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NRCFORM366AIB1999)LICENSEEEVENTREPORT(LER)TEXTCONTINUATIONU.S.NUCLEARREGULATORYCOMMISSIONFACILITYNAME{1)R.E.GinnaNuclearPowerPlantDOCKET(2)05000244LERNUMBERI6)SEQUENTULREVIIONNUMBERNUMBER1999-001-01PAGEI3)6OF8TEXTllfmorespaceisrequired,useeddidonelcopiesofNRCForm366A/I17)IV.ANALYSISOFEVENT:Thiseventisreportableinaccordancewith10CFR21andinaccordancewith10CFR50.73,LicenseeEventReportSystem,item(6)(2)(ii)(B),whichrequiresareportof,"Anyeventorcondition...thatresultedinthenuclearpowerplantbeing...Inaconditionthatwasoutsidethedesignbasisoftheplant".ThemodelingerrorsintheWestinghouseMSLBmassandenergyreleaseanalysishadthepotentialtopressurizetheGinnaStationcontainmentbeyonditsdesignpressureduetothispostulatedpost-accidentscenario.Anassessmentwasperformedconsideringboththesafetyconsequencesandimplicationsofthiseventwiththefollowingresultsandconclusions:TherewerenooperationalorsafetyconsequencesorimplicationsattributedtothedeficienciesintheWestinghouseMSLBmassandenergyreleaseanalysisbecause:TheMSLBcontainmentanalysisispresentedinGinnaStationUFSARSection6.2.1.2.3.Arevisedanalysiswasperformed(inMarch/April1999)byoffsettingtheadverseeffectsoftheadditionalmassandenergyreleasethroughrefinementsintheexistinganalysisassumptions.Theseimprovementsdonotalterthetotalquantityofsteamreleasedtocontainment,butprovidebenefitsinloweringtherateofthereleaseandincreasingtherateofcontairimentheatremoval.ApplyingtheseanalysisimprovementstotheMFRVfailurecasesyieldspeakcontainmentpressuresthatarelessthanthecontainmentdesignpressure.TheWestinghouseanalysis,asofMarch24,1999,showedthatthepeakcontainmentpressuredesignbasisvalueof60psigwouldnotbeexceededprovidedthatservicewater(SW)temperature(SWsuppliesthecontainmentrecirculationfans)islimitedtolessthan45degreesFahrenheit.PriortoenteringMode4fortheplanned1999refuelingoutage,thescreenhousebaytemperaturewasbeingmaintainedatapproximately39degreesFahrenheit,whilelaketemperaturewasapproximately35degreesFahrenheit.Thus,plantoperationremainedwithinitsdesignbasissincethetimeofdiscovery.ThecurrentWestinghouseanalysis,completedduringthe1999refuelingoutage,showsthatthepeakcontainmentpressuredesignbasisvalueof60psigwasnotexceededforCycle27,norwillitbeexceededforCycle28(thecurrentoperatingcycle).Operationduringfuturecyclesarealsojustified,withrestrictionssimilartothoseimposedforCycle28.Anysmallincreaseincontainmentpressurebeyondthe60psigdesignbasisvaluewouldnotbeexpectedtofailthecontainment.In1996,thecontainmentwassuccessfullytestedto72psigduringtheStructuralIntegrityTestforthesteam.generatorreplacementproject.AsteamlinebreakdoesnotresultinsevereradiologicalconsequencesatGinnaStation;thusfullcontainmentintegrityisnotconsideredrequiredforthisevent(eventhoughcontainmentisolationisassumedtooccur).
NRCFORM366AIB1999)LICENSEEEVENTREPORT(LER)TEXTCONTINUATIONU.S.NUCLEARREGULATORYCOMMISSIONFACILITYNAME{1)R.E.GinnaNuclearPowerPlantDOCKET(2)05000244LERNUMBERI6)SEQUENTULREVIIONNUMBERNUMBER1999-001-01PAGEI3)6OF8TEXTllfmorespaceisrequired,useeddidonelcopiesofNRCForm366A/I17)IV.ANALYSISOFEVENT:Thiseventisreportableinaccordancewith10CFR21andinaccordancewith10CFR50.73,LicenseeEventReportSystem,item(6)(2)(ii)(B),whichrequiresareportof,"Anyeventorcondition...thatresultedinthenuclearpowerplantbeing...Inaconditionthatwasoutsidethedesignbasisoftheplant".ThemodelingerrorsintheWestinghouseMSLBmassandenergyreleaseanalysishadthepotentialtopressurizetheGinnaStationcontainmentbeyonditsdesignpressureduetothispostulatedpost-accidentscenario.Anassessmentwasperformedconsideringboththesafetyconsequencesandimplicationsofthiseventwiththefollowingresultsandconclusions:TherewerenooperationalorsafetyconsequencesorimplicationsattributedtothedeficienciesintheWestinghouseMSLBmassandenergyreleaseanalysisbecause:TheMSLBcontainmentanalysisispresentedinGinnaStationUFSARSection6.2.1.2.3.Arevisedanalysiswasperformed(inMarch/April1999)byoffsettingtheadverseeffectsoftheadditionalmassandenergyreleasethroughrefinementsintheexistinganalysisassumptions.Theseimprovementsdonotalterthetotalquantityofsteamreleasedtocontainment,butprovidebenefitsinloweringtherateofthereleaseandincreasingtherateofcontairimentheatremoval.ApplyingtheseanalysisimprovementstotheMFRVfailurecasesyieldspeakcontainmentpressuresthatarelessthanthecontainmentdesignpressure.TheWestinghouseanalysis,asofMarch24,1999,showedthatthepeakcontainmentpressuredesignbasisvalueof60psigwouldnotbeexceededprovidedthatservicewater(SW)temperature(SWsuppliesthecontainmentrecirculationfans)islimitedtolessthan45degreesFahrenheit.PriortoenteringMode4fortheplanned1999refuelingoutage,thescreenhousebaytemperaturewasbeingmaintainedatapproximately39degreesFahrenheit,whilelaketemperaturewasapproximately35degreesFahrenheit.Thus,plantoperationremainedwithinitsdesignbasissincethetimeofdiscovery.ThecurrentWestinghouseanalysis,completedduringthe1999refuelingoutage,showsthatthepeakcontainmentpressuredesignbasisvalueof60psigwasnotexceededforCycle27,norwillitbeexceededforCycle28(thecurrentoperatingcycle).Operationduringfuturecyclesarealsojustified,withrestrictionssimilartothoseimposedforCycle28.Anysmallincreaseincontainmentpressurebeyondthe60psigdesignbasisvaluewouldnotbeexpectedtofailthecontainment.In1996,thecontainmentwassuccessfullytestedto72psigduringtheStructuralIntegrityTestforthesteam.generatorreplacementproject.AsteamlinebreakdoesnotresultinsevereradiologicalconsequencesatGinnaStation;thusfullcontainmentintegrityisnotconsideredrequiredforthisevent(eventhoughcontainmentisolationisassumedtooccur).
NRCFORM366A(61998)LICENSEEEVENTREPORT(LER)TEXTCONTINUATIONU.S.NUCLEARREGULATORYCOMMISSIONFACILITYNAME(1)DOCKET(2)LERNUMBER(6)PAGE(3)R.E.GinnaNuclearPowerPlant05000244SEI)ENTIAEREVSIOMHUMBER)(UMBER1999-.001-017OFBTEXTillmorespeceisrequired,useadditionelcopiesolNRCForm366Al(17)oForGinnaStationCycles1(theoriginalcyclein1970)through11,theMSLBcontainmentpressurewasnotpartoftheGinnaStationlicensingbasis.ForCycles12through25,containmentpressureonaMSLBwaspartoftheGinnaStationlicensingbasisandthepotentialexistedtoexceed60psigunderthepostulatedaccidentscenariodescribedabove.Cycles26and27operatedatthecurrentTavgof561degreesF,andwouldhavehadapeakcontainmentpressurelessthan60psigunderthepostulatedconditions.Cycle28hasalsobeenshownbeacceptable.oAtnotimeintheoperationofGinnaStationhasamainsteamlinebreakoccurred.Basedontheabove,itcanbeconcludedthattherewerenounreviewedsafetyquestions,andthatthepublic'shealthandsafetywasassuredatalltimes.V.CORRECTIVEACTION:A.ACTIONTAKENTORETURNAFFECTEDSYSTEMSTOPRE-EVENTNORMALSTATUS:FortheoperationofGinnaStationbetweenthetimeofdiscoveryandplantshutdownonMarch1,1999,thescreenhousebaytemperaturewasmaintainedatapproximately39degreesFahrenheit,whilelaketemperatureremainedatapproximately35degreesFahrenheit.Thus,plantoperationremainedwithinitsdesignbasisfromthediscoverydateuntilthe1999refuelingoutage.GinnaStationplacedatemporaryadministrativerestrictionof40degreesFahrenheitmaximumonscreenhousebaytemperatureforModes1through4(whencontainmentisrequiredtobeoperable)toensureadequatemarginexisted.CompletionofanalysesdemonstratedthatoperationforCycle28wouldbewithindesignbasis.Therestrictionpreviouslyimposedonlaketemperaturewaslifted.'B.ACTIONTAKENORPLANNEDTOPREVENTRECURRENCE:oAdditionalanalyseswereperformedtosupportcurrentandfuturecycleoperation.TheMSLBanalysis(withtheassumedMFRVfailure)wasreanalyzed.Significantassumptionchangestosupportoperationwereasfollows:Assumedshutdownmarginof2.40%versusthebasecasereferencecyclevalueof1.80%.TheGinnaStationCoreOperatingLimitsReport(COLR)wassubsequentlyrevisedtoincorporatethisvalue.
NRCFORM366A(61998)LICENSEEEVENTREPORT(LER)TEXTCONTINUATIONU.S.NUCLEARREGULATORYCOMMISSIONFACILITYNAME(1)DOCKET(2)LERNUMBER(6)PAGE(3)R.E.GinnaNuclearPowerPlant05000244SEI)ENTIAEREVSIOMHUMBER)(UMBER1999-.001-017OFBTEXTillmorespeceisrequired,useadditionelcopiesolNRCForm366Al(17)oForGinnaStationCycles1(theoriginalcyclein1970)through11,theMSLBcontainmentpressurewasnotpartoftheGinnaStationlicensingbasis.ForCycles12through25,containmentpressureonaMSLBwaspartoftheGinnaStationlicensingbasisandthepotentialexistedtoexceed60psigunderthepostulatedaccidentscenariodescribedabove.Cycles26and27operatedatthecurrentTavgof561degreesF,andwouldhavehadapeakcontainmentpressurelessthan60psigunderthepostulatedconditions.Cycle28hasalsobeenshownbeacceptable.oAtnotimeintheoperationofGinnaStationhasamainsteamlinebreakoccurred.Basedontheabove,itcanbeconcludedthattherewerenounreviewedsafetyquestions,andthatthepublic'shealthandsafetywasassuredatalltimes.V.CORRECTIVEACTION:A.ACTIONTAKENTORETURNAFFECTEDSYSTEMSTOPRE-EVENTNORMALSTATUS:FortheoperationofGinnaStationbetweenthetimeofdiscoveryandplantshutdownonMarch1,1999,thescreenhousebaytemperaturewasmaintainedatapproximately39degreesFahrenheit,whilelaketemperatureremainedatapproximately35degreesFahrenheit.Thus,plantoperationremainedwithinitsdesignbasisfromthediscoverydateuntilthe1999refuelingoutage.GinnaStationplacedatemporaryadministrativerestrictionof40degreesFahrenheitmaximumonscreenhousebaytemperatureforModes1through4(whencontainmentisrequiredtobeoperable)toensureadequatemarginexisted.CompletionofanalysesdemonstratedthatoperationforCycle28wouldbewithindesignbasis.Therestrictionpreviouslyimposedonlaketemperaturewaslifted.'B.ACTIONTAKENORPLANNEDTOPREVENTRECURRENCE:oAdditionalanalyseswereperformedtosupportcurrentandfuturecycleoperation.TheMSLBanalysis(withtheassumedMFRVfailure)wasreanalyzed.Significantassumptionchangestosupportoperationwereasfollows:Assumedshutdownmarginof2.40%versusthebasecasereferencecyclevalueof1.80%.TheGinnaStationCoreOperatingLimitsReport(COLR)wassubsequentlyrevisedtoincorporatethisvalue.
NRCFORM366hIBIBBBILICENSEEEVENTREPORT(LER)TEXTCONTINUATIONU.S.NUCLEARREGULATORYCOMMISSIONFACILITYNAME(1)R.E.GinnaNuclearPowerPlantDOCKETIz)05000244LERNUMSER(6)BrppaRMLRNBIONIIUMBTRIIUMBER1999-001-01PAGEI3)8OF8TEXT(Ifmorespaceisrequired,useadditionalcopiesofNRCForm866AII17)AssumedoperationatthenormalGinnaStationaverageoperatingtemperature(Tavg)of561degreesFversustheupperendoftheanalyzedTavgwindowof573.5degreesF.ThisoperatingrestrictionhasbeenplacedinGinnaStationoperatingproceduresandcorrespondstothefullpowerrodcontrolprogramsetpoint.PlantmodificationstorecoverthefullrangeofthepreviouslyanalyzedTavgwindowandtorestorethepreviousshutdownmarginlimitswillbeconsideredinthefuture.NuclearEngineeringServices(NES)hasimplementedaprocessforindependentreviewofvendorinputssuppliedbyRG&Eandisintheprocessofperforminganindependentreviewofallaccidentanalysisassumptions.Westinghouseisevaluatingtheneedforinternalcorrectiveactionsaspartoftheirreviewofthiscondition.VI~ADDITIONALINFORMATION:A.FAILEDCOMPONENTS:NoneB.PREVIOUSLERsONSIMILAREVENTS:AsimilarLERhistoricalsearchwasconductedwiththefollowingresults:NodocumentationofsimilarLEReventswiththesamerootcauseatGinnaStationcouldbeidentified.C.SPECIALCOMMENTS:None  
NRCFORM366hIBIBBBILICENSEEEVENTREPORT(LER)TEXTCONTINUATIONU.S.NUCLEARREGULATORYCOMMISSIONFACILITYNAME(1)R.E.GinnaNuclearPowerPlantDOCKETIz)05000244LERNUMSER(6)BrppaRMLRNBIONIIUMBTRIIUMBER1999-001-01PAGEI3)8OF8TEXT(Ifmorespaceisrequired,useadditionalcopiesofNRCForm866AII17)AssumedoperationatthenormalGinnaStationaverageoperatingtemperature(Tavg)of561degreesFversustheupperendoftheanalyzedTavgwindowof573.5degreesF.ThisoperatingrestrictionhasbeenplacedinGinnaStationoperatingproceduresandcorrespondstothefullpowerrodcontrolprogramsetpoint.PlantmodificationstorecoverthefullrangeofthepreviouslyanalyzedTavgwindowandtorestorethepreviousshutdownmarginlimitswillbeconsideredinthefuture.NuclearEngineeringServices(NES)hasimplementedaprocessforindependentreviewofvendorinputssuppliedbyRG&Eandisintheprocessofperforminganindependentreviewofallaccidentanalysisassumptions.Westinghouseisevaluatingtheneedforinternalcorrectiveactionsaspartoftheirreviewofthiscondition.VI~ADDITIONALINFORMATION:A.FAILEDCOMPONENTS:NoneB.PREVIOUSLERsONSIMILAREVENTS:AsimilarLERhistoricalsearchwasconductedwiththefollowingresults:NodocumentationofsimilarLEReventswiththesamerootcauseatGinnaStationcouldbeidentified.C.SPECIALCOMMENTS:None}}
}}

