ML113060277

2010 Emergency Core Cooling System Annual 10 CFR 50.46 Report

ML113060277
Person / Time
Site:	San Onofre
Issue date:	11/01/2011
From:	St.Onge R Southern California Edison Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
Download: ML113060277 (10)

Text

SOUTHERN CALIFORNIA EDISONRichard J.St.Onge Director,NuclearRegulatoryAffairs an d Emerge nc y Planning An EDISONINTERNATIONAL CompanyU.S.Nuclear Regulatory Commission ATTN: DocumentControlDesk Wash ington,D.C.20555 November 1, 201110CFR50.46

References:

DocketNos.50-361and50-362, 2010 EmergencyCoreCoolingSystem Annual10CFR50.46Report,SanOnofre Nuclear GeneratingStation,Units2and3 Letter from R.J.St.Onge(SCE)to DocumentControlDesk(NRC)

, dated December 15 ,2010, Subjec t:DocketNos.50-361and50-362, 2009 EmergencyCoreCoolingSystem, Annual10CFR50.46Report,SanOnofre Nuclear Generating Station ,Units2and3

DearSiror Madam:

This letter transmits as Enclosures1and2theSanOnofreUnits2and3 annual reportforthe 2010 calenda ryearrequiredby paragraph(a)(3)(ii)o f10CFR50.46,"Acceptance criteria for emergencycorecooling systems for light-wate r nuclear power reacto rs." This regulation requires Southern CaliforniaEdison(SCE)to annually reporttotheNRC for San OnofreUnits2and3 t he natureofeachchangeto

, or error discovered in , the EmergencyCoreCoolingSystem(ECCS) evaluation model ,orinthe app licationofthismodel that affects the temperature calculation and estimated effectsofanysuch changes , errors , o r appl icationsonthelimitingECCSanalysis.Any signif icant change or errorisrequiredtobereportedtotheNRCwithin30days.Thep revious EmergencyCoreCoolingSystem Annual10CFR50.46 Report was s ubmittedtotheNRCintheabove Reference.

Enclosure1isa descript ion of changesorerrorsinthe Westinghouse evaluationmodels(EM)usedintheSanOnofre Nuclear Generating Station (SONGS)Units2and3ECCS performance analyses Enclosure2isa summaryofthe effectonPeakClad Temperature(PCT)oftheerrors or changesinthe West inghouse evaluation modelsusedinthe SONGSUnits2and3 ECCS performance Analyses.WhilenotlimitingwithregardtoPCT, informationfortheSmallBreakLossof Coolant Accident(LOCA)isalsoincludedin Enclosure2(in accordance with Supplement1toInformation Notice 97-15).SCEmadeno changestotheLOCA evaluation models.P.O.Bo x 128 Sa n C lemente, CA 92672 Document Control Desk Operating Cycle Information November 1, 2011 Unit2andUnit3 operationforthe current reportingperiodis outlined below.Reporting CalendarYear2010 UnitCycle15Cycle16April11 ,2010*2Ended prior to 2010 through December 31, 2010 January 1 , 2010 3 ThroughDidnot start in 2010 October 10 ,2010***Unit2wasin refueling outage the earlypartof2010.

• • Unit 3 was in refueling outage the remainderof2010.2010 REPORTING PERIOD SONGSUnits2and3Large Break LOCA EvaluationModel(EM)The Large Break LOCA (LBLOCA)analysisusedthe1999 evaluation modeforthis reporting period.The limiting Large Break LOCAPCTdidnot exceed the 10CFR50.46(b)(1) acceptance criterion of 2,200 of.Thisis documented in Enclosure 2 (Table 1).Thereareno cumulative(sumofthe absolute magnitudesofPCT changes)1999EM Large Break LOCA1OCFR 50.46 model changes or model errors.This is documented in Enclosure 2 (Table 2).SONGSUnits2and3 Small Break LOCA Evaluation Model (EM)TheSmall Break LOCA (SBLOCA)analysisusedthe Supplement 2 Model(S2M)Small Break LOCA evaluation model for this reporting period.

Document Control Desk-3-November 1, 2011 The limitingSmallBreak LOCAPCTdidnot exceed the 10CFR50.46(b)(1) acceptance criterionof2 ,200 of , and remained boundedbythelarge break LOCAPCT.Thisis documented in Enclosure 2 (Table 3).Thereareno cumulative(sumofthe absolute magnitudesofPCT changes)S2M EvaluationModelSmall Break LOCA 10CFR50.46 model changesandmodelerrors.Thisis documented in Enclosure2(Table4).Ifyouhaveany questionsorneed additional informationonthis subject , please contact Ms.L.T.Conklin at 949/368-9443.

Enclosures:

1.Description of ChangesandErrorsinthe Westinghouse Evaluation Modelsusedinthe SONGSUnits2and3ECCS Performance Analyses (Calendar Year 2010)2.Summaryofthe EffectonPCToftheErrorsor Changesinthe Westinghouse Evaluation Modelsusedinthe SONGSUnits2and3 ECCS Performance Analyses (Calendar Year 2010)cc:E.E.Collins , Regional Administrator

,NRCRegionIVR.Hall , NRC Project Manager , San OnofreUnits2and3G.G.Warnick , NRC Senior Resident Inspector, San OnofreUnits2and3 Description of ChangesandErrorsinthe Westinghouse EvaluationModelsUsedinthe SONGSUnits2and3ECCS Performance Analyses (Calendar Year 2010)(2pagesinclud ingthispage)Enclosure1,Page1of2 1.1999EM Version of the Westinghouse Appendix K Large Break LOCA Evaluation Model for Combustion Engineering PWRs None.2.S2M Version of the Westinghouse Appendix K Small Break LOCA Evaluation Model for Combustion Engineering PWRs None.Enclosure 1 ,Page2of2 Summaryofthe EffectonPCToftheErrorsor Changesinthe Westinghouse Evaluation ModelsUsedintheSONGSUnits2and3 ECCS Performance Analyses (Calendar Year 2010)(5pagesincludingthispage)

Enclosu re 2 ,Page1of5 2010 REPORTING PERIODLOSSOF COOLANT ACCIDENT(LOCA)MARGIN

SUMMARY

SAN ONOFRE NUCLEAR GENERATINGSTATIONUNITS2AND3LargeBreakLOCATable1 providesatimelineoftheitems whichcouldaffecttheLarge Break LOCA (LBLOCA)peak cladding temperature(PCT)forthisreportingperiod

.The LBLOCA 10CFR50.46PCTlimitof2,200°Fwasnot exceeded.Table1LimitingLargeBreakLOCAPCT Unit2Unit3LimitingLargeBreakLOCAPCT End 0'2009 2,170°F 2 ,170 o f ChangesinPCTduring2010dueto:a)Model changesorModelerrors(1999EM)*Cycle15*o o f*Cycle16 o OF**b)Cycle Dependent Input Changes*Cycle15*o of*Cycle16 4 o f**LimitingLarge BreakLOCAPCT End 0'2010 2 ,174°F 2 ,170 o f***Unit2ope rated on lyunderCycle16in2010

,hencenoinputforthisentry.

Un it3ope ratedonlyunderCycle15i n 2010 ,hencenoinputforthisentry.

Enclosu re 2 ,Page2of5 The cumulative effectofthe10CFR50.46model changesandmodelerrorsfortheLargeBreak LOCA 1999 EvaluationModelareshowninTable2.Table2 Cumulative Large Break LOCA10CFR 50.46 Model ChangesandModelErrors r ILl PCTI (1)t2 IUnit31 Cumulative LBLOCA10CFR50.46Model ChangesandModelErrors

[;J Prior to 2010 o of Changes in LBLOCAPCTduetoModel ChangesandModelErrorsDuring2010*Cycle15**o o f*Cycle16 o of**Cumulative LBLOCA10CFR50.46Model ChangesandModelErrors End 0'2010 o of O°F***Unit2operatedonlyunderCycle16in2010,hencenoinputforthisentry

.Unit3operatedonlyunderCycle15in2010

,hencenoinputforthisentry. ,Page3of5 (1)Sumofthe absolutemagnitudeofthe10CFR50.46modelchangesandmodelerrors.

Small Break LOCATable3 providesatimelineoftheitemswhichcouldaffecttheSmallBreakLOCA (SBLOCA)peak cladding temperature(PCT)forthisreportingperiod.The SBLOCA 10CFR50.46PCTlimitof2200 o fwasnot exceeded,andthe SBLOCAPCTrema inedboundedbythe LBLOCA PCT.Table3LimitingSmallBreakLOCAPCT Unit2Unit3LimitingSmallBreak LOCA PCT End 0'2009 2,077 of 2 ,077 o f ChangesinPCT during 2010dueto:a)Model changesorModelerrors*Cycle15*°of*Cycle16°of**b)Cycle Dependent Input Changes*Cycle15*°of*Cycle16°of**LimitingSmallBreak LOCA PCT End 0'2010 2,077 of 2,077 o f***Un it2operatedonlyunderCycle16in2010

,hencenoinputforthisentry

.Unit3operatedonlyunderCycle15in2010

,hencenoinputforthisentry. ,Page4o f 5 The cumulative10CFR50.46modelchangesandmodele rrorsfortheSmallBreakLOCAS2MEvaluationModelareshowninTable4.

Table 4 Cumulative Small Break LOCA10CFR50.46 Model ChangesandModelErrors r 1 L1 PCTI (2)Unit2 Unit3 Cumulative SBLOCA10CFR50.46Mo del ChangesandModelErro rs Priorto2010 o o f o o f Changes in SBLOCAPCTduetoModelChangesandModelErrorsDuring2010Cycle15*o o f**Cycle16 o o f**Cumu lative SBLOCA10CFR50.46Model ChangesandModelErrors End of 2010 o o f o o f***Unit2opera ted only underCycle16 in2010 ,henceno inputforth is en try.Uni t 3 operated only underCycle15in2010

,henceno inputfort his entry.Enclosure 2 ,Page5of5 (2)Sumof the absolute magnitude o fthe10CFR50.46model changes and modelerrors.