ML17229A654

Forwards Summary of Results of Any Change to or Error Discovered in Evaluation Models for Eccs,Or Application of Such Models,That Affect Fuel Cladding Temp Calculation.Info Submitted Per 10CFR50.46(a)(3)(ii)

ML17229A654
Person / Time
Site:	Saint Lucie
Issue date:	03/04/1998
From:	STALL J A FLORIDA POWER & LIGHT CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
L-98-057, L-98-57, NUDOCS 9803100326
Download: ML17229A654 (6)

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CATEGORY1REGULATYINFORMATIONDISTRIBUTIOSYSTEM(RIDS)PACCESSIONNB/:9803100326DOC.DATE:98/03/04NOTARIZED:NO'FACIL:50-335St.LuciePlant,Unit1,FloridaPower6LightCo."50-389St.LuciePlant,Unit2,Florida'owerSLightCo.AUTH.NAMEAUTHORAFFILIATIONSTALL,J.A.FloridaPowerSLightCo.RECIP.NAMERECIPIENTAFFILIATIONDocumentControlBranch(DocumentControlDesk)DOCKET¹0500033505000389

SUBJECT:

ForwardssummaryofresultsofanychangetoorerrordiscoveredinevaluationmodelsforECCS,orapplicationofsuchmodels,thataffectfuelcladdingtempcalculation.Infosubmittedper10CFR50.46(a)(3)(ii).DISTRIBUTIONCODE:A001DCOPIESRECEIVED:LTRENCLSIZE:TITLE:ORSubmittal:GeneralDistributionNOTES:AERECIPIENTIDCODE/NAMEPD2-3LAGLEAVES,WCOPIESLTTRENCL1111RECIPIENTIDCODE/NAMEPD2-3PDCOPIESLTTRENCL11RINTERNAL:ACRSNRR/DE/ECGB/ANRR/DRCH/HICBNRR/DSSA/SRXBOGC/HDS31111111110FIECENRRDEEMCBNRR/DSSA/SPLBNUDOCS-ABSTRACT11111111EXTERNAL:.'NOAC11NRCPDR11DENOTETOALL"RIDS"RECIPIENTS:PLEASEHELPUSTOREDUCEWASTE.TOHAVEYOURNAMEORORGANIZATIONREMOVEDFROMDISTRIBUTIONLISTSORREDUCETHENUMBEROFCOPIESRECEIVEDBYYOUORYOURORGANIZATION,CONTACTTHEDOCUMENTCONTROLDESK(DCD)ONEXTENSION415-2083TOTALNUMBEROFCOPIESREQUIRED:LTTR14ENCL13 FloridaPower5LightCompany,6351S.OceanDrive,JensenBeach,FL34957FPLMarch4,1998L-98-057'0CFR50.46U.S.NuclearRegulatoryCommissionAttn:DocumentControlDeskWashington,DC20555Re:St.LucieUnits1and2DocketNos.50-335and50-389AcceptanceCriteriaforEmergencyCoreCoolingSystemsforLightWaterNuclearPowerReactors:10CFR50.46AnnualReortPursuantto10CFR50.46(a)(3)(ii),thenatureofanychangetoorerrordiscoveredintheevaluationmodelsforEmergencyCoreCoolingSystems(ECCS),orintheapplicationofsuchmodels,thataffectthefuelcladdingtemperaturecalculationsforSt.LucieUnits1and2isreportedintheattachmenttothisletter.TheestimatedeFectfromanysuchchangeorerroronthelimitingECCSanalysisforeachunitisalsoaddressed.ThedataintervalforthereportisfromJanuary1throughDecember31,1997.Shouldtherebeanyquestions,pleasecontactus.Verytrulyyours,J.A.StallVicePresidentSt.LuciePlantJAS/RLDAttachmentcc:RegionalAdministrator,RegionII,USNRCSeniorResidentInspector,USNRC,St.LuciePlant9803'i003205000335PDRADQCKPDRPlllllllllilllllllllllllllllllllllllllllanFPLGroupcompany St.LucieUnits1and2DocketNos.50-335and50-38910CFR50.46AnnualReortL-98-057ATTACHMENTPage1of3Emergencycorecoolingsystem(ECCS)analysesforSt.LucieUnit1andSt.LucieUnit2areperformedbySiemensPowerCorporation(SPC)andAseaBrownBoveri-CombustionEngineering(ABB-CE),respectively.Thefollowinginformationpertainingtotheevaluationmodelsforsmallbreaklossofcoolantaccidents(SBLOCA)andlargebreaklossofcoolantaccidents(LBLOCA),andtheapplicationofsuchmodelstoeachSt.Lucieunit,isprovidedpursuantto10CFR50.46(a)(3)(ii).Asummaryofcalculatedpeakcladdingtemperature(PCT)changesisprovidedinTable1.ThedataintervalforthisreportisfromJanuary1throughDecember31,1997.1.ST.LUCIEUNIT1SBLOCA:Achangewasmadetotheevaluationmodelassumptionsinvolvinghighpressuresafetyinjection(HPSI)flowasymmetry.Re-evaluationofSBLOCAusingtherevisedHPSIflowasymmetryidentifiedanewlimitingbreaksizeof0.05ft~,andresultedinaPCTincreaseof149'F(previouslyreportedinReference3.1).ThecalculatedPCTforthelimitingSBLOCAis1953'F.LBLOCA:AZ-equivalentmodeldiscrepancy,whichwasreportedinthe1996AnnualReport(Reference3.2),wascorrectedandexplicitlyevaluatedfortheUnit1LBLOCAanalysisofrecord.Theimpact&omthiserrorhadbeenconservativelyestimatedasamaximumPCTincreaseof15'F.Followingcorrectionofthediscrepancy,theactualchangeincalculatedPCTis-1.0'F.Theevaluationmodelwasalsoupdatedtoconservativelyusetheminimumcontainmentsprayandfancoolerinitiationtime.Thischangeresultedina14'FPCTincrease.ThecombinationofrevisionstotheZ-equivalentmodelandtheminimumcontainmentsprayandfancoolerinitiationtimeyieldsacalculatedPCTof2040'FforthelimitingLBLOCA.SPCalsoidentifiedavariabilityinRELAP-4coderesultsthatmayaffectthepe'akcladdingtemperaturecalculatedinLBLOCAanalyses.Thevariabilityischaracterizedasalargechangeinthecodeoutputresultthatisproducedbysmallchangesinthecodeinput,andforwhichsignificantlylargechangesshouldnotbeexpectedwhenconsideringphysicalbehavior.SPCisassessingthecause(s)andimpactofthisdeviation(Reference3.3).ApreliminaryassessmentindicatesthattheeffectoncalculatedPCTisnotsignificantandthattheSt.LucieUnit1LBLOCAanalysisofrecordremainsincompliancewithacceptancecriteriaof10CFR50.46.Correctiveactionshavenotbeenfinalizedandquantifiedresultsarenotexpectedtobeavailableuntillaterin1998.