Revision as of 12:03, 18 May 2018

LER 99-001-01:on 990222,deficiencies in NSSS Vendor steam- Line Brake Mass & Energy Release Analysis Results in Plant Being Outside Design Bases Occurred.Caused by Deficiencies in W.Temporary Administrative Replaced.With 990621 Ltr
ML17265A685
Person / Time
Site: Ginna Constellation icon.png
Issue date: 06/21/1999
From: MECREDY R C, ST MARTIN J T
ROCHESTER GAS & ELECTRIC CORP.
To: VISSING G S
NRC (Affiliation Not Assigned), NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
REF-PT21-99 LER-99-001, LER-99-1, NUDOCS 9906290303
Download: ML17265A685 (13)


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pCATEGORY1gjREGULATORYINFORMATIONDISTRIBUTIONSYSTEM(RIDS)ACCESSIONNBR:9906290303DOC.DATE:99/06/21NOTARIZED:NOFACIL:50-244,RobertEmmetGinnaNuclearPlant,Unit1,RochesterGAUTH.NAMEAUTHORAFFILIATIONSTMARTIN,J.T.RochesterGas&:ElectricCorp.MECREDY,R.C.RochesterGas&,ElectricCorp.RECIP.NAMERECIPIENTAFFILIATIONDOCKET05000244VISSING,G.S.

SUBJECT:

LER99-001-01:on990222,deficienciesinNSSSvendorsteam-linebrakemass&energyreleaseanalysisresultsinplantbeingoutsidedesignbasesoccurred.CausedbydeficienciesinW.Temporaryadministrativereplaced.With990621ltr.DISTRIBUTIONCODE:IE22TCOPIESRECEIVED:LTRIENCL1SIZE:TITLE:50.73/50.9LicenseeEventReport(LER),IncidentRpt,etc.NOTES:LicenseExpdateinaccordancewith10CFR2,2.109(9/19/72).Q050002440RECIPIENTIDCODE/NAMELPD1-1PDINTERNAL:AEOD/SPD/RRABNRR/DIPM/IOLBNRR/DRIP/REXBRES/DET/EIBEXTERNAL:LSTLOBBYWARDNOACPOORE,W.NRCPDRCOPIESLTTRENCL1111111111111111RECIPIENTIDCODE/NAMEVISSING,G.FILECEDER/DUPEIQMBNRR/DSSA/SPLBRGN1FILE01LMITCOMARSHALLNOACQUEENER,DSNUDOCSFULLTXTCOPIESLTTRENCL1111111111111111RD'ENNOTETOALL"RIDS"RECIPIENTS:PLEASEHELPUSTOREDUCEWASTETOHAVEYOURNAMEORORGANIZATIONREMOVEDFROMDISTRIBUTIONLISTSORREDUCETHENUMBEROFCOPIESRECEIVEDBYYOUORYOURORGANIZATION,CONTACTTHEDOCUMENDESK(DCD)ONEXTENSION415-2083HEDOCUMENTCONTROLFULLTEXTCONVERSIONREQUIREDTOTALNUMBEROFCOPIESREQUIRED:LTTR16ENCL16 0

ROCHESTERGASANDELECTRICCORR7RATION+89EASTAVENLJE,ROCHESTER,N.Y.14'-0001AREACODE7I6SrI6-2700ROBERTC.MECREDYVicePresidentgvc!earOperationsJune21,1999U.S.NuclearRegulatoryCommissionDocumentControlDeskAttn:GuyS.VissingProjectDirectorateI-1Washington,D.C.20555

Subject:

LER1999-001,Revision1,DeficienciesinNSSSVendorSteamlineBreakMassandEnergyReleaseAnalysisResultsinPlantBeingOutsideitsDesignBasisR.E.GinnaNuclearPowerPlantDocketNo.50-244

DearMr.Vissing:

TheattachedLicenseeEventReportLER1999-001,Revision1,issubmittedinaccordancewith10CFR50.73,LicenseeEventReportSystem,item(a)(2)(ii)(B),whichrequiresareportof,"Anyeventorcondition...thatresultedthenuclearpowerplantbeing...Inaconditionthatwasoutsidethedesignbasisoftheplant",andinaccordancewith10CFR21,"ReportingofDefectsandNoncompliances".Verytrulyyours,RobertC.Mecedyxc:Mr.GuyS.Vissing(MailStopSC2)ProjectDirectorateI-1DivisionofReactorProjects-I/IIOfficeofNuclearReactorRegulationU.S.NuclearRegulatoryCommissionWashington,D.C.20555RegionalAdministrator,RegionIU.S.NuclearRegulatoryCommission475AllendaleRoadKingofPrussia,PA19406U.S.NRCGinnaSeniorResidentInspector09906290308990b21PDRADOCK05000244SPDR

NRCFORM366IILIBBS)U.S.NUCLEARREGULATORYCOMMISSIONLICENSEEEVENTREPORT(LER)(Seereverseforrequirednumberofdigits/charactersforeachblock)OPAL)WZ<~Is~>R;&0AL:%N(P"informaaoncosectlonrequest:50hrs.Reportedlessonslearnedareincorporatedhtothelicensingprocessandfedbacktoindustry.ForwardcommentsregardingburdenestimatetotheRecordsManagementBranch(TAF33).U.S.NudearRegulatoryCommissbn.Washington.DC205554001,andtothePaperworkReductionProject(31~104).OfrceofManagementandBudget.Washington,DC20503.IfaninformationcolectiondoesnotdisplayacurrentlyvalidOMBcontrolnumber.LheNRCmaynotconductorsponsor.andaFACILITYNAME(1)R.E.GinnaNuclearPowerPlantDocKETNUMBERI2)05000244PAGEI3)1OF8TITlEtelDeficienciesinNSSSVendorSteamlineBreakMassandEnergyReleaseAnalysisResultsinPlantBeingOutsideitsDesignBasisEVENTDATE(5)MONTHOAY0222LERNUMBER(6)SEQUENTIALREYSIONNUMBERNUMBER19991999-001"01MONTHOAY06211999REPORTDATE(7)FACIUTYNAMEFACILITYNAMEDOCKETNUMBER05000DOCKETNVMBER05000OTHERFACILITIESINVOI.VED(6)OPERATINGMODE(B)POWERLEVEL(10)7520.2201(b),20.2203(a)(1)20.2203(a)(2)(i)20.2203(a)(2)(ii)20.2203(a)(2)(iii)20.2203(a)(2)(iv)20.2203(a)(2)(v)20.2203(a)(3)(i)'0.2203(a)(3)(ii)20.2203(a)(4)50.36(c)(1)50.36(c)(2)LICENSEECONTACTFORTHISLER(12)5073(a)(2)(i)(B)50.73(a)(2)(ii)50.73(a)(2)(iii)50.73(a)(2)(iv)~50.73(al(2)(v)50.73(a)(2)(vii)TSOF10CFR5:(CheckTHISREPORTISSUBMITTEDPURSUANTTOTHEREQUIREMENoneormore)(11)50.73(a)(2)(viii]50.73(a)(2)(x)73.71XOTHERPart21SpecifyInAbstractbeloworinNRCForm366ATELEPHONENVMSERaootvdeAreeCode)JohnT.St.Martin-TechnicalAssistant(716)771-3641CAUSECOMPONENTMANUPACTURERREPORTABLETOEPOSSYSTEMCOMPONENTMANUPACTURERREPORTABLETOEPIXSUPPLEMENTALREPORTEXPECTED(I4)YES(Ifyes,completeEXPECTEDSUBMISSIONDATE).NOXEXPECTEDSUBMISSIONDATE(15)MONTHOAYTEARABSTRACT(Limitto1400spaces,i.e.,approximately15single-spacedtypewrittenlines)(16)OnFebruary22,1999,GinnaStationwasnotifiedbyitsNSSSvendor(Westinghouse)oftwomodelingerrorsintheanalysisforamainsteam)incbreakinsidecontainmentwithanassumedsinglefailureofamainfeedwaterregulatingvalve.Theseerrorshadanonconservativeimpactoncalculatedpeakcontainmentpressure.Thefirsterrorinvolvedtheomissionofapreviouslyunaccountedforvolumeofhightemperaturefeedwater.Theseconderrorresultedinanincorrectfeedwaterisolationtime.Theconsequencesofthesetwomodelingerrorspreviouslycreatedthepotentialforcontainmenttoexceeditsdesignbasisvalueof60psigforamainsteamlinebreakwithaconcurrentfailureofamainfeedwaterregulatingvalveforR.E.GinnaCycles12through25.ThecauseoftheplantbeinginaconditionthatwasoutsidethedesignbasisoftheplantfromCycle12toCycle25wasdeficienciesintheWestinghousemainsteam)inebreakmassandenergyreleaseanalysis.ImmediatecorrectiveactionforCycle27wastoplaceatemporaryadministrativerestrictionof40degreesFahrenheitmaximumonscreenhousebaytemperature,ameasureofServiceWater/Containment'fancoolerheatremovalandpressurereductioncapability,forModes1through4(whencontainmentisrequiredtobeoperable)toensureadequatepost-accidentenvironmentalconditionsmarginexisted.CorrectiveactiontojustifyreturntopowerforCyc)e28includedacycle-specificanalysisshowingpeakcontainmentpressurelessthan60psig.CorrectiveactiontopreventrecurrenceisoutlinedinSectionV.B.

NRCFORM366AIBIBBB)LICENSEEEVENTREPORT(LER)TEXTCONTINUATIONU.S.NUCLEARREGULATORYCOMMISSIONFACILITYNAMEI1)R.E.GinnaNuclearPowerPlantDOCKETIz)05000244LERNUMBER(6)BEOUENTNLREVISIONNUMBERNUMBER1999-001-01PAGEI3)2OFI)TEXTflfmorespeceisrequired,useeddirionelcopiesofNRCForm366A)I17)PRE-EVENTPLANTCONDITIONS:In1992,theNSSSvendorforGinnaStation(Westinghouse)analyzedafullspectrumofcasesforthemainsteamlinebreak(MSLB)andcontainmentresponsefortheR.E.Ginnaplant.Thesetofanalyseswasperformedtosupporttheprogramtoreducetheboricacidstoragetank(BAST)boronconcentrationto2000ppm.Thisanalysisentailedover120cases,whichvariedbreaksizeandlocation,initialpowerlevel,singlefailure,offsitepoweravailability,anddifferentreactivitycoefficients(roddedversusunrodded)~In1995,Westinghousere-visitedthesteamlinebreakmassandenergyreleaseeventduetoreplacementsteamgenerators(RSGs)andanincreaseto18monthfuelcycles.Manyofthepreviouscasescouldbeeliminateddueto:AnintegralflowrestrictorontheRSGs,eliminatinganybreakslargerthan1.4squarefeet(theRSGshaveflowrestrictingoutletnozzleswhichmakeanybreaksizelargerthanthethroatareaoftherestrictornotcredibleandthus,breakflowareasgreaterthan1.4squarefeetnolongerneedtobeconsidered),and2.Creditbeingtakenforthemainsteamnon-returncheckvalve,whicheliminatedseveraltypesofbreaksandtheneedtoconsideramainsteamisolationvalve(MSIV)singlefailureforcontainmentoverpressurizationcases.Aftereliminatingcasesthatwerenolongercredible,casesforthe1995analyseswereselectedfromthe1992BASTreductionprogram.Sixofthemostlimitingcaseswereselected,includingdifferentbreaksizes,initialpowerlevels,singlefailures,andoffsitepowerassumptions.AnotherdifferencefromthepreviousanalysesisexplainedintheGinnaStationUpdatedFinalSafetyAnalysisReport(UFSAR)Section6.2.1.2.3:"IntheReference3analyses[1992BASTreductionprogram),themostlimitingfeedwatercontrolsystemfailurewasassumedtobeafailureintheauxiliaryfeedwatersystemcontrol.Thisfailureresultedinincreasedauxiliaryfeedwaterflowratesfortheentiredurationofthetransient.Afailureoftheisolationfunctionofthemainfeedwaterregulatingvalves(MFRVs)wasnotconsideredbecauseafeedwaterisolationsignalalsoresultsinamainfeedwaterpumptripandinclosureofthepumpdischargevalve(MFPDV).Thus,nosinglefailurewouldhaveresultedinafailuretoisolatemainfeedwaterorasignificantdelayintheisolationofmainfeedwatertotheaffectedsteamgenerator.Ithassubsequentlybeenrealizedthatthecondensatepumpswouldcontinuetopumpthroughthemainfeedwaterpumpsatlowsteamgeneratorpressuresandthatthepumpdischargevalve(MFPDV)closuretimeisapproximately80seconds.Therefore,afailureoftheisolationfunctionofthemainfeedwaterregulatingvalve(MFRV)couldresultinmainfeedwaterflowviathecondensatepumpsforapproximately80secondstotheaffectedsteamgenerator.Thisnewfailurescenarioisamorelimitingfailurethanwasassumedinthepreviousanalysesduetothetimingandmagnitudeoftheincreasedflow."Therequirementforthe80secondstroketimerequirementoftheMFPDVisaddressedintheGinnaStationImprovedTechnicalSpecifications(ITS)Section3.7.3.

NRCFORM366A(BIBBS)LICENSEEEVENTREPORT(LER)TEXTCONTINUATIONU.S.NUCLEARREGULATORYCOMMISSIONFACILITYNAME(1)DOCKET(2)LERNUMBER(6)SEmINTIAEAEVISIBHNUMB(AIIUMBEAPAGE(3)R.E.GinnaNuclearPowerPlant050002441ass()()13OF8TEXTfffmorespeceisrequired,useeddidonelcopiesofNRCForm366A/(17)DESCRIPTIONOFEVENT:DATESANDAPPROXIMATETIMESOFMAJOROCCURRENCES:February22,1999:Eventdate.February22,1999,1540EST:Discoverydateandtime.February22,1999,1601EST:NRCisnotifiedofthisconditionper10CFR50.72(b)(1)(ii)(8).March1,1999,2018EST:PlantisshutdowninMode4fortheplanned1999refuelingoutage.April16,1999:NSSSanalysisshowsMSLBcontainmentpressureislessthan60psig.B.EVENT:OnFebruary22,1999,inactivitiesunrelatedtoplantconditions,GinnaStationwasnotifiedbyitsNSSSvendor(Westinghouse)oftwomodelingerrorsintheanalysisforaMSLBinsidecontainmentwithanassumedsinglefailureofaMFRV.(RefertotheletterRGE-99-207fromMr.SteveM.IraoftheWestinghouseElectricCorporationtoMr.PeterBamford,RochesterGasandElectricCorporation(RGSE),datedFebruary22,1999,

Subject:

SteamlineBreakMassandEnergyReleaseAnalysisNonconformance.)Theseerrorshadanonconservativeimpactoncalculatedpeakcontainmentpressure.Thefirsterrorinvolvesthevolumeoffeedwaterthatexistsbetweenthespecifiedisolationvalveandthefaultedsteamgenerator.WhentheMFRVisassumedtofailtoperformitsisolationfunction,thentheisolationfunctionisperformedbytheMFPDV.Becauseoftherelativelocationsofthesevalvestothesteamgenerator,thevolumeofwaterisgreaterbetweentheMFPDVandthesteamgeneratorthanbetweentheMFRVandthesteamgenerator.Thisincreasedvolumeofhightemperaturefeedwaterwasnotaccountedforintheanalysis.Theseconderrorwasinadvertentlyisolatingfeedwaterflowat15secondsinsteadofat85seconds(80secondsvalvestroketimeand5secondsforsignaldelay)aswasintended.Thismeantthatfeedwaterflowshouldhavecontinuedfor70secondslongerthanwasassumedintheanalysis.Theconsequencesofthesetwomodelingerrorshasthepotentialforcontainmenttoexceeditsdesignbasisvalueof60psigforaMSLBwithanassumedconcurrentfailureofaMFRV.Thisisduetoaddinghigherenergyfluidtocontainmentfor70secondslongerthanwasassumedinthe1995MSLBanalysisofrecord.Therewasalsothepotentialforthecontainmenttoexceeditsdesignbasisvalueasdocumentedinthe1992analyses,duetodiscoveryofamorelimitingsinglefailure.

NRCFORM366A(919991LICENSEEEVENTREPORT(LER)TEXTCONTINUATIONU.S.NUCLEARREGULATORYCOMMISSIONFACILITYNAME(1)R.E.GinnaNuclearPowerPlantDOCKET(2)05000244LERNUMBER(6)BEUUENTIALAENSIONNUMBEANUMBER1999-001-01PAGE(3)4OF8TEXTllfmorespaceisrequired,useadditionalcopiesofNRCForm366AI(17)AtthetimeofdiscoveryanduntiltheplannedshutdownonMarch1,1999,thescreenhousebaytemperaturewasmaintainedatapproximately39degreesFahrenheit,whilelaketemperatureremainedatapproximately35degreesFahrenheit.GinnaStationplacedatemporaryadministrativerestrictionof40degreesFahrenheitmaximumonscreenhousebaytemperature,ameasureofServiceWaterSystemtemperature,forModes1through4(whencontainmentisrequiredtobeoperable)toensureadequatemarginexisted.Bymaintainingthistemperaturelessthan40degreesFahrenheit,increasedcontainmentfancoolerheatremovalabilitywasensuredandthis,combinedwithahighcycle-specificexcessshutdownmargin,wassufficienttoensurecontainmentpressurewouldremainlessthan60psigforthispostulatedscenario.TosupportoperationinCycle28andbeyond,theMSLBanalysis(withtheassumedMFRVfailure)wasreanalyzed.Significantassumptionchangestosupportoperationwereasfollows:Assumedshutdownmarginof2.40%versusthebasecasereferencecyclevalueof1.80%.TheGinnaStationCoreOperatingLimitsReport(COLR)wassubsequentlyrevisedtoincorporatethisvalue.PAssumedoperationatthenormalGinnaStationaverageoperatingtemperature(Tavg)of561degreesFversustheupperendoftheanalyzedTavgwindowof573.5degreesF.ThisoperatingrestrictionhasbeenplacedinGinnaStationoperatingproceduresandcorrespondstothefullpowerrodcontrolprogramsetpoint.Thesechanges,whencombinedwithseveralminormodelingrefinements,ledtopeakcontainmentpressureunderthisscenariotobelessthan60psig.Accordingly,operationsforallofCycle28wasjustified.Thisincludestheremovalofthelaketemperaturerestrictionpreviouslyimposed.C.INOPERABLESTRUCTURES,COMPONENTS,ORSYSTEMSTHATCONTRIBUTEDTOTHEEVENT:NoneD.OTHERSYSTEMSORSECONDARYFUNCTIONSAFFECTED:NoneE.METHODOFDISCOVERY:ThiseventwasdisclosedtoRGSEbythenotificationfromitsNSSSvendor(Westinghouse)oftwomodelingerrorsintheanalysisforaMSLBinsidecontainmentwithanassumedsinglefailureofaMFRV.(RefertoletterRGE-99-207fromMr.SteveM.IraoftheWestinghouseElectricCorporationtoMr.PeterBamford,RochesterGasandElectricCorporation(RG(t(E),datedFebruary22,1999,

Subject:

SteamlineBreakMassandEnergyReleaseAnalysisNonconformance.)

NRCFORM366AISISSSILICENSEEEVENTREPORT(LER)TEXTCONTINUATIONU.S.NUCLEARREGULATORYCOMMISSIONFACILITYNAME11IDOCKETl2lLERNUMBERI6)PAGEI3IR.E.GinnaNuclearPowerPlant05000244SEGUENEMEREVISIUNNUMBERNUMBER1999-001-015OF8TEXTllfmorespaceisrequired,useaddidonalcopiesofNRCForm366Al117)OPERATORACTION:AfterreviewofthisWestinghousecorrespondence,ReactorEngineeringandAnalysispersonnelnotifiedOperationssupervision,whonotifiedtheControlRoomoperators.TheNRCResidentwasnotifiedatthistime.Atapproximately1540ESTonFebruary22,1999,plantstaffdeterminedthatanon-emergencyonehournotification,per10CFR50.72(b)(1)(ii)(B),shouldbemadetotheNRCOperationsCenter.TheShiftSupervisormadethisnotificationatapproximately1601ESTonFebruary22,1999.Operatorsmaintainedarestrictionof40degreesFahrenheitmaximumonscreenhousebaytemperaturefromthetimeofdiscoveryuntilplantshutdownonMarch1toensureadequatemarginexisted.AnalysesforCycle28havebeencompleted.Theseanalysesdemonstratethatthereisadequatecontainment(CNMT)pressuremarginforaMSLBforCycle28.Therestrictionpreviouslyimposedonlaketemperaturewaslifted.G.SAFETYSYSTEMRESPONSES:NoneIII.CAUSEOFEVENT:A.IMMEDIATECAUSE:TheimmediatecauseottheplantbeinginaconditionthatwasoutsidethedesignbasisoftheplantwasdeficienciesintheWestinghouseMSLBmassandenergyreleaseanalysis.B.INTERMEDIATECAUSE:TheintermediatecauseofthedeficienciesintheWestinghouseanalysiswastheanalysisdidnotaccountforagreatervolumeofhightemperaturefeedwaterandusedanincorrectfeedwaterisolationtime.TheadditionalmassandenergyreleasefromtheMSLBarepenaltiesinthecontainmentpressurecalculation.C.ROOTCAUSE:TheunderlyingcauseoftheerrorinthevolumeoffeedwaterassumptionwasinsufficientknowledgebyWestinghousepersonnelofthespecificconfigurationoftheGinnaStationfeedwaterpiping.TheUnderlyingcauseoftheerrorintheassumedfeedwaterisolationtimewashumanerrorintheuseoftheLOFTRANcodebyWestinghousepersonnel.

NRCFORM366AIB1999)LICENSEEEVENTREPORT(LER)TEXTCONTINUATIONU.S.NUCLEARREGULATORYCOMMISSIONFACILITYNAME{1)R.E.GinnaNuclearPowerPlantDOCKET(2)05000244LERNUMBERI6)SEQUENTULREVIIONNUMBERNUMBER1999-001-01PAGEI3)6OF8TEXTllfmorespaceisrequired,useeddidonelcopiesofNRCForm366A/I17)IV.ANALYSISOFEVENT:Thiseventisreportableinaccordancewith10CFR21andinaccordancewith10CFR50.73,LicenseeEventReportSystem,item(6)(2)(ii)(B),whichrequiresareportof,"Anyeventorcondition...thatresultedinthenuclearpowerplantbeing...Inaconditionthatwasoutsidethedesignbasisoftheplant".ThemodelingerrorsintheWestinghouseMSLBmassandenergyreleaseanalysishadthepotentialtopressurizetheGinnaStationcontainmentbeyonditsdesignpressureduetothispostulatedpost-accidentscenario.Anassessmentwasperformedconsideringboththesafetyconsequencesandimplicationsofthiseventwiththefollowingresultsandconclusions:TherewerenooperationalorsafetyconsequencesorimplicationsattributedtothedeficienciesintheWestinghouseMSLBmassandenergyreleaseanalysisbecause:TheMSLBcontainmentanalysisispresentedinGinnaStationUFSARSection6.2.1.2.3.Arevisedanalysiswasperformed(inMarch/April1999)byoffsettingtheadverseeffectsoftheadditionalmassandenergyreleasethroughrefinementsintheexistinganalysisassumptions.Theseimprovementsdonotalterthetotalquantityofsteamreleasedtocontainment,butprovidebenefitsinloweringtherateofthereleaseandincreasingtherateofcontairimentheatremoval.ApplyingtheseanalysisimprovementstotheMFRVfailurecasesyieldspeakcontainmentpressuresthatarelessthanthecontainmentdesignpressure.TheWestinghouseanalysis,asofMarch24,1999,showedthatthepeakcontainmentpressuredesignbasisvalueof60psigwouldnotbeexceededprovidedthatservicewater(SW)temperature(SWsuppliesthecontainmentrecirculationfans)islimitedtolessthan45degreesFahrenheit.PriortoenteringMode4fortheplanned1999refuelingoutage,thescreenhousebaytemperaturewasbeingmaintainedatapproximately39degreesFahrenheit,whilelaketemperaturewasapproximately35degreesFahrenheit.Thus,plantoperationremainedwithinitsdesignbasissincethetimeofdiscovery.ThecurrentWestinghouseanalysis,completedduringthe1999refuelingoutage,showsthatthepeakcontainmentpressuredesignbasisvalueof60psigwasnotexceededforCycle27,norwillitbeexceededforCycle28(thecurrentoperatingcycle).Operationduringfuturecyclesarealsojustified,withrestrictionssimilartothoseimposedforCycle28.Anysmallincreaseincontainmentpressurebeyondthe60psigdesignbasisvaluewouldnotbeexpectedtofailthecontainment.In1996,thecontainmentwassuccessfullytestedto72psigduringtheStructuralIntegrityTestforthesteam.generatorreplacementproject.AsteamlinebreakdoesnotresultinsevereradiologicalconsequencesatGinnaStation;thusfullcontainmentintegrityisnotconsideredrequiredforthisevent(eventhoughcontainmentisolationisassumedtooccur).

NRCFORM366A(61998)LICENSEEEVENTREPORT(LER)TEXTCONTINUATIONU.S.NUCLEARREGULATORYCOMMISSIONFACILITYNAME(1)DOCKET(2)LERNUMBER(6)PAGE(3)R.E.GinnaNuclearPowerPlant05000244SEI)ENTIAEREVSIOMHUMBER)(UMBER1999-.001-017OFBTEXTillmorespeceisrequired,useadditionelcopiesolNRCForm366Al(17)oForGinnaStationCycles1(theoriginalcyclein1970)through11,theMSLBcontainmentpressurewasnotpartoftheGinnaStationlicensingbasis.ForCycles12through25,containmentpressureonaMSLBwaspartoftheGinnaStationlicensingbasisandthepotentialexistedtoexceed60psigunderthepostulatedaccidentscenariodescribedabove.Cycles26and27operatedatthecurrentTavgof561degreesF,andwouldhavehadapeakcontainmentpressurelessthan60psigunderthepostulatedconditions.Cycle28hasalsobeenshownbeacceptable.oAtnotimeintheoperationofGinnaStationhasamainsteamlinebreakoccurred.Basedontheabove,itcanbeconcludedthattherewerenounreviewedsafetyquestions,andthatthepublic'shealthandsafetywasassuredatalltimes.V.CORRECTIVEACTION:A.ACTIONTAKENTORETURNAFFECTEDSYSTEMSTOPRE-EVENTNORMALSTATUS:FortheoperationofGinnaStationbetweenthetimeofdiscoveryandplantshutdownonMarch1,1999,thescreenhousebaytemperaturewasmaintainedatapproximately39degreesFahrenheit,whilelaketemperatureremainedatapproximately35degreesFahrenheit.Thus,plantoperationremainedwithinitsdesignbasisfromthediscoverydateuntilthe1999refuelingoutage.GinnaStationplacedatemporaryadministrativerestrictionof40degreesFahrenheitmaximumonscreenhousebaytemperatureforModes1through4(whencontainmentisrequiredtobeoperable)toensureadequatemarginexisted.CompletionofanalysesdemonstratedthatoperationforCycle28wouldbewithindesignbasis.Therestrictionpreviouslyimposedonlaketemperaturewaslifted.'B.ACTIONTAKENORPLANNEDTOPREVENTRECURRENCE:oAdditionalanalyseswereperformedtosupportcurrentandfuturecycleoperation.TheMSLBanalysis(withtheassumedMFRVfailure)wasreanalyzed.Significantassumptionchangestosupportoperationwereasfollows:Assumedshutdownmarginof2.40%versusthebasecasereferencecyclevalueof1.80%.TheGinnaStationCoreOperatingLimitsReport(COLR)wassubsequentlyrevisedtoincorporatethisvalue.

NRCFORM366hIBIBBBILICENSEEEVENTREPORT(LER)TEXTCONTINUATIONU.S.NUCLEARREGULATORYCOMMISSIONFACILITYNAME(1)R.E.GinnaNuclearPowerPlantDOCKETIz)05000244LERNUMSER(6)BrppaRMLRNBIONIIUMBTRIIUMBER1999-001-01PAGEI3)8OF8TEXT(Ifmorespaceisrequired,useadditionalcopiesofNRCForm866AII17)AssumedoperationatthenormalGinnaStationaverageoperatingtemperature(Tavg)of561degreesFversustheupperendoftheanalyzedTavgwindowof573.5degreesF.ThisoperatingrestrictionhasbeenplacedinGinnaStationoperatingproceduresandcorrespondstothefullpowerrodcontrolprogramsetpoint.PlantmodificationstorecoverthefullrangeofthepreviouslyanalyzedTavgwindowandtorestorethepreviousshutdownmarginlimitswillbeconsideredinthefuture.NuclearEngineeringServices(NES)hasimplementedaprocessforindependentreviewofvendorinputssuppliedbyRG&Eandisintheprocessofperforminganindependentreviewofallaccidentanalysisassumptions.Westinghouseisevaluatingtheneedforinternalcorrectiveactionsaspartoftheirreviewofthiscondition.VI~ADDITIONALINFORMATION:A.FAILEDCOMPONENTS:NoneB.PREVIOUSLERsONSIMILAREVENTS:AsimilarLERhistoricalsearchwasconductedwiththefollowingresults:NodocumentationofsimilarLEReventswiththesamerootcauseatGinnaStationcouldbeidentified.C.SPECIALCOMMENTS:None