ML17309A821

Provides 180-day Response to GL 95-07, Pressure Locking & Thermal Binding of Safety-Related Power-Operated Gate Valves.

ML17309A821
Person / Time
Site:	Saint Lucie
Issue date:	02/13/1996
From:	BOHLKE W H FLORIDA POWER & LIGHT CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
GL-95-07, GL-95-7, L-96-31, NUDOCS 9602220094
Download: ML17309A821 (63)

Text

CATEGORY1REGULAT(QINFORMATIONDISTRIBUTIONOSTEM(RIDE)ACCESSIONNBR:9602220094DOC.DATE:96/02/13NOTARIZED:YESFACIL:50-335St.LuciePlant,Unit.1,FloridaPower&LightCo.50-389St.LuciePlant,Unit.2,FloridaPower&LightCo.-AUTH.NAMEAUTHORAFFILIATIONBOHLKE,W.H.FloridaPower.&LightCo.RECIP.NAMERECIPIENTAFFILIATIONDocumentControlBranch(DocumentControlDesk)NPDRY'UBJECT:Provides180-dayresponsetoGL95-07,"PressureLocking&ThermalBindingofSafety-RelatedPower-OperatedGateValves."DOCKETI0500033505000389NOTES:DISTRIBUTIONCODE:A056DCOPIESRECEIVED:LTRIENCL+SIZE:TTITLE:GenericLtr95-07-PressureLocking&ThermalBindingofSafetyRelaERECIPIENTIDCODE/NAMENRR/DRPE/EATONNORRISFJVlINTERNAL:ILECENTERO'IlEXTERNAL:NOACNUDOCSABSTRACTCOPIESLTTRENCL1111111111RECIPIENTIDCODE/NAMEPD2-1PDNRR/EMEB/BNRCPDRCOPIESLTTRENCL1111110DENNOTETOALL"RIDS"RECIPIENTS:PLEASEHELPUSTOREDUCEWASTE)CONTACTTHEDOCUMENTCONTROLDESK,ROOMOWFNSD-5(EXT.415-2083)TOELIMINATEYOURNAMEFROMDISTRIBUTIONLISTSFORDOCUMENTSYOUDON'TNEED!TOTALNUMBEROFCOPIESREQUIRED:LTTR"8,ENCL,8 FloridaPower&LightCompany,P.O.Box128,FortPierce,FL34954-0128IFebruary13,1996L-96-3110CFR50.410CFR50.54(f)U.S.NuclearRegulatoryCommissionAttn:DocumentControlDeskWashington,D.C.20555RE:St.LucieUnits1and2DocketNos.50-335and50-389GenericLetter95-07-180-DaResonseThisletterprovidestheFloridaPowerandLightCompany(FPL)180-dayresponsetoNRCGenericLetter(NRCGL)95-07"PressureLockingandThermalBindingofSafetyRelatedPowerOperatedGateValves"forSt.LucieUnits1and'.FPLletterL-95-282datedOctober11,1995,statedthatFPLplanstoimplementtheactionsproposedinNRCGL95-07andthattherequestedinformationwouldbeprovidedonorbeforeFebruary13,1996.Inaddition,ourresponsestatedthatifourevaluationsdeterminedthatmodificationswererequiredandtheywouldnotbecompletedbythatsubmissiondate,FPLwouldprovideaschedulealongwiththenecessaryjustificationinourFebruary1996submittal.InaccordancewiththereportingrequirementsofNRCGL95-07,Attachment1tothisletterprovidesasummaryoftheevaluationsperformedtodemonstratethatpoweroperatedgatevalvesinstalledatSt.LucieUnits1and2willnotbepreventedfromperformingtheiractivesafetyfunctionsbythephenomenaofpressurelockingorthermalbinding.Attachment1alsoprovidestheplansandschedulesforthecorrectiveactionsimplementedorplannedtoassurethesusceptiblepoweroperatedgatevalveswillremaincapableofperformingtheirintendedsafetyfunctions.Attachment2providesasummaryoftheoperabilityassessmentforthethreeshutdowncoolingsystemvalvesthatremaintobemodifiedandthejustificationforourimplementationschedule.ThecorrectiveactionsontheremainingthreevalvesthatmaybesusceptibletopressurelockingarescheduledtobecompletedduringthenextSt.LucieUnit2refuelingoutage(SL2-10)whichiscurrentlyscheduledfortheSpringof1997.'ir602220094960213PDRADQCK05000335'PDRI.,anFPLGroupcompany

~,p>II RE:St.LucieUnits1and2DocketNo.50-335and50-389GenericLetter95-07-180-DaResonseL-96-31ThisresponseisprovidedpursuanttotherequirementsofSection.182aoftheAtomicEnergyActof1954,asamended,and10CFR50.54(f).Pleasecontactusifthereareanyquestionsaboutthissubmittal.Verytrulyyours,W.H.olkeVicePresidentSt.LuciePlantWHB/GRMAttachmentscc:StewartD.Ebneter,RegionalAdministrator,RegionII,USNRCSeniorResidentInspector,USNRC,St.LuciePlant v

St.LucieUnits1and2DocketNo.50-335and50-389GenericLetter95-07-180-DaResonseSTATEOFFLORIDA))COUNTYOFST.LUCIE)ssW.H.Bohlkebeingfirstdulysworn,deposesandsays:ThatheisVicePresident,St.LuciePlantfortheNuclearDivisionofFloridaPower&LightCompany,theLicenseeherein;Thathehasexecutedtheforegoingdocument;thatthestatementsmadeinthisdocumentaretrueandcorrecttothebestofhisknowledge,informationandbelief,andthatheisauthorizedtoexecutethedocumentonbehalfofsaidLicensee.H.oeSTATEOFFLORIDACOUNTYOFSt.LucieTheforegoinginstrumentwasacknowledgedbeforemethisdayof19g~byW.H.Boe,whoispersonallknowntomeandwhodidtakeanoath.k'.I-Ill=4W%>lNameofNotaryPuicMyCommissionexpiresCommissionNo.95'72KARENWEST=".~$+'=,.WCOMMISSION~CCSS9929EXPIRESAPIII18,1998if'>r'jj,e80NOEOTIERITROYFARIINEURANCE,INO.

~0~

St.LucieUnits1and2~~~DocketNo.50-335and50-389GenericLetter95-07-180-DaResonseATTACHMENT1ST.LUCIEUNITSj.G.2PRESSURELOCKINGANDTHERMALBINDINGOFPOWEROPERATEDGATEVALVESEVALUATIONMETHODOLOGYSUMMARY96O222009$1-1 0

EVALUATIONMETHODOLOGYSUMMARYTheassessmentofthesusceptibilityofSt.LucieUnits1and2poweroperatedvalves(POVs)topressurelockingandthermalbindingutilizedathreephasemethodconsistingof:2)InitialscreeningtoeliminatePOVsthatobviouslydonotmeettheconditionsconducivetopressurelockingand/orthermalbinding.hGatevalveevaluationtodeterminethepoweroperatedgatevalvesthatmaybesusceptibletopressurelockingand/orthermalbinding.3)Adetailed,valvespecificanalysistodeterminewhetherapoweroperatedgatevalveissusceptibletopressurelockingand/orthermalbinding.PHASE1INITIALSCREENINGCRITERIAThevalveinitialscreeningwasathreestepreviewtodeterminewhetheraPOVwasavalvetypesusceptibletopressurelockingand/orthermalbinding.Thefirststepwaspoweroperatedvalvetypescreening,thesecondstepwaspressurelockingsusceptibilityscreening,andthethirdstepwasthermalbindingsusceptibilityscreening.Theresultsofthevalvescreeningprocessofmotoroperatedvalves(MOV)forpressurelockingand/orthermalbindingaredelineatedinTable1forSt.LucieUnit1andTable2forSt.LucieUnit2.TheresultsofthevalvescreeningprocessforotherPOVsforpressurelockingand/orthermalbindingaredelineatedinTable3forSt.LucieUnit1andTable4forSt.LucieUnit2.Power0cratedValveTeScreeninCriteriaAllnon-safetyrelategatevalveshavebeenexcluedwiththeexceptionofthosenon-safety-relatedgatevalvesthatperformasafety-relatedorquality-relatedfunctionasdefinedinplantoperatingprocedures.POVswerereviewedtodeterminesafetysignificanceundertheNRCGL89-10Program.Motoroperatedvalves(MOVs)excludedfromNRCGL89-10Programwereexcludedfromtheevaluation.Pressurelockingandthermalbindingonlyconcernsgatevalves.Therefore,alloftheremainingvalvedesignshavebeenexcludedfromtheevaluationofthermalbindingandpressurelockingconditions.Theplantequipmentdatabasewasutilizedtodeterminethevalvetypes.Valvespressurelockorthermallybindwhenopenedfromafullclosedposition.Therefore,onlygatevalvesthathaveasafety-relatedfunctiontoopenwereevaluatedforpressurelockingand/orthermalbinding.1-2 00 PressureLockinScreeninCriteriaAfterallsafety-relatedpower-operategatevaveswereidentified,thispopulationofvalveswasthenscreenedbasedonvalvetypeandactivesafetyfunctiontodeterminewhethertherewasapotentialforpressurelockingorthermalbindingthatcouldpreventthevalvesfromperformingtheirintendedsafetyrelatedfunctions.Pressurelockingcanonlyoccurindoublediscorflexiblewedgegatevalves;thereforesolidwedgedesignswerenotevaluatedforpressurelocking.Valvetypeswerebasedonareviewofthevalvedrawings.Pressurelockingiscausedbyfluidgettingintothevalvebonnetandbetweenthediscsofaflexible-wedgeordouble-discwedge.Thiscouldpreventdiscmovementduetothepressurebeinghigherinthevalvebonnetandbetweenthediscsthaninthevalvebodyandtheincompressibilityofthefluidinthebonnet.Compressiblefluidshavetheabilitytooccupyasmallervolumeandallowthedisctomove,whereasincompressiblefluidsdonot.Steamsystemscanbesusceptibletopressurelockingduetothecondensationofsteamthatmayoccurinthevalvebonnet.Gatevalveswithdesignfeaturesthatpreventpressurelocking(e.g.,smallholeindisc,reliefvalveonbonnet,etc.)werescreened.ThermalBindinScreeninCriteriaDouble-discparallel-seatdiscvavesarenotsusceptietotermalbinding.Fromareviewofthevalvedrawings,alltheNRCGL89-10gatevalvesatSt.Lucieareeitherflexible-wedgeorsolid-wedgedesignwiththeexceptionoftheUnit2auxiliaryfeedwatersteamsupplyisolationvalves(MV-08-12andMV-08-13)whicharedoublediscgatevalves.Theconditionconducivetothermalbindingiswhenawedgegatevalveisclosedwhilethesystemishot,thenthermalbindingcanoccurasthesystemcools.Therefore,thermalbindingwillnotoccurifthegatevalveisclosedatnormalambienttemperatures.PHASE2GATEVALVEEVALUATIONMETHODOLOGYThemethodologyusedfortheevaluationofmotoroperatedgatevalvesnotexcludedbyinitialscreeningconsistedofapressurelockingevaluationandathermalbindingevaluation.Thirty-fourmotoroperatedvalesremainedtobeevaluatedduringthisphase.SummariesofthegateevaluationsfortheSt.LucieUnit1MOVsareprovidedinAppendix1A.SummariesofthegateevaluationsfortheSt.LucieUnit2MOVsareprovidedinAppendix1B.PressureLockinEvaluationMethodoloVariousplantoperationalsequencescouintrouceconitionsconducivetopressurelocking.Irrespectiveofinitialbonnetcavityfluidpressure(loworhigh)andtemperature,itisclearthatasubsequenttemperatureincreaseofthefluidcouldcauseanincreaseinbonnetcavitypressuredue1-3 tothermalexpansionofthefluid.Thetemperatureincreasecanoccurasfluidoneithersideofadischeatsupduringvariousmodesofplantoperationorpossiblechangesinambientairtemperaturecausedbyplantoperation,leakingpumpsorvalves,orintheeventofahigh-energylinebreak.Inthesesituations,therateoftemperatureincrease,whichmayberelativelyslowtoveryhigh,controlsthebonnetcavitypressureandvalvesusceptibilitytopressurelocking.Conversely,abonnetcavityfilledwithhighpressurefluid,suchasleakagefromthereactorcoolantsystem,becomesapressurelockingcandidateshouldaloss-of-coolantaccident(LOCA)orothertransientcausepipelinedepressurization.Basedupontheabove,theevaluationforpotentialsusceptibilityofaPOVtopressurelockingconsistsoftwoquestions:2)CanthebonnetbepressurizedduetoaPacrossthevalveandsubsequently,thevalvebodyisdepressurized?Canthebonnetbefilledwithfluidwithasubsequenttemperatureincreaseofthefluidwhichcausesanincreaseinbonnetcavitypressureduetothermalexpansion?Apositiveresponsetoeitherofthesequestionsindicatesthatavalvemaybesusceptibletopressurelockingandfurtheranalysisisrequired.ThermalBindinEvaluationMethodoloTheevaluationforpotentxasusceptiiityofapoweroperatedgatevalvetothermalbindingconsistsofonequestion:Canthevalvebeclosedwhilehotandrequiredtoopenwhenatalowertemperature?Apositiveresponsetothisquestionindicatesthatagatevalvemaybesusceptibletothermalbindingandfurtheranalysisisrequired.PHASE3VALVESPECIFICANALYSISAdetailed,valvespecificanalysiswasperformedonMOVsthatwerenotexcludedbyeithertheinitialvalvescreeningorgatevalveevaluationprocesses.Ninemotoroperatedvalveswereidentifiedaspotentiallysusceptibletopressurelockingand/orthermalbindingandwereevaluatedinthisphase.Sixvalvesweremodifiedasdescribedbelow.ThreevalvesonUnit2remaintobemodified;thebasisfortheircontinuedoperabilityisdescribedinAttachment2.OnSt.LucieUnit1,theshutdowncooling(SDC)systemisolationvalves(V-3480,V-3481,V-3651,andV-3652),whichisolatethereactorcoolantsystem(RCS)hotlegsfromtheSDCsystem,are1-4 susceptibleonlytopressurelocking.NopoweroperatedvalveswereidentifiedasbeingsusceptibletothermalbindingonUnitl.Acalculationwasperformedto'determinethethrustrequiredtoopenthesevalvesassumingthebonnetbecomespressurelockedat2235psig.Asaresult,theactuatorgearratiowaschangedduringtheFall1994St.LucieUnit1refuelingoutage(SLl-13).Themodificationincreasedtheactuatorcapabilitysufficientlytoovercometheworstcasepressurelockingscenario.Therefore,pressurelockingisnolongeraconcernfortheUnit1valves(V-3480,V-3481,V-3651,andV-3652).OnSt.LucieUnit2,theSDCisolationvalves(V-3480,V-3481,V-3651,andV-3652),whichisolatetheRCShotlegsfromtheSDCsystem,andtheSDCsuctioncross-tievalve(V-3545),aresusceptibleonlytopressurelocking.,Nopoweroperatedvalveswereidentifiedasbeingsusceptibletothermalbinding.ThecorrectiveactionfortheSt.LucieUnit2gatevalves,V-3481andV-3545,wasimplementedduringtheFall1995Unit2refuelingoutage(SL2-9).AplantmodificationwasimplementedtoaddanequalizationholeinthehighpressuresidediscofV-3481andasecondmodificationwasimplementedtochangethenormalpositionofV-3545tonormallyopen.Attachment2ofthisletterprovidesasummaryoftheoperabilityassessmentandtheschedulejustificationforSt.LucieUnit2Cycle9fortheremainingthreeSDCisolationmotor-operatedgatevalves,V-3480,V-3651andV-3652.ThecorrectiveactionsforthesevalveswillbeimplementedduringtheSt.LucieUnit2Cycle10refuelingoutage(SL2-10)currentlyscheduledfortheSpringof1997.ThemodificationtoV-3481wasthepilotimplementationoftheplannedcorrectiveactionsfortheremainingthreevalves.Thesafety-relatedfunctionoftheseSDCvalvesistoopentoestablishshutdowncoolingfordecayheatremovalfollowingapostulatedaccident.Sincethesevalvesarenotrequiredtoopenfor3to4hoursfollowinganaccident,itwasdeterminedthatapressurelockingconditionwouldnotexistifadequateseatleakageexistedtoequalizethepressurebetweenthevalvebonnetandthevalvebody.Theknownvalveseatleakagewoulddepressurizethebonnetoverthistimeperiodandpermitthemotoroperatortoopenthevalve.1-5 TABLEj.ST.LUCIEUNITj.PRESSURELOCKINGANDTHERMALBINDINGSCREENINGFORMOTOROPERATEDVALVESVALVENO.NRCGLiGATE'AFETY'RESSURE89-10VALVEFUNCTIONLOCKINGbTOOPEN123THERMALBINDING12v-1403V-1405V-2501V-2504v-2508v-2509V-2514V-2525v-3206V-3207V-3432V-3444V-3452V-3453V-3456V-3457v-3480v-3481V-3614HCV-3615HCV-3616HCV-3617V-3624HCV-3625YESYESYESYESYESYESYESYESYESYESYESYESYESYESYESYESYESYESNOYESYESYESNOYESYESYESYESYESYESYESYESYESYESYESYESYESYESYESYESYESYESYESNONONONOYESNOYESNONOYESYESYESYESYESYESYESYESYESYESYESYESNONONONONOYESYESYESYESYESYESYESYESYESYESYESYESYESYESYESYESYESYESYESYESYESNOYESNOYESNOYESNOYESYESYESYESYESYESYESYESYESYESYESYESYESYESNONONONOYESYESYESYESYESYESIfthoansworinanyofthosocolumnsisNO,thenadditionalscrooningforsusceptibilitytoprossurolockingand/orthormalbindingisnotroquirod.PRESSURELOCKINGSCREENINGCRITERIA)IfthoanswertoanyofthofollowingQuestionsisHOthonthevalveisnotsusceptibletopressurelockingandfurtherevaluationisnotroquirod.l.2~3.DoesthoValvehaveaFloxiblo-WedgeorDouble-DiscWodgeDosign2IsthoVolvoinstalledinaprccossmediacontainingincomprossiblofluidand/orsteam2IsthoValvolackindosignfeaturesthatpreventprossurolocking(o.g.,smallholeindisc,roliofvavoonbcnnot,otc.).2THERHALBINDIHGSCREENIHGCRITERIA:IfthoanswertoanyofthofollowingQuestionsisNO,thenthevalveisnotsusceptibletothormalbindingandfurtherevaluationisnotrequired.l.2~DoesthoValvehaveaFlexible-Wedge,Solid-WedgoorSplit-WodgeDesign'2CanthoValvoboclosedundertemperatureconditionsgreaterthannormalambientconditionsorduotoHOTambientconditions(o.g.,HELBorHSLB/LOCA)21-6 TABLEj.ST.LUCIEUNITj.PRESSURELOCKINGANDTHERMALBINDINGSCREENINGFORNOTOROPERATEDVALVESVALVENO.NRCGLiGATE'AFETY'RESSURE89-10VALVEFUNCTIONLOCKINGb123THERMALBINDING12HCV-3626HCV-3627v-3634HCV-3635HCV-3636HCV-3637V-3644HCV-3645HCV-3646HCV-3647V-3651v-3652V-3653V-3654.V-3655V-3656V-3659V-3660v-3662v-3663MV-02-1MV-02-2MV-03-2Mv-03-1AYESYESNOYESYESYESNOYESYESYESYESYESNOYESNOYESYESYESYESYESNONOYESYESNONONONONONONONOYESYESYESYESYESYESYESYESNONOYESYESNONONONOYESYESYESYESYESYESYESYESYESYESYESYESYESYESYESYESYESYESYESYESYESYESIfthsanswerinanyofthesecolumnsisNO,thenadditionalscreeningforsusceptibilitytopressurelockingand/orthermalbindingisnotrequired.PRESSURELOCKINGSCREENINGCRITERIA)IftheanswertoanyofthefollowingQuestionsisNOthenthevalveisnotsusceptibletopressurolockingandfurtherevaluationisnotrequired.1.2~3.DoesthsValvehavoaFloxiblo-WedgeorDouble-DiscWodgeDosign2IsthoValveinstalledinaprocossmediacontainingincomprossiblofluidand/orsteam?IsthoValvo~lackindesignfeaturesthatpreventpressurelocking(o.g.,smallholeindisc,relief~vavoonbonnot,otc.).2THERMALBINDINGSCREENINGCRITERIA:IfthoanswertoanyofthofollowingQuestionsisNO,thonthovalveisnotsusceptibletothermalbindingandfurtherevaluationisnotrequired.1.2.DoesthoValvehaveaFlexible-Wedge,Solid-WedgeorSplit-WsdgoDesign2CantheValvebeclosedundortemperatureconditionsgreaterthannormalambientconditionsorduetoHOTambientconditions(e.g.,HELBorMSLB/LOCA)21-7 0eI TABLEj.ST.LUCIEUNITj.PRESSURELOCKINGANDTHERMALBINDINGSCREENINGFORMOTOROPERATEDVALVESVALVENO.NRCGL'ATEaSAFETY'RESSURE89-10VALVEFUNCTIONLOCKINGbTOOPEN123THERMPJBINDINGc12MV-03-1BMV-07-lAMV-07-1BMV-07-2AMV-07-2BMV-08-1AMV-08-1BMV-08-3MV-08-13MV-08-14MV-09-1MV-09-2MV-09-7MV-09-8MV-09-9MV-09-10MV-09-11MV-09-12MV-09-13MV-09-14MV-14-1MV-14-2MV-14-3MV-14-4YESYESYESYESYESYESYESYESYESYESYESYESYESYESYESYESYESYESYESYESYESYESYESYESNONONONONONONONONONOYESYESYESYESNONONONONONONONONONONONONONOaIfthoansworinanyofthosocolumnsisNO,thonadditionalscreeningforsusceptibilitytopressurolockingand/orthermalbindingisnotrequired.PRESSURELOCKINGSCREENINGCRITERIAIIftheanswertoanyofthofollowingQuestionsisNOthonthovalveisnotsusceptibletoprossurolockingandfurtherevaluationisnotrequired.1.2.3.DossthoValvohaveaFlexible-WedgeorDouble-DiscWedgeDesign?IstheValvoinstalledinaprocessmediacontainingincompressiblefluidand/orsteam?IsthoValvolackindosignfeaturosthatpreventpressurelocking(e.g.,smellboloindisc,reliofvavoonbonnet,etc.).TTHERHALBINDINGSCREENINGCRITERIA:IftheanswertoanyofthefollowingQuestionsisNO,thenthevalveisnotsusceptibletothermalbindingandfurtherevaluationisnotrequired.1~2.DoosthoValvehaveaFlexible-Wedge,Solid-WedgeorSplit-WedgeDesign?CanthoValvoboclosedundertemperatureconditionsgreaterthannormalaabientconditionsorduotoHOTaabiontconditions{e.g.,HELBorHSLB/LOCA)21-8 TABLEj.ST.LUCIEUNITj.PRESSURELOCKINGANDTHERMALBINDINGSCREENINGFORMOTOROPERATEDVALVESNRCGLiGATEAUSAFETY'ALVFNO.89-10VALVEFUNCTIONTOOPENPRESSURELOCKINGb123THERMALBINDINGc12MV-14-5mr-14-6MV-14-7MV-14-8MV-15-1MV-18-1MV-21-2MV-21-3FCV-25-9YESYESYESYESYESYESYESYESYESNONONONOYESYESNONONONONOIftheanswerinanyofthesecolumnsisHO,thenadditionalscreeningforsusceptibilitytopressurelockingand/orthermalbindingisnotrequired.PRESSURELOCKINGSCREENINGCRITERIAIIftheanswertoanyofthefollowingQuestionsisHOthenthevalveisnotsusceptibletopressurelockingandfurtherevaluationisnotrequired.l.2.3.DoestheValvehaveaI'lexible-WedgeorDouble-DiscWedgeDesign?IstheValveinstalledinaprocessmediacontainingincompressiblefluidand/orsteam?IstheValvelacklnc[designfeaturesthatpreventpressurelocking(e.g.,smallholeindisc,relief~vaveonbonnet,etc.).TTHERMALBINDINGSCREENINGCRITERIA:IftheanswertoanyofthefollowingQuestionsisNO,thenthevalveisnotsusceptibletothermalbindingandfurtherevaluationisnotrequired.l.2.DoestheValvehaveaplexible-Wedge,Solid-WedgeorSplit-WedgeDesign?CantheValvebeclosedundertemperatureconditionsgreaterthannormalambientconditionsorduetoHOTambientconditions(e.g.,HELBorMSLB/LOCA)I1-9 v'5'Q~~p TABLE2ST.LUCIEUNIT2PRESSURELOCKINGANDTHERMALBINDINGSCREENINGFORMOTOROPERATEDVALVESVALVENO.HRCGLa89-10GATEaVALVESAFETYaFUNCTIONTOOPENPRESSURELOCKINGb123THERMALBINDIHGc12V-1476V-1477V-2185V-2501V-2504v-2508V-2509V-2514V-2525v-2553V-2554V-2555V-2598FCV-3301FCV-3306V-3432V-3444V-3456V-3457V-3480V-3481HCV-,3512V-3517V-3523V-3536v-3539YESYESNOYESYESYESYESYESYESYESYESYESNOYESYESYESYESYESYESYESYESYESYESYESYESYESYESYESYESYESYESYESYESYESNONONONONOYESYESYESYESYESYESNOYESNONONOYESYESNOYESYESYESYESNONONOYESYESYESYESYESYESYESYESYESYESYESYESYESYESYESYESYESYESYESYESYESYESYESYESYESYESYESYESYESYESYESYESYESYESYESYESYESYESYES,YESYESYESYESYESYESYESYESYESYESYESYESNONONONOYESYESYESYESYESIfthoansworinanyofthesecolumnsisHO,thenadditionalscreeningforsusceptibilitytopressurelockingand/crthermalbindingisnotrequired.PRESSURELOCKINGSCREENINGCRITERIA1IitheanswertoanyofthefollowingQuestionsisNOthonthovalveisnotsusceptibletoprossurelockingandfurtherevaluationisnotrequired.1~2.3.DoestheValvehaveaFloxiblo-WedgeorDouble-DiscWedgeDesign?IstheValveinstalledinaprocossmodiacontainingincomprossiblefluidand/orsteam?IsthoValve~lackindosignfeaturosthatprevontprossurelocking(o.g.,smallholeindisc,relief~vavoonbonnet,otc.).TcTHERMALBINDINGSCREENIHGCRITERIA:IftheanswertoanyofthefollowingQuestionsisNO,thonthovalveisnotsusceptibletothermalbindingandfurtherevaluationisnotrequired.1.2~DoestheValvehaveaFlexible-Wedge,Solid-WedgeorSplit-WedgeDesign?CantheValveboclosedundertemporaturoconditionsgreaterthannormalambiontconditionsorduetoHOTambientconditions(o.g.,HELBorMSLB/LOCA)T1-10 TABLE2ST.LUCIEUNIT2PRESSURELOCKINGANDTHERMALBINDINGSCREENINGFORMOTOROPERATEDVALVESVALVENO.HRCOLa89-10GATEaVALVESAFETYaPRESSVRELOCHIHObFUNCTIOH123TOOPENTHERMALBINDIHGc12V-3540V-3545V-3550V-3551v-3614HCV-3615HCV-3616HCV-3617V-3624HCV-3625HCV-3626HCV-3627v-3634HCV-3635HCV-3636HCV-3637V-3644HCV-3645HCV-3646HCV-3647V-3651V-3652V-3654V-3656HCV-3657v-3658YESYESYESYESNOYESYESYESNOYESYESYESNOYESYESYESNOYESYESYESYESYESYESYESYESYESNOYESNONO~NONONONONONONONONONONONOYESYESYESYESNOYESYESYESNONOYESYESYESYESYESYESYESYESYESYESYESYESYESYESYESYESYESYESYESYESYESYESIftheanswerinanyofthesecolumnsisNO,then.additionalscreeningforsusceptibilitytoprossurelockingand/orthermalbindingisnotrequired.PRESSURELOCKINGSCREENINGCRITERIA)IftheanswertoanyofthofollowingQuestionsisHOthenthovalveisnotsusceptibletoprossurolockingandfurtherevaluationisnotroquirod.1~2.3.DoestheValvehaveaFlexible-WodgeorDouble-DiscWedgeDesign?IsthsValveinstalledinaprocessmediacontainingincompressiblefluidand/orsteam?IstheValvelackindesignfeaturesthatpreventpressurelocking{o.g.,smallholeindisc,reliefvavoonbonnet,stc.)~2THERMALBINDINGSCREENINGCRITERIA:IftheanswertoanyofthefollowingQuestionsisNO,thenthevalveisnotsuscoptiblotothermalbindingandfurtherevaluationisnotrequired.1.2.DoestheValvehaveaFlexible-Wedge,Solid-WedgeorSplit-WedgeDesignTCantheValvebeclosedundertomperaturoconditionsgreaterthannormalambientconditionsorduetoHOTambientconditions{o.g.,HELBorMSLB/LOCA)21-11 I

TABLE2ST.LUCIEUNIT2PRESSURELOCKINGANDTHERMALBINDINGSCREENINGFORMOTOROPERATEDVALVESVALVENO.NRCGLa89-10GATEVALVESAFETYaFVNCTIONTOOPENPRESSVRELOCHIHGb123THERMALBIHDIHGc12V-3659v-3660v-3664v-3665mr-07-1AMV-07-1BMV-07-2AMV-07-2BMV-08-1AMV-08-1BMV-08-3MV-08-12MV-08-13mr-08-14MV-08-15MV-08-16MV-08-17MV-08-18AMV-08-18BMV-08-19AMV-08-19BMV-09-9MV-09-10MV-09-11MV-09-12MV-09-13YESYESYESYESYESYESYESYESYESYESYESYESYESYESYESYESYESYESYESYESYESYESYESYESYESNOYESYESYESYESNONONONONONONOYESYESYESYESYESYESNONONONONONONONONONOYESYESYESYESNONONONOYESYESYESYESYESYESYESYESYESYESYESYESYESYESNONOYESYESIfthoanswerinanyofthosocolumnsisNO,thenadditionalscreeningforsusceptibilitytopressurelockingand/orthermalbindingisnotrequired.PRESSURELOCKINGSCREENINGCRITERIA;IfthoanswertoanyofthefollowingQuestionsisNOthenthevalveisnotsusceptibletopressurelockingandfurtherevaluationisnotrequired.l.2.3.DoesthoValvohaveaFlexible-WedgeorDouble-DiscWedgoDesign?IstheValvoinstalledinaprocessmediacontainingincompressiblefluidand/orsteam?IsthoValvo~lsckindosignfeaturesthatprovontpressurelocking(o.g.,smallholoindisc,roliof~vavoonbonnot,otc.).TTHERMALBINDINGSCREENIHGCRITERIA:IfthoanswertoanyofthofollowingQuestionsisNO,thonthovalveisnotsuscoptiblotothermalbindingandfurtherevaluationisnotroquired.1.2.DoesthoValvohaveaFlexible-Wedge,Solid-WedgoorSplit-WedgeDesign?CantheValveboclosedundertemperatureconditionsgreaterthannormalambientconditionsorduetoHOTambientconditions{e.g.,HELBorMSLB/LOCA)T1-12 TABLE2ST.LUCIEUNIT2PRESSURELOCKINGANDTHERMALBINDINGSCREENINGFORMOTOROPERATEDVALVESVALVENO.NRCGL'g-IOGATEaVAIVESAFETYaPRESSVRELOCNING"FUNCTION123TOOPENTHERMALBINDIHGc12MV-09-14MV-14-1MV-14-2MV-14-3MV-14-4MV-14-9MV-14-10MV-14-11MV-14-12MV-14-13MV-14-14MV-14-15MV-14-16MV-14-17MV-14-18MV-14-19MV-14-20MV-21-2MV-21-3MV-21-4AMV-21-4BFCV-25-29FCV-25-32FCV-25-33FCV-25-34NOYESYESYESYESYESYESYESYESYESYESYESYESYESYESYESYESYESYESYESYESYESYESYESYESNONONONONONONONONONONONONONONONONONONONONONONONOIftheanswerinanyofthesecolumnsisNO,thenadditionalscreeningforsusceptibilitytopressurelockingand/orthermalbindingisnotrequired.PRESSURELOCKINGSCREENINGCRITERIArIftheanswertoanyofthofollowingQuestionsisNOthenthovalvoisnotsuscoptiblotopressurelockingandfurtherevaluationisnotrequired.l.2.3~DoestheValvehaveaFloxiblo-WodgeorDouble-DiscWedgoDesign?IstheValveinstalledinaprocossmediacontainingincompressiblofluidand/orsteam?IstheValvelackindosignfeaturesthatpreventpressurelocking{e.g.,smallholeindisc,reliefvavoonbonnet,etc.).?THERMALBINDINGSCREEHINGCRITERIA:IfthoanswortoanyofthofollowingQuestionsisNO,thenthevalveisnotsusceptibletothermalbindingandfurtherevaluationisnotrequired.l.2.DoesthoValvehaveaFloxiblo-Wodge,Solid-WedgoorSplit-WodgoDosign?CantheValveboclosedundertemperatureconditionsqroatorthannormalambientconditionsorduetoHOTambientconditions(e.g.,HELBorMSLB/LOCA)?1-13

TABLE3ST.LUCIEUNITj.PRESSURELOCKINGANDTHERMALBINDINGSCREENINGOFPOWEROPERATEDVALVESVALVENO.POV~GATEVALVESAFETY'UNCTIONTOOPENPRESSURELOCKINGa123THERMALBIHDIHG~12V-3459YESNOIftheanswerinanyofthosecolumnsisNO,thenadditionalscreoningforsusceptibilitytopressurelockingand/orthormalbindingisnotrequired.hPRESSURELOCKIHGSCREENINGCRITERIA'ftheanswertoanyofthofollowingQuestionsisNOthonthevalveisnotsusceptibletopressurelockingandfurtherevaluationisnotroquired.1.2.3.DoesthoValvohaveaFlexible-WedgeorDouble-DiscWedgeDesign?IstheValveinstalledinaprocossmediacontainingincompressiblefluidand/orsteam?IstheValve~lackindosignfoaturesthatprovontprossurolocking(o.g.,smallhaloindisc,relief~vavoonbonnet,otc.).TcTHERMALBINDINGSCREENINGCRITERIA:IftheanswertoanyofthofollowingQuestions1sHO,thonthovalvoisnotsusceptibletothermalbindingandfurtherevaluationisnotrequired.1.2.DoesthoValvehavoaFlexible-Wedge,Solid-WedgeorSplit-WedgeDesign?CanthoValveboclosedundertemperatureconditionsgreaterthannormalambientconditionsorduetoHOTambiontconditions(e.g.,HELBorMSLB/LOCA)T1-14 TABLE4ST.LUCIEUNIT2PRESSURELOCKINGANDTHEKItALBINDINGSCREENINGFORPOWEROPERATEDVALVESVALVENO.FCV-07-1AFCV-07-1BHCV-09-1AHCV-09-1BHCV-09-2AHCV-09-2BPOV'ATEVALVEYESYESYESYESYESYESSAFETY'UNCTIONTOOPENYESYESNONONONOPRESSURELOCKINGn123NONOTHERMPJBINDING12NONOIfthoanswerinanyofthesecolumnsisNO,thenadditionalscreeningforsusceptibilitytopressurelockingand/orthormalbindingisnotrequired.PRESSURELOCKINGSCREENINGCRITERIA'fthoanswertoanyofthofollowingQuestionsisNOthonthovalveisnotsusceptiblotoprossurolockingandfurtherevaluationisnotrequirod.l.2.3.DoestheValvehaveaFloxiblo-WodgoorDouble-DiscWedgeDesign2IsthoValveinstalledinaprocossmediacontainingincompressiblefluidand/orstoam2IsthoValve~lackindesignfoaturosthatpreventprossurolocking(e.g.,smallholoindisc,relief~vavoonbonnet,etc.).2THERHALBINDINGSCREENINGCRITERIA:IfthoanswortoanyofthofollowingQuestionsisNO,thenthevalveisnotsusceptibletothermalbindingandfurtherevaluationisnotrequired.l.2.DoestheValvehaveaFlexible-Wodge,Solid-WedgeorSplit-WedgeDesign2CantheValvebeclosedundertemperatureconditionsgreaterthannormalambientconditionsorduetoHOTambientconditions{e.g.,HELBorHSLB/LOCA)21-15

~~St.LucieUnits1and2DocketNo.50-335and50-389GenericLetter95-07-180-DaResonseAPPENDIX1AST.LUCIEUNIT1GATEEVALUATIONSUMMARYOFPRESSURELOCKINGANDTHERMALBINDINGFORPOWEROPERATEDGATEVALVES

ST.LUCIEUNIT1PHASE2GATEVALVEEVALUATIONSUMMARYV-1403andV-1405"PowerOperatedReliefValve(PORV)BlockValves"Descrition:V-1403andV-1405are2'/,"VelansolidwedgegatevaveswitSMB-00actuators.Thevalvesarelocatedin,thecontainmentbuilding,outsidethepressurizercubicle.Themaximumopeningdifferentialpressureis2485psid.Duringpoweroperationbothblockvalvesarerequiredtoremainopen.V-1403andV-1405performthesafety-relatedfunctiontopassivelymaintainRCSpressureboundary.Thequality-relatedfunctionofthesevalvesistoisolatethepressurizerintheeventaPORVisstuckopen.Inaddition,thePORVsareutilizedforcontingenciesforfunctionalrecovery:RCSpressurecontrolsuccesspath5,PORVsandRCSandcoreheatremoval,successpath4,"once-through-cooling".BothofthesecontingenciesrequireverifyingthePORVblockvalvesareopen.PressureLockin:NoevaluationisrequiredbecauseV-1403andV-4aresoiwedgegatevalveswhichhavenotbeendemonstratedtobesusceptibletopressurelocking.ThermalBindin:DuringaLOCA,ifactionstoisolatetheLOCAcannoteaccomplished,theOperatorsaredirectedtoclosethePORVsorcloseV-1403orV-1405.ThesevalvescouldbeclosedathightemperatureearlyinaLOCAscenariothenlaterberequiredtoopen,aligningaPORVforlowtemperatureoverpressureprotection(LTOP)oronce-through-cooling,aftertheRCShasbeendepressurizedandcooleddown.TheLTOPscenarioisconsideredtobetheboundingthermalbindingscenario.AreviewwasconductedtodetermineifV-1403andV-1405hadeverbeenclosedhot(e.g.,toisolatealeakingPORV)andsubsequentlyopenedtoalignforLTOP.ItwasdeterminedthatbothV-1403&V-1405hadbeenusedtoisolatealeakingPORVwhentheunitwasat100%powerandsubsequentlysuccessfullyopenedtoalignforLTOP.Inaddition,subsequenttothisevent,thesevalveswerechangedtocloseonlimitswitch-inlieuoftorqueswitch.Theuseoflimitswitchcontrolintheclosingdirectionreducesthevalveseatingloadsandthepotentialforthermalbinding.Conclusion:,V-1403andV-1405arenotsusceptibletothermalgh1bbjdhp1dworstcasethermalbindingscenario,atatimewhenthepotentialofthermalbindingwasgreaterduetotorqueswitchseatingofthevalves,andthevalvesopened.V-1403andV-1405arenotsusceptibletopressurelocking.V-2504"RefuelingWaterTank(RWT)IsolationValve"Descrition:Thisvalveisa3"Velanflex-wedgegatevalvewithanSMB-actuator.Thevalveislocatedinthe2Achargingpumpcubicleatelevation0'9".Themaximumopeningdifferential pressureis93psid.Thevalveisnormallyclosed.Thesafety-relatedfunctionofV-2504isopentoalignthechargingpumpstotheRWTforanalternateboratedwatersupplyrequiredbyTechnicalSpecifications.Thequality-relatedfunctionofV-2504istoautomaticallyopenuponreceiptofavolumecontroltank(VCT)lowlowlevelsignaltoaligntheRWTtothechargingpump(s)suction.PressureLockin:ThereisnoseveredepressurizationpostulatedfortepipingsystemupstreamofV-2504ontheorderofaLOCAorahigh-energy-line-break(HELB).ThemostseveredepressurizationwouldoccurduetolossofRWTlevel.Therefore,pressurelockingduetoupstreamdepressurizationisnotcredible.Inregardstothermalexpansionoffluidtrappedinthebonnet,significanttemperaturechangesatthisvalvearenotpostulatedduetothelimitationonsolutiontemperaturebetween55'Fand100'F.Duetothephysicallocationofthevalve,V-2504shouldremainclosetoambienttemperaturesatalltimesandpressurelockingisnotaconcern.Thermal-Bindin:V-2504isrestrictedbytheTechnicalSpecificationlimitationontemperaturefortheRWTof55'Fto100'F.Therefore,itispostulatedthatV-2504wouldnotbeclosedhot.Therefore,thermalbindingisnotaconcern.Conclusion:V-2504isnotsusceptibletopressurelockingord'.V-2508&V-2509"BoricAcidGravityFeedValves"Descrition:V-2508&V-2509are3"Velanflex-wedgegatevalveswitSMB-actuators.Thevalvesareloc'atedinthereactorauxiliarybuilding(RAB)insidetheboricacidmakeuptank(BAMT)cubicleatelevation2'-7'/,".V-2508&V-2509arelocatedattheoutletofBAMTs.Themaximumopeningdifferentialpressureis28psid.Thesafety-relatedfunctionofthesevalvesistoopenuponreceiptofasafetyinjectionactuationsignal(SIAS)toprovideconcentratedboratedwatertothechargingpumps.PressureLockin:ThereisnoseveredepressurizationpostulatedfortepipingsystemupstreamofthesevalvesontheorderofaLOCAorHELB.Themostseveredepressurizationwouldoccurduetochangesinboricacidmakeuptanklevel.Therefore,pressurelockingduetoupstreamdepressurizationisnotcredible.Inregardstothermalexpansionoffluidtrappedinthebonnet,significanttemperaturechangesatthesevalvesisnotpostulatedbecauseofthelowtemperaturesinthesystem.ThermalBindin:Duetothelowtemperaturesinthesystem,termainingisnotconsideredtobecredible.Conclusion:V-2508andV-2509arenotsusceptibletopressuregggg.

V-2514'Make-upBypasstoChargingPumps"Descrition:V-2514isa3"AnchorDarlingflex-wedgegatevalvewitanSMB-000actuator.Thevalveislocatedinthereactorauxiliarybuilding(RAB)-0.5elevation.Themaximumopeningdifferentialpressureis146psid.Thevalveisnormallyclosed.Thesafety-relatedfunctionofV-2514isopentoalignthechargingpumpstotheboricacidmake-up(BAM)pumpsforanalternateboratedwatersupplyrequiredbyTechnicalSpecifications.PressureLockin:ThereisnoseveredepressurizationpostulatedfortepipingsystemupstreamofV-2514ontheorderofaLOCAorHELB.ThemostseveredepressurizationwouldoccurduetolossBAMTlevelorlossofaBAMpump.Therefore,pressurelockingduetoupstreamdepressurizationisnotcredible.Inregardstothermalexpansionoffluidtrappedinthebonnet,significanttemperaturechangesatthisvalvearenotpostulatedduetotheflowofBAMTfluidbecauseofthelimitationonsolutiontemperature>55'Fandenvironmentalconditions<120'F.ThermalBindin:Duetothelimitationonsystemandenvironmentaltemperaturesetween55'Fand120'F,thermalbindingisnotaconcern.Conclusion:V-2514isnotsusceptibletopressurelockingor~'.V-3452,V-3453,V-3456andV-3457"ShutdownCoolingHeatExchangerIsolationValves"Descrition:Thesevalvesare10"Velanflex-wedgegatevalveswitSMB-actuators.Thevalvesarelocatedoutsidethecontainmentbuilding,insidetheRAB,inthe1Aand1Bshutdowncoolingheatexchangerroomsatelevation4'7".V-3452,V-3453,V-3456andV-3457arenormallylockedclosedisolationvalvesthatservetoisolatetheSDCheatexchangers(HXs)fromthelowpressuresafetyinjection(LPSI)systemwhentheSDCHXsarenotinuse.Thesafety-relatedfunctionforthesevalvesistoopentoallowwarmupandoperationoftheSDCHXs.Themaximumopeningdifferentialpressureis207psid.PressureLockin:FornormalSDCsystemwarm-up,forplacingtheSDCsysteminoperation,andrestorationofSDCHXs,thesevalvesareopenedwithaLPSIpumprunning.Thereisnorapiddepressurizationeventupstreamordownstreamofthesevalves(e.g.,duetoalinebreak)thatwouldrequirethesevalvestoopen.Inregardstothermalexpansionoffluidtrappedinthebonnet,thesevalvesarerequiredtoopenforwarminguptheSDCsystemandforrestoringtheSDCsystemtoservicefollowingisolationoftheSDCHXs.Therefore,thevalveswouldnotbeheatedpriortoopening.ForrestorationoftheSDCHX,duringthetimeframewheretheSDCHXisbypassed,thereisapotentialforanincreaseinSDCsystemtemperature.However,thesevalvesarenotaffectedbythesystemtemperatureincreasesbecauseofthe

~Ie physicallocationofthevalverelativetotheSDCHXinlet/outletlinesandtheSDCbypassline.Therefore,thesevalveswillnotheatupafterclosingduetosystemtemperatureincreases.ThermalBindin:Themostlimitingscenarioforthesevalvesisuetoaossofcomponentcoolingwater(CCW)totheSDCHXs.Forthisevent,thesevalvescouldbeclosedhot(300'F)andrequiredtoopenafterthesystemhascooledduetotherestorationofCCWorduetoambientconditions.However,thermalbindingisnotlikelybecauseitisanticipatedthattherestorationofCCWtotheSDCHXswouldbeashortevolution(i.e.,theSt.LucieUnit1TechnicalSpecificationsrequirecorrectiveactiontorestoretheSDCloopstooperablewithin1hourorestablishotherappropriatecorrectiveactions)andthebodyandwedgearecomposedofmaterialswhichhavecomparablemeancoefficientsofthermalexpansion.Therefore,thermalexpansiondifferenceswouldbesmallandare.withinthecapabilityoftheactuators.Conclusion:V-3452,V-3453,V-3456andV-3457arenotsusceptibletopressurelockingand/orthermalbinding.V-34806V-3652"ShutdownCoolingIsolationValves"Descrition:Thesevalvesare10"Velanflex-wedgegatevalveswitSMB-actuators.Thevalvesarelocatedinthecontainmentbuilding,insidethesecondaryshieldwallatelevation34'1".V-3480andV-3652aretheinboard(totheRCS)isolationvalvesthatisolate1Aand1BtrainsofSDCsystemfromtheRCS.Themaximumopeningdifferentialpressureis273psid.Thesafety-relatedfunctionforthesevalvesistoopentoaligntheRCStotheSDCsysteminordertocooltheRCSfromhotshutdown(Mode4)tocoldshutdown(Mode5).ThermalBindin:Typically,V-3480andV-3652areclosedunderhotconditions('F)whenisolatingtheSDCsystemduringheatupandopenedcold(<120'Fduetothevalvescoolingtoambientconditions).Inaddition,thesevalvescouldbeisolatedunderhotconditionsduetoaninadvertentisolationofSDCandcoolifleftisolatedforasignificantperiodoftime.Undertheseconditions,thermalbindingcouldoccur.However,itisimportanttonotethatthermalbindinghasnotbeenobservedinthesevalveswhenthevalvesareopenedtoaligntheSDCsystemtotheRCSduringaplantcooldown.Conclusion:V-3480andV-3652arepotentiallysusceptibletopressurelockingbutnotthermalbinding.Inaddition,thesevalvesmaybesusceptibletoanincreaseinbonnetpressuresabovemaximumRCSpressureduetoambienttemperatureincreaseassociatedwithamainsteamlinebreak(MSLB)insidecontainmentandduetosystemheatupeffectsafterthevalvebonnetshavebecomepressurized.Thesevalvesrequiredaphase3review,thedetailedvalvespecificanalysisdescribedinAttachment1(seepage1-4),inorderto determineifsufficientheatinputfromcontainmentisavailabletoincreasethevalvebonnettemperature.V-3481&3651"ShutdownCoolingIsolationValves"Descrition:Thesevalvesare10"Velanflex-wedgegatevalveswxtSMB-actuators.Thevalvesarelocatedinthecontainmentbuilding,insidethesecondaryshieldwallatelevation36'9"(V-3481)and29'7"(V-3651).V-3481andV-3651aretheoutboard(totheRCS)isolationvalvesthatisolatelAand1BtrainsofSDCsystemfromtheRCS.Themaximumopeningdifferentialpressureis273psid.Thesafety-relatedfunctionforthesevalvesistoopentoaligntheRCStotheSDCsysteminordertocooltheRCSfromhotshutdown(Mode4)tocoldshutdown(Mode5).ThermalBindin:Typically,V-3481andV-3651areclosedunderhotconxtz.ons'F)whenisolatingtheSDCsystemduringheatupandopenedcold(<120'F)duetothevalvescoolingtoambientconditions.Inaddition,thesevalvescouldbeisolatedunderhotconditionsduetoaninadvertentisolationofSDC.Asaresult,thevalvescouldcoolifleftisolatedforasignificantperiodoftimeduetothedistanceofthevalvesfromtheRCS.Undertheseconditions,thermalbindingcouldoccur.However,itisimportanttonotethatthermalbindinghasnotbeenobservedinthesevalveswhenthevalvesareopenedtoaligntheSDCsystemtotheRCSduringaplantcooldown.Conclusion:V-3481andV-3651arepotentiallysusceptibletopG1'hh11.dd'.h1maybesusceptibletoanincreaseinbonnetpressuresabovemaximumRCSpressureduetoambienttemperatureincreaseassociatedwithamainsteamlinebreak(MSLB)insidecontainmentafterthevalvebonnetshavebecomepressurized.Thesevalvesrequiredaphase3review,thedetailedvalvespecificanalysisdescribedinAttachment1(seepage1-4),inordertodetermineifsufficientheatinputfromcontainmentisavailabletoincreasethevalvebonnettemperature.V-3662&V-3663"HighPressureSafetyInjection(HPSZ)PumpSuctionValvesFromSDCHXs"DESCRIPTION:V-3662&V-3663are4"Velanflexwedgegatevalves~.h11dhatelevation4'6".Themaximumopeningdifferentialpressureis223psid.ThesafetyfunctionofthesevalvesistoopentosupplycooledwaterfromtheSDCHXtothesuctionofthehighpressuresafetyinjection(HPSI)pumpsjustpriortoinitiationofanrecirculationactuationsignal(RAS).PressureLockin:ThesevalvesarenotaffectedbytherapidepressurizationassociatedwithMSLBorLOCAduetheirlocationintheemergencycorecoolingsystem(ECCS).ThemostsignificantdepressurizationwouldbeassociatedwiththestartingandstoppingofaLPSIpump.However,thesevalvesarestroketestedquarterly whichadequatelydemonstratesthecapabilityofthesevalvestostrokeafterstartingandstoppingaLPSIpump.Inregardstothermalexpansionoffluidtrappedinthebonnet,V-3662&V-3663arerequiredtoopenpost-LOCAafterthecontainmentspraypumpshavebeeninjecting55'F-100'FwaterfromtheRWTandpriortoRAS.Therefore,thereisnoheatinputintotheSDCsystem(priortoRAS)whenV-3662andV-3663arerequiredtoopen.ThermalBindin:ItisnotcredibletopostulateathermalbindingconitionforthesevalveswhentheyarerequiredtoopentoperformtheirsafetyfunctionbecausethetemperatureoftheSDCsystemisgreaterthanambientonlywhentheSDCHXsarein-servicetoshutdowntheunit.ThesevalvesarenotcycledduringthetimetheSDCsystemisalignedtotheRCStoshutdowntheunit.Conclusion:V-36626V-3663arenotsusceptibletopressuregd/h1b.1A-7 0

St.LucieUnits1and2DocketNo.50-335and50-389GenericLetter95-07-180-DaResonseAPPENDIX1BST.LUCIEUNIT2GATEEVALUATIONSUMMARYOFPRESSURELOCKINGANDTHERMALBINDING'FORPOWEROPERATEDGATEVALVES P

ST.LUCZEUNIT2PHASE2GATEVALVEEVALUATIONSUMMARYV-1476andV-1477"PowerOperatedReliefValve(PORV)BlockValves"Descrition:Thesevalvesare3"Westinghouseflex-wedgegatevaveswitSB-00actuators.Thevalvesarelocatedinthecontainmentbuilding,outsidethepressurizercubicle.Themaximumopeningdifferentialpressureis2485psid.InaccordancewithSt.LucieUnit2TS,duringpoweroperationonlyoneblockvalveispermittedtoremainopen,theotherisclosed.V-1476andV-1477performthesafety-relatedfunctiontopassivelymaintainRCSpressureboundary.Thequality-relatedfunctionofthesevalvesistoberemote-manuallyactuatedtoisolatetheassociatedPORVinordertosatisfythe"fail-closed"requirementsoftheirrespectivePORV.Inaddition,thePORVsareutilizedforcontingenciesforfunctionalrecovery:theRCSpressurecontrolsuccesspath5,PORVs,andtheRCSandcoreheatremovalsuccesspath4,once-through-cooling.BothofthesecontingenciesrequireverifyingthePORVblockvalvesareopen.PressureLockin:InModes1,2and3,thepressurizerlevelismax.ntainesothatthePORVsandsafetyreliefvalves(andV-1476&V-1477)willrelieveonlysteam.Thebonnetcouldbe'comepressurizedinasteamsystemandduetoalargeorsmallbreakLOCA,experiencerapiddepressurizationupstreamofthevalve.However,thecompressibilityofthesteaminthebonnetprecludesthisscenariofromcausingapressurelockedcondition.SteampressurizationofMOVbonnetsisapressurelockingconcernduetoconfigurationsthatpermitcondensatetocollectanddrainintothevalvebonnet(e.g.,verticalpiperuns)withasubsequenttemperatureincreaseofthevalvebonnet."Upright"valveshavenotexperiencedpressurelockingduetosteaminthebonnet.V-1476andV-1477areorientedinthe"upright"position.ThermalBindin:Undernormalconditions,eitherV-1476orV-1477a.scosepriortoheatinguptheRCStoabove325'F.Inaddition,thevalvesaredemonstratedoperableatleastonceper92daysbyoperatingthevalvethroughonecompletecycleoffulltravel(unlessclosedwithpowerremoved).Thevalvesarere-openedtoalignforLTOPwhenRCStemperatureislessthan240'F.ThereisnoevidencethatthermalbindingoccurswiththesevalvesbecausethesevalveshaveperformedthefunctionofopeningtoalignforLTOPatlessthan240'FafteroperationinModes1,2and3.Inaddition,thesevalveshaveLimitorquetypeSBoperatorswhichhavecompensatingspringpacksthatabsorbinertialclosingforcesandpreventexcessivewedgingofthediscintotheseat.Theinstallationofcompensatingspringpacksonmotoroperatorsreducesthevalveseatingloadsandthepotentialforthermalbinding.Conclusion:V-1476andV-1477arenotsusceptibletopressuregd/h11"g.

V-2504"RWTIsolationValve"Descrition:Thisvalveisa3"Westinghouseflex-wedgegatevavewitanSB-00actuator.Thevalveislocatedinthe2Achargingpumpcubicleatelevation0'9".Themaximumopeningdifferentialpressureis29psid.Thevalveisnormallyclosed.Thesafety-relatedfunctionofV-2504isopentoalignthechargingpumpstotherefuelingwatertank(RWT)foranalternateboratedwatersupplyrequiredbyTechnicalSpecifications.However,creditisnottakenforremoteoperationofV-2504becausetheoperatorisnotClass1E.Instead,theassumptionisplantoperatorswillmanuallyopenthevalve.Inaddition,thequality-relatedfunctionifV-2504istoautomaticallyopenuponreceiptofaVCTlowlowlevelsignaltoaligntheRWTtothechargingpump(s)suction.PressureLockin:ThereisnoseveredepressurizationpostulatedortepipingsystemupstreamofV-2504ontheorderofaLOCAorHELB.ThemostseveredepressurizationwouldoccurduetolossofRWTlevel.Therefore,pressurelockingduetoupstreamdepressurizationisnotcredible.Inregardstothermalexpansionoffluidtrappedinthebonnet,significanttemperaturechangesatthisvalvearenotpostulatedduetotheflowofRWTfluidbecauseofthelimitationonsolutiontemperaturebetween55'Fand100'F.ThermalBindin:FluidtemperatureinV-2504isrestrictedbytheTecnicaSpecificationlimitationontemperaturefortheRWTof55'Fto100'F.ItispostulatedthatV-2504wouldnotbeclosedattemperaturesgreaterthan100'F;thereforethermalbindingisnotaconcern.Conclusion:V-2504isnotsusceptibletopressurelockingordg.V-2508&V-2509"BoricAcidGravityFeedValves"Descrition:V-2508&V-2509are3"Westinghouseflex-wedgegatevaveswitSB-00actuators.Thevalvesarelocatedinthereactorauxiliarybuilding(RAB)insidetheboricacidmakeuptank(BAMT)cubicleatelevation13'-6.5".V-2508&V-2509arelocatedattheoutletofBAMTs.Themaximumopeningdifferentialpressureis16.2psid.Thesafety-relatedfunctionofthesevalvesistoopenuponreceiptofaSIAStoprovideconcentratedboratedwatersupplytothechargingpumps.PressureLockin:ThereisnoseveredepressurizationpostulatedortepipingsystemupstreamofthesevalvesontheorderofaLOCAorHELB.Themostseveredepressurizationwouldoccurduetochangesinboricacidmakeuptanklevel.Therefore,pressurelockingduetoupstreamdepressurizationisnotcredible.Inregardstothermalexpansionoffluidtrappedinthebonnet,significanttemperaturechangesatthesevalvesisnotpostulatedbecauseofthelowtemperaturesinthesystem.

ThermalBindin:Duetothelowtemperaturesinthesystem,thermalindingisnotconsideredtobecredible.Conclusion:V-2508andV-2509arenotsusceptibletopressureghh.V-2514"BoricAcidMakeupBypasstoChargingPumps"Descrition:V-2514isa3"Westinghouseflex-wedgegatevalvewitanSB-00actuator.Thevalveislocatedintheboricacidmakeup(BAMT)cubicleatelevation2'".Themaximumopeningdifferentialpressureis132.2psid.Thevalveisnormallyclosed.Thesafety-relatedfunctionofV-2514isopentoalignthechargingpumpstotheBAMpumpsforanalternateboratedwatersupplyrequiredbyTechnicalSpecifications.PressureLockin:ThereisnoseveredepressurizationpostulatedfortepipingsystemupstreamofV-2514ontheorderofaLOCAorHELB.ThemostseveredepressurizationwouldoccurduetolossBAMTlevelorlossofaBAMpump.Therefore,pressurelockingduetoupstreamdepressurizationisnotcredible.Inregardstothermalexpansionoffluidtrappedinthebonnet,significanttemperaturechangesatthisvalvearenotpostulatedduetothelimitationonsolutiontemperaturebetween55'Fand100'F.ThermalBindin:DuetothelimitationonsolutiontemperatureetweenFan100'F,thermalbindingisnotaconcern.Conclusion:V-2514isnotsusceptibletopressurelockingord'.V-34566V-3457"ShutdownCoolingHeatExchangerOutletValves"Descrition:Thesevalvesare10"Westinghouseflex-wedgegatevaveswitSB-0actuators.Thevalvesarelocatedoutsidethecontainmentbuilding,insidetheRAB,inthe2Aand2Bsafeguardsrooms.V-3456andV-3457arenormallylockedclosedisolationvalvesthatservetoisolatetheSDCheatexchangersfromtheLPSIsystemwhentheSDCHXsarenotinuse.Thesafety-relatedfunctionforthesevalvesistoopentoallowwarmupandoperationoftheSDