ML17241A339: Difference between revisions

From kanterella
Jump to navigation Jump to search
(Created page by program invented by StriderTol)
(Created page by program invented by StriderTol)
Line 16: Line 16:


=Text=
=Text=
{{#Wiki_filter:CATEGORY'EGULAT.INFORMATIONDISTRIBUTIOSYSTEM(RIDS)$~~eACCESSIONNBR:9905270115DOC.DATE:99/05/20NOTARIZED:NOFACIL:50-335gt.LuciePlant,Unit1,FloridaPower&.LightCo.AUTK.NAPE.AUTHORAFFILIATIONSTALL,u.A.FloridaPower8LightCo.RECIP.NAMERECIPIENTAFFILIATIONRecordsManagementBranch(DocumentControlDesk)
{{#Wiki_filter:CATEGORY'EGULAT
.INFORMATION DISTRIBUTIO SYSTEM(RIDS)$~~eACCESSION NBR:9905270115 DOC.DATE:
99/05/20NOTARIZED:
NOFACIL:50-335 gt.LuciePlant,Unit1,FloridaPower&.LightCo.AUTK.NAPE.AUTHORAFFILIATION STALL,u.A.
FloridaPower8LightCo.RECIP.NAME RECIPIENT AFFILIATION RecordsManagement Branch(Document ControlDesk)


