HomeMy WebLinkAboutNC0039586_Amendment to Permit Application_19910513- -
a i�f- - 1`r 4
Carolina «oyver & 'light Company
MAY 1 3 1991
Mr. Dale Overcash, P.E.
N.C. Division of Environmental Management ;
P.O. Box 27687
Raleigh, N.C. 27611-7687
RE: Shearon Harris Nuclear Power Plant
NPDES Permit No. NCO039586
Amendment to Permit Application
Dear Mr. Overcash:
On September 27, 1990, Carolina Power & Light Company (CP&L)
submitted a request for the Shearon Harris Nuclear Power Plant
(SHNPP) permit to be renewed. ..Currently, the existing permit and
permit renewal application only address hydrazine discharges
through low volume waste. Because of changing plant conditions
since submittal of the application, wastewater containing hydrazine
may occasionally need to be discharged through the radwaste system,
as well as the low-volume waste system. Therefore, this is
intended to amend the application to reflect this additional source
of hydrazine discharge.
Additionally, CP&L is respectfully requesting modifications to
the current hydrazine discharge period and the notification
requirements. A description of the alternate routing of hydrazine
and the requested permit changes are included in the enclosure.
Thank you for your cooperation. Should you have any questions
or require further information, please call Mr. Cam Wheeler at
546-6725 or Ms. Barbara Stephens at 546-7777.
Yours very truly,
George J. Oliver, Ph.D.
Manager
Environmental Services
Enclosure
cc: Mr. A. Mouberry, Raleigh Regional Office, DEM
411 Fayetteville Street e P. O. Box 1551 Raleigh, N. C. 27602
AMENDMENT TO SHEARON HARRIS NUCLEAR-POWER.PLANT
NPDES PERMIT APPLICATION
CHANGES IN PLANT OPERATION - HYDRAZINE DISCHARGES
The present NPDES permit allows for low volume wastes to be
routed to either of two systems, the low-volume waste system
(Serial No. 004) for non -radioactive wastes or the radwaste system
(Serial No. 005) for radioactive wastes. (Flow diagrams submitted
previously to the Division of Environmental Management (DEM)
indicate both of these flow paths.) One component of low volume
waste is secondary waste, which. consists of water from the
secondary cooling system (the normally non -contaminated steam
component in this nuclear power plant). The secondary cooling
system contains hydrazine as an oxygen scavenger for corrosion
control.
The "Summary Description of Hydrazine Wastes" submitted to DEM
in February of 1989 stated that "all wastes that might contain
hydrazine flow via plant drains to the low volume waste treatment
system." This statement is no longer valid. Within the past year,
there has been an occurrence of a steam. generator (primary system)
tube leak, causing the secondary, waste to become radioactively
contaminated for a brief period. During this incident, secondary
waste was routed to the radwaste system (Serial No. 005) for
treatment rather than through the low-volume waste system (Serial
No. 004). The plant promptly corrected the leaks, treated the
contaminated wastewater, and resumed the routing of secondary waste
to the regular low volume waste treatment system. Such incidents
,are expected to occur infrequently.
REQUEST FOR PERMIT MODIFICATIONS OF HYDRAZINE REQUIREMENTS.
CP&L requests two changes to_ the current hydrazine
requirements:
1. RELEASE PERIOD
The permit currently allows the discharge of hydrazine at
a concentration above 60 Ag/1 and no greater than 2 mg/1
for a- period of no more than 24'hours. It is requested
that this be changed from 'a 24-hour to a 48-hour total
period. The additional.time is needed primarily due to
the. extra time required to treat and release water
through the radwaste system, in the event that secondary
waste is' routed through this system. Following wet
layup, if the steam generators contained radioactivity,
the water would be drained from the generators and batch -
treated for removal of radioactivity. Only 25,000
II4VV
gallons can be treated at the time in the radwaste tanks,
and the 'discharge rate from radwaste, based on NRC
requirements, is limited to 34-90 gpm according to the
activity level. A minimum of six hours processing time
is needed between releases.
Normally, secondary -waste containing hydrazine is routed
through low volume waste rather than radwaste. Normal
low volume wastes typically can be released in a 24-hour.
total period; however, there could be instances in which
a longer time may be needed.
2. NOTIFICATION PERIOD
The current permit.requires that CP&L "shall notify the
DEM Raleigh Regional Office at least one week prior to
the conclusion of any wet layup-periodand shall specify
if there will be a 24 hour period in, which hydrazine will
be.discharged at a level greater than 60.0 gg/1." CP&L
requests that. the notification requirement be- dropped.
This change is requested because it would be impractical
to provide prior notification since hydrazine -containing
equipment may be needed at a moment's notice during
normal plant operation and since plant outage schedules
are often subject to change.
Alternatively,- the permit could be changed to require
notification within one working day after a release of
hydrazine at a concentration exceeding 60 µg/1.
Per recent conversation between Mr. Tim Donnelly of
DEM's Raleigh Regional Office and Mr. Cam Wheeler of
CP&L, it is our understanding that this notification is
not necessary.
2
K�
t.;,+ , ��