ML20004C232
| ML20004C232 | |
| Person / Time | |
|---|---|
| Site: | Nine Mile Point  |
| Issue date: | 05/22/1981 |
| From: | Lempges T NIAGARA MOHAWK POWER CORP. |
| To: | Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| References | |
| IEB-81-03, IEB-81-3, NUDOCS 8106020369 | |
| Download: ML20004C232 (3) | |
Text
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NINE MILE P'MNT NUCLEAR STATION /P.O. BOX 32 LYCOMING, NEW YORK 13093 / TELEPHONE (315) 343-2110 May 2 2, 1981 e
A
%t. Boyce H. Grier, Ditector b
pf 1
A1 Uni.ted States Nucleat Reguistory Commission hU T Region I N u,Jfjy 0 119g 9
631 Pa.tk Avenue King of Prussia, PA.
19406 p'
wal%e,,o.,
a RE: Docket No. 50-220
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I.E.Bulletin 81-03 s
-.i Dea,1 St. Grier:
The following response concerns I.E. Buttexin 81-03, " Flow Blockage of Cooling Water to Safety System Components by Corbicula sp. (Asiatic Ciam) and Mytitus sp. (Masset)".
Respanse to Ltem #1
' Inspections fat de presence of Corbicula sp. were undertaken in de
- source cooling wu.ter for Nine blite Point Unit 41.
Mutilus sp. was not
.teviewed since tJtis genus is associated with satt water environments.
An ecological consulting firm aus hited by Niagara Mohawk to perform an ecological assessment as to de ptesence of Corbicula sp.
This assessment entailed ben.thic surveys to de cast and west af the Site, near the intet situctuates, near de discharge sttactures and in de inte,t forebay of Unit #1.
Results ctd,icate.that Corbicula sp. does not pase a biofouting ptoblem.
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Atuough further action was not requited pursuant.to de findings j
of the above investigation, sevenal other station inspections were made l
as follows.
The debris from he intet canal stavelling screens and service 1
attter filteu were inspected by biological consulting petsonnel on l
thirty-four (34), boenty-fou,t (24) hour samples from January 1 f.o l
May 10, 1981. As pa,tt of a,tegula,t inspection 'ptogram, de pump sttaineu l
of various safety reia.ted systems were checked behoeen httch 11 and
%Dtch 14, 1981. These systems included: emergency senvice an.ter, dieset generator cooling, raw wa.ter conta.u1 ment spray, and elechtic and diesel driven fite pump sttainers were inspected.
In conjunction, condenser wa.ter box inspections were made by station environmental peuannel on April 4, 1981.
The results of ptevious Aquatic Ecology Studies Reponts for Nine blite Point Unic W1 wete reviewed and inspection of de bendic survey data (species 1
inventory) was made fan de years 1973-1978.
No evidence of Corbicula sp. was noted in any of uese inspections Gy or surveys.
\\ 'No i
h 810602 0369 1
b Page 8 T.E. Su d etin 81-03 Response to 1. tem n2 and Item *3 Not applicable..
Response to I. tem d4 Presently, tJte station's fLte protection sydem, safety systems, service water syMem, and main condenset cooling syt.tems ate inspeeted on a periodic bash. The results of dese inspections would indica.tc whether debris or organ, isms, such as Corbienfa sp. a.te present in.the source cooling water or hplant cooling Kktems that would effeet tJte design ope.1ating cri.teria.
The fhe ptotection syaem is checked for pump operability and de change in pressure across the pump sttainers (dischar3e side of de pumps) on a weekly basis. The sttainers are visually inspe.eted every.tefueling outage.
If Corbienta sp. utts in he cooling water source, insteases in the sttainer a? would be noted fattowed by inspection and cleaning of.the strainers.
The presence of clam shetts k the sttainen would alert station penannel to de possible presence of Corbicula sp.
Safety related systans, such as de emergency service mier and raw water containment sptay syaems ste inspected quarterly for adequate flaw.