==SUBJECT:==
==SUBJECT:==
ForwardsnotificationofchangetosmallbreakLOCAECCSevaluationmodelusedforSTLucieUnit1.AnomalywasdiscoveredEcorrected.LimitingPCTiswellwithin10CFR50.46acceptancecriteria.DISTRIBUTIONCODE:A001DCOPIESRECEIVED:LTRENCLSIZE:TITLE:ORSubmittal:GeneralDistributionDOCKET05000335NOTES:RECIPIENTIDCODE/NAMELPD2-2LAGLEAVES,WCOPIESLTTRENCL1111RECIPIENTIDCODE/NAMELPD2-2PDCOPIESLTTRENCL110RINTERNAL:ACRSNRR/DE/EEIBNRR/DE/EMEBNRR/DSSA/SRXBNUDOCS-ABSTRACTEXTERNAL:NOAC11'111.111111FPLECENTER~011NRR/DE%EMCB1NRR/DSSA/SPLB1NRR/SPSBJUNG,I1OGC/RP1NRCPDR11110D'ENOTETOALL"RIDS"RECIPIENTS:PLEASEHELPUSTOREDUCEWASTE.TOHAVEYOURNAMEORORGANIZATIONREMOVEDFROMDISTRIBUTIONLISTSORREDUCETHENUMBEROFCOPIESRECEIVEDBYYOUORYOURORGANIZATION,CONTACTTHEDOCUMENTCONTROLDESK(DCD)ONEXTENSION415-2083TOTALNUMBEROFCOPIESREQUIRED:LTTR15ENCL14 FioridaPower&LightCompany,6351S.OceanDrive,JensenBeach,FL34957May20,1999L-99-11210CFR50A6U.S.NuclearRegulatoryCommissionATTN:DocumentControlDeskWashington,DC20555Re:St.LucieUnit1Docket50-335SBLOCAEvaluationModel30-Da10CFR50A6ReortTheattachedreportissubmittedpursuantto10CFR50A6(a)(3)(ii)toprovidenotificationofachangetothesmallbreaklossofcoolantaccident(SBLOCA)emergencycorecoolingsystemevaluationmodelusedforSt.LucieUnit1.Ananomalywasdiscoveredandcorrectedthatresultedinreducingthecalculatedpeakcladdingtemperature(PCT)forthelimitingSBLOCAbymorethan50'F,andmeetsthecriteriaforreportingwithin30days.ThelimitingPCTiswellwithinthe10CFR50A6acceptancecriteria.Pleasecontactusifyouhaveanyquestionsaboutthismatter.Verytrulyyours,J.A.StallVicePresidentSt.LuciePlantJAS/RLDAttachmentCC:RegionalAdministrator,RegionII,USNRCSeniorResidentInspector,USNRC,St.LuciePlant99052701i5990520PDRADQCK05000335iPPDRanFPLGroupcompany 4.frsllIIII St.LucieUnit1DocketNo.50-335SBLOCAEvaluationModel30-Da10CFR50.46ReortL-99-112AttachmentSiemensPowerCorporation(SPC)analyzestheSt.LucieUnit1emergencycorecoolingsystem(ECCS)performanceinpostulatedlossofcoolantaccidentspursuanttotherequirementsof10CFR50.46.SPCidentifiedandresolvedadeviationfromthe10CFR50,AppendixK,requirementsinthatthespecificationsfornodesinthecoremodelforthesmallbreaklossofcoolantaccident(SBLOCA)evaluationdidnotprovideaconvergedsolution.Correctionoftheanomalyresultedinasignificantdecreaseinthecalculatedpeakcladdingtemperature(PCT)forthelimitingsmallbreak.ItshouldbenotedthatthelargebreakLOCAcontinuestobethelimitinglossofcoolantaccidentanalyzedforSt.LucieUnit1.NatureofDeviation:SpecificationsfornodesintheSBLOCAcoremodeldidnotprovideaconvergedsolutionforthehotassemblyPCT.DescritionofErrorandCorrectiveAction:AconcerninvolvingproperdemonstrationofsolutionconvergenceforcorehotassemblycalculationswasidentifiedinSPCConditionReport(CR)6272.TheconcernledtothedeterminationthatthenodalrepresentationusedintheSBLOCAmethodologydidnotresultinaconvergedsolutionwithrespecttocorenodelength.Twomodelswereidentifiedasprinciplecontributorstotheanomaly:thetwo-velocitycross-flowmodelandthelevelmodel.Thetwo-velocitycross-flowmodellackssophisticatedtreatmentforthetwo-phasemomentumequationsthatareused,andcausessevereoscillationsduringtwo-phaseflowconditions.Inaddition,thelevelmodel,whichsharpenstheliquid-vaporinterface,canhavespuriousbehaviorundersomeconditions.Whenthesetwomodelsareusedinconjunction,solutionconvergenceisnotdemonstratedforthehotassemblyPCT.Theanomalywascorrectedbyspecifyinghomogeneousflow(single-velocity)atthecross-flowjunctionsandbyusingsmallequal-sizednodesinthecoremodel.TheserevisionstotheapplicationoftheSBLOCAmodelresultinconsistentandconvergedcoresolutionsinbothsteadystateandtransientcalculations.Calculationswiththecorrectedmodelincludedabreak-sizespectrumanalysis,whichdeterminedthatthelimitingsmallbreakchangedfrom.05ftto0.1ft.Thefinalresultisasignificantreductioninthecalculatedpeakcladdingtemperature.Thecorrectiveactioneliminatestheoscillatorybehaviorandresolvestheissueofsolutionconvergence.SPCreviewedthebenchmarkcalculationsforthecurrentSBLOCAmodelandconcludedthatthebenchmarkswerenotsensitivetothemodelchanges.ImactoftheError/Deviation:FortheSt.LucieUnit1SBLOCAanalysis,theimpactofthemodelchangeonthecalculatedPCTis-188'F.TherevisedPCTforthelimitingSBLOCAis1765'F.}}
Forwardsnotification ofchangetosmallbreakLOCAECCSevaluation modelusedforSTLucieUnit1.Anomaly wasdiscovered Ecorrected.
LimitingPCTiswellwithin10CFR50.46 acceptance criteria.
DISTRIBUTION CODE:A001DCOPIESRECEIVED:LTR ENCLSIZE:TITLE:ORSubmittal:
GeneralDistribution DOCKET05000335NOTES:RECIPIENT IDCODE/NAME LPD2-2LAGLEAVES,W COPIESLTTRENCL1111RECIPIENT IDCODE/NAME LPD2-2PDCOPIESLTTRENCL110RINTERNAL:
ACRSNRR/DE/EEIB NRR/DE/EMEB NRR/DSSA/SRXB NUDOCS-ABSTRACT EXTERNAL:
NOAC11'111.111111FPLECENTER~01 1NRR/DE%EMCB 1NRR/DSSA/SPLB 1NRR/SPSBJUNG,I1OGC/RP1NRCPDR11110D'ENOTETOALL"RIDS"RECIPIENTS:
PLEASEHELPUSTOREDUCEWASTE.TOHAVEYOURNAMEORORGANIZATION REMOVEDFROMDISTRIBUTION LISTSORREDUCETHENUMBEROFCOPIESRECEIVEDBYYOUORYOURORGANIZATION, CONTACTTHEDOCUMENTCONTROLDESK(DCD)ONEXTENSION 415-2083TOTALNUMBEROFCOPIESREQUIRED:
LTTR15ENCL14 FioridaPower&LightCompany,6351S.OceanDrive,JensenBeach,FL34957May20,1999L-99-11210CFR50A6U.S.NuclearRegulatory Commission ATTN:DocumentControlDeskWashington, DC20555Re:St.LucieUnit1Docket50-335SBLOCAEvaluation Model30-Da10CFR50A6ReortTheattachedreportissubmitted pursuantto10CFR50A6(a)(3)(ii) toprovidenotification ofachangetothesmallbreaklossofcoolantaccident(SBLOCA)emergency corecoolingsystemevaluation modelusedforSt.LucieUnit1.Ananomalywasdiscovered andcorrected thatresultedinreducingthecalculated peakcladdingtemperature (PCT)forthelimitingSBLOCAbymorethan50'F,andmeetsthecriteriaforreporting within30days.ThelimitingPCTiswellwithinthe10CFR50A6acceptance criteria.
Pleasecontactusifyouhaveanyquestions aboutthismatter.Verytrulyyours,J.A.StallVicePresident St.LuciePlantJAS/RLDAttachment CC:RegionalAdministrator, RegionII,USNRCSeniorResidentInspector, USNRC,St.LuciePlant99052701i5 990520PDRADQCK05000335i PPDRanFPLGroupcompany 4.frsllIIII St.LucieUnit1DocketNo.50-335SBLOCAEvaluation Model30-Da10CFR50.46 ReortL-99-112Attachment SiemensPowerCorporation (SPC)analyzestheSt.LucieUnit1emergency corecoolingsystem(ECCS)performance inpostulated lossofcoolantaccidents pursuanttotherequirements of10CFR50.46.SPCidentified andresolvedadeviation fromthe10CFR50,AppendixK,requirements inthatthespecifications fornodesinthecoremodelforthesmallbreaklossofcoolantaccident(SBLOCA)evaluation didnotprovideaconverged solution.
Correction oftheanomalyresultedinasignificant decreaseinthecalculated peakcladdingtemperature (PCT)forthelimitingsmallbreak.ItshouldbenotedthatthelargebreakLOCAcontinues tobethelimitinglossofcoolantaccidentanalyzedforSt.LucieUnit1.NatureofDeviation:
Specifications fornodesintheSBLOCAcoremodeldidnotprovideaconverged solutionforthehotassemblyPCT.DescritionofErrorandCorrective Action:Aconcerninvolving properdemonstration ofsolutionconvergence forcorehotassemblycalculations wasidentified inSPCCondition Report(CR)6272.Theconcernledtothedetermination thatthenodalrepresentation usedintheSBLOCAmethodology didnotresultinaconverged solutionwithrespecttocorenodelength.Twomodelswereidentified asprinciple contributors totheanomaly:thetwo-velocity cross-flow modelandthelevelmodel.Thetwo-velocity cross-flow modellackssophisticated treatment forthetwo-phase momentumequations thatareused,andcausessevereoscillations duringtwo-phase flowconditions.
Inaddition, thelevelmodel,whichsharpenstheliquid-vapor interface, canhavespuriousbehaviorundersomeconditions.
Whenthesetwomodelsareusedinconjunction, solutionconvergence isnotdemonstrated forthehotassemblyPCT.Theanomalywascorrected byspecifying homogeneous flow(single-velocity) atthecross-flow junctions andbyusingsmallequal-sized nodesinthecoremodel.Theserevisions totheapplication oftheSBLOCAmodelresultinconsistent andconverged coresolutions inbothsteadystateandtransient calculations.
Calculations withthecorrected modelincludedabreak-size spectrumanalysis, whichdetermined thatthelimitingsmallbreakchangedfrom.05ftto0.1ft.Thefinalresultisasignificant reduction inthecalculated peakcladdingtemperature.
Thecorrective actioneliminates theoscillatory behaviorandresolvestheissueofsolutionconvergence.
SPCreviewedthebenchmark calculations forthecurrentSBLOCAmodelandconcluded thatthebenchmarks werenotsensitive tothemodelchanges.ImactoftheError/Deviation:
FortheSt.LucieUnit1SBLOCAanalysis, theimpactofthemodelchangeonthecalculated PCTis-188'F.TherevisedPCTforthelimitingSBLOCAis1765'F.}}

Revision as of 14:12, 29 June 2018

Forwards Notification of Change to Small Break LOCA ECCS Evaluation Model Used for St Lucie Unit 1.Anomaly Was Discovered & Corrected That Resulted in Reducing Calculated PCT for Limiting SBLOCA by More than 50 F
ML17241A339
Person / Time
Site: Saint Lucie NextEra Energy icon.png
Issue date: 05/20/1999
From: STALL J A
FLORIDA POWER & LIGHT CO.
To:
NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
L-99-112, NUDOCS 9905270115
Download: ML17241A339 (4)


Text

CATEGORY'EGULAT

.INFORMATION DISTRIBUTIO SYSTEM(RIDS)$~~eACCESSION NBR:9905270115 DOC.DATE:

99/05/20NOTARIZED:

NOFACIL:50-335 gt.LuciePlant,Unit1,FloridaPower&.LightCo.AUTK.NAPE.AUTHORAFFILIATION STALL,u.A.

FloridaPower8LightCo.RECIP.NAME RECIPIENT AFFILIATION RecordsManagement Branch(Document ControlDesk)

SUBJECT:

Forwardsnotification ofchangetosmallbreakLOCAECCSevaluation modelusedforSTLucieUnit1.Anomaly wasdiscovered Ecorrected.

LimitingPCTiswellwithin10CFR50.46 acceptance criteria.

DISTRIBUTION CODE:A001DCOPIESRECEIVED:LTR ENCLSIZE:TITLE:ORSubmittal:

GeneralDistribution DOCKET05000335NOTES:RECIPIENT IDCODE/NAME LPD2-2LAGLEAVES,W COPIESLTTRENCL1111RECIPIENT IDCODE/NAME LPD2-2PDCOPIESLTTRENCL110RINTERNAL:

ACRSNRR/DE/EEIB NRR/DE/EMEB NRR/DSSA/SRXB NUDOCS-ABSTRACT EXTERNAL:

NOAC11'111.111111FPLECENTER~01 1NRR/DE%EMCB 1NRR/DSSA/SPLB 1NRR/SPSBJUNG,I1OGC/RP1NRCPDR11110D'ENOTETOALL"RIDS"RECIPIENTS:

PLEASEHELPUSTOREDUCEWASTE.TOHAVEYOURNAMEORORGANIZATION REMOVEDFROMDISTRIBUTION LISTSORREDUCETHENUMBEROFCOPIESRECEIVEDBYYOUORYOURORGANIZATION, CONTACTTHEDOCUMENTCONTROLDESK(DCD)ONEXTENSION 415-2083TOTALNUMBEROFCOPIESREQUIRED:

LTTR15ENCL14 FioridaPower&LightCompany,6351S.OceanDrive,JensenBeach,FL34957May20,1999L-99-11210CFR50A6U.S.NuclearRegulatory Commission ATTN:DocumentControlDeskWashington, DC20555Re:St.LucieUnit1Docket50-335SBLOCAEvaluation Model30-Da10CFR50A6ReortTheattachedreportissubmitted pursuantto10CFR50A6(a)(3)(ii) toprovidenotification ofachangetothesmallbreaklossofcoolantaccident(SBLOCA)emergency corecoolingsystemevaluation modelusedforSt.LucieUnit1.Ananomalywasdiscovered andcorrected thatresultedinreducingthecalculated peakcladdingtemperature (PCT)forthelimitingSBLOCAbymorethan50'F,andmeetsthecriteriaforreporting within30days.ThelimitingPCTiswellwithinthe10CFR50A6acceptance criteria.

Pleasecontactusifyouhaveanyquestions aboutthismatter.Verytrulyyours,J.A.StallVicePresident St.LuciePlantJAS/RLDAttachment CC:RegionalAdministrator, RegionII,USNRCSeniorResidentInspector, USNRC,St.LuciePlant99052701i5 990520PDRADQCK05000335i PPDRanFPLGroupcompany 4.frsllIIII St.LucieUnit1DocketNo.50-335SBLOCAEvaluation Model30-Da10CFR50.46 ReortL-99-112Attachment SiemensPowerCorporation (SPC)analyzestheSt.LucieUnit1emergency corecoolingsystem(ECCS)performance inpostulated lossofcoolantaccidents pursuanttotherequirements of10CFR50.46.SPCidentified andresolvedadeviation fromthe10CFR50,AppendixK,requirements inthatthespecifications fornodesinthecoremodelforthesmallbreaklossofcoolantaccident(SBLOCA)evaluation didnotprovideaconverged solution.

Correction oftheanomalyresultedinasignificant decreaseinthecalculated peakcladdingtemperature (PCT)forthelimitingsmallbreak.ItshouldbenotedthatthelargebreakLOCAcontinues tobethelimitinglossofcoolantaccidentanalyzedforSt.LucieUnit1.NatureofDeviation:

Specifications fornodesintheSBLOCAcoremodeldidnotprovideaconverged solutionforthehotassemblyPCT.DescritionofErrorandCorrective Action:Aconcerninvolving properdemonstration ofsolutionconvergence forcorehotassemblycalculations wasidentified inSPCCondition Report(CR)6272.Theconcernledtothedetermination thatthenodalrepresentation usedintheSBLOCAmethodology didnotresultinaconverged solutionwithrespecttocorenodelength.Twomodelswereidentified asprinciple contributors totheanomaly:thetwo-velocity cross-flow modelandthelevelmodel.Thetwo-velocity cross-flow modellackssophisticated treatment forthetwo-phase momentumequations thatareused,andcausessevereoscillations duringtwo-phase flowconditions.

Inaddition, thelevelmodel,whichsharpenstheliquid-vapor interface, canhavespuriousbehaviorundersomeconditions.

Whenthesetwomodelsareusedinconjunction, solutionconvergence isnotdemonstrated forthehotassemblyPCT.Theanomalywascorrected byspecifying homogeneous flow(single-velocity) atthecross-flow junctions andbyusingsmallequal-sized nodesinthecoremodel.Theserevisions totheapplication oftheSBLOCAmodelresultinconsistent andconverged coresolutions inbothsteadystateandtransient calculations.

Calculations withthecorrected modelincludedabreak-size spectrumanalysis, whichdetermined thatthelimitingsmallbreakchangedfrom.05ftto0.1ft.Thefinalresultisasignificant reduction inthecalculated peakcladdingtemperature.

Thecorrective actioneliminates theoscillatory behaviorandresolvestheissueofsolutionconvergence.

SPCreviewedthebenchmark calculations forthecurrentSBLOCAmodelandconcluded thatthebenchmarks werenotsensitive tothemodelchanges.ImactoftheError/Deviation:

FortheSt.LucieUnit1SBLOCAanalysis, theimpactofthemodelchangeonthecalculated PCTis-188'F.TherevisedPCTforthelimitingSBLOCAis1765'F.