St.LucieUnits1and2DocketNos.50-335and50-38910CFR50.46AnnualReortL-98-057ATTACHMENTPage2of32.ST.LUCIEUNIT2General:TheECCSperformanceanalysiscomputercodesforSBLOCAandLBLOCAwereconvertedforuseonHewlettPackard(HP)workstationsoper'atingundertheHP/UXoperatingsystem.ThecodeswerepreviouslyusedwithHPApolloworkstationsundertheDomainoperatingsystem,andtheoverallimpactoftheconversionisestimatedtohavenoeffectonthecalculatedPCT(totheprecisionofprintedresults,i.e.,lessthan.01'F).Inadditiontothecomputerplatformchange,anoptionwasaddedtotheSBLOCAmethodswhichautomatesthetransferofdata(coreboundaryconditions)betweentheCEFLASH-4ASblowdownhydraulicscomputercodeandthePARCHhotrodheatupcode.Previously,thisdatatransferwasperformedmanually.TheautomatedprocessprovidesamoreaccurateandeAicientmethodoftransferringthedata,andtheeffectontheECCSperformanceanalysisforSBLOCAisestimatedtobeareductionincalculatedPCTofapproximately4'F.ThelimitingECCSanalysesofrecordhavenotbeenperformedwiththechangesdescribedabove.SBLOCA:NoerrorswerefoundintheSBLOCAanalysisforthisreportingperiod.Thepeakcladdingtemperaturefortheanalysisofrecordremainsat1915'F.LBLOCA:Anerrorwasdiscoveredandcorrectedinthedecayheatenergyredistributionfactor(ERF)usedintheECCSperformanceevaluationmodelforLBLOCA.TheimpactoncalculatedpeakcladdingtemperaturewasconservativelyestimatedandpreviouslyreportedinReference3.4.CorrectingtheERFerrorresultedina28'Fincrease,andthelimitingECCSanalysisPCTis2171'F.3.REFERENCES1.FPLLetterL-97-313,J.A.StalltoUSNRC(DCD),"ErrorintheApplicationofSBLOCAEvaluationModel;30Day,10CFR50.46Report:"December17,1997.2.FPLLetterL-97-034,J.A.StalltoUSNRC(DCD),"AcceptanceCriteriaforEmergencyCoreCoolingSystemsforLightWaterNuclearPowerReactors:10CFR50.46AnnualReport:"March6,1997.3.SPCLetterNRC:98:001,J.S.HolmtoUSNRC,"InterimReportofEvaluationofaDeviationPursuantto10CFR21.21(a)(2):"January15,1998.4.FPLLetterL-97-205,J.A.StalltoUSNRC(DCD),"ErrorintheUseofLBLOCAEvaluationModel;30Day10CFR50.46Report:"August8,1997.

St.LucieUnits1and2DocketNos.50-335and50-38910FR5046AnnualReortL-98-057ATTACHMENTPage3of3TableISt.LucieUnits1and21997SBLOCAandLBLOCAPCTSummaryUnit1SBLOCASumma199610CFR50.46AnnualReortnote1Chanedueto30%SGtubeluinanalsisnote2ChaneduetorevisedHPSIflowasmmet199710CFR50.46AnnualReortPCT1765'F+39'F+149'F1953'FUnit1LBLOCASumma199610CFR50.46AnnualReortZ-euivalenterrorenaltestimatedmaximumimactonPCT+15'FChanefollowincorrectionofZ-euivalenterrorChaneduetorevisedcontainmentsraandfancoolerminimumdelatime199710CFR50.46AnnualReort2027'F-1'F+14'F2040'FUnit2SBLOCASumma199610CFR50.46AnnualReortChanedurin1997199710CFR50.46AnnualReortPCT1915'F0'F1915'FUnit2LBLOCASumma199610CFR50.46AnnualReortERFerrorenaltestimatedmaximumimactonPCT+30'FChanefollowincorrectionofERFerror199710CFR50.46AnnualReortPCT2143'F+28'F2171'FNotes:(1)Calculatedpeakcladdingtcmpcraturcisforstcamgenerator(SG)tubeplugginglevelof25%.(2)Analysiswasperformedin1996,butdidnotbccomcanalysisofrecorduntilissuanceofAmendmcntNo.151(5/16/97)tothcfacilityoperatinglicense.Thcvalueisincludedinthistabletoidentifycomponentscontributingtothccumulativeimpacton1997PCTofrecord.