Pump sttainen reta.ted to.these various sys.tems are inspected during every refaeLing outage. The diesel generator cooling sgaens are opetated h conjunction with tJte monthly 1-hour diesel generator surveillance and de associated pmp sttainers are checked every refueling outage.
The presence of Corbicula sp. in dese safety systems would significantty reduce tJte ftow through such systems, and would cause mot.or or diesel overheating, detefore, prompting an investigation.
In addition, during pump strainst inspections, de ptesence of mollusk shetts would. alert Mation peMonnet to possible infestations by Corbicula sp.
Flow from tJte main circula. ting water pumps and service mter pumps is checked frequen. tty.
Records are kept by station personnel of daily flow
.tates for de citev9ating and service wa. tea pumps. A significant reduction l
h flow.tates (as 25% for example), would be brough.t to de attention of supervbory operations peMaanet. An investigation would follow.
In l
ndditinn, seteenings from ne intake f.unnets (3/8 inch mesh Ltavetting l
ssteens) and from the service wa.tet sys. tem (Adams Sttainers) empty into kJte fish collection basket. The collection h~.sket is put in a sampling position on a. regular frequency (78 days per yest) for scenty-four (24) hou.t time intervals by ecological consultant penannel.
Fish, as well as l
hvent<kra.tes (as mattusks), a.te identified.
The presence of Corbicula sp.
l in de cooling wa.ter source would be indicated by de sheus af these mollusks in samples.taken from tJte cooling mter ssteenings via tJ1e fish collection basket.
(
Finaug, during st.ation shutdowns lasting more.than five (5) days, main condenser inspections are usually made by st.a. tion envitonmental l
peMonnel when.the wa.ter boxes are drained and opened.
The presence of Corbicula sp. would be indicated by the growtJt of dese mollusks on tJte
[
htet side of.the main wa.ter boxes. Station suptruisory pensonnel would
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kmediately be notified.
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Page 3 I.E. R"ffeth 8 7-03 Respanse to item *4 (codinued)
The kapecticu and checks of various sydems deta.ited above are part of the station's normal routine impection/ surveillance program or environmedal program.
It is felt.tha.t t.hrough these methods, the presence of Corbic"In sp., bot.h in.the cooling meer source and h inplant systems, woutd be detec.ted.
The potential for Corblenin sp., if present h t.he cooling meer source, for inttuding iMo V.re and cooling wa.ter syaems is possible at de st.ation. Several syaem components exhibit areas of Loa flow velocity where larval or adult forms may attach.
In de event.that Corblenta sp. presents itself n:, a. safsty hazard concerning fire and safsty. tela.ted componen.cs at Nhe Mile Point Unit #1, possible preven. tion and clean up procedures will be formulated. At the present, biocides such as chlorine seem to be relatively ineffective agaba the motiusk adult and larval forms.
Only high chlorine concen-Ltations seem f.o have limited sue:ess against Corbienta sp. hfest.ctions.
The use of residual chlorine stea.bnents k once t.hrough cooling wa.ter sydems at high chloride concentrations is not permLtted in New Vork *ta.te.
Methods 2.0 pteven.c entry of.this speciss into cocLing sys.cemo in Light of the fact.the larval fo.us may attach and develop within sys.tems, is impknctient. The size of fitst stage Latvat fonma is approxima.tely 220 mictons long. Shce adult and larval forms are no.c resistant.t.o heated envitonments, heated au.ter flow t.htough cooling sydems follouting by hydro blasting may be. necessary during refueling ou.tage.
Res90nse.to item W5 The preceding item responses include f.he informatt.cn for t.his item.
The amount of time expended ccncerni.ng investiga. tion and report pteparatio:t for both Licensee and consultant personnel is estbna.ted at approximately 95 manhours.
Cordially, Yf" i s*wM-Th: mas E. Leppges Vice President -
Nuclear Genera.tian atm 4
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