of the impinged Striped Bass and White Bass during the historical study were collected from May to September (EPRI 2010c). As cool -water species stocked in Lake Norman, higher rates of impingement during the summer months may have been due to increased stress caused by naturally -high water temperatures and/or lower dissolved oxygen concentrations (Crance 1984). Fragile clupeids consisted of approximately 60 percent of total numbers lost and 83 percent of the biomass contributing to PF. As stated previously, clupeids are sensitive to cool temperatures and increased rates of impingement of these species may be due to cooler weather stress. 11.5.1.3 Estimated Changes under Mechanical Draft Cooling Towers Scenario Entrainment Aside from the Without -Entrainment scenario, MDCTs represent the largest reduction in entrainment and greatest potential benefit to the fishery with a reduction of 98.4 percent. Under this scenario, losses in recreational and forage fish stocks would be between 306 (119 Ibs) and 687 (47 Ibs) adults (Table 11-11). Forage biomass losses would be reduced to between 1,041 and 10,785 Ibs. Total impact to the recreational fishery would amount to between 9 and 267 Ibs of EY biomass lost. As Duke Energy 1209 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Benefits Valuation Study [§122.21 (r)(1 1)] r with the other scenarios, EA and EY were largely driven by Channel Catfish and the majority of PF losses estimated comprised clupeid species (with the exclusion of Inland Silverside). Impingement Such as with entrainment estimated losses, IM estimates under this scenario are also the lowest of the scenarios evaluated. Estimated IM for 2016 under the MDCT scenario represents the greatest reduction in impingement losses and potential benefit to the fishery, with a reduced loss of approximately two adults (2 Ibs of EA biomass) (Table 11-12). Forage species biomass losses were estimated at 2 Ibs of PF. Total impact to the recreational fishery would be 2 Ibs of EY biomass lost. 11.5.2 Summary of Estimated Changes in Stock and Harvest, and Monetization of Benefits for Candidate Measures Decreasing water withdrawals via MDCTs would result in the greatest reduction, overall, in entrainment and IM losses with a reduction of 98.4 percent in EA, PF, and EY (Table 11-14 and Table 11-15. Installation of modified Ristroph 2.0-mm FMS with an aquatic organism return system may reduce entrainment losses by up to 54.1 percent in 2016; however reduction estimates were marginal for EA and PF in 2017. The higher reduction estimates for 2016 were caused by the collection of the Inland Silverside and Channel Catfish; in absence of these collections in 2017, the reduction of losses was less than three percent for EA and PF due to the addition of convert mortalities (mainly, fragile clupeids). The efficacy of FMS would be much greater for older life stages (i.e., adults and juveniles) as compared to early life stages, with reductions in IM of up to 75.5 percent. Reductions in IM PF under the FMS scenario were slightly less (approximately 35 percent) due to the increased mortality of fragile clupeids. Table 11-14. Percent Reductions under Entrainment Compliance Technology Scenarios Relative to the Baseline Condition at McGuire Nuclear Station 2016 Annual Percent Entrainment Loss Reduction Existing Condition -- -- -- -- FMS' 50.6 35.8 50.6 54.1 MDCT 98.4 98.4 98.4 98.4 2017 Annual Percent Entrainment Loss Reduction Existing Condition -- -- -- -- FMS' 1.5 2.4 0.1 22.5 MDCT 98.4 98.4 98.4 98.3 'FMS scenario includes convert mortalities. Duke Energy 1 210 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Benefits Valuation Study [§122.21 (r)(1 1)] r Table 11-15. Percent Reductions under Impingement Compliance Technology Scenarios Relative to the Baseline Condition at McGuire Nuclear Station 2016 Annual Percent Impingement Loss Reduction Existing Condition -- -- -- " -- FMS 73.6 75.5 34.7 75.0 MDCT 98.4 98.4 98.4 " 98.4 2017 Annual Percent Impingement Loss Reduction Existing Condition -- -- -- -- FMS 73.9 75.3 35.3 75.2 M DCT 98.4 98.4 98.4 98.4 The EY and total PF estimates for McGuire were used to determine the entrainment reduction benefits (ecological and economic) achievable under each candidate entrainment reduction compliance scenarios. With incorporation of trophic transfer efficiency, the total recreational yield incorporated to the benefits valuation represents the losses of direct IM and entrainment of recreational species, as well as the indirect reduction in harvest due to reduced prey availability. Because parameter uncertainty has the potential to significantly impact the monetization of benefits, the estimated losses and entrainment reduction benefits were calculated with conservative estimates. The actual annual entrainment reduction benefits, both biological (EY and total PF) and economic (monetized or dollar value) under each of the compliance scenarios would likely be much lower on any given year. 11.5.3 Summary of Monetized Benefits The results presented throughout this section demonstrate the effects of each step to develop the benefits of a complete reduction in McGuire's entrainment. In addition to a 100-percent reduction, the analysis also considers the benefits that would result from the entrainment reduction alternatives that have been evaluated at McGuire. The present and annual recreational benefit values for each evaluated technology are provided in Table 11-16. To develop the present value estimates, the benefits estimated for each feasible alternative are discounted at 3 and 7 percent annually and summed over the specified time period used in the analysis. The benefits under the MDCT scenario are estimated from $10,463 to $309,275 for present value. Annualizing these results over the specified 13-year time period results in annual benefits ranging from $805 to $23,790. The high end of the range is driven by two factors: the entrainment of juvenile Channel Catfish in 2016 that are not present in the 2017 entrainment data, and the PF estimates associated with the entrainment of Inland Silverside that were present in 2016, but not the 2017 entrainment data. Results presented for 2017 entrainment data likely represent normal or anticipated conditions, while 2016 results are not anticipated to be repeated on a recurring or frequent basis. Duke Energy 1 211 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Benefits Valuation Study [§122.21 (r)(1 1)] r Table 11-16. Summary of Monetized Recreational Social Benefits of Entrainment Reduction Alternatives at McGuire Nuclear Station (Source: Veritas 2018) 100% Reduction $314,188 $24,168 $25,121 $1,932 3% MDCT $309,275 $23,790 $24,723 $1,902 2.0-mm FMS $478,043 $25,160 $25,790 $1,357 100% Reduction $139,283 $10,714 $10,632 $818 7% MDCT $137,106 $10,547 $10,463 $805 2.0-mm FMS $238,348 $12,545 $11,906 $627 Note: Higher present values for fine mesh screens are due to the timing of the technologies (Table 11-10). Totals may not sum due to rounding. Based on the 2.0-mm FMS scenario, the present value estimate ranges from $11,906 to $478,043. Annualizing these results over the specified period results in annual benefits ranging from $627 to $25,160. Similar to the MDCT scenario, the high -end of the range is also driven by entrainment of juvenile Channel Catfish and Inland Silverside in 2016, with the addition of a longer specified time period for this technology. 11.5.4 Summary of Social Costs and Net Benefits The Director must consider the social costs and benefits of each evaluated entrainment compliance option when determining the maximum entrainment reduction warranted at an individual facility. In benefit -cost analysis, determinations of compliance alternatives apply the concept of economic efficiency under increasing costs and diminishing benefits. In this context, compliance alternatives are economically efficient if they either have higher benefits and higher costs or lower benefits and lower costs than other compliance alternatives; compliance alternatives with higher costs and lower benefits are ruled out. When these economically efficient technologies are ordered by increasing cost (or benefit), net benefits (benefits minus costs) increase, reach a maximum, and then decrease, as illustrated in Figure 11-10. As the figure illustrates, net benefits are positive for Alternatives 1-3. Net benefits increase from Alternative 1 to Alternative 2 where they hit a maximum. Net benefits decrease after Alternative 2, are zero for Alternative 4, and are negative for Alternative 5. Alternatives 1-4 are all economically efficient (benefits greater than or equal to costs). Alternative 5 is not economically efficient and is included for explanatory purposes only. Duke Energy 1 212 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Benefits Valuation Study [§122.21 (r)(1 1)] r Figure 11-10. Example of Optimal Compliance Alternatives in a Benefit -Cost Analysis Under this commonly accepted framework for economic decision -making (Freeman et al. 2014), McGuire's current configuration represents the BTA for meeting the Rule's site -specific entrainment requirement (§125.98 (f)). Similar to Alternative 5 presented in the example illustrated in Figure 11-10, each compliance option evaluated for McGuire results in negative net benefits—i.e., the social costs of each entrainment compliance option are greater than the social benefits. A comparison of the estimated social costs (also see Table 10-17) and social benefits of each compliance option evaluated for McGuire (impingement and entrainment), as well as the net benefits of those options, is provided in Table 11-17 and illustrated in Figure 11-11, which indicates that each evaluated compliance option is estimated to result in negative net benefits. TechnologiesTable 11 -17. Net Benefits of Alternative Impingement and Entrainment Reduction Regulatory Social Benefits Standard TechnologyTotal Social Net Cost' Impingement Entrainment Total Benefits Addressed Benefits I Benefit2 Benefits ImpingementD- Impingement and Entrainment 2.0-mm FMS $51.2M $457 $0.5M $0.51M -$50.7M Closed -Cycle $1.47B $397 $0.3M $0.3M-$1.47B Retrofit 'Social Costs and Social Benefits are presented in 2018 dollars using a 3% discount rate. 2Entrainment benefits are based on 2016 entrainment data to present benefits associated with the most conservative or highest social benefit and social cost values. Duke Energy 1 213 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Benefits Valuation Study [§122.21 (r)(1 1)] r Total Social Costs and Benefits ($) $1.500M , 51.000r•d $50M $0.5M $500 so ;qn 5 Impingement Compliance Option Legend Total Total Social F Social Benefit Cost Net Benefits Benefits minus Costs Entrai nment Compliance Alternatives I $51.2M $1 A76 $0.5M $0.3M' $457 I I -$457 i De Minimis I §125.94(c)(11) I -$50.7M 2.0-mm Fine -Mesh Screens -S 1.5o01N J i• ` -51.478 Net Benefits ($) Mechanical Draft (Benefits minus Costs) Cooling Towers Notes: Social benefits are estimated using the 2016 entrainment data to present the benefits associated with the highest observed entrainment. Social costs and social benefits V E R I T A S are discounted at 3%_ The total benefits for cooling towers are less than the total benefits for fine -mesh soreens Economic Consulting because fine mesh screens will be in operation longer. Figure 11-11. Comparison of Social Benefits and Costs at McGuire By comparing the entrainment reduction options to the impingement options, the evaluation provides context for what is warranted for entrainment versus what is required for impingement. The vertical axis in the top portion of Figure 11-11 presents the total social costs and total social benefits of each Duke Energy 1 214 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal Benefits Valuation Study [§122.21 (r)(1 1)] compliance option, and the bottom portion presents the net benefits (total social benefits minus total social costs) of each compliance option. The horizontal axis presents each compliance option. As the top portion of the figure shows, the total social costs are greater than the social benefits for each of the entrainment compliance options. The total social benefits are illustrated by the green bar and the total social costs are illustrated by the red bar. The bottom portion of the figure illustrates the net benefits of each compliance option. As the figure shows, McGuire's chosen method to comply with the impingement compliance requirement has zero net benefits: the social benefits and social costs are the same. By comparison, 2.0-mm fine mesh screens have net benefits of-$50.7M and mechanical draft cooling towers have net benefits of-$1.47B. Given that the net benefits beyond what is required for impingement are negative, neither entrainment compliance option is warranted as the BTA for meeting the site -specific entrainment requirement. 11.5.5 Discussion, with Quantification and Monetization where Possible, of Other Benefits Other benefits from reducing entrainment can include ecosystem effects such as population resilience and support, nutrient cycling, natural species assemblages, and ecosystem health and integrity (79 FR 158, 48371). The fisheries benefits study does not evaluate other effects on the fish community, such as density -dependent influences including increased competition, predation, or increased introduced species populations. Increased survival of forage species would increase competition among the forage fishes, as well as provide a greater forage base for predators. The dynamic effects among native and non-native predators are not known (for instance, improved Largemouth Bass relative weight [Duke Energy 2017], or greater increases in the Spotted Bass population). The existing Main Intake does not include an aquatic organism return system and has no means to return biomass to the source waterbody. A reduction in entrainment or impingement, as well as the installation of an organism return system would allow carbon (as live or dead fish) to be returned to Lake Norman. Live returned organisms would then be made available as prey or to grow as adults, and dead organisms would be made available as a resource for scavengers, detritivores, or decomposers. 11.5.6 Discussion of Benefits Resulting from Reductions in Thermal Discharges Under certain BTA scenarios, the reduction or elimination of warm water discharges at McGuire could occur, and could potentially lead to certain social costs or benefits. Reducing warm water discharges may negatively affect angler catch rates during the winter season; this is viewed as a social cost and is discussed in Appendix 10-C. Other aspects of reducing warm water discharges can be seen as a benefit. For example, a reduction in the volume of warm water discharged to Lake Norman may improve water quality (specifically, higher DO concentrations) in the localized area of the plume, particularly during the summer season when the lake water temperatures are already warm. However, DO does not typically decrease to levels below the North Carolina water quality standards within the McGuire discharge zone; therefore, the reduction in thermal discharges may not alter water quality substantially in this area (Duke Energy 2017, 2018). Duke Energy 1 215 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal Benefits Valuation Study [§122.21 (r)(1 1)] The fish species composition found in the vicinity of the discharge may also change in response to reduced warm water discharges. Depending on the species, this may be seen as either a cost or a benefit. Introduced species native to tropical regions may find refuge in the discharge areas of power plants, which allows these species to persist in their non-native range and the reduction or elimination of this refuge would be seen as a benefit. However, an example of a species which may use the thermal discharge as refuge in Lake Norman is the Threadfin Shad, which also provides an important forage base for recreational predator species. Annual fish community sampling throughout Lake Norman shows that abundance and size structure of representative important species (defined as Largemouth Bass, Alabama Bass, Bluegill, and Redbreast Sunfish) are not statistically different between thermally -influenced zones and non - influenced zones (Duke Energy 2017, 2018). Therefore, the effects (i.e., benefits) of reducing thermal discharges with the installation of MDCTs at McGuire are not expected to be substantial. 11.6 Uncertainty Analyses A level of uncertainty is inherent with biological models like the EA and PF models due the complex interactions of biological systems. It is important to have an understanding of the potential influence that uncertainty may have on model -developed estimates presented in the benefits evaluation and the subsequent monetization of those benefits. The EA and PF models used to model the McGuire entrainment data are sensitive to varying age - specific natural mortality rates, especially for older life stages (e.g. juvenile and adult), and are applicable to both forage and recreational species (fishing mortality rates are not applied to forage species). Although unlikely to substantially change the results of the benefits analysis performed for McGuire, one of the primary sources of model uncertainty is how changes to the model parameters can affect the model -derived entrainment reduction benefits and their associated costs which are used to support entrainment BTA determinations. Natural mortality rates are one of the model parameters with the largest potential impact on model estimates (USEPA 2006). Therefore, a quantitative analysis of the natural mortality values used for modeling was performed due to the impact that this species has on the model -derived entrainment losses and subsequent benefits analysis. The evaluation of natural mortality rate uncertainty was performed following guidelines provided in the literature (EPRI 2006, 2012). For this analysis, the minimum, mean, and maximum natural mortality rates were identified from available literature (EPRI 2004, 2005, 2012; USEPA 2006) for two species (Channel Catfish and Inland Silverside) that contributed substantially to the model -derived entrainment loss and entrainment reduction benefit estimates for McGuire (Appendix 11-E). At McGuire, the EA model for Channel Catfish was more sensitive to variation in the natural mortality rate, with as much as a 99.4 percent change in EY from the model estimates. The PF model for Inland Silverside was less sensitive to variation in the natural mortality rate, with a maximum percent reduction in total PF of 20 percent. Estimates of EY were used to determine the entrainment reduction benefits (ecological and economic) achievable at McGuire under each candidate entrainment reduction technology scenario; therefore, uncertainty surrounding underlying model parameters has the potential to significantly impact the monetization of benefits. In order to present the most conservative estimation of annual Duke Energy 1 216 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal Benefits Valuation Study [§122.21 (r)(1 1)] entrainment losses and associated benefits under existing and candidate entrainment reduction technology scenarios, the input parameters (including natural mortality rates) used in the Benefits Valuation Study were based on the most conservative data from the literature so as to present the largest estimates of potential technology benefits. As such, the estimated losses and entrainment reduction benefits presented in this section are conservative estimates and the actual annual entrainment reduction benefits, both biological (equivalent yield and total PF) and economic (monetized or dollar value), under each of the compliance scenarios would likely be much lower for any given year. 11.7 Baseline Entrainment and Impingement Summary Duke Energy has performed annual monitoring of Lake Norman through the MMP since 1987 (Duke Energy 2017). This monitoring includes surveys of water quality/chemistry, phytoplankton, zooplankton, and fish communities. A review of these data was performed and summarized in Section 4, with specific focus on evaluating trends across the most recent data years (2012 through 2016). These data show that Lake Norman supports diverse plankton and fish communities, with no discernible short-term or long-term influence from operations at McGuire. Water quality within the reservoir has also remained consistent across the monitored data period. During this period and previously, multiple non-native species (such as Alewife, Threadfin Shad, black Alabama Bass, White Perch, Common Carp, and Channel Catfish) have been introduced into Lake Norman to supplement the sport fishery. Based on the popularity of Lake Norman as a sport fishing lake, it is not surprising that Lake Norman exhibits higher concentrations of non-native species than other nearby reservoirs. Annual monitoring of the fish community indicates increasing biomass in Lake Norman with increasing distance uplake — a trend likely attributable to typical spatial nutrient dynamics common to reservoir systems (Green et al. 2015). There were no statistically significant differences in species diversity or abundance between fish communities documented within the thermally -influenced zones of Lake Norman compared to reference areas. Although the fish community appeared generally healthy, the mean weight of black bass and Largemouth Bass was relatively low. The introduction of Alabama Bass in the early 2000s is likely one of the factors causing the declining abundance of Largemouth Bass in Lake Norman (Duke Energy 2017). The low relative weight of Largemouth Bass is partially attributable to congeneric competition, although other introduced species may also contribute (such as White Perch). Additionally, lower densities and relative weights documented in Lake Norman may also be attributed to the oligotrophic nature of the reservoir. Based on a comparison of the existing fish community documented through the MMP with the species composition and abundance of annual entrainment and IM loss estimates, operations at McGuire do not appear to affect the Lake Norman fishery. The patterns observed in the long-term data set show a fishery adapting to several non-native species introduced intentionally (through stocking programs) or incidentally (by anglers). These data further demonstrate that Lake Norman, including areas near McGuire, supports a typical southeastern Piedmont fishery with a littoral zone community largely dominated by centrarchids and a pelagic community dominated by clupeids. Up to 87 percent of entrained species (excluding Inland Silverside) and 60 percent of impinged species are fragile species (Alewife, Gizzard Shad, and Threadfin Shad). Purse seine sampling data indicate that this forage fish community continues to provide a stable prey base for recreational predator Duke Energy 1 217 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal Benefits Valuation Study [§122.21 (r)(1 1)] species in Lake Norman. It also demonstrates that forage fish densities and species -specific relative abundance fluctuate across years, and is likely driven by a variety of environmental conditions (i.e., temperature, year class strength, resource availability), and not due to entrainment or impingement losses at McGuire. Natural mortality of clupeids is high, which is compensated for by high fecundity and multiple spawning events each year. Thus, the estimated annual losses of clupeids documented for McGuire are not anticipated to have an impact on population viability for these forage species. Since the fish community within Lake Norman is considered healthy and balanced, the return of the clupeids to the ecosystem (i.e., reduction of clupeid losses to entrainment and impingement) is not expected to provide a substantial benefit to the fishery, as evidenced by the low EY impact of the various scenarios presented above. Long-term monitoring data demonstrate a diverse and abundant community of recreational species including bass, sunfish, crappie, and catfish, thus indicating that the recreational fishery in Lake Norman is not substantially affected by operations at McGuire. Further, entrainment and impingement sampling data also shows limited losses of recreational species due to operations at McGuire. Lake Norman's diverse fish community continues to support a strong sport fishery with annual angler expenditures estimated at over $3.9M in 2007 (NCWRC 2008), and expected to be equivalent or greater in value today. The recent success of the NCWRC Striped Bass -White Bass hybrid stocking program will likely continue to increase annual angler effort and expenditures in future years as the program increases stocks of harvestable-sizes of these sport fish. While the estimated entrainment and impingement reduction benefits presented in this section vary substantially between sample years (2016 and 2017) and by technology scenarios, the 2017 estimates are most representative of typical conditions in Lake Norman. A conservative approach was taken in the development of biological modeling for incremental losses under each scenario. This likely produced an overestimation of losses from entrainment and impingement at McGuire's Main Intake, which in turn, overestimates the potential benefits of the technologies considered in this section. However, even with "high -end" estimates of benefits developed through this environmental and economic analysis, the estimated social benefit values of installing entrainment -reducing technologies are modest ($10,463 to $25,790 for present values, $627 to $1,932 for annualized values). Duke Energy 1 218 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal �� Non -water Quality Environmental and Other Impacts Study [§122.21(r)(12)] 12 Non -water Quality Environmental and Other I m pacts Study [§ 122.21(r)(12)] The information required to be submitted per §122.21(r)(12), Non -water Quality Environmental and Other Impacts Study, is outlined as follows: "The owner or operator of an existing facility that withdraws greater than 125 mgd AIF must develop for submission to the Director a detailed facility -specific discussion of the changes in non -water quality environmental and other impacts attributed to each technology and operational measures considered in paragraph (r)(10) of this section, including both impacts increased and impacts decreased." Pursuant to the regulations, a facility -specific report must be submitted that addresses the non -water quality environmental (and other) impacts for each technology or operational measure considered under §122.21(r)(10). The evaluation must address, if relevant to the alternative technology being assessed, the following items pursuant to the regulations at §122.21(r)(12): (i) Estimates of changes to energy consumption, including but not limited to, auxiliary power consumption and turbine backpressure energy penalty; (ii) Estimates of air pollutant emissions and of the human health and environmental impacts associated with such emissions; (iii) Estimates of changes in noise; (iv) A discussion of impacts to safety, including documentation of the potential for plumes, icing, and availability of emergency cooling water, (v) A discussion of facility reliability, including but not limited to facility availability, production of steam, impacts to production based on process unit heating or cooling, and reliability due to cooling water availability; (vi) Significant changes in consumption of water, including a facility -specific comparison of the evaporative losses of both once -through cooling and closed -cycle recirculating systems, and documentation of impacts attributable to changes in water consumption; and (vii) A discussion of all reasonable attempts to mitigate each of these factors. Each of these requirements is addressed in the following subsections. 12.1 Background Information 12.1.1 McGuire Nuclear Station Population Distribution Understanding population density and population centers surrounding an electric generating station is important when evaluating potential environmental impacts of constructing and operating additional equipment. Figure 12-1 and Figure 12-2 provide population distribution information, but at Duke Energy 1 219 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal Non -water Quality Environmental and Other Impacts Study [§122.21(r)(12)] Figure 12-1. Population Density Surrounding McGuire Nuclear Station — Census Block Group Level (U.S. Census 2014) Duke Energy 1 220 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal �� Non -water Quality Environmental and Other Impacts Study [§122.21(r)(12)] LEGEND Estimated Popolabon Per Sq Mi of Lantl W Cenws Sfock (2010) 0-50C 501 - 1.000 1.001 -2.000 = ' 29C0 FEZ +t f�DUKE Ik SOURCE: ESRI{AERIAL PHOTOS) POPULATION IN IMMEDIATE SURROUNDING ENERGY, 0 Feel 2,000 HS CENSUS (POPULATION DENSITY) MCGUIRE NUCLEAR STATIO Figure 12-2. Population Density Surrounding McGuire Nuclear Station — Census Block Level (U.S. Census 2014) Duke Energy 1 221 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� Non -water Quality Environmental and Other Impacts Study [§122.21(r)(12)] r different resolutions. Figure 12-1 shows population distribution at the census block group level, which has a relatively coarser resolution. Figure 12-2 shows population distribution at the census block level, which has a relatively finer resolution. Based on census block information, there is a population cluster immediately to the southwest of McGuire. Within the immediate vicinity of the station, the population density is generally higher to the northwest and east than the south and west (Figure 12-2). From the northwest to the southeast, moving in clockwise direction, the population density ranges from 500 to greater than 2,000 people per square mile, whereas the population density from the southeast to the west ranges from 0 to 500 people per square mile (U.S. Census Bureau 2014102). Because of the recreational opportunities provided by Lake Norman, the transient, recreation population of the area during the summer months increases (Duke Energy 2O15b). Several population centers are located along Interstate 77 (1-77), which runs in a north -south direction east of McGuire. The population centers include Huntersville, Cornelius, and Davidson. The population density of these areas is greater than 2,000 people per square mile. The areas between these population centers and McGuire have densities ranging from 500 to 2,000 persons per square mile. The areas of the southeast and northwest are primarily rural non -farming areas, with population densities of up to about 500 people per square mile. 12.1.2 Evaluation Approach for Compliance with §122.21(r)(12) The following sections present the results of the evaluations of non -water quality and other environmental impacts of each feasible reduction technology, as required under the Rule. The objective of these evaluations is to understand the environmental and social impacts associated with implementing an entrainment reduction technology or operational measure at McGuire. According to §125.98(f), the NCDEQ and other environmental regulators must consider certain measures and may consider others in making a BTA determination for entrainment. Section 10 of this document presents the feasibility of implementing entrainment reduction technologies at McGuire and associated costs to the owner and to stakeholders. As a result, several entrainment reduction technologies were determined as infeasible and removed from further consideration. The following technologies or operational measures were retained for impact and cost evaluation because they were deemed potentially feasible or practical for implementation at McGuire, or because they are required by the Rule to be evaluated relevant to §122.21(r)(12): • Mechanical draft cooling towers (closed -cycle recirculating system); and • Permanent installation of 2.0-mm mesh traveling water screens. 102 The U.S. Census Bureau releases annual population estimates based on the most recent decennial census, considered the "population base". To estimate the annual population, the estimate starts with the population base, then adds births, subtracts deaths, and finally adds the net international and domestic migration. Duke Energy 1 222 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Non -water Quality Environmental and Other Impacts Study [§122.21(r)(12)] r As specified by §122.21(r)(12), the evaluation described in this section assesses energy consumption, emissions, noise, safety, facility reliability, and consumptive use of water associated with closed -cycle recirculating cooling and FMS. Visual impacts with respect to a hypothetical MDCT retrofit for McGuire are also evaluated. Some potential impacts are more readily quantifiable (e.g., energy consumption) than others (e.g., safety). This evaluation describes relevant impacts to the station and surrounding communities and quantifies the impacts where possible. The organization of each impact evaluation follows a similar layout. Each evaluation begins by describing the respective impact. The subsection that follows quantifies the impact, if possible, after describing the method and data employed for the calculation. Engineering calculations are provided in Appendices. Each impact evaluation includes a discussion regarding potential mitigation methods and uncertainty. 12.2 Closed -cycle Recirculating System This section discusses non -water quality and other environmental impacts associated with a CCRS retrofit using MDCTs for operation at McGuire. 12.2.1 Energy Consumption 12.2.1.1 Description There are two forms of energy consumption associated with a closed -cycle cooling tower retrofit at a power plant: auxiliary energy requirements and backpressure energy penalty. The auxiliary energy requirement (sometimes referred to as parasitic loads) is the energy that is used to operate additional equipment. With a cooling tower retrofit, auxiliary energy requirements would occur as a result of additional pump and fan operation. All technologies will likely consume a small quantity of energy by way of additional lighting, signage, and meters, among other items; however, these are minor usages and will not be quantified herein. Auxiliary energy requirements, where quantified, will be evaluated directly using the horsepower (hp) rating of the equipment and the anticipated hours of operation per year. Use of an MDCT, which results in warmer condenser cooling water, reduces the efficiency of the turbine and its capacity to produce electricity; this is referred to as the backpressure energy penalty. The backpressure energy penalty is the energy that the power plant is unable to produce because the production capacity would be constrained by the retrofit. The turbine's power generation efficiency depends on the temperature of cooling water, quality of exhaust steam, and various other condenser losses. The temperature of once -through cooling water depends on the source waterbody temperature. The temperature of closed -cycle cooling water depends on the ambient wet bulb temperature and the design of the cooling tower. During most of the year, the temperature of the recirculating cooling water in a cooling tower is higher than the temperature of water from a once - through system, but there may be short periods of time each year when the reverse is true. Duke Energy 1 223 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� Non -water Quality Environmental and Other Impacts Study [§122.21(r)(12)] r 12.2.1.2 Quantification Quantification of Auxiliary Energy Requirements for McGuire The auxiliary energy requirements to operate the hypothetical cooling towers at McGuire would include the operation of cooling tower fans, booster pumps, make-up water pumps, blowdown pumps, new pumps at the LLI structure (for Unit 2 only), lighting, signage, chemical pumps, flow meters, etc. The existing cooling system has four circulating water pumps per unit, with each pump rated at 254,000 gpm. These pumps would remain in place and continue to route water from the intake structure to the condensers. Existing pumps provide sufficient head to move water through the current condensing units and through the discharge network, but each generating unit would require additional motive force to route cooling water through the closed -cycle system. The retrofitted system would therefore require: • Booster pumps to route water to the top of the cooling towers; • Make-up water pumps to replenish water lost to the recirculating system due to evaporation, drift, and blowdown; • Blowdown pumps to purge a portion of the recirculating flow to help control the concentration of parameters; and • For Unit 2 only, to enable use of the existing pipes from the LLI pump structure to the intake and avoid impact on the water supply line to the SNSWP, replacement of the LLI condenser cooling water pumps would be required. Large pumps such as circulating water pumps can move large quantities of water, but they cannot develop significant dynamic head. Therefore sixteen booster pumps, each rated at 59,975 gpm, are assumed to route hot water up to the cooling tower wet deck. Cooling tower booster pump energy consumption was estimated based on 3,250 ft of coal tar epoxy -coated carbon steel103 pipe for Unit 1 and 4,175 ft of pipe for Unit 2 sized to maintain in -pipe velocities between 7 and 10 fps for routing water between the condensers and cooling towers, which results in approximately 5 ft of friction loss in the hypothetical Unit 1 system and approximately 6.4 ft in the Unit 2 system. This assumes that the pipeline for each unit would have ten 90-degree elbows and eight wye-fittings, which would result in approximately 4.4 ft of minor losses for each unit, 78 ft of static head for Unit 1 and 83 ft for Unit 2, plus a 20 percent contingency. Pumps are assumed to be 85 percent efficient and motors are assumed to be 90 percent efficient. The energy usage per booster pumps was estimated to be 2,079 hp for Unit 1 and 2,232 hp for Unit 2. Each unit is assumed to require one make-up water pump rated at approximately 15,354 gpm and 101 hp. Each unit is assumed to require one blowdown pump rated at approximately 3,066 gpm and 21 hp. 103 Hazen -Williams roughness coefficient of 147. Duke Energy 1 224 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Non -water Quality Environmental and Other Impacts Study [§122.21(r)(12)] r The energy consumption of each cooling tower fan is 250 hp (SPX 2016b), which, for 56 fans, is estimated to be approximately 10.4 MW per unit or 20.9104 MW for the plant. The energy consumption by the pumps is estimated to be approximately 24.9 MW for Unit 1 and 31.4 MW for Unit 2. The total energy consumption by fans and pumps is estimated to be approximately 35.3 MW for Unit 1 and 41.9 MW for Unit 2. Annual energy consumption is provided in Table 12-1. See Appendix 12-A for engineering calculations. Increased Turbine Backpressure Due to the dynamic nature of weather and operating conditions, the temperature of cold water produced by cooling tower fluctuates. Accurately estimating cooling tower and condenser performance is data -intense. As discussed below, this evaluation uses parametric relationships developed by the U.S. Department of Energy (USDOE) for the potential energy penalty that would result from retrofitting McGuire with MDCTs (USDOE 2002). The Technical Development Document (USEPA 2014) refers to the EPRI (2011 b) approach which estimates backpressure based on ambient meteorological conditions. The USDOE (2002) method incorporates ambient conditions and the condenser temperature rise. The USDOE (2002) reported estimates of the energy penalty for a range of steam turbine back pressure penalties at the 1 percent highest temperature conditions and annual averaged conditions. Using a cooling tower/condenser range of 17°F the modeled backpressure energy penalty reduces the plant efficiency by 2.8 percent during peak conditions and approximately 1.1 percent over the course of the year. The gross energy production of each existing unit is approximately 1,220 MW, such that the associated annual energy penalty is 12.8 MW for Unit 1 and 12.7 MW for Unit 2, for a total of 25.5 MW105 total. Further information can be found in Veritas (2018) (see Appendix 10-C) Reduction in Generation when Design Wet Bulb Temperature is Exceeded When the wet bulb temperature exceeds the design wet bulb temperature (anticipated to occur one percent of the time, on average, each year because the hypothetical cooling towers are designed for the 99th percentile high wet bulb temperature), the station would need to reduce its power production rate because the cooling towers would not be able to support the full heat load. Tie -In Outage Replacement Power In addition to the recurring energy losses associated with increases in auxiliary loads and increases in turbine backpressures, there would be a one-time loss in energy from the end of October 2030 to end of February 2031 required to tie in the MDCTs (see Section 10). This tie-in outage was estimated to last twelve months. The maximum energy loss assuming 100 percent capacity factor is 104 Values rounded to one decimal point. 105 Please disregard discrepancies from rounding. Duke Energy 1 225 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Non -water Quality Environmental and Other Impacts Study [§122.21(r)(12)] r estimated to be approximately 10.5 terawatt-hours for Unit 1 and 10.4 terawatt-hours for Unit 2. See Appendix 12-A for engineering calculations. Quantification of Energy Consumption Summary The cumulative energy consumption (due to auxiliary energy use and backpressure energy penalty) from the addition of a closed -cycle cooling tower would be approximately 443 gigawatt-hours per year (GWhr/year) for Unit 1 and 499 GWhr/year for Unit 2 or approximately 942 GWhr/year for the plant if each unit were to operate continuously. Considering the capacity utilization of 95 percent for Unit 1 and 95 percent for Unit 2106, the energy penalty is expected to be approximately 421 GWhr/year for Unit 1 and 474 GWhr/year for Unit 2, for a total of 895 GWhr/year for the station. Annual energy consumption is provided in Table 12-1; energy loss owing to the tie-in is provided in Table 12-2. Table 12-1. Energy Consumption due to Hypothetical MDCT Retrofit Energy Requirement ��Nc Pumps (MW): 24.9 31.4 51.6 Fans (MW): 10.4 10.4 20.9 Backpressure Energy Penalty (MW): 12.8 12.7 25.5 Annual Maximum Auxiliary Use (MWhr/year) 309,502 366,905 676,406 Annual Maximum Backpressure Energy Penalty (MWhr/year) 112,418 111,312 223,730 Annual Reduction in Power when Wet Bulb Temperature is 21,006 20,800 41,806 Exceeded (MWhr/year) Total Annual (MWhr/year): 442,926 499,016 941,943 Total Annual with 95% Capacity Utilization Rate (MWhr/year): 420,780 474,066 894,846 Table 12-2. Energy Loss due to Construction Outage for Hypothetical MDCT Retrofit Energy Loss FMMIPM Potential Maximum Energy Loss due to Tie-in Outage (MWhr): 10,503,240 10,399,872 20,903,112 Tie-in Energy Loss with 95% Capacity Utilization Rate 9,978,078 9,879,878 19,857,956 (MWhr): As an approximate benchmark, an American household consumes approximately 10.8 MWhr/year of electricity on average (EIA 2016). Retrofitting McGuire to operate with MDCTs could consume the 106 Per Duke Energy direction, capacity utilization rate is assumed to be 95 percent. Duke Energy 1 226 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� Non -water Quality Environmental and Other Impacts Study [§122.21(r)(12)] r equivalent amount of electricity that could otherwise be used to supply electricity to approximately 80,000 homes (disregarding the tie-in outage).107 12.2.1.3 Impact Mitigation Methods Energy consumed by the closed -cycle cooling system may be reduced or replaced in a variety of ways, and may include the following. However, none of these measures are practical; therefore, they are not incorporated into the design or costs. 1. Using cooling tower fans with two -speed motors. If the fans were operated at half -speed during nighttime, when cooler temperatures would compensate for lack of air flow, they could provide for a periodic reduction in energy consumption. Costs presented under §122.21(r)(10) do not assume variable -speed fans. 2. Constructing a new combined -cycle power plant elsewhere within the grid to be operated as needed, and especially during summer months when the McGuire backpressure energy penalty is high. This option would trigger a series of permitting efforts. The advantage of this option is that the combined -cycle plant would be able to operate to complement the nuclear station. Cost of this measure is not incorporated to the project costs. 3. Constructing a larger cooling tower. A temperature of 5°F is the theoretical minimum approach temperature that a MDCT can be designed for; 10°F is the practical minimum. The hypothetical McGuire cooling tower has been designed for an approach temperature of 10°F and 99th percentile wet bulb temperature, yet its backpressure energy penalty is 26.1 MW or 229 GWhr/year. Making the cooling tower larger still would reduce backpressure energy penalty, but would increase the auxiliary energy requirements. Therefore, this is not assumed to be implemented. 4. Managing the demand for electricity. This would be a long-term effort where consumers are educated about steps they could take to reduce their energy consumption. Duke Energy already implements this measure. Within the service territory, Duke Energy currently provides free light bulbs, free energy use surveys, and monthly efficiency statements to customers. Potential additional costs of this measure are not incorporated to the project costs. 12.2.1.4 Uncertainty The uncertainties associated with the energy consumption estimate include, but are not limited to: The pipe network lengths for hot and cold water pipes were based on measurements from an aerial image, but are reasonable for the purposes of this evaluation. Additional pipe route evaluations would need to be performed to improve the alignment and estimate pipe length with greater accuracy. Increases in pipe length and/or elevations, as well as additional fittings, would increase the total dynamic head needed from the pumps. Increases in total dynamic head would require larger pumps that would consume more energy. 107 Grid stability would need to be evaluated if this technology were to be selected as BTA for the McGuire. Duke Energy 1 227 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� Non -water Quality Environmental and Other Impacts Study [§122.21(r)(12)] r Future backpressure energy penalty and future losses in energy losses are difficult to estimate; the actual penalty would depend on station operations and atmospheric conditions and may deviate from this estimate. • Auxiliary energy requirements assume approximate pipe and pump sizes (that are representative of the McGuire system); the actual in -pipe water velocities may be different and may result in higher or lower auxiliary energy requirements. 12.2.2 Air Pollutant Emissions, Environmental Impacts, and Human Health 12.2.2.1 Air Pollutant Emissions Implementation of cooling towers at a nuclear power plant can increase air emissions in three ways: 1. On -site cooling tower emissions. These are emissions caused by the operation of cooling towers and consist primarily of PM derived from the recirculating cooling water; 2. Off -site auxiliary emissions during the tie -in -related unit outage. This would result in a transfer of energy generation to other power plants; and 3. Off -site auxiliary emissions during the operational period to replace the energy lost due to backpressure energy penalty and auxiliary energy requirements. McGuire is a base load station; therefore it cannot increase its power production to compensate for MDCT-related energy consumption. McGuire is a nuclear station and does not generate nitrogen oxides (NOX), sulfur dioxide (S02), or carbon dioxide (CO2) in the process of generating electricity. All additional energy is assumed to be generated off -site by a fossil -fueled station. Particulate Matter Emissions Operation of cooling towers results in the emission of several trace elements, but the levels of emissions are highly variable depending upon the source water. PM, driven by the concentration of TDS and total suspended solids (TSS) in the source waterbody and the cooling tower operating regime, would be the largest source of air emissions from McGuire after the installation of cooling towers. Therefore, cooling tower -related emissions will be evaluated under the umbrella of PM. Drift droplets resulting from evaporative cooling tower operation contain solids in the form of dissolved minerals and organic matter entrained in the cooling water. The water portion of drift droplets exiting the cooling towers evaporate, leaving the remaining solid matter in the air column. These solids range in size based on the cooling water TDS and drift droplet size and they are generically designated as PM. Smaller PM can potentially have an impact on human health. PM10 and PM2.5 emissions are regulated, therefore this section evaluates total PM, PM10 and PM2.5. PM10 refers to PM that is 10 microns108 or smaller in diameter, and PM2.5 refers to PM that is 2.5 microns or smaller in diameter. PM10 particles have a larger diameter and are heavier than PM2.5 108 A micron is a common reference for a micrometer, which is equal to one -millionth (10-6) of a meter. Duke Energy 1 228 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Non -water Quality Environmental and Other Impacts Study [§122.21(r)(12)] r particles. Therefore, compared to PM2.5, PM10 particle deposition velocity is faster and the deposition distance is shorter. Based on the size and weight of PM, the highest rate of mineral deposition can occur between approximately 2,500 ft and 3,600 ft from an MDCT (EPRI 2011a). PM2.5 would be carried longer distances during periods of strong winds. PM is emitted from approximately 60 ft from MDCTs or approximately 500 ft in height from NDCTs. Because of their emission height and particle weight, dispersion and deposition of PM from MDCTs are relatively local; dispersion and deposition of PM from NDCTs is more widespread due to their high exit height. The TDS concentration in the source waterbody is directly proportional to the TDS concentration in the drift particles: the TDS concentration in drift particles is equal to the TDS concentration in the circulating water system, and is estimated as the source water TDS times the cycles of concentration (COC)109, 110 The quality of the blowdown stream depends on the quality of water in the circulating water system and the treatment system or systems (if any) to remove parameters prior to blowdown. Removing dissolved solids requires reverse osmosis/thermal/crystallizing-type treatment methods which are rarely employed for blowdown treatment. Hence it is reasonable to assume that the TDS concentration in the blowdown is the same as the TDS concentration in the circulating water system. The TDS concentration allowable in the discharge is governed by the NPDES permit. As the source water TDS concentration increases, the cooling tower is operated at a lower COC to modulate the discharge concentration''' Combustion Emissions Nuclear power plants are typically base load facilities and cannot increase their instantaneous generation rates. Hydroelectric power plants are operated on an as -needed basis depending energy demand and based on available water supply, and as a result, their ability to off -set base load generation needs is limited. Renewable energy is not a form of dispatchable12 power due to intermittent generation; therefore, they are not viable replacement sources. 109 COC is discussed in more detail under §122.21(r)(10). COC is defined by the USEPA as "the ratio of dissolved solids in the recirculated water versus that in the make-up water" (USEPA 2014). 110 This evaluation uses TDS as the all -encompassing parameter to determine COC. If cooling towers were determined to be BTA, Duke Energy would need to evaluate the impact of water quality parameters on COC, and assess the distribution of suspended vs. dissolved components, and reassess if cooling towers at McGuire may be operated at 5 COCs. 111 If MDCTs would be chosen as BTA, additional evaluations would be required to assess an appropriate COC value that addresses TDS and other water quality parameters. 112 Dispatchable generation refers to a source of electricity that can provide power on demand. Duke Energy 1 229 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� Non -water Quality Environmental and Other Impacts Study [§122.21(r)(12)] r All replacement electricity during the hypothetical cooling tower tie-in outage or to make up for increases in auxiliary energy requirements or decreases in generation due to backpressure is assumed to be from fossil -fuel -fired power plants'13 Generation of heat from nuclear fission is emission -free and is therefore a `clean' fuel with respect to gaseous emissions14. Nuclear stations are different than fossil fuel stations, which have emissions due to the combustion process. Combustion of fossil fuel produces a range of air pollutants of concern and includes NOx, S02, and CO2. Combustion stack emissions do occur; however, there is uncertainty in the emissions rates because the specific fuel mix (e.g., coal, oil, gas), and the specific composition of each fuel (i.e., the relative quantity of impurities in the fuel) that would be used to generate additional power are presently not known with precision and are unknown in the future. Every fleet has a particular dispatch order, but that order can change annually, or seasonally, in some cases. Therefore, the specific location of additional power generation is not known with certainty. Stacks emit NOx, S02, and CO2 from a height of approximately 500 ft and each emissions particle is neutrally buoyant, and is therefore carried longer distances than PM. The following sections quantify the potential increases in off -site stack emissions resulting from a cooling tower retrofit at McGuire. McGuire and its surroundings are currently in attainment for all the parameters discussed. The air permit for each power plant evaluates not only the plant's emissions, but also cumulative emissions from other sources. If a power plant is allowed to increase generation, it may be assumed that the impacts are negligible and are allowed by the corresponding air permit. Therefore, potential impacts (if any) are not quantified. Off -site stack emissions due to a cooling tower retrofit at McGuire may occur in two forms: one-time emissions during cooling tower tie-in outage and recurring emissions from producing replacement electricity to compensate for generation inefficiencies at McGuire (owing to auxiliary energy requirements and backpressure energy penalty; see Section 12.1). Human Health Health -related impacts are a function of the change in emissions, dispersion, deposition, human population density relative to the emissions, and the sensitivity of those populations. While increased emissions may have environmental and human health impacts, emissions are regulated by each power plant's emissions permit (Title V). Emissions standards and allowances are based on the cumulative impacts caused by most emissions sources; therefore, a facility's emissions that would be allowed by the facility's air permit are expected to be generally protective of surrounding populations. 113 In the future, other newer renewable sources of energy may enter this mix. At this time, the only Duke Energy assets with available capacity are fossil fuel -fired plants. 114 Nuclear stations are required to have emergency power supplies, some of which may be diesel -driven. While these systems are required to be tested periodically to ensure startup in the event of an unlikely emergency, these generators are not operated continuously. Therefore, any emissions from safety -related diesel -driven power supplies or pumps have not been included in the calculations. Duke Energy 1 230 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� Non -water Quality Environmental and Other Impacts Study [§122.21(r)(12)] r As shown on Figure 12-1 and Figure 12-2 of this evaluation and Figure 10-7 under Section 10, the predominant summer wind is in the southwest to northeast direction, and the 2,500 ft potential PM deposition area falls well within the area of Lake Norman. Therefore potential impacts to residences would be negligible. The predominant wind during the winter is from the north and from the southwest and northeast. Per Figure 12-1, the population density to the south and southwest of McGuire is relatively low and the lake is located to the northeast; therefore, potential wintertime impacts are also expected to be low. The predominant wind during spring months is from the south, and with the lake to the northeast of McGuire, springtime impacts from PM deposition are expected to be low. The predominant wind during the fall months is from the northeast and north. The population density to the south and southwest is less than 500 persons per square mile. Therefore, again, potential impacts, if any, are expected to be low. The population density over two miles east of McGuire is over 2,000 persons per square mile (Figure 12-1). PM deposition is expected to occur between 2,500 ft and 3,600 ft from the MDCTs. Under typical meteorological conditions, no impact is anticipated in the densely populated areas. 12.2.2.2 Environmental Impacts The corrosive nature of common PM components such as mineral compounds leads to degradation of terrestrial vegetation and man-made objects. Deposition of salts, and, more specifically, chloride (Walton et al. 1982), causes damage to automobiles and various metal surfaces, shorting of electrical equipment, and window marking. These effects typically occur within the facility property, but in urban areas and locations where intake of cooling water from ocean or estuary sources is prevalent, off -site property damage can occur (EPRI 2011 a). 12.2.2.3 Quantification Estimated Cooling Tower Particulate Matter Emissions PM and drift are the primary emissions from a typical evaporative cooling tower that could result in potential environmental effects on receptors. A receptor is assumed to be any point of reception (e.g., residential dwellings or business, buildings, environment) that is impacted by PM emissions. Droplets of water that become entrained in the air traveling through the cooling tower are called drift. Drift droplets contain the same types and concentrations of dissolved solids (i.e., sodium, calcium, chlorides, and sulfates) as contained in the water flowing through the cooling tower that can be converted to airborne emissions. Drift droplets also contain organic matter (bacteria, spores, animals (insects], and vegetation) entrained into the towers by the fans (EPRI 2011a). Unless the circulating water is treated, the concentration of solids (suspended and dissolved) entrained in cooling tower drift is proportional to the concentration of solids in the circulating water, which, by definition, is the product of the COC of the cooling tower and source water solids concentration. To reduce drift from cooling towers, drift eliminators are usually incorporated into the tower design to remove water droplets from the exiting air stream. The drift eliminators used in cooling towers rely on inertial separation caused by directional changes while passing through the eliminators. The most efficient drift eliminator currently available can limit the drift rate to 0.0005 percent of the circulating Duke Energy 1 231 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� Non -water Quality Environmental and Other Impacts Study [§122.21(r)(12)] r water flow rate; the conceptual design and costs in §122.21(r)(10) assumed this type of drift eliminator. Data Required annual monitoring of Lake Norman physicochemical characteristics for the period of 2012 to 2013 provided input TDS for PM emission calculations (Duke Energy 2015a). Two locations near the McGuire intake structures were isolated, where quarterly measurements of specific conductance were measured 1 ft below the water surface and 3 ft above the lake bottom. Specific conductivity is a measure of a solution's capacity to transmit electrical current, in which dilute solutions can be directly comparable to the total number of ions in solution or TDS. Over the two-year period, TDS approximations ranged from 33 to 44 ppm at the surface, and 40 to 120 ppm at the lake bottom. Near surface water had lower TDS concentrations than deeper lake bottom water. In the most recent set of NPDES permit renewal applications for McGuire (Duke Energy 2014b, Duke Energy 2009), the TSS concentration was reported between 4 and 5 ppm. Particulate Matter Estimation Method For the McGuire system, make-up water would originate from a freshwater source with a TDS concentration range from 33 to 120 ppm (Duke Energy 2015a) and maximum measured TSS of 5 ppm (Duke Energy 2014b). Therefore, the total solids (TS) concentration would be between approximately 38 and 125 ppm. The low solids concentration allows for higher COC of the circulating water; in this case it is assumed that 5 COC is appropriate. The actual COC would be modulated to meet effluent water quality standards. The amount of TS in the circulating water (TSCT) is the product of TS intake concentration and the COC, resulting in a range from 190 to 625 ppm. The total PM lost is calculated as the product of the cooling water circulation rate per unit (QCT), the drift eliminator efficiency (DE), and TSCT. Drift eliminators act to reduce the amount of drift lost from a cooling tower system by providing multiple airflow direction changes to enhance capture of larger water droplets. At McGuire: • QCT would be 959,602 gpm, The lost drift totals 0.0005 percent of the QCT per DE specifications; and The TSCT range is 190 to 625 ppm. The magnitude of a specific particulate matter size (PM10 and PM2.5) lost as drift is influenced by the number and size of drift water droplets produced within the cooling tower. The relative magnitudes of PM10 and PM2.5 emissions were estimated by incorporating a drift droplet size distribution per Marley TU12 eliminator drift droplet distribution (SPX 2017). Since drift contains the same TS concentration as the circulating water, the amount of PM per water droplet is directly dependent upon the size, and thus volume of each drift droplet. Following SPX (2017) drift droplet distribution, PM10 represents between 86.7 percent and 94.7 percent of total PM, and PM2.5 represents between 42 percent and 54.4 percent for the range of TSCT. Duke Energy 1 232 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� Non -water Quality Environmental and Other Impacts Study [§122.21(r)(12)] r Estimated PM Emissions from Hypothetical MDCT at McGuire Considering the capacity utilization rate of 95 percent for Unit 1 and 95 percent for Unit 2, the estimated PM emissions are summarized in Table 12-3. PM calculations are provided in Appendix 12-B. PM (pounds/hour) 0.46 - 1.5 0.46 - 1.5 0.91 - 3.00 PM (tons/year) 1.90 - 6.25 1.90 - 6.25 3.80 - 12.50 PMio (pounds/hour) 0.43 - 1.30 0.43 - 1.30 0.86 - 2.61 PMio (tons/year) 1.80 - 5.42 1.80 - 5.42 3.43 - 10.3 PM2.5 (pounds/hour) 0.25 - 0.63 0.25 - 0.63 0.5 - 1.26 PM2.5 (tons/year) 1.03 - 2.63 1.03 - 2.63 2.07 - 5.25 Per USEPA (2017) Mecklenburg County is in attainment for PM2.5 and PM1o, and the PM2.5 and PM10 values estimated in Table 12-3 do not, themselves, trigger Prevention of Significant Deterioration approval. Therefore, the increase in PM emissions is not expected to be a concern. Estimated CO2 Emissions from the Cooling Tower Retrofit Nuclear power plants do not directly emit CO2 in the process of energy production in the same manner as fossil fuel combustion. This section summarizes the findings of Veritas (2018) (see Appendix 10-C). According to Veritas (2018), effects between baseline and with a CCRS retrofit have been simulated using the Duke Energy Power System Simulation Model (PROSYM). Given various inputs, such as electric demand, fuel price, generating unit characteristics, and transmission constraints, the model simulates the operation of the electric power system. The current PROSYM evaluation assumed a year -long outage for the CCRS retrofit of Units 1 and 2 in 2030, with the units coming back online in 2031 and operating through the assumed plant retirement date of 2043. The increased total weight of CO2 produced during tie-ins related downtime and the annual increase in CO2 emissions due to fossil fuel burning have been developed by Veritas (2018) and are also provided in Table 12-4. The outage related emissions are seen in years 2030 and 2031, and the annual emissions with the units coming back online are shown in subsequent years. Zero emissions are shown in 2043. Duke Energy 1 233 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal �� Non -water Quality Environmental and Other Impacts Study [§122.21(r)(12)] Table 12-4. Increased CO2 Emissions Due to McGuire Downtime and McGuire Cooling Tower Energy Consumption (Veritas 2018) 2030 8,425 2031 ' 1,815 2032 432 2033 4 501 K11, W Estimated S02 Emissions from the Cooling Tower Retrofit The S02 estimation method is similar to the CO2 estimation method described above. The increased total weight of S02 produced during tie-ins related downtime and the annual increase in S02 emissions due to fossil fuel burning have been developed by Veritas (2018) and are also provided in Table 12-5. The outage related emissions are seen in years 2030 and 2031, and the annual emissions with the units coming back online are shown in subsequent years. Zero emissions are shown in 2043. These values have been provided by the Duke Energy PROSYM and are presented in Veritas (2018) (see Appendix 10-C). Table 12-5. Increased S02 Emissions Due to McGuire MDCT Tie-in Downtime and McGuire MDCT Energy Consumption (Veritas 2018) 2030 W 2031 '1 ' 1.0 2032 2033 2043 0.2 r 0.3 0 Estimated NO, Emissions from the Cooling Tower Retrofit The NOx estimation method is similar to CO2 estimation method described above. The increased total weight of NOx produced during tie-ins related downtime and the annual increase in NOx emissions due to fossil fuel burning have been developed by Veritas (2018) and are also provided in Table 12-6. The outage related emissions are seen in years 2030 and 2031, and the annual emissions with the units coming back online are shown in subsequent years. Zero emissions are shown in 2043. These values have been provided by the Duke Energy PROSYM and are presented in Veritas (2018) (see Appendix 10-C). Duke Energy 1 234 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal �� Non -water Quality Environmental and Other Impacts Study [§122.21(r)(12)] Table 12-6. Increased NOX Emissions Due to MDCT Tie-in Downtime and MDCT-related Recurring Energy Losses (Veritas 2018) 2030 4.0 2031 0.9 2032 0.2 2033 0.3 2043 Offsetting the hydroelectric generation with fossil generation would also lead to system -level changes in air emissions. Based on average emission rates from Duke power system models, generating the additional 4,995 MWh leads to annual increased emissions of 8,210 tons of CO2, 3.8 tons of S02, and 3.8 tons of NOX. 12.2.2.4 Impact Mitigation Methods Potential measures to reduce emissions from tie-in related downtime or recurring energy losses are listed below. Any measure that reduces energy consumption would reduce emissions correspondingly. As discussed in 12.2.1.3, no additional energy use reductions are considered. 2. This evaluation assumes that energy -efficient fans and pumps would be utilized by a hypothetical retrofit, and that they are already incorporated into the conceptual design. 12.2.2.5 Uncertainty Key sources of uncertainty associated with the emissions estimates and costs include the following: PM and drift are driven by water quality and there is uncertainty in TDS concentrations, hence the high and low estimates. While the PM emissions are expected to lie within the range of values estimated, the actual value is not known with certainty. 2. Cooling tower tie-ins related downtime at McGuire may be different than the twelve months assumed here. 3. It is known with relative certainty that replacement power would be generated by fossil -fueled power plants, but it is not known which plant and location would generated the additional electricity. Therefore, specific impacts are not known. Additionally, jet streams can carry stack emissions over long distances, therefore potential impacts, if any, could be experienced in areas significant distances away from McGuire. 4. Due to changes in fuel mix, emissions controls, and regulations governing emissions etc. emissions factors assumed in the PROSYM may not necessarily represent the Duke Energy emissions factors at the time hypothetical cooling towers are installed or operated. Duke Energy 1 235 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� Non -water Quality Environmental and Other Impacts Study [§122.21(r)(12)] r 12.2.3 Changes in Noise 12.2.3.1 Description MDCTs would add to the noise generated at McGuire. If hypothetical cooling towers were to be constructed and operated, falling water and operation of pumps, fans, and other appurtenances would create additional noise that would not otherwise be generated at McGuire. Pile driving, vehicular traffic, and other construction activity will add to the noise during the construction period. The noise level due to a hypothetical retrofit depends on the combination (superimposition) of existing noise level and the noise level due to the hypothetical noise source. Depending on the sound level of the noise source, noise can be considered an annoyance to those nearby. For the purposes of this evaluation, a noise source is assumed to be any equipment (e.g., falling water, fans, pumps, and related appurtenances) that would generate noise at McGuire; a noise receptor is assumed to be any point of reception (e.g., residential, commercial, or industrial buildings) where extraneous noise and/or vibration would be perceived. Because there are no federal regulations limiting environmental noise levels, the USEPA released a document that provided a basis for state and local governments' judgment in setting standards for noise levels (USEPA 1974; USEPA 2014). Noise exposure goals for various locations depend on the noise sensitivities of its surroundings, and areas zoned for residential use usually have more stringent noise exposure limits than commercial, industrial, or agricultural areas. Similarly, specific institutions, such as places of worship, schools, hotels, hospitals, and libraries, may also have more stringent noise sensitivities. Noise pollution can generally fall into two groups: acute sound levels that can lead to hearing impairment, and nuisance sounds that impact the wellbeing of surrounding communities. Acute sounds (such as from construction work) are often controlled but nuisance noise is not. The USEPA states that a noise level of 55 decibels (dB) is satisfactory in protecting the public health and welfare and does not create an annoyance in most cases (USEPA 2014).15 In Mecklenburg County, sound level at the boundary line of the nearest residential property is limited to 55 A -weighted decibels [dB(A)] between 9 AM and 9 PM and 50 dB(A) between 9 PM and 9 AM. Mecklenburg County Noise Ordinance has found that activities that create mechanical noise that registers more than 60 dB and are carried out either in a residential zone, or within 300 ft of a structure used as a residence, would exceed the limits set in the ordinance. Sounds exceeding these general limits (or other more specific limits that would apply to entities unlike McGuire) require a permit (Mecklenburg County 2016b). Should a retrofit project be implemented, it must meet local zoning requirements, which includes the control of noise. Therefore, this evaluation assumes that noise would be mitigated to meet the most stringent of the federal, state, or local requirements. 12.2.3.2 Quantification The quantification of noise levels within and outside the station property would require noise propagation modeling, with considerations for topography, noise level of each point source, barriers 115 A decibel is a logarithmic unit of base 10 expressing the ratio of two physical quantity values, such as noise. Duke Energy 1 236 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Non -water Quality Environmental and Other Impacts Study [§122.21(r)(12)] r (such as buildings), and atmospheric conditions. These data would be collected to support applications for state and local approvals for the MDCT project in the event MDCTs are selected as BTA; therefore, noise propagation modeling is performed as a part of this effort. The USEPA states (as cited in USNRC 1996) that power plants usually do not result in off -site levels of noise more than 10 dB(A) above background (USEPA 2014). A dB(A) is a sound level measured with an instrument to account for the relative loudness to a human ear16 Table 12-7 lists noise level from common noise sources. Table 12-7. Common Noise Levels (Cowan 1994) Sound Source (dBA) Military jet; air raid siren 130 Amplified rock music 11 D Jet takeoff at 500 meters 10D Freight train at 30 meters Train horn at 30 meters 90 Heavy truck at '15 meters Busy city street, loud shoat 80 Busy traffic intersection Highway traffic at 15 meters, train 10 Predominantly industrial area 60 Light car traffic at 15 meters, city or commercial areas or residential areas close to industry Background noise in an office 50 Suburban areas with medium density transportation Public library 40 Soft whisper at 5 meters 30 Threshold of hearing 0 The USEPA further states (as cited in SPX 2009) that stations might expect cooling towers to have a typical noise level of approximately 70 dB approximately 50 ft from the tower (USEPA 2014). When started at 70 dB, sound levels diminish approximately 5 dB every doubled distance away from the source (Table 12-8). This section compares USEPA and Mecklenburg County noise limit of 55 dB for daytime and 50 dB for nighttime to typical cooling tower noise levels (USEPA 2014). A noise level of 116 There are two main weighting scales regarding decibel ratings: the A -weighting, dBA, and the C-weighting, dBC; the A -weighting takes into account how the human ear reacts to different frequencies, while the C-weighting is more for louder, peak noises (Lindeburg 2003). Duke Energy 1 237 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� Non -water Quality Environmental and Other Impacts Study [§122.21(r)(12)] r 55 dB is comparable to the sound of rainfall or normal conversation and is not considered to be noise pollution (USEPA 2014). Due to these findings, the USEPA indicates that a buffer of 400 ft is sufficient to provide for noise abatement at most sites (USEPA 2014). However, based on the 50 dB nighttime sound level threshold, this evaluation considers an 800-ft buffer as well. Table 12-8. Noise Level Compared to Distance 50 70 100 65 200 60 400 55 800 50 The approximate cooling tower alternate locations, as described in Section 10 of this document, have been overlain on a Mecklenburg County, NC property map (Figure 12-3). Using the county's mapping service, distances between the locations and the property boundary have been estimated in order to compare to the 800-ft buffer. Location A (Figure 12-3) is the westernmost potential location for Unit 2 cooling towers. The distance between this location and the closest potential receiver is around 1,550 ft. Location B is the northernmost location for Unit 1 cooling towers and has an estimated distance of 785 ft to the nearest boundary with potential receptors. For Locations A and B, the potential cooling towers are all located at a distance greater than 400 ft to the closest probable noise receptor; Location B is within 800 ft. For Location A, the distance alone may be sufficient for noise abatement. Location B equipment may require containment. This evaluation therefore assumes that pumps used for Location B (Unit 1) would be contained to mitigate for noise. Duke Energy 1 238 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� Non -water Quality Environmental and Other Impacts Study [§122.21(r)(12)] r Figure 12-3. Cooling Tower Alternate Locations and Distance to Property Boundary (Mecklenburg County 2017) 12.2.3.3 Impact Mitigation Methods (§122.21(r)(12)(vii)) If a station's noise sources are to be located close to sensitive receptors, or if existing noise levels at the property boundary are known to approach ordinance noise thresholds, then the station may evaluate the use of noise mitigation methods, techniques, or technologies. Prior to this step, McGuire would perform detailed noise propagation modeling to understand the level of mitigation needed. Noise propagation modeling and employed mitigation methods would increase mitigation costs. The distance between Location A and the nearest sensitive receptor is sufficient to provide natural sound attenuation. The booster pumps for Unit 1 are assumed to be installed on the Station side of the MDCTs to use the MDCTs themselves as sound barriers, and reduce noise exposure of residences to the east of McGuire. 12.2.3.4 Uncertainty Key sources of uncertainty associated with the noise evaluation are listed below. Many factors can influence the sound perceived by noise receptors such as topography, equipment location, and equipment to be installed. Existing noise sources and their specific locations, and the sound levels generated from cooling towers and received at off -site receptors are not known at McGuire at this time. Natural topographic relief alone would likely attenuate some of the noise. Superimposing cooling tower -related noise over existing noise would increase overall noise levels, and incorporating the impact of natural topography and existing infrastructure would help better assess noise impact (if any). Duke Energy 1 239 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� Non -water Quality Environmental and Other Impacts Study [§122.21(r)(12)] r The noise levels quantified (see 12.2.2.3) use the USEPA's general assumption of 70 dB for noise generated at cooling towers. In addition, the 5 dB reduction starting from 70 dB, per doubled distance starting from an initial 50 ft separation distance from the source (as presented in Table 12-8) is an approximation that may vary depending on site -specific conditions. The evaluation assumes an open terrain between the noise sources and noise receptors; but McGuire site has moderate topographic relief. 12.2.4 Safety Impacts 12.2.4.1 Description Per the Rule at §122.21(r)(12)(iv), this section will provide a "discussion of impacts to safety, including documentation of the potential for plumes, icing, and availability of emergency cooling water". In addition, the regulations at §125.94(f) provide the following description for nuclear power stations and compliance impacts on safety requirements: If the owner or operator of a nuclear facility demonstrates to the Director, upon the Director's consultation with the Nuclear Regulatory Commission, the Department of Energy, or the Naval Nuclear Propulsion Program, that compliance with this subpart would result in a conflict with a safety requirement established by the Commission, the Department, or the Program, the Director must make a site -specific determination of best technology available for minimizing adverse environmental impact that would not result in a conflict with the Commission's, the Department's, or the Program's safety requirement. Per these regulations, conflicts between the potential retrofit of cooling towers and with nuclear power station safety requirements will be indicated in the following sections. Plumes and Fogging Through evaporation, cooling towers produce a plume, which is an exhaust airstream that is saturated with water vapor. Depending on the atmospheric conditions, the plume can condense and become visible as a fog. The plume condenses due to the cooler, ambient air not having as much moisture assimilating capacity (SPX 2012). The plume is more visible in the wintertime, when the difference between the cool, ambient atmosphere and the warm exhaust air is high. When the cooling tower plume is cooled, the buoyancy decreases. It is possible that in adverse wind conditions, the plume can remain at low levels until it dissipates, resulting in ground level fogging (SPX 2012). While the cooling tower retrofit option includes the use of MCDTs, plumes and fogging can occur with NDCTs as well (usually at greater distances from the cooling tower and to a lesser degree under specific meteorological conditions). Plumes and fogging have incidental consequences due to loss of visibility downwind of the cooling towers. Loss of visibility along Highway 73 and other nearby roads can impact public health and safety. Loss of visibility of the perimeter can impact nuclear safety and security. Duke Energy 1 240 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Non -water Quality Environmental and Other Impacts Study [§122.21(r)(12)] r As described in Section 10 of this document, wind at McGuire can originate from any direction. See the discussion on wind roses in Section 10 and the winter wind rose inset on Figure 12-4. Most of the land south and southeast of the plant is rural and potential fogging could affect the state and local roadways in these areas and present a hazard to drivers. The area north and east of McGuire includes residential development, as well as Lake Norman. Similarly, visibility is a concern to recreational boaters on the lake. A school (Southlake Christian Academy) is located within a one -mile radius of the hypothetical cooling towers for Unit 1. The school is southeast of the station and hypothetical Unit 1 towers. Meteorological data from the World Meteorological Organization (WMO Station Number 723140) for Charlotte, NC indicate that the predominant wind direction is not in the same direction as the school (WMO 2016); however, if MDCTs are chosen as BTA for McGuire, the potential impact of fogging on outdoor actitivites at the school would need to be studied in more detail prior to siting the hypothetical cooling towers. Plumes and fogging are typically unacceptable in areas close to airports; the Charlotte Douglas International Airport is located approximately 15 miles south of the station. The airports' runways are oriented in a north -south direction, such that McGuire is potentially within the flight path of aircrafts. Plume and ground level fogging impacts on the Charlotte Douglas International Airport and aircraft landing, takeoff, or maneuvering, while expected to be low, would need to be further evaluated if the cooling tower retrofit were progressed. In addition to roadway and airport hazards, loss of visibility near the property line and perimeter of the Protected Area' 17 owing to fogging would adversely impact the safety of McGuire. Line -of -sight and monitoring of the physical barriers and perimeter of the station is pertinent for the safety and security of the public, station, and surrounding area. Per U.S. National Regulatory Commission (USNRC) Regulations at 10 CFR Part 73.55(e)(8)(ii): Penetrations through the protected area barrier must be secured and monitored in a manner that prevents or delays, and detects the exploitation of any penetration. Such security and monitoring is further explained in the USNRC's Regulatory Guide 5.44, Perimeter Intrusion Alarm Systems, which describes the functions of such a perimeter intrusion alarm system, as well as the methods acceptable for meeting the USNRC requirements (USNRC 1997). Using watchtowers and a perimeter intrusion detection system, security personnel monitor the property line and perimeter of protected areas for potential unauthorized penetration or activities at a nuclear power station. Environmental factors, such as fogging, can reduce the effectiveness of the monitoring system, and thus, reduce the security of the station. 117 Protected area is defined at 10 CFR Part 73.2 as "an area encompassed by physical barriers and to which access is controlled". Duke Energy 1 241 Figure 12-4. Road Network Surrounding McGuire Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal LN Non -water Quality Environmental and Other Impacts Study [§122.21(r)(12)] r Duke Energy 1 242 Duke Energy Corporation I McGuire Nuclear Station Draft CWA 316(b) Compliance Submittal L�� Non -water Quality Environmental and Other Impacts Study [§122.21(r)(12)] r A cooling tower plume that impacts the line -of -sight of authorized security personnel or perimeter intrusion alarm systems could impact the security of the station; thus, fogging can adversely impact the health and safety of the public, the station and station's personnel, and the surrounding area. Icing Icing occurs in freezing weather when moisture from the plume of a cooling tower causes frost or ice crystals to form on nearby surfaces and/or structures. Icing within the station's property boundaries and on adjacent roads, transmission lines, and switchyard can potentially impact the health and safety of the public, as well as the security of the station. Icing impacts would likely be found in areas in the direction of the prevailing winter winds. Potential icing could affect state and local roadways and bridges in these areas (Figure 12-4) and present a hazard to drivers. The area north and east of McGuire includes residential development, as well as Lake Norman; similar roadway and bridge icing hazards are a concern to drivers in the surrounding area. As stated previously, a school (Southlake Christian Academy) is located within a one -mile radius of the hypothetical cooling towers for Unit 1. Meteorological data from Charlotte, NC indicate that the predominant wind direction is not in the same direction as the school (WMO 2016); however, if MDCTs were selected as BTA for McGuire, the potential impact of icing on outdoor actitivites at the school would need to be studied in more detail prior to siting the hypothetical cooling towers. While the cooling towers will not cause ice on roads on a regular basis, during the coldest days, the probability of road ice formation will increase along Cowans Ford Dam Road, Highway 73, Hagers Ferry Road, Clarendon Pointe Court, and Island Drive, etc. This increase in probability could have potential impacts during the unlikely event of an evacuation during the winter. In addition to hazards to roadways and bridges, icing can also impact power lines in the area and other station equipment and buildings. Cooling tower locations assumed for this evaluation are surrounded by transmission corridors. During normal winters, the heat of the cables may be sufficient"$ to prevent ice on transmission lines; the innate heat may not be sufficient to counter cooling tower induced ice during an ice storm or other severe winter weather. Transmission corridors and switchyards would likely be at risk during these rare events. Icing can also have an adverse impact on the health and safety of personnel and security at McGuire. Icing can make conditions slippery, thus increasing the potential for slips, trips, and falls related to personnel walking on ice, as well as increasing the reaction time of security to respond to potential unauthorized penetration of McGuire's perimeter. Availability of Emergency Cooling Water "Safety -related" is defined by the USNRC as applying "to systems, structures, components, procedures, and controls (of a facility or process) that are relied upon to remain functional during and following design -basis events. Their functionality ensures that key regulatory criteria, such as levels 118 This is an opinion not verified with heat transfer calculations. Duke Energy 1 243 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Non -water Quality Environmental and Other Impacts Study [§122.21(r)(12)] r of radioactivity released, are met" (USNRC 2016b). Design -basis accidents (DBA) are defined as, "A postulated accident that a nuclear facility must be designed and built to withstand without loss to the systems, structures, and components necessary to ensure public health and safety" (USNRC 2016a). Shutting down and maintaining the nuclear reactor in a safe -shutdown condition is an example of a safety -related function (USNRC 2016b). With respect to the USNRC Regulatory Guide 1.27, Ultimate Heat Sink for Nuclear Power Plants, and regulations at 10 CFR (Parts 50 and 52), nuclear power stations establish a safety -related ultimate heat sink (UHS) to aid in performing principal safety functions, such as dissipation of residual heat after reactor shutdown or after an accident and dissipation of the maximum expected decay heat from the spent fuel pool. Generally, the UHS should be capable of delivering sufficient cooling water to accomplish these safety functions for either a single -unit, or multiple units simultaneously, for a period of 30 dayslls The SNSWP is the primary emergency water source that would be utilized during a DBA, such as a loss -of -coolant accident (LOCA). A LOCA at McGuire might be the loss of Lake Norman as a cooling water supply through dike failure. The SNSWP would still function, despite the LOCA. As described in USNRC Regulatory Guide 1.27: The UHS is the system of structures and components and associated assured water supply and atmospheric condition(s) credited for functioning as a heat sink to absorb reactor residual heat and essential station heat loads after a normal reactor shutdown or a shutdown following an accident or transient including a loss -of -coolant accident (LOCA). This includes those necessary water -retaining structures (e.g., a pond, a reservoir with its dam) and the canals, aqueducts, or piping systems connecting those cooling water sources with the essential or safety -related cooling water intake structure of the nuclear power units. Non -safety systems (e.g., circulating water supply) may share this safety -related water supply. If cooling towers or portions of cooling towers are required to accomplish the UHS safety functions, they should satisfy the same requirements as the UHS. McGuire's UHS, originally designed as the SNSWP, "is the only cooling water source qualified as the ultimate heat sink" (Duke Energy 2014a). Because the UHS is designed to operate separately from the current once -through system, it is assumed that cooling towers as part of a potential retrofit of the station would likely be independent from the UHS and not be designated as safety -related. The potential retrofit discussed in Section 10 attempts to circumvent impacts to the water supply pipes from the LLI, as well as impacts to the SNSWP. However, the planned tie-ins for both units occur close to the LLI supply line runs. If a closed -cycle retrofit were to be implemented, the supply lines and the SNSWP would need to be protected during the construction period with additional setbacks and shoring to allow for uninterrupted operation. The LLI is located near the base of the dam and withdraws water from pipes with a centerline elevation of 715.92 ft msl (Duke Power Company 1974). Lake Norman full pond elevation is at 760 ft 119 The USNRC's Regulatory Guide 1.27 provides more discussion on the specific design of the UHS. Duke Energy 1 244 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� Non -water Quality Environmental and Other Impacts Study [§122.21(r)(12)] r msl, and normal pond elevation is at 756 ft msl. Therefore, the excess evaporation due to the cooling towers (discussed further in Section 12.2.6) is not expected to impact the safety of the station. Additionally, changes that would be required due to the installation of cooling towers (e.g., updates to the existing condensers, piping network) would need to undergo an extensive review to evaluate possible impacts to the UHS, the safety -related cooling system, and related water requirements for a DBA. Such changes would need to be reviewed, approved, and permitted by the appropriate federal and state agencies. 12.2.4.2 Quantification Plumes and Fogging Fog and plumes occur throughout the year; however, the possibility for fog and plumes occurs more frequently in the colder months, when there is a greater difference between the warm saturated exhaust air of the cooling towers and the cool atmospheric air. While plumes and fogging are difficult to objectively forecast, fog and other meteorological events (e.g., rain, snow, thunderstorms) are recorded with other weather data at WMO Station 723140, Charlotte Douglas International Airport (Table 12-9). The days with fog reported indicate that there is an increase in the percent of time fog has been reported in the winter months (December, January, and February), as well as March and November, compared to the rest of the year. This aligns with the time of year with typically cooler temperatures compared to the summer and shoulder120 months. Fog occurs approximately 37 percent of the time in the winter months. Of the period of record for the station between January 1994 and October 2016, fog has historically occurred between 15 to 18 percent of the time on days when fog was reported in each winter month and between 7 and 12 percent of the time on days when fog was reported during the rest of the year. On average, on days when fog occurred, it occurred approximately 11 percent of the time. 120 Shoulder months are typically defined as the spring and fall months. Duke Energy 1 245 Duke Energy Corporation i McGuire Nuclear Station Draft CWA 316(b) Compliance Submittal L� Non -water Quality Environmental and Other Impacts Study [§122.21(r)(12)] r Table 12-9. Days with Fog Reported at WMO Station 723140* January 127 6 14% 18% February 94 4 10% 15% March 79 4 9% 12% April 48 2 5% 7% May 60 3 6% 8% June 64 3 7% 9% July 69 3 7% 10% August 65 3 7% 9% September 63 3 7% 9% October 67 3 7% 9% November 74 3 8% 11 % December 116 5 13% 17% Totalt 926 41 100% 11 % *Data is assuming fog has been reported between January 1994 and October 2016. tTotal number of data points between January 1994 and October 2016 is 8,256. Source: (WeatherUnderground 2016) The installation of cooling towers would likely increase the duration of fog by a few minutes on these days (EPRI 2011 a). The exhaust air can be carried with the prevailing wind to cause fogging both on and off site. Icing While similar to fog in that localized conditions can vary, the possibility for ice can be more easily predicted with forecasted freezing temperatures in the region. Air temperature has been recorded at WMO Station 723140, Charlotte Douglas International Airport and has been reviewed for days with a recorded minimum temperature of being less than or equal to 32°F (Table 12-10). The days with freezing temperatures recorded indicate that freezing conditions121 occur predominantly in the winter months (December, January, and February), with approximately 76 percent of all reported freezing days occurring within these three months. As anticipated, there is 121 For the purposes of this report, freezing conditions are defined as any period of time when a recorded temperature was at or below the freezing temperature of 32°F. Duke Energy 1 246 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� Non -water Quality Environmental and Other Impacts Study [§122.21(r)(12)] r minimal freezing in the shoulder months, as well as no recorded freezing conditions in the summer months. The period of record for the WMO station between January 1994 and June 2016 incudes freezing conditions nearly 47 percent of the time in December on days when freezing was reported, 57 percent of the time in January on days when freezing was reported, and 46 percent of the time in February on days when freezing was reported. As with fogging, installation and operation of cooling towers will likely increase the icing incidents/duration by a few minutes on typical freezing days noted in Table 12-10 (EPRI 2011 a). Table 12-10. Days with a Recorded Freezing Temperature at WMO Station 723140* January 408 18 30 57 February 296 13 22 46 March 136 6 10 20 April 12 1 1 2 May 0 0 0 0 June 0 0 0 0 July 0 0 0 0 August 0 0 0 0 September 0 0 0 0 October 23 1 2 3 November 162 7 12 24 December 323 14 24 47 Total$ 1,360 60 100 16 *Data is assuming the minimum recorded temperature between January 1994 and October 2016. tMay include rounding errors $Total number of data points between January 1994 and October 2016 is 8,256. Source: (Weather Underground 2016) 12.2.4.3 Impact Mitigation Methods (§122.21(r)(12)(vii)) Because cooling towers produce a visible plume that can adversely impact the health and safety of the public as well as personnel at McGuire, one potential mitigation method is the installation of plume -abated towers. Plume abatement is defined as the reduction of the cooling tower's plume visibility. Plume abatement is accomplished with an additional technology installed in the cooling tower prior to the exhaust point. According to SPX, "the plume can be made to become invisible within one or two fan diameters above the top of the tower fan cylinder" (SPX 2012). Duke Energy 1 247 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� Non -water Quality Environmental and Other Impacts Study [§122.21(r)(12)] r There are two main plume abatement technologies on the market. One technology causes the exhaust air temperature to increase so that the exhaust air is no longer saturated when leaving the cooling tower. This is accomplished by installing an air cooled tower above the wet portion of the tower. (See the discussion on hybrid cooling towers in Section 10). In the second technology, additional ambient air is drawn into the tower, passes through the typical wet section of the tower, and then travels through a section where additional ambient air is drawn into the cooling tower to mix with the warmed, saturated air in pairs of plates122 (SPX 2016a). The mixing of these two sources or air removes a portion of the exhaust moisture through condensation; the exhaust air is then less humid, which reduces the potential for the creation of a visible plume when interacting with the atmosphere (Power Engineering 2009). See the evaluation in Section 10 of this document for additional information, including relative costs. Plume abatement could reduce the potential impacts to the health and safety of the public and the station, by mitigating the effects of the plume and ground fogging on roadway, boating, aircraft, and security personnel visibility and line -of -sight. Plume -abated towers are longer and narrower than standard MDCTs. Given the topography in the vicinity of McGuire, the space availability, transmission corridors, etc., siting plume -abated towers at this station would be more challenging and would be infeasible at any of the alternate locations considered. 12.2.4.4 Uncertainty Key sources of uncertainty associated with the safety evaluation include the following. • While the wind roses provide data on long-term average wind speed and direction, specific wind speeds have not been reviewed against the number of recorded days with a freezing temperature or fog conditions. Therefore, it is important to note that icing and fogging can occur in any radial direction from the station and will follow the prevailing wind direction at the time. • Fog and ice formations are highly localized and depend on atmospheric and ground conditions. Fog and freezing conditions reported at the Charlotte Douglas Airport weather station may not necessarily be representative of local conditions at McGuire (which is located near Lake Norman). • The Charlotte Douglas Airport is located approximately 15 miles away from McGuire; the station may be outside approach zones and height regulations for any landing and takeoff aircraft at the airport. The potential impact of the cooling tower plume and fogging on the airport is inconclusive; therefore, further evaluation should be performed prior to selection of cooling towers as a compliance option. 122 The additional fan operation during the winter for plume abatement purposes in this second technology exerts a larger energy penalty in the winter as well. Duke Energy 1 248 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Non -water Quality Environmental and Other Impacts Study [§122.21(r)(12)] r • The evaluation was based on large time steps like days and months but unsafe conditions can occur within much shorter time spans. If McGuire were required to operate MDCTs, a more detailed safety evaluation would be performed at a finer time resolution. 12.2.5 Station Reliability 12.2.5.1 Description "Station reliability" refers to a power plant's ability to produce power when the station is required to provide power. McGuire's reliability could be affected by the design criteria for the MDCT in summer months and icing during winter months. The hypothetical cooling towers used in this evaluation have been designed to the upper 99th percentile wet -bulb temperature obtained from the WMO meteorological data station in Charlotte (WMO Station No. 723140), which explicitly means that the cooling tower will not be fully available, on average, for one percent of the time. Each year for approximately 88 hours with the highest wet - bulb temperatures, the station would need to be operated at reduced power. The highest percentile wet bulb temperature occurs during the late afternoons in July and/or August when the electricity demand is at its annual peak. In addition to the reliability issues associated with the 99th percentile design criterion, the potential for icing at McGuire's switchyard and/or on off -site transmission lines could also impact McGuire's reliability during periods of peak demand in the winter. During normal winters, the heat of the cables may be sufficient to prevent or minimize icing123; however, the innate heat may not be sufficient to counter cooling tower induced ice during an ice storm or other severe winter weather. Transmission corridors and switchyards would likely be at risk during these rare events. 12.2.5.2 Quantification Based on the design parameters, McGuire would need to operate at reduced power for approximately 88 hours per year during the warmest and most humid periods. The magnitude of the percent reduction in power would depend on actual meteorological conditions. Assuming a 20 percent reduced power for 88 hours per year amounts to approximately 21.5 GWhr124 per year per unit, or approximately 43 GWhr for the station, which is 0.2 percent compared to the station's annual gross generation. Given the uncertainty associated with icing conditions, it is not possible to quantify the risks to the transmission system. 123 This is an opinion not verified with heat transfer calculations. 124 This is equivalent to the annual power consumption of approximately 2,000 homes, assuming 10.8 MlWhr average consumption reported by EIA (2016). Duke Energy 1 249 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� Non -water Quality Environmental and Other Impacts Study [§122.21(r)(12)] r 12.2.5.3 Impact Mitigation Methods Designing the cooling tower for the maximum ambient wet bulb temperature (with an allowance for recirculation) would decrease the likelihood of reduced power operations at McGuire, but such a tower would be significantly more costly and would require a larger footprint. This evaluation therefore does not assume that the cooling tower would be upsized regarding the criteria presented in Section 10 of this document. 12.2.5.4 Uncertainty Key uncertainties associated with the reliability evaluation are listed below. The conceptual design used the 99t" percentile wet bulb temperature, which means that the wet bulb temperature would exceed the design value approximately one percent of the time each year but, this is a long-term indicator. There may be some years when the actual wet bulb temperature would not exceed the design value, and other years when it is exceeded more frequently. • If the demand increases or decreases differently from the present forecast, or if one or more regulations were to cause several power plants to operate differently, the actual impacts could be different than discussed above. 12.2.6 Consumptive Use of Water 12.2.6.1 Description Changes in the consumption of water are primarily attributable to evaporative losses from once - through cooling and CCRSs; therefore, the only entrainment mitigation options discussed in this section will be the closed -cycle cooling retrofit. This section evaluates the increase in evaporation due to a hypothetical cooling tower retrofit, as compared to McGuire's current evaporation rate. 12.2.6.2 Quantification Forced Evaporation Evaporation occurs naturally in surface waterbodies and is affected by the stored energy in water. Many variables factor into surface water evaporation, including incoming solar radiation, ambient water temperatures, and psychrometric and atmospheric conditions at the location. When heated water is discharged to a surface waterbody, the evaporation rate in the waterbody is increased because of the added heat (measured in Btu). The increase in evaporation due to the thermal discharge is referred to as forced evaporation and depends directly on the additional heat being routed to the receiving waterbody. Consumptive water use rates from Lake Norman calculated and reported by Duke Energy are summarized in Table 12-11. Duke Energy 1 250 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal �� Non -water Quality Environmental and Other Impacts Study [§122.21(r)(12)] Table 12-11. Summary of Historical Evaporation Rates between 2014 and 2016 (Duke Energy 2017) January 26.5 February 26.5 March 26.5 April 26.3 May 25.6 June 25.8 July 25.9 August 25.5 September 25.0 October 25.6 November 26.3 December 26.7 15.6 I I 1 14.9 1 L 15.2 15.1 15.0 12.0 11.8 14.2 15.7 See Appendix 12-C for monthly forced evaporation data from 2014 through 2016. Cooling Tower Evaporation Evaporation is also the mechanism utilized by cooling towers, where a small amount of water, compared to a once -through cooling withdrawal, is consumed through evaporation to cool the water circulating through the cooling tower. The flow rate through the cooling tower and the difference in cold and hot water temperatures are the primary functions relating to cooling tower evaporation. Forced evaporation in the waterbody due to the cooling tower blowdown would be small compared to the evaporation from the cooling tower; therefore, it will not be quantified. MDCTs are evaporative -type towers125, which utilize evaporation as the primary means of cooling. The cooling tower evaporative water loss as a result of the cooling effect is governed by latent heat transfer and the direct contact of water and air in the tower. This direct contact is designed to expose a maximum amount of water surface to a maximum flow of air for the greatest amount of heat transfer with respect to structural and operational feasibilities (SPX 2009). Thus, the rate of 125 Other types of towers include dry towers where heat is transferred directly to the atmosphere through dry surface fins; there is no direct contact between air and water (SPX 2009). Duke Energy 1 251 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� Non -water Quality Environmental and Other Impacts Study [§122.21(r)(12)] r evaporation (Eq. 12-1) and other water losses can be estimated using the following formulae and variables121. E = 0.0008 x R X QCT Eq. 12-1 Where, E = Rate of Evaporation, gpm R = Condenser Range, OF QCT = Cooling Tower Water Flow Rate, gpm Drift is a water loss and occurs as circulating water, in the form of liquid droplets, becomes entrained in the exhaust air stream (SPX 2009) (Eq. 12-2). D=DEXQCT Eq. 12-2 Where, D = Drift Flow Rate, gpm DE = Drift Eliminator Efficiency, % Blowdown is the water discharged from the system to control the concentrations of dissolved minerals, organic matter, and other impurities in the recirculating water; the volume of the blowdown is a function of evaporation, COC, and drift (SPX 2009) (Eq. 12-3). M (E — [(C — 1) x D]) (C — 1) Where, B = Blowdown Flow Rate, gpm C = Cycles of Concentration Eq. 12-3 Make-up water is the water that is needed to replenish the circulating water due to losses from evaporation, blowdown, and drift. M = E + B + D Where, M = Make-up Flow Rate, gpm Eq. 12-4 Using these equations, evaporation from cooling towers at McGuire has been estimated (Table 12-12). Evaporation from the cooling tower is approximately 24,566 gpm (35.4 MGD). The make-up water flow rate to McGuire is approximately 30,707 gpm (44.2 MGD). 126 The formulae and variables are detailed in SPX (2009). Duke Energy 1 252 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� Non -water Quality Environmental and Other Impacts Study [§122.21(r)(12)] r Annually, the consumptive use due to cooling tower evaporation would be approximately 6,456 MGY per unit (12,912 MGY total for the station). Drift would be approximately 2.5 MGY per unit (5 MGY total for the station). The total consumption, assuming evaporation plus drift, would be approximately 6,458.5 MGY per unit (12,917 MGY total for the station). Table 12-12. Estimated Cooling Tower Evaporation Estimated Water Flow Rates Cooling Tower Evaporation Rate E gpm 12,283 12,283 24,566 Drift Flow Rate D gpm 4.8 4.8 9.6 Blowdown Flow Rate B gpm 3,066 3,066 6,132 Make-up Flow Rate M gpm 15,354 15,354 30,707 See Appendix 10-A for engineering calculations. The cooling tower evaporation is compared against the forced evaporation in the following section. As indicated earlier in Section 12, it is anticipated that the potential retrofit of McGuire with cooling towers would not impact the water available to the emergency cooling water; therefore, this will not be further discussed in this section. Change in Consumptive Water Use Cooling towers, as part of closed -cycle cooling, use evaporation as the main cooling method; therefore, the consumptive use of water due to cooling towers is typically higher compared to forced evaporation, as part of once -through cooling. The increase in evaporation due to the closed -cycle retrofit is estimated as the percent increase in evaporation compared to the current forced evaporation rate as shows in Eq. 12-5). Post retro evap — Forced evap Increase in evaporation = x 100 Forced evap Eq. 12-5 The percent increase in evaporation due to a closed -cycle cooling tower retrofit is presented in Duke Energy 1 253 Duke Energy Corporation I McGuire Nuclear Station Draft CWA 316(b) Compliance Submittal L�� Non -water Quality Environmental and Other Impacts Study [§122.21(r)(12)] r Table 12-13. The cooling tower evaporation for McGuire has been estimated to be higher than forced evaporation associated with once -through cooling for all months of the year, with the percent increase ranging from 33 percent to 42 percent. Duke Energy 1 254 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal �� Non -water Quality Environmental and Other Impacts Study [§122.21(r)(12)] Table 12-13. Percent Difference between Once -through Cooling Forced Evaporation and Cooling Tower Evaporation for the Period 2014 through 2016 January 26.5 35.4 34% February 26.5 35.4 34% March 26.5 35.4 34% April 26.3 35.4 34% May 25.6 35.4 38% June 25.8 35.4 37% July 25.9 35.4 36% August 25.5 35.4 39% September 25.0 35.4 42% October 25.6 35.4 38% November 26.3 35.4 35% December 26.7 35.4 33% 12.2.6.3 Impact Mitigation Methods If plume abatement technologies were used (which this evaluation did not consider), it is possible that a portion of the water vapor in the exhaust could be condensed, collected, and potentially reused in the system to reduce the total water requirement. Evaluations provided in Section 10 of this document determined plume -abated towers to be infeasible at McGuire. Additionally, the volume of water collected through such a technology is anticipated to be a small portion of the total water withdrawn (SPX 2016a). Evaporation is critical to the cooling process; therefore, mitigation measures that would reduce evaporative losses would not be incorporated into a potential design. 12.2.6.4 Uncertainty Key uncertainties associated with evaporation are listed below. • Evaporation rates are dependent on psychrometrics and ambient conditions at any given time. Local meteorological conditions can influence evaporation characteristics. • A change in water surface elevation of even a few inches can impact recreation and the shoreline. However, this evaluation did not extend to a shoreline investigation. Duke Energy controls the water level in Lake Norman with the use of upstream reservoirs. Therefore this evaluation assumed that the water level would remain unchanged with no impact to the shoreline. Duke Energy 1 255 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal Non -water Quality Environmental and Other Impacts Study [§122.21(r)(12)] • The forced evaporation estimation method assumed a well -mixed thermal discharge. It is unknown if the McGuire discharge conforms to the characteristics of that assumed in the calculation. 12.2.6.5 Visual Impacts Visual impacts are assumed to be changes to the scenic landscape by the introduction of additional industrial development and how those associated changes affect the human visual experience of the landscape. A formal visual impacts assessment has not been completed for this report; if MDCTs are chosen as BTA, a visual impacts assessment may be required prior to selection and siting of cooling towers at McGuire. Hypothetical Unit 1 towers at Location B would be northeast of the reactors and less than 100 ft in height from the ground surface (Figure 12-3); therefore, the towers may potentially be at a location where the equipment could be concealed behind trees and other foliage from public roadways. The towers would likely be visible to boaters on Lake Norman. Hypothetical Unit 2 towers at Location A would be east of the reactors near the eastern shore of the Catawba River (Figure 12-3). While the towers would likely be less than 100 ft in height, the trees and other foliage near this area would need to be cleared to install two separate retaining walls to support the cooling towers. The towers would be constructed on ground built up to the main plant elevation, which is approximately 80 ft above Catawba River water surface. It is likely that the Unit 2 towers would be visible from Catawba River, the dam, and the Highway-73 Bridge over the Catawba River. At both locations, the towers would emit a plume that would be visible above the towers to the surrounding area, including residential communities, the school, and recreational users on Lake Norman and on the Catawba River. 12.3 Fine -mesh Screens 12.3.1 Energy Consumption 12.3.1.1 Description Traveling water screens with a mesh size of 2.0 mm were selected for further evaluation at McGuire, as provided in Section 10 of this document. A FMS retrofit would increase the energy requirements of the station both directly and indirectly. 12.3.1.2 Fine -Mesh Traveling Screens The use of fine -mesh traveling water screens with a fish return system would require the continuous rotation of screens, continuous operation of low-pressure and high-pressure screenwash headers, and continuous make-up of the fish trough water flow. Continuous rotation of screens and use of pumps will increase energy consumption. Additionally, modified-Ristroph screens are heavier, and the fine mesh would create a greater drag as it moves through water, all of which would contribute to higher energy use. This operation will include motors, which rotate the screens, pumps, which drive Duke Energy 1 256 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal Non -water Quality Environmental and Other Impacts Study [§122.21(r)(12)] the pressure wash system, and operation of any related monitoring, meters, lighting, or other requirements for traveling water screens. 12.3.1.3 Quantification The additional energy consumed through the use of hypothetical FMS is dependent upon the water quality and anticipated debris loadings at McGuire. Screen cleaning requirements are assumed to be directly proportional to the amount of debris in the waterbody and the electricity consumed (i.e., through the operation of additional pumps, motors, and other items that are required for the low and high-pressure wash systems). Therefore, it can be assumed that an increase in debris loading and the need to protect organisms would increase. The difference in energy use from converting coarse - mesh intermittently operated traveling water screens to continuously operated FMS is listed in Table 12-14. Duke Energy 1 257 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal �� Non -water Quality Environmental and Other Impacts Study [§122.21(r)(12)] Table 12-14. Increase in Energy Consumption due to a Fine -mesh Traveling Water Screen Retrofit Existing Coarse -mesh System Existing Screen Motor Rating 0.75 hp/screen Low Pressure Screen Wash Pump Rating 0 hp/screen High Pressure Screen Wash Pump Rating 18 hp/screen Weekly Hours of Operation 1 hour/week Number of Screens 16 screens Total Weekly Energy Consumption 0.22 MWhr/week Total Annual Energy Consumption 11.4 MWhr/year Hypotheticali Fine -mesh Screen Motor Rating 3.0 hp/screen Low-pressure Screen Wash Pump Rating �■ hp/screen High-pressure Screen Wash Pump Rating 15.0 hp/screen Auxiliary Fish Header hp/screen Fish Trough Make-up 0.1 hp/unit Estimated Increase in Screen Headloss 4.3 inches Hours of operation per week 168 hour/week Number of Screens 16 screens Total Weekly Increase in Energy Consumption 65.6 MWhr/week (95% Capacity Utilization Rate) Total Annual Increase in Energy Consumption (95% Capacity Utilization Rate) 3,413 MWhr/year See Appendix 12-D for engineering calculations of energy consumption. 12.3.1.4 Impact Mitigation Methods Use of variable speed motors for screens, which are incorporated into the design and costs, would help to reduce the additional energy consumption. Regular maintenance and inspection of spray wash nozzles, which are also incorporated into the design and costs, would help reduce nozzle clogging and over -working spray wash pumps. These two mitigation measures are already incorporated into the conceptual design discussed in Section 10; therefore, no additional mitigation measures are included. Duke Energy 1 258 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal �� Non -water Quality Environmental and Other Impacts Study [§122.21(r)(12)] 12.3.1.5 Uncertainty The debris and organism loading expected with fine -mesh is unknown. Therefore, further evaluation on debris loading would be required to assess the feasibility of installation of FMS at McGuire. 12.3.2 Air Pollutant Emissions, Environmental Impacts, and Human Health 12.3.2.1 Description The continuous operation of screens and high- and low-pressure pumps would contribute to increased emissions. 12.3.2.2 Quantification Annual increased CO2, NOx and S02 emissions from replacing the existing coarse -mesh screens with FMS are provided in Table 12-15. These estimates have been calculated using the anticipated annual increase in energy consumption due to fine -mesh screen installation of 1,706 MWhr per year for Unit 1 and 1,706 MWhr per year for Unit 2, and under the assumption that the additional energy would be generated at fossil fuel -powered generating stations. The emission factors used in calculating the increased emissions for CO2, NOx and S02 were 0.78 ton CO2/MWhr, 1.1 Ibs NOx/MWhr, and 0.8 lb S02/MWhr, respectively (Bradley Associates 2017). Table 12-15. Increase in Emissions at McGuire from Replacing Coarse -mesh Screens with FMS Increase in Emissions (95% Capacity Utilization Rate) Annual Increase in CO2 Emissions (tons/year) 1,404 1,404 2,808 Annual Increase in S02 Emissions (tons/year) 0.7 0.7 1.4 Annual Increase in NO. Emissions (tons/year) 1.0 1.0 2.0 See Appendix 12-E, Appendix 12-F, and Appendix 12-G for CO2, S02, and NOx emissions calculations, respectively. This evaluation assumed that the screen replacement would be staggered, with four screens replaced during refueling outages. Therefore, no screens -related outage is anticipated. 12.3.3 Impact Mitigation Methods The largest emissions are associated with nuclear unit outages. This evaluation has staggered screen replacements to allow the replacements to occur during refueling outages, thereby avoiding retrofit -related outages. Mitigation measures discussed in an earlier section (see Section 12.3.1.4) apply here as well, albeit at a much smaller scale. Optimal use of power would facilitate further reductions in emissions. Duke Energy 1 259 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal �� Non -water Quality Environmental and Other Impacts Study [§122.21(r)(12)] 12.3.3.1 Uncertainty Key sources of uncertainty associated with the emissions estimates are listed below. 1. Historical emissions factors may not be representative of future emissions due to changes in fuel mix, emissions controls, etc. 2. If the screen replacement cannot be implemented in a staggered fashion, then the retrofit would require unit outages which would result in significant emissions. 3. There may be changes in regulations that govern emissions. 12.3.4 Changes in Noise Additional pumps and motors and the use of finer mesh in the traveling water screens would result in what is expected to be a negligible increase in the noise level at the cooling water intake structure. Moreover, there would be little chance, if any, that the slight increase would have off -site effects since the equipment at the intake would be shielded by other structures and would be located approximately 2,600 ft from the nearest property boundary (Figure 12-5). It is assumed that the distance is sufficient to provide for noise abatement from the increased traveling water screen operation. Therefore, this potential impact is not quantified for this evaluation. Property Boundary M"kfenbarg Existing CWIS and Cowans Ford Dam Potential Location for Wedgewire Screens Approx. 2,600-ft 0 0.03751.075 Il This map or report is prepared for the inventory of real property within Mecklenburg County and is compiled from recorded deeds, plats, taK maps, surveys, planimetric maps, antl otherpublic records and data. I L red that the aforementioned pudic primary information sources should be ccnsuked for verification. Mecklenburg County and its mapping contractors assume no legal Users of this map or report are hereby Figure 12-5. Intake Distance to Property Boundary (Mecklenburg County 2016a) Duke Energy 1 260 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal Non -water Quality Environmental and Other Impacts Study [§122.21(r)(12)] 12.3.5 Safety Impacts Retrofitting with fine -mesh traveling water screens is not expected to impact the safe operation of McGuire, or the safety to station personnel or surroundings, therefore safety is not discussed further. 12.3.6 Station Reliability "Station reliability" refers to a power plant's ability to produce power when the station is required to provide power. If water were unable to flow through the screens or if screens were structurally damaged or collapsed due to large differential pressures from clogging and blinding, McGuire's reliability would be adversely impacted; however, the screens are assumed to be rotated and cleaned continuously to avoid excessive debris loading which could trigger a potential screen collapse. Therefore it is unlikely that screens would collapse. 12.3.6.1 Description If the retrofitted FMS foul and clog because of debris or aquatic organism loading and prevent the flow of water from Lake Norman to the condensers, then this retrofit could potentially impact the reliability of the station. If such clogging were to occur, McGuire would need to be operated at reduced power until the screens are clear again. Alternatively, the screens can be lifted out of water and debris and water allowed to flow into the condenser, and later clean out the condenser during reduced power operations. Either way, operating at reduced power is possible under heavy loading. McGuire does not typically experience heavy debris or aquatic loading under normal conditions. If a reduced -power operating scenario were to occur, the duration and severity of the event is unknown As discussed in Section 10, there is only a 9-ft difference between the circulating water pump bell and low water elevation. A potential short -during clogging event could trigger pump cavitation, which in turn impacts station reliability. Extensive pump and debris loading evaluations are needed if FMS were selected as the BTA at McGuire. 12.3.6.2 Impact Mitigation Methods (§122.21(r)(12)(vii)) This evaluation assumed that the screens would be rotated and spray -washed continuously, and the screens would be maintained and inspected regularly to allow for unimpeded operations. Therefore, no additional mitigation measures are included. 12.3.6.3 Uncertainty The extent of debris loading impacts reliable screen operation. The seasonal variability in debris loading would affect reliability of the screens. Pump performance and cavitation potential would need additional evaluation. Duke Energy 1 261 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal Non -water Quality Environmental and Other Impacts Study [§122.21(r)(12)] 12.4 Alternate Water Sources As provided in Section 10, no viable alternate water source within a 5-mile radius was identified. The following is a brief description of the results of the water source evaluation: If the use of an alternate water source (whether groundwater or grey water) were viable, then energy consumption would increase owing to additional pumping, and emissions would increase correspondingly. Depending on McGuire's dependence on the alternate water source and fraction of water provided by the alternate source, the reliability of station operations could also be compromised. 12.5 Engineering Summary A summary of findings for the technologies reviewed for compliance with §122.21(r)(10) and (r)(12) is presented in Table 12-16. Table 12-16. Summary of Engineering EvaluationS127 Technology =mr, I ". I Anticipated Year when Commissioned 2031 2031 2025 and 2026 2026 and 2027 End of Life of Technology and Station 2041 2043 2041 2043 Anticipated Outage 12 months 12 months None None Capital Costs (2017 $M) $750 $750 $17 $17 Annual O&M Costs (2017 $M) $67 $67 $1.2 $1.2 Number of Technology None None One One Replacements Net Present Value (2017 $M) $852 $900 $34 $33 Energy Losses: Auxiliary Energy Losses 309,502 366,905 1,706 1,706 (MWhr/year) 112,418 111,312 0 0 Backpressure Energy Penalty (MWhr/year) Reduction in power when Design 21,006 20,800 0 0 Wet Bulb Temperature Exceeded (MWhr/year) 10,503,240 10,399,872 0 0 127 Costs are presented in 2017 U.S. dollars. Inflation escalation rate is assumed to be three percent per year. Duke Energy 1 262 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal Non -water Quality Environmental and Other Impacts Study [§122.21(r)(12)] �hnology MDCT — Unit 1 MDCT — Unit 2 FMS— Unit 1 FMS — Unit mJL Tie-in outage related energy loss (MWhr) Increase in PM Emissions: PM2.5 (tons/year) 1.03 — 2.63 1.03 - 2.63 0 0 PM,o (tons/year) 1.80 — 5.42 1.80 - 5.42 0 0 Increase in CO2, SO2, NOX (1000s tons/year) (tons/year) (tons/year) Emissions: Approximately 500 1,404 1,404 S02 SOX Approximately 0.3 0.7 0.7 Approximately 0.3 1.0 1.0 N Ox Potential low - Increase in Noise level noise to Negligible Negligible the east of the Station Impact on Station Reliability Impacted due to backpressure Inconclusive; Need to evaluate circulating water energy penalty pump cavitation potential Increased evaporation; Assume Increase in Consumptive Water McGuire would increase releases Use into Lake Norman to mitigate for No impact increased evaporation Visual Impacts Significant impact due to Unit 1 No impact M DCTs Duke Energy 1 263 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal Peer Review [§ 122.21 (r)(1 3)] 13 Peer Review [§ 122.21 (r)(1 3)] The information required to be submitted per §122.21(r)(3), Peer Review, is outlined as follows: If the application is required to submit studies under paragraphs (r)(10) through (12) of this section, the application must conduct an external peer review of each report to be submitted with the permit application. McGuire has a DIF of greater than 125 MGD (see Section 10); therefore submittal documents under paragraphs §122.21(r)(10)—(12) are required as well as external peer review of each report. The regulation goes on to state: The applicant must select peer reviewers and notify the Director in advance of the peer review. The Director may disapprove of a peer reviewer or require additional peer reviewers. The Director may confer with EPA, Federal, State and Tribal fish and wildlife management agencies with responsibility for fish and wildlife potentially affected by the cooling water intake structure, independent system operators, and state public utility regulatory agencies, to determine which peer review comments must be addressed. The applicant must provide an explanation for any significant reviewer comments not accepted. Peer reviewers must have appropriate qualifications and their names and credential must be included in the peer review report. This section introduces the peer reviewers, a summary of the peer review process, and the results of peer review. Each of these requirements is addressed in the following subsections. 13.1 Peer Reviewers Peer Reviewers were selected in accordance with their expertise in the disciplines necessary to adequately and thoroughly evaluate approaches to entrainment BTA under the §316(b) Rule; these disciplines include economics, engineering, and aquatic ecology. Peer reviewers were also chosen due to their level of familiarity with the §316b process and the request to utilize the selected peer reviewers was sent to the NCDEQ for approval. Information regarding peer reviewers for McGuire Sections 122.21 (r)(10) — (12) of the CWA compliance submittal is presented in this section and their resumes are included in Appendix 13-A. Expert level assessments of Sections 122.21 (r)(10) — (r)(12) were obtained from the following four peer reviewers: Paul Jakus, PhD — Dr. Jakus is professor and Head of the Department of Applied Economics at Utah State University and was selected to review the economics portions of the §122.21(r)(10) Comprehensive Technical Feasibility and Social Cost Evaluation as well as the §122.21(r)(11) Monetized Benefits Evaluation. John Maulbetsch, PhD, PE — Dr. Maulbetsch is owner and principal of Maulbetsch Consulting in Menlo Park, California, and was selected to review the Closed -cycle Duke Energy 1 264 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal Peer Review [§ 122.21 (r)(1 3)] Recirculating Systems Retrofit Approach and Technologies engineering portions of the §122.21(r)(10) Comprehensive Technical Feasibility and Cost Evaluation Study. • Joe Raulli, PE — Mr. Raulli is the Technical Director at O'Brien and Gere and was selected to review Fine -Mesh and Fine -Slot Screen Retrofit and Alternate Cooling Water Sources engineering portions of the §122.21(r)(10) Comprehensive Technical Feasibility and Cost Evaluation Study as well as the §122.21(r)(12) Non -water Quality Environmental and Other Impacts Assessment. James Rice, PhD — Dr. Rice is a professor in the Department of Applied Ecology at North Carolina State University and was selected to review the biological portion of the §122.21(r)(11) Benefits Valuation Study and portions of the §122.21(r)(9) Entrainment Characterization Plan. 13.2 Peer Review Process In 2015 (i.e., prior to the beginning the entrainment BTA process), Duke Energy identified and selected a pool of potential peer reviewers to provide (1) input on the approach for formally addressing the Rule requirements in §122.21(r)(10) — (12); (2) an informal review of proposed economic, engineering, and biology study methodologies; and (3) an informal review of proposed entrainment and impingement study plans. While an informal review on approaches and methodology is not mandatory under the Rule, Duke Energy considered this an important step to gain information on the peer reviewers' professional perspectives and expectations. On July 27, 2015, Duke Energy submitted a list of selected peer reviewers and their credentials to NCDENR (now NCDEQ). A follow-up letter was submitted to NCDEQ on September 21, 2018 identifying additional selected peer reviewers and their credentials. The four peer reviewers ultimately selected to review the McGuire compliance package (listed in Section 13.1) were among the pool of candidates included in the two letter submittals. A Peer Review Kick-off Meeting was held in Charlotte, North Carolina on January 28-29, 2016. Participants included Duke Energy, HDR (including representatives from individual sub -consultants directly involved with the project), selected peer reviewers (at the time), and representatives from the South Carolina Department of Health and Environmental Control (SCDHEC).128 The objectives of the kick-off meeting were to: 1. Introduce peer reviewers to the Duke Energy §316(b) program and provide a high level overview of the facilities subject to requirements under §122.21(r)(10)-(12). 2. Introduce peer reviewers to the technical approaches and proposed methodologies anticipated for the required biology, engineering, and economic studies. 3. Discuss the overall formal peer review process, timelines, and responsibilities, including introduction to the Peer Review Facilitator. 128 Representatives from NCDEQ were invited to attend, but were not able to due to other commitments. Duke Energy 1 265 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� Peer Review [§122.21(r)(13)] r The peer review process depicted in Figure 13-1 is administered by the Peer Review Facilitator. This process was presented to peer reviewers during the kick-off meeting. Figure 13-1. Peer Review Process Flow Chart Following the kick-off meeting, the peer reviewers were asked to review and provide comments in response to the technical approaches and methodologies presented during the kick-off meeting. Comments were received and incorporated into the study project protocol. All contact with peer reviewers related to technical content and/or project schedule was either made by, or facilitated by, the Peer Review Facilitator. Although not specifically required by the Rule, Duke Energy elected to ask Dr. Rice to perform an informal review of the proposed study plan for the 2-year Entrainment Characterization Study on February 12, 2016. Comments were received on February 19, 2016 and incorporated prior to the start-up of entrainment sampling activities at McGuire in March 2016. Duke Energy 1 266 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal Peer Review [§ 122.21 (r)(1 3)] On June 11, 2018, a letter outlining an issue related to collection of Inland Silverside in Lake Norman (which were collected in the 2016 sampling effort, but not in 2017) was submitted to Dr. Rice as information along with the proposed approach for addressing the collection under §122.21(r)(11). A summary of the 2016 and 2017 entrainment sampling results was provided to Dr. Rice to facilitate his review. On June 25, 2018 Dr. Rice subsequently concurred with the proposed approach and provided additional information that supported placing the anomalous species sampling results into context. The formal peer review process officially commenced on September 25, 2018 with submittal of the draft McGuire compliance submittal package §122.21(r)(10)-(12) to the four peer reviewers listed in Section 13.1. The package included a set of instructions, charge document (or list of specific questions the peer reviewers were asked to respond to), and the draft §122.21(r)(2)-(9) reports as reference material. The instructions and charge document were specific to each peer reviewer as each was asked to review different portions of the §122.21(r)(10)-(12) documents. Two peer reviewers, Mr. Raulli and Dr. Maulbetsch, who did not attend the Peer Review Kick-off meeting in January 2016, were invited to separate conference calls to provide introductions to the project team and technical approaches related to engineering, and to answer any questions regarding the peer review process. These conference calls were conducted on October 24, 2018 (Mr. Raulli) and November 7, 2018 (Dr. Maulbetsch). Subsequent to the conference call, Mr. Raulli sent (via email on October 26, 2018) follow-up information related to comments he made during the call clarifying his interpretation of benchmark air emissions presented in §122.21(r)(12). Responses to Mr. Raulli's comments were provided by the project team (via email) on October 29, 2018. Return of the completed charge documents, along with any other comments, questions, and/or recommendations was requested by November 30, 2018 (approximately two months). Correspondence between the peer reviewers and the Peer Review Facilitator was tracked and communication logs are included in Appendix B. All peer reviewers completed their reviews within the requested time with the exception of Mr. Maulbetsch who requested, and was granted, an extension to December 2, 2018. Upon receipt of peer reviewer comments, the Peer Review Facilitator transmitted the completed charge documents along with additional comments received to both the HDR and Duke Energy project teams for review and evaluation (see Appendix 13-C). A comment response table was developed and responses to peer reviewer comments are provided in Appendix 13-D. All correspondence and documents exchanged are stored within HDR's project files as well as a SharePoint site administered by HDR. 13.3 Comment Response Criteria This section documents the external Peer Review process by categorizing and developing responses to peer reviewers' comments on McGuire §122.21(10)-(12) report sections using the following criteria: • Category 1: Comments that are clearly applicable (i.e., relevant under the charge and improve the quality of the work product). These comments will be incorporated into the Reports. Duke Energy 1 267 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal Peer Review [§ 122.21 (r)(1 3)] • Category 2: Comments that represent a misunderstanding by peer reviewers and should not be incorporated into the Report. These comments will not be incorporated into the Reports. • Category 3: Comments that are minor and do not materially change or lend additional value to the Reports (e.g., comments provided for informational purposes, or meant as preferential suggestions, or are beyond the scope of the charge). These comments may or may not be incorporated into the Reports at the discretion of the Report Originator. • Category 4: Major peer reviewer comments that the Report Originators do not agree with and choose not to incorporate into the Reports. These comments will be provided along with an explanation as to why they were not incorporated into the Reports in §122.21(13). 13.4 Peer Review Results Peer reviewer comments and responses to the Directed Charge Questions are included in Appendix 13-C. Dr. Jakus and Dr. Maulbetsch submitted additional suggestions (i.e., not in response to the Directed Charge Questions), which are also included in Appendix 13-C. HDR developed comprehensive comment response tables in which all peer reviewer comments were addressed; the tables are presented in Appendix 13-D. Additional comments were logged in a separate table and are also included in Appendix 13-D. Revisions to the compliance document were made based on reviewer comments and suggestions; however, if a peer reviewer comment was not addressed in the revised submittal document, an explanation is provided in the comment response table. Responses from all four peer reviewers were assigned as Category 1 (i.e., clearly applicable) or Category 3 (i.e., minor) comments and were either addressed in the compliance document, or an explanation as to why the comment was not addressed is included in Appendix 13-D (Responses to Peer Reviewer Comments). There were no Category 2 (i.e., misunderstanding) or Category 4 (i.e., major comments not incorporated) comments. The comment response table, along with revised §122.21(10)-(12) report sections, were subsequently provided to the peer reviewers to confirm that all questions and/or comments were adequately addressed. Confirmation was provided (via email) by: • Dr. Maulbetsch on July 7, 2019 • Mr. Raulli on July 10, 2019 • Dr. Jakus on July 4, 2019 • Dr. Rice on July 9, 2019 Documentation is included in Appendix 13-B (Peer Reviewer Correspondence Log) and Appendix 13-C (Peer Reviewer Comments). Duke Energy 1 268 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� References r 14 References 14.1 Executive Summary References Duke Energy Carolinas, LLC (Duke Energy). 2015. Lake Norman Maintenance Monitoring Program 2013 Summary, McGuire Nuclear Station, NPDES Permit No. NC0024392. Draft Report. Huntersville, NC. . 2017. Lake Norman Maintenance Monitoring Program 2016 Summary, McGuire Nuclear Station, NPDES Permit No. NC0024392. Draft Report. Huntersville, NC. Electric Power Research Institute (EPRI). 2003. Evaluating the Effects of Power Plant Operations on Aquatic Communities. Final Report 1007821. Palo Alto, CA. . 2004a. Extrapolating Impingement and Entrainment Losses to Equivalent Adults and Production Foregone. Technical Report 1008471. Palo Alto, CA. 2004b. Chapter 1. Traveling Water Screens. 1011546. Palo Alto, CA. 2011. Seasonal Patterns of Fish Entrainment for Regional U.S. Electric Generating Facilities. Technical Update 1023102. Palo Alto, CA. . 2012. Fish Life History Parameter Values for Equivalent Adult and Production Foregone Models: Comprehensive Update. Technical Report 1023103. Palo Alto, CA. MacArthur, R.H. and E.O. Wilson. 1967. The Theory of Island Biogeography. Princeton University Press. Princeton, New Jersey. Rohde, F.C., Rudolf, G.A., Lindquist, D.G., and J.F. Parnell. 1994. Freshwater Fishes of the Carolinas, Virginia, Maryland, and Delaware. The University of North Carolina Press, Chapel Hill, North Carolina. United States Environmental Protection Agency (USEPA). 2002. Economic and Benefits Analysis for the Proposed Section 316(b) Phase II Existing Facilities Rule. Report Number 821-R-02- 001. Washington, DC: U.S. Environmental Protection Agency. . 2006. Regional Benefits Analysis for the Final Section 316(b) Phase III Existing Facilities Rule. EPA-821-R-04-007. Washington, DC: U.S. Environmental Protection Agency. . 2014. National Pollutant Discharge Elimination System — Final Regulations to Establish Requirements for Cooling Water Intake Structures at Existing Facilities and Amend Requirements at Phase I Facilities. United States Nuclear Regulatory Commission (USNRC). 2002. Generic Environmental Impact Statement for License Renewal of Nuclear Plants Supplement 8 Regarding McGuire Nuclear Station, Units 1 and 2. Final Report NUREG-1437. Washington, D.C. Veritas Economic Consulting (Veritas). 2018. Entrainment Reduction Benefits Study: McGuire Nuclear Station. Prepared for Duke Energy Carolinas, LLC. Cary, North Carolina. Duke Energy 1 269 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� References r 14.2 Section 1 through Section 8 References Alden Research Laboratory, Inc. (Alden). 2004. Evaluation of the McGuire Nuclear Generating Station with Respect to the Environmental Protection Agency's 316(b) Rules for Existing Facilities. Holden, Massachusetts. Bakuneeta, C., Bogan, A., Bringolf, R.B., and J. Levine. 2010. Fish hosts of the Carolina Heelsplitter (Lasmigona decorata), a federally endangered freshwater mussel (Bivalvia: Unionidae). American Malacological Bulletin, 28: 151-158. Brey, M.K., Feinger, Z.S., Godbout, J.D., Aday, D.D., and J.A. Rice. 2012. Trophic interactions and reservoir food web dynamics. North Carolina Wildlife Resources Commission, Federal Aid in Sport Fish Restoration, Project F-68-08, Final Report. Raleigh, North Carolina. Brierley, A.S. 2014. Diel vertical migration. Current Biology 24(22): R1074-R1076. Buetow, D. 2016. 2014 Lake Monitoring Report: Mecklenburg County Water Quality Program, SWIM Phase I Part 2-CO Final Report for FY2014-2015. Charlotte -Mecklenburg Storm Water Services, Charlotte, North Carolina. Dobson, M., and C. Frid. 2009. Ecology of Aquatic Systems. 2nd ed. Oxford University Press Inc. New York, New York. Duke Energy. 1971. Drawing No. MC-1002-01.00, Rev 15. General Plan, Duke Energy, McGuire Nuclear Station - Units 1 & 2. 18. Huntersville, North Carolina. . 1975. Drawing No. MC-1003-01.00, Rev 14. Plot Plan, General Arrangement. Duke Energy, McGuire Nuclear Station Units 1 & 2. Huntersville, North Carolina. . 2001. Applicant's Environmental Report Operating License Renewal Stage. McGuire Nuclear Station. Huntersville, North Carolina. . 2005. Relationships of Fish Community Characteristics to Environmental Parameters in the Catawba-Wateree Reservoirs. Application for new license FERC No. 2232. Charlotte, North Carolina. . 2007. Catawba-Wateree Project FERC No. 2232, Application for New License, Exhibit E - Water Quantity, Quality, & Aquatic Resources. . 2008. McGuire Nuclear Station Calculation #MCC-1223.24-00-0101, Rev 3. 2009. NPDES Permit renewal application 2009. 2013. Oconee Nuclear Station 316(a) Demonstration Report. Oconee Nuclear Station: NPDES No. SC0000515. Huntersville, North Carolina. . 2014a. Lake Norman Maintenance Monitoring Program: 2012 Summary. McGuire Nuclear Station NPDES No. NC0024392. Huntersville, North Carolina. . 2014b. NPDES Permit Renewal Application 2014. . 2014c. Plant Systems: Standby Nuclear Service Water Pond, Technical Specification Bases 3.7.3, Revision No. 128. McGuire Units 1 and 2. 4 Nov 2014. . 2015. Lake Norman Maintenance Monitoring Program: 2013 Summary. McGuire Nuclear Station NPDES No. NC0024392. Huntersville, North Carolina. Duke Energy 1 270 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� References r . 2016a. McGuire Nuclear Station. Accessed 10/04/2016. [URL]: https://www.duke- energy.com/power-plants/nuclear/mcguire.asp. . 2016b. Cowans Ford Hydro Station. Accessed 10/06/2016. [URL]: https://www.duke - energy.com/power-plants/hydro/cowans-ford.asp. 2016c. Drawing MC-1330-01.00. Condenser Cooling Water Intake Discharge Low Level Intakes Pipe General Layout. Rev 14. Huntersville, North Carolina. . 2016d. Lake Norman Maintenance Monitoring Program: 2014 Summary. McGuire Nuclear Station NPDES Permit No. NC0024392. Huntersville, North Carolina. . 2016e. Lake Norman Maintenance Monitoring Program: 2015 Summary. McGuire Nuclear Station NPDES Permit No. NC0024392. Huntersville, North Carolina. . 2017a. Duke Energy spreadsheet dated October 15, 2017 with summer and winter generating unit capacity ratings. . 2017b. Lake Norman Maintenance Monitoring Program: 2016 Summary. McGuire Nuclear Station NPDES Permit No. NC0024392. Huntersville, North Carolina. <STILL IN DRAFT FORM> . 2018. Capacity Factors - Steam units - 2011-2016 - All Jurisdictions. Spreadsheet provided by N. Craig, January 2018. Duke Energy Progress. 2013a. H. B. Robinson Steam Electric Plant 2012 Environmental Monitoring Report. Raleigh, North Carolina. . 2013b. Roxboro Steam Electric Plant 2012 Environmental Monitoring Report. Raleigh, North Carolina. Duke Power. 2003. Fish Impingement at the McGuire Nuclear Station: December 2000-November 2002. Huntersville, North Carolina. Duke Power Company. 1961. Site `H' Intake Structure Concrete Outline Plan & Elevation. DWG No. CF-394, Rev 4. . 1974. Drawing No. MC-1330-2, Rev 2. Condenser Cooling Water Intake, Discharge, and Low Level Intake Pipes Profile and Hydraulic Gradients, Duke Power Company, McGuire Nuclear Station - Units 1 & 2. 21 Huntersville, North Carolina. 1978. McGuire Nuclear Station 316(b) Predictive Study of Impingement and Entrainment. Chapter I Summary and Conclusions. Charlotte, North Carolina. . 1987. NPDES Environmental Monitoring Program for Lake Norman. Duke Power Company. Charlotte, North Carolina. Ehrlich, K. F. 1974. Chemical changes during growth and starvation of herring larvae. Pages 301- 323 in J. H. S. Blaxter, editor. The early life history of fish. Springer-Verlag, New York. Electric Power Research Institute [EPRI]. 2000. Technical Evaluation of the Utility of Intake Approach Velocity as an Indicator of Potential Adverse Environmental Impct under Clean Water Act Section 316(b). 1000731. EPRI, Palo Alto, California. 2004. Using Computational Fluid Dynamics Techniques to Define the Hydraulic Zone of Influence of Cooling Water Intake Structure. 1005528. EPRI, Palo Alto, California. Duke Energy 1 271 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� References r . 2005. Parameter Development for Equivalent Adult and Production Foregone Models. Final Report, December 2005. 1008832. EPRI, Palo Alto, California. . 2007. Cooling Water Intake Structure Area -of -Influence Evaluations for Ohio River Ecological Research Program Facilities. 1015322. EPRI, Palo Alto, California. . 2008. The Role of Temperature and Nutritional Status in Impingement of Clupeid Fish Species. 1014020. EPRI, Palo Alto, California. . 2010a. McGuire Nuclear Station: 2006-2007 Impingement Study and Assessment of Adverse Environmental Impact. Palo Alto, California. . 2010b. Evaluation of Factors Affecting Juvenile and Larval Fish Survival in Fish Return Systems at Cooling Water Intakes. Technical Report 1021372. Palo Alto, CA. . 2011. Bioindicators of Performance and Impingement Susceptibility of Gizzard and Threadfin Shad. 1023101. EPRI, Palo Alto, California. Etnier, D.A., and W.C. Starnes. 1993. The Fishes of Tennessee. The University of Tennessee Press. Knoxville, Tennessee. Federal Energy Regulatory Commission (FERC). 2006. Comprehensive Relicensing Agreement for the Catawba-Wateree Hydro Project, FERC Project No. 2232. December 2006. . 2009. Final Environmental Impact Statement for Hydropower License, Catawba-Wateree Hydroelectric Project - FERC Project No. 2232, North Carolina and South Carolina. July 2009. Fuller, P., and M. Neilson. 2019. Dorosoma petenense (Gunther, 1867). United States Geological Survey Nonindigenous Aquatic Species Database, Gainesville, Florida. Accessed 04/05/2019. [URL]: https://nas.er.usgs.gov/queries/FactSheet.aspx?specieslD=493. Fuller, P., E. Maynard, J. Larson, A. Fusaro, T.H. Makled, and M. Neilson. 2019. Osmerus mordax (Mitchill, 1814): U.S. Geological Survey, Nonindigenous Aquatic Species Database. Gainesville, FL. Accessed 04/02/2019. [URL]: https://nas.er.usgs.gov/queries/factsheet.aspx?SpecieslD=796. Gebhart, G. E., and R.C. Summerfelt. 1978. Seasonal Growth of Fishes in Relation to Conditions of Lake Stratification. Oklahoma Cooperative Fishery Research Unit 58 (1978): 6-10. Oklahoma State University. Stillwater, Oklahoma. Golder Associates. 2005. Crystal River Energy Complex Proposal for Information Collection. NPDES Permit No. FL0000159. Prepared for Progress Energy. Green, W.R., Robertson, D.M., and F.D. Wilde. 2015. Chapter A 10: Lakes and Reservoirs: Guidelines for Study Design and Sampling, in: National Field Manual for the Collection of Water -Quality Data. U.S. Geological Survey, Virginia. Griffith, G., et al. 2002. Ecoregions of North Carolina and South Carolina (color poster with map, descriptive text, summary tables, and photographs). U.S. Geological Survey (map scale 1: 1,500,000). Reston, Virginia HDR. 2015. Site visit notes. McGuire Nuclear Station. Huntersville, North Carolina. 2019. 2016-2017 Entrainment Characterization Study Report. McGuire Nuclear Station. Huntersville, NC. Prepared for Duke Energy. Duke Energy 1 272 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� References r Hodson, R.G. 1989. Hybrid Striped Bass Biology and Life History. Southern Regional Aquaculture Center Publication No. 300. King, R.G., G. Seegert, J. Vondruska, E.S. Perry, and D.A. Dixon. 2010. Factors influencing impingement at 15 Ohio River power plants. North American Journal of Fisheries Management 30(5): 1149-1175. Leonard, P. M. and Orth, D. J. 1988. Use of habitat guilds of stream fishes to determine instream flow requirements. North American Journal of Fisheries Management 8(4): 399-409. Link -Belt Company. 2006. General Arrangement Model 45-A ID Water Screen for Duke Power Company Cowans Ford Dam, NC. Drawing Number CZ14439. Loar, J.M., J.S. Griffith, and K.D. Kumar. 1978. An analysis of factors influencing the impingement of threadfin shad at power plants in the southeastern United States. Pages 245-255 in L.D. Jensen, editor. Fourth national workshop on entrainment and impingement. EA Communications, Melville, New York. Lincoln Economic Development Association (LEDA). 2013. Lake Norman. Accessed 07/20/2017. [URL]: http://www.lincolneda.org/wp-content/uploads/2013/06/Lake-Normanl.pdf. Matthias, B.G., Allen, M.S., Ahrens, R.N.M., Beard, T.D., Jr., and J.A. Kerns. 2014. Hide and seek: interplay of fish and anglers influences spatial fisheries management. Fisheries 39: 261-269. May, R. C. 1974. Larval mortality in marine fishes and the critical period concept. Pages 3-19 in J. H.S. Blaxter, editor. The early life history of fish. Springer-Verlag, New York. Mehner, T. 2012. Diel vertical migration of freshwater fishes - proximate triggers, ultimate causes and research perspectives. Freshwater Biology 57: 1342-1359. Menhinick. E.F. 1991. The freshwater fishes of North Carolina. North Carolina Wildlife Resources Commission. Raleigh, North Carolina. Miller, T.J., Crowder, L.B., Rice, J.A., Marshall, E.A. 1988. Larval size and recruitment mechanisms in fishes: toward a conceptual framework. Canadian Journal of Fisheries and Aquatic Sciences 45:1657-1670. North Carolina Department of Environment and Natural Resources (NCDENR). 2016. Alphabetical List of NC Waterbodies — Catawba River Basin. North Carolina Department of Environmental Quality, Raleigh, North Carolina. North Carolina Division of Water Quality (NCDWQ). 2013. Lake and Reservoir Assessments Catawba River Basin. Raleigh, North Carolina. North Carolina Natural Heritage Program (NCNHP). 2018. Species/Community Search. Accessed 12/17/2018. http://www.ncnhp.org/data/species-community-search. (Topographic maps referenced: Lake Norman North and Lake Norman South, North Carolina) North Carolina Wildlife Resources Commission (NCWRC). 2008. Lake Norman Creel Survey 2006- 2007. North Carolina Wildlife Resources Commission. PowerPoint Presentation, Raleigh, North Carolina. National Marine Fisheries Service (NMFS). 2018. Essential Fish Habitat Mapper. Accessed 10/31/2018. [URL]: http://www.habitat.noaa.gov/protection/efh/efhmapper/index.html. Duke Energy 1 273 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� References r Page, L.M., and B.M Burr. 2011. Peterson Field guide to Freshwater Fishes of North American North of Mexico. Houghton Mifflin Harcourt, Boston, Massachusetts. 663 pp. Price, C. 2018. Are white perch a prized catch or destructive nuisance? Herald Citizen. Accessed 02/18/2019. [URL]: http://www.lakenormanpublications.com/herald_ citizen/are-white-perch- a-prized-catch-or-destructive-nuisance/article_2217eb82-7ed1-11 e8-8ff3- bf0a81 abe657.html. Rohde, F.C., Rudolf, G.A., Foltz, J.W., and J.M. Quattro. 2009. Freshwater Fishes of South Carolina. University of South Carolina Press, Columbia, South Carolina. Rohde, F.C., Rudolf, G.A., Lindquist, D.G., and J.F. Parnell. 1994. Freshwater Fishes of the Carolinas, Virginia, Maryland, and Delaware. The University of North Carolina Press, Chapel Hill, North Carolina. Stone, N. 2008. Forage Fish — Introduction and Species. Southern Regional Aquaculture Center SRAC Publication No. 140. United States Department of Agriculture. [URL]: http://www2.ca.uky.edu/wkrec/foragespecies.pdf. United States Fish and Wildlife Service [USFWS]. 1973. Endangered Species Act of 1973, As Amended through the 108th Congress. Department of the Interior. Washington, D.C. . 2002. Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for the Carolina Heelsplitter; Final Rule. 67 FR 44501-445252. Effective August 1, 2002. Accessed 03/29/2019. [URL]: https://www.federalregister.gov/documents/2002/07/02/02- 16580/endangered-and-threatened-wildlife-and-plants-designation-of-critical-habitat-for-the- Carolina. . 2015. Carolina Heelsplitter (Lasmigona decorata). Raleigh Ecological Services Field Office. Accessed 07/14/2017. [URL]:https://www.fws.gov/raleigh/species/es_carolina_heeIsplitter.html. . 2017. Carolina Heelsplitter. Charleston Ecological Services Field Office. Accessed 03/29/2019. [URL]: http://fws.gov/charlestone/heelsplitter.html. . 2018. Information for Planning and Consultation, Environmental Conservation Online System. Accessed: 10/26/ 2018. [URL]: https:Hecos.fws.gov/ipac/. United States Geological Survey [USGS]. 2017. StreamStats Development Version Alpha 4.1.3. Department of the Interior. Accessed 11/11/2017. [URL]: https:Hstreamstats.usgs.gov/ss/. United States Nuclear Regulatory Commission [USNRC]. 2002. Generic Environmental Impact Statement for License Renewal of Nuclear Plants Supplement 8 Regarding McGuire Nuclear Station, Units 1 and 2. Final Report NUREG-1437. Washington, D.C. . 2017a. McGuire Nuclear Station, Unit 1. [URL]: https://www.nrc.gov/info- finder/reactors/mcgl.html. . 2017b. McGuire Nuclear Station, Unit 2. [URL]: https://www.nrc.gov/info- finder/reactors/mcg2.html. . 2017c. Approved Applications for Power Uprates. [URL]: https://www.nrc.gov/reactors/operating/licensing/power-uprates/status-power-apps/approved- applications.html. Duke Energy 1 274 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� References r Wiegel, R.L., 1964. Oceanographic Engineering, Prentice -Hall, Inc. Englewood Cliffs, NJ. Duke Energy 1 275 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L� References r 14.3 Section 9 References Auer, N.A. (ed.). 1982. Identification of Larval Fishes of the Great Lakes Basin with Emphasis on the Lake Michigan Drainage. Great Lakes Fisheries Committee Special Publication 82-3, Ann Arbor, MI. 744 pp. Duke Energy. 2017. Lake Norman Maintenance Monitoring Program: 2016 Summary. McGuire Nuclear Station NPDES Permit No. NC0024392. Huntersville, NC. . 2018. Condenser Cooling Water Flows at the Low Level Intake (LLI) during the period from January 1, 2015 through December 31, 2017 at McGuire Nuclear Station. Data provided by Duke Energy. January 2018. Electric Power Research Institute (EPRI). 2011. Seasonal Patterns of Fish Entrainment for Regional U.S. Electric Generating Facilities. Technical Update, December 2011. DCN 10-23102. . 2012. Fish Life History Parameter Values for Equivalent Adult and Production Foregone Models: Comprehensive Update. Final Report 1023103. Palo Alto, CA. . 2016. Larval Fish and Egg Keys. Accessed 9/2/2016. http://www.larvalfishid.com/home.html. Etnier, D.A., and W.C. Starnes. 1993. The Fishes of Tennessee. The University of Tennessee Press. Knoxville, TN. HDR Engineering, Inc. (HDR). 2016. McGuire Nuclear Station Entrainment Characterization Study Plan. September 2, 2016. Prepared for Duke Energy. . 2019. 2016-2017 Entrainment Characterization Study Report. McGuire Nuclear Station. Huntersville, NC. Prepared for Duke Energy. Hendrickson, Dean A., and Adam E. Cohen. 2015. Fishes of Texas Project Database (Version 2.0) doi: 10. 1 7603/C3WC70. Kay, L.K., R. Wallus, and B.L. Yeager. 1994. Reproductive Biology and Early Life History of Fishes in the Ohio Drainage. Volume 2: Catostomidae. Tennessee Valley Authority, Chattanooga, TN. Mehner. 2012. Diel Vertical Migration of Freshwater Fishes — Proximate Triggers, Ultimate Causes and Research Perspectives. Freshwater Biology, 57, 1342-1359. Normandeau Associates, Inc. (NAI). 2017. Quality Assurance Plan and Standard Operating Procedures for Entrainment Sampling at McGuire Nuclear Station, Huntersville, North Carolina. Rev 3 R-23415.0041. Charlotte, NC. Rohde, F.C., Arndt, R.G., Foltz, J.W., and J.M. Quattro. 2009. Freshwater Fishes of South Carolina. University of South Carolina Press, Columbia, South Carolina. Simon, T.P. and R. Wallus. 2004. Reproductive Biology and Early Life History of Fishes in the Ohio River Drainage, Volume 3: Ictaluridae — Catfish and Madtoms. CRC Press. 204 pp. Stone, N. 2008. Forage Fish — Introduction and Species. Southern Regional Aquaculture Center SRAC Publication No. 140. United States Department of Agriculture. [URL]: http://www2.ca.uky.edu/wkrec/foragespecies.pdf. Duke Energy 1 276 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal L�� References r Wallus, R., B.L. Yeager, and T.P. Simon. 1990. Reproductive Biology of Early Life History Fishes in the Ohio River Drainage, Volume 1: Acipenseridae through Esocidae. Tennessee Valley Authority, Chattanooga, TN. 273 pp. Duke Energy 1 277 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal References 14.4 Section 10 References AACE International (AACE). 2016. AACE International Recommended Practice No. 18R-97. Cost Estimate Classification System - As Applied in Engineering, Procurement, and Construction for the Process Industries. TCM Framework: 7.3 - Cost Estimating and Budgeting. Rev. March 1, 2016. Bingham, M.F., Z. Li, K.E. Mathews, C. Spagnardi, J. Whaley, S. Veale, and J. Kinnell. 2011. An Application of Behavioral Modeling to Characterize Urban Angling Decisions and Values. North American Journal of Fisheries Management 31:257-268. Amec Foster Wheeler (AMEC). 2013. Report of Geotechnical Services, FLEX Storage Project, AMEC Project No. 6234-13-0089. . 2014. McGuire Nuclear Station Floodplain Map, prepared for Duke Energy as a part of the Amec Foster Wheeler Project No. 6480-15-5119 dated December 29, 2015. . 2015. McGuire Nuclear Station Wetlands Inventory per US Fish and Wildlife, prepared for Duke Energy as a part of the Amec Foster Wheeler Project No. 6480-15-5119 dated December 29, 2015. Charlotte Observer. 2015. Outage causes spill at McDowell Creek treatment plant. Accessed August 2016. [URL]: http://www.charlotteobserver.com/news/local/article22695207.html. Crance, J. H. 1984. Habitat Suitability Index Models and Instream Flow Suitability Curves: Inland Stocks of Striped Bass. U.S. Fish and Wildlife Service FWS/OBS-82/10.85. 63 pp. CTI. 2003. Why every air cooled steam condenser needs a cooling tower, prepared by Luc de Backer, William M. Wartz and Hamon Dry Cooling. Technical Paper 03-01. . 2010. Plume Abatement - The Next Generation. Prepared by Lindahl, Paul; Mortensen, Ken; and SPX Cooling Technologies. Technical Paper: TP10-09. Presented at the 2010 Cooling Tower Institute Annual Conference, 7-11 Feb 2010. Duke Energy. 2001. Applicant's Environmental Report Operating License Renewal Stage. McGuire Nuclear Station. June 2001. 2008. McGuire Nuclear Station Calculation #MCC-1223.24-00-0101, Rev 3. 2009. NPDES Permit renewal application 2009. 2012a. Drawing No. MC-1330-07.00, Rev. 11. Condenser Cooling Water Low Level Intake Pipes Pumps to Intake Structure Layout and Details. McGuire Nuclear Station - Units 1 & 2. 14 Aug 2012. 2012b. McGuire Nuclear Station Units 1&2 Condenser Cooling Water, Intake, Discharge and Low Level Intake Pipes General Layout. Drawing No. MC-1330-01.00, Rev. 13. 2014a. NPDES Permit renewal application 2014. 2014b. McGuire Nuclear Station - Unit 1 &2 General Plan. Drawing No. MC-1002-01.00. Rev 15. . 2015a. Drawing No. MC-1330-03.00, Rev 19. Condenser Cooling Water Unit 1 Intake Pipes Layout and Details. McGuire Nuclear Station. 2 Feb 2015. Duke Energy 1 278 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal References . 2015b. Drawing No. MC-1330-05.00, Rev 15. Condenser Cooling Water Discharge Pipes Layout and Details. McGuire Nuclear Station. 2 Feb 2015. . 2015c. Updated Final Safety Analysis Report, Chapter 2. McGuire Nuclear Station. 09 Oct 2015. . 2015d. Lake Norman Maintenance Monitoring Program 2013 Summary. McGuire Nuclear Station: NPDES No. NC0024392. Huntersville, North Carolina .2017. Lake Norman Maintenance Monitoring Program: 2016 Summary DRAFT. McGuire Nuclear Station NPDES Permit No. NC0024392. Huntersville, North Carolina. . 2019. Electronic correspondence from Duke Energy dated July 3, 2019. Duke Power Company. 1971 a. Condenser Cooling Water Pipe System. Specification MCS-1151.00- 1, April 30, 1971. 1971 b. Surface Condenser Equipment for the Main Turbine. Specification MCS-1202.00, July 15, 1971, Addendum #1. . 1974. Drawing No. MC-1330-2, Rev 2. Condenser Cooling Water Intake, Discharge, and Low Level Intake Pipes Profile and Hydraulic Gradients, Duke Power Company, McGuire Nuclear Station - Units 1 & 2. 21 Jan 1974. Electric Power Research Institute (EPRI). 2002. Comparison of Alternate Cooling Technologies for California Power Plants: Economics, Environmental and Other Tradeoffs. Prepared by John Maulbetsch for EPRI and California Energy Commission. . 2007. Issues Analysis of Retrofitting Once -through Cooled Plants with Closed -Cycle Cooling: California Coastal Plants. Technical Report No. 052907. Final Report. Palo Alto, CA, October 2007. . 2011. Net Environmental and Social Effects of Retrofitting Power Plants with Once -Through Cooling to Closed -Cycle Cooling. 2011 Technical Report. No. 1022760, Final Report. Palo Alto, CA, Jul 2011. Enexio. 2016. Classic ACC. September 2016. Accessed May 2017. [URL]: http://www.enexio.com/products/dry-cooling-systems/air-cooled-condensers/classic-air- cooled-condenser/. Evoqua Water Technologies. 2016. Intake Traveling Water Screens, at http://www.evoqua.com/en/brands/intake-screens/Pages/Traveling-Water-Screens.aspx viewed in December 2016. . 2017. Evoqua Water Technologies Budget Proposal File No. 45032 dated 21 April 2017. HDR. 2015. Site visit notes. Intake Screens, Inc. (ISI). 2016. Brush -cleaned wedgewire intake screens for fish protection and filtration. Accessed December 2016. [URL]: http://intakescreensinc.com. Lincoln County. 2012. Minutes, Lincoln County Board of Commissioners. 20 Feb 2012. . 2016. Lincoln County Sewer System - Killian Creek WWTP, Annual Performance Report, January 01, 2015 thru December 31, 2015. 10 Feb 2016. Duke Energy 1 279 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal References Lindeburg, Michael, R., 2003. Environmental Engineering Reference Manual for PE Exam, Second Edition. Professional Publications, Inc. Link -Belt Company. 2006. General Arrangement Model 45-A ID Water Screen for Duke Power Company Cowans Ford Dam, NC. Drawing Number CZ14439. Maulbetsch, J., and Stallings, J. 2012. Evaluating the Economics of Alternative Cooling Technologies, published in Power Engineering on November 1, 2012. Mecklenburg Union Metropolitan Planning Organization (MUMPO). 2011. Northwest Huntersville Transportation Study. Preliminary Study Corridor Alignment of Highway 73 Widening Project. 16 Nov 2011. National Resources Conservation Service (NRCS). 2016. Wind Rose Resources: What is a wind rose? Accessed 10/13/2016. [URL]: http://www.wcc.nres.usda.gov/climate/windrose.html. North Carolina Department of Environmental Quality (NCDEQ). 2015. Division of Water Resources, Public Water Supply System, Public Supply Water Sources. North Carolina Rural Economic Development Center (NCREDC). 2000. Sewer Treatment Plants. Ovivo. 2014. Specification for a Fish Handling Thru Flow Band Screen, B114-079R0. Pardue, G.B. 1983. Habitat Suitability Index Models: Alewife and Blueback Herring. U.S. Department of the Interior, U.S. Fish and Wildlife Service FWSjOBS-82/10.58. 22 pp. Reutter, J.M. and C.E. Herdendorf. 1976. Thermal Discharge from a Nuclear Power Plant: Predicted Effects on Lake Erie Fish. The Ohio Journal of Science 76(1): 39-45. SPX Cooling Technologies, Inc. (SPX). 2009. Cooling Tower Fundamentals, Second Edition. . 2016a. Cooling Tower Performance, Basic Theory and Practice. Sep 2016. 2016b. Electronic correspondence from SPX to HDR. 01 Sep 2016. 2016c. Marley PPWD Hybrid Plume Abatement, at http://spxcooling.com/products/hybrid- cell-type-cooling-tower, viewed November 2016. United Stated Department of Energy (USDOE). 2016. Best Management Practices #10: Cooling Tower Management. Accessed 10/18/ 2016. [URL]: http://energy.gov/eere/femp/best- management-practice-10-cooling-tower-management. United States Environmental Protection Agency (USEPA). 2010. Guidelines for Preparing Economic Analyses. Report Number EPA 240-R-10-001. Washington, DC: U.S. EPA. Accessed 6/19/2013. [URL]: http://yosemite.epa.gov/ee/epa/eerm.nsf/vwAN/EE-0568-50.pdf/$file/EE- 0568-50. pdf. . 2013. EPA Federal Registry: Wastewater Treatment Plants, National Pollutant Discharge Elimination System. . 2014. Technical Development Document for the Final Section 316(b) Existing Facilities Rule. EPA-821-R-14-002. May 2014. . 2016a. Detailed Facility Report, Forney Creek WWTP. Accessed 9/26/2016. [URL]: https://echo.epa.gov/detailed-facility-report?fid=l 10064226760&sys=1CP. Duke Energy 1 280 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal References . 2016b. Detailed Facility Report, McDowell Creek WWTP. Accessed 9/26/2016. [URL]: https://echo.epa.gov/detailed-facility-report?fid=l 10009716995 US Filter Corporation (US Filter). 2016. Communication between US Filter staff and HDR staff. U.S. Nuclear Regulatory Commission (USNRC). 2002. Generic Environmental Impact Statement for License Renewal of Nuclear Plants Supplement 8 Regarding McGuire Nuclear Station, Units 1 and 2 Final Report. Veritas Economic Consulting (Veritas). 2018. Social Costs of Purchasing and Installing Entrainment Reduction Technologies: McGuire Nuclear Station. Prepared for Duke Energy Carolinas, LLC. Veritas Economic Consulting, Cary, NC. August 2018. Williamson, K. L., and P. C. Nelson. 1985. Habitat Suitability Index Models and Instream Flow Suitability Curves: Gizzard Shad. U.S. Fish Wildlife Service Biological Report 82(10.112). 33 PP. World Meteorological Organization (WMO). (2016). Charlotte Douglas International Airport, WMO No. 723140. Accessed 8/5/ 2016. [URL]: http://wwwl .ncdc.noaa.gov/pub/data/EngineeringWeatherData_CDROM/engwx/. Duke Energy 1 281 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal References 14.5 Section 11 References Burns, T.P. 1989. Lindeman's Contradiction and the Trophic Structure of Ecosystems. Ecology 70(5): 1355-1362. Bingham, M.F., Z. Li, K.E. Mathews, C. Spagnardi, J. Whaley, S. Veale, and J. Kinnell. 2011. An Application of Behavioral Modeling to Characterize Urban Angling Decisions and Values. North American Journal of Fisheries Management 31:257-268. Caswell, H. 2001. Matrix Population Models. Construction, Analysis, and Interpretation, 2nd Edition. Sunderland, MA: Sinauer. Crance, J.H. 1984. Habitat Suitability Index Models and Instream Flow Suitability Curves: Inland Stocks of Striped Bass. U.S. Fish and Wildlife Service. FWS/OBS-82/10.85. 63 pp. Duke Energy. 2017. Lake Norman Maintenance Monitoring Program 2016 Summary DRAFT. McGuire Nuclear Station: NPDES Permit No. NC0024392. Huntersville, NC. . 2018. Lake Norman Maintenance Monitoring Program 2017 Summary DRAFT. McGuire Nuclear Station: NPDES Permit No. NC0024392. Huntersville, NC. Duke Power. 2003. Fish Impingement at the McGuire Nuclear Station: December 2000-November 2002. Huntersville, North Carolina. Electric Power Research Institute (EPRI). 2003. Evaluating the Effects of Power Plant Operations on Aquatic Communities. Final Report 1007821. Palo Alto, CA. 2004a. Extrapolating Impingement and Entrainment Losses to Equivalent Adults and Production Foregone. Technical Report 1008471. Palo Alto, CA. 2004b. Chapter 1. Traveling Water Screens. 1011546. Palo Alto, CA. 2005. Parameter Development for Equivalent Adult and Production Foregone Models. Final Report 1008832. December 2005. Palo Alto, CA. 2006. Laboratory Evaluation of Modified Ristroph Traveling Screens for Protecting Fish at Cooling Water Intakes. Final Report 1013238. Palo Alto, CA. 2010a. Evaluation of Factors Affecting Juvenile and Larval Fish Survival in Fish Return Systems at Cooling Water Intakes. Technical Report 1021372. Palo Alto, CA. 2010b. Laboratory Evaluation of Fine -Mesh traveling Water Screens. Final Report 1019027. Palo Alto, CA. 2010c. McGuire Nuclear Station: 2006-2007 Impingement Study and Assessment of Adverse Environmental Impact. Palo Alto, California. 2012. Fish Life History Parameter Values for Equivalent Adult and Production Foregone Models: Comprehensive Update. Technical Report 1023103. Palo Alto, CA. Duke Energy 1 282 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal References 2013. Engineering and Biological Assessment of Fine Mesh Fish Protection -Modified Traveling Water Screens. Technical Update 3002001104. Palo Alto, CA. Freeman, A. Myrick, III. 2003. The Measurement of Environmental and Resource Values: Theory and Methods, Second Edition. Washington, DC: Resources for the Future, Inc. Freeman, A. Myrick, III, Joseph A. Herriges, and Catherine L. Kling. 2014. The Measurement of Environmental and Resource Values: Theory and Methods. Third Edition. Washington, DC: Resources for the Future, Inc. Froese, R. and D. Pauly, Editors. 2018. FishBase. World Wide Web electronic publication. www.fishbase.org, version (10/2018). Goodyear, C. Phillip. 1984. Entrainment Impact Estimates using the Equivalent Adult Approach. Rep. FWS/OBS-78/65. U.S. Department of the Interior, U.S. Fish and Wildlife Services. Green, W.R., Robertson, D.M., and F.D. Wilde. 2015. Chapter A 10: Lakes and Reservoirs: Guidelines for Study Design and Sampling, in: National Field Manual for the Collection of Water -Quality Data. U.S. Geological Survey and U.S. Department of the Interior. Krutilla, John V. 1967. Conservation Reconsidered. American Economic Review 57(4):777-786. Leslie, P.H. 1945. On the Use of Matrices in Certain Population Mathematics. Biometrika 33:183- 212. . 1948. Some Further Notes on the Use of Matrices in Population Mathematics. Biometrika 35:213-245. North Carolina Wildlife Resources Commission (NCWRC). 2008. Lake Norman Creel Survey 2006- 2007. North Carolina Wildlife Resources Commission. PowerPoint Presentation, Raleigh, NC. 2017. Black Bass Population Characteristics in Lake Norma, North Carolina After the Introduction of Alabama Bass. North Carolina Wildlife Resources Commission. Fisheries Research Fact Sheet. August 2017. Turnage, Sheila. 2009. Compass American Guide: North Carolina. New York: Random House Inc. U.S. Environmental Protection Agency (USEPA). 2006. Regional Benefits Analysis for the Final Section 316(b) Phase III Existing Facilities Rule. EPA-821-R-04-007. Washington, DC: U.S. Environmental Protection Agency. . 2010. Guidelines for Preparing Economic Analyses. Report Number EPA 240-R-10-001. Washington, DC: U.S. EPA. Accessed 6/9/2013. [URL]: http://yosemite.epa.gov/ee/epa/eerm.nsf/vwAN/EE-0568- . 2014. National Pollutant Discharge Elimination System —Final Regulations to Establish Requirements for Cooling Water Intake Structures at Existing Facilities and Amend Requirements at Phase I Facilities, 79 FR 48299. 15 Aug 2014. Duke Energy 1 283 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal References U.S. Ocean Commission. 2002. Developing a National Ocean Policy: Mid-term Report of the U.S. Commission on Ocean Policy. [URL]: http://govinfo.library.unt.edu/oceancommission/documents/midterm_report/midterm_report.ht ml Veritas Economic Consulting (Veritas). 2012. The Role of Knowledge in Assessing Nonuse Values for Site -Specific 316(b) Determination: Results and Implications from the National Environmental Impacts Awareness Survey. Accessed 5/3/2017. http://www.veritaseconomics.com/pubIications.asp?p=3. . 2018. Entrainment Reduction Benefits Valuation Study: McGuire Nuclear Station. Prepared for Duke Energy Carolinas, LLC. Veritas Economic Consulting, Cary, NC. August 2018. Duke Energy 1 284 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal References 14.6 Section 12 References Bradley Associates. 2017. Benchmarking Air Emissions of the 100 Largest Electric Power Producers in the United States. Duke Energy 2016 emissions rate from fossil -fueled plants. Cowan, James P. 1994. Handbook of Environmental Acoustics, Van Nostrand Reinhold, New York. Duke Energy. 2009. NPDES Permit renewal application 2009. . 2014a. Plant Systems: Standby Nuclear Service Water Pond, Technical Specification Bases 3.7.3, Revision No. 128. McGuire Units 1 and 2. 4 November 2014. 2014b. NPDES Permit renewal application 2014. 2015a. Lake Norman Maintenance Monitoring Program 2013 Summary. McGuire Nuclear Station: NPDES No. NC0024392. . 2015b. Updated Final Safety Analysis Report, Chapter 2. McGuire Nuclear Station. 09 Oct 2015. . 2017. Duke Energy spreadsheet on Consumptive use of water for McGuire for 2014, 2015, 2016. April 17, 2017. Duke Power Company. 1974. Drawing No. MC-1330-2, Rev 2. Condenser Cooling Water Intake, Discharge, and Low Level Intake Pipes Profile and Hydraulic Gradients, Duke Power Company, McGuire Nuclear Station - Units 1 & 2. 21 Jan 1974. Electric Power Research Institute (EPRI). 2011 a. Net Environmental and Social Effects of Retrofitting Power Plants with Once -Through Cooling to Closed -Cycle Cooling. EPRI, Palo Alto, CA: 2010. Technical Report 1022760. . 2011 b. Closed -cycle Retrofit Study. EPRI, Palo Alto, CA: 2011. Technical Report 1022491. Energy Information Administration (EIA). 2016. How much electricity does an American home use? Accessed November 2016. https://www.eia.gov/tools/faqs/faq.cfm?id=97&t=3. Mecklenburg County. 2016a. Polaris 3G Map - Mecklenburg County, North Carolina. Accessed 11/11/2016. 2016b. Noise Ordinance, Accessed November 2016. [URL]: http://charmeck.org/mecklenburg/county/countymanagersoffice/bocc/ordinances/noise.pdf. . 2017. Polaris 3G Map - Mecklenburg County, North Carolina. Accessed 6/7/2017. Power Engineering. 2009. Plume Abatement. Issue 11, Volume 113. Accessed 11/10/2016. [URL]: http://www.power-eng.com/articles/print/volume-1 13/issue-1 1/departments/what- works/plume-abatement.html. Lindeburg, Michael, R., 2003. Environmental Engineering Reference Manual for PE Exam, Second Edition. Professional Publications, Inc. SPX Cooling Technologies, Inc. (SPX). 2009. Cooling Tower Fundamentals, Second Edition. 2012. F400 ClearSky Cooling Tower, Operation - Maintenance. Document No.: M2012- 1248. Jun 2012. 2016a. ClearSky Plume Abatement System. Document No.: CLEARSKY-09A. Aug 2016. Duke Energy 1 285 Duke Energy Corporation I McGuire Nuclear Station CWA §316(b) Compliance Submittal References . 2016b. Communication between SPX and HDR staff. 17 Oct 2016. 2017. Marley TU12 Eliminator Drift Droplet Distribution. United States Bureau of the Census (U.S. Census). 2014. American Community Survey 5 Year Block Group Geodatabase. United States Department of Energy (USDOE). 2002. Energy Penalty Analysis of Possible Cooling Water Intake Structure Requirements on Existing Coal Fired Power Plants. United States Environmental Protection Agency (USEPA). 1974. EPA Identifies Noise Levels Affecting Health and Welfare. EPA Press Release -April 2, 1974. Accessed 10/19/2016. [URL]: https://archive.epa.gov/epa/aboutepa/epa-identifies-noise-levels-affecting-health-and- welfare. html. . 2014. Technical Development Document for the Final Section 316(b) Existing Facilities Rule. EPA-821-R-14-002. May 2014. . 2017. North Carolina Non attainment/Maintenance Status for Each County by Year for All Criteria Pollutants. Accessed 8/17/2017. [URL]:https://www3.epa.gov/airquality/greenbook/anayo_nc.html. . 2018. Clean Air Act Title IV Noise Pollution - Clean Air Act Overview. [URL]: https://www.epa.gov/clean-air-act-overview/clean-air-act-title-iv-noise-pollution. United States Nuclear Regulatory Commission (USNRC). 1996. Generic Environmental Impact Statement for License Renewal of Nuclear Plants. NUREG-1437 Vol. 1. [URL]: http://www. nrc.gov/reading-rm/doc-collections/nuregs/staff/srl437/ 1997. Regulatory Guide 5.44: Perimeter Intrusion Alarm Systems. Office of Nuclear Regulatory Research. Revision 3, October 1997. . 2016a. Design -basis accident. Accessed 11/8/2016. [URL]: http://www.nrc.gov/reading- rm/basic-ref/glossary/design-basis-accident.html. . 2016b. Safety -related. Accessed 11/8/2016. [URL]: http://www.nrc.gov/reading-rm/basic- ref/glossary/safety-related. html Veritas Economic Consulting (Veritas). 2018. Social Costs of Purchasing and Installing Entrainment Reduction Technologies: McGuire Nuclear Station. Prepared for Duke Energy Carolinas, LLC. Veritas Economic Consulting, Cary, NC. August 2018. Walton, J. R., Johnson, J.B, and Wood, G.C. 1982. Atmospheric Corrosion Initiation by Sulfur Dioxide and Particulate Matter: II. Characterisation and corrosivity of individual particulate atmospheric pollutants. British Corrosion Journal. Weather Underground. 2016. Weather History for KCLT between January 1994 and November 2016. Charlotte -Douglas International. Accessed 11/11/2016. World Meteorological Organization (WMO). 2016. Charlotte Douglas International Airport, WMO No. 723140. Accessed 8/5/2016. [URL]: https://www1.ncdc.noaa.gov/pub/data/EngineeringWeatherData_CDROM/engwx/. Duke Energy 1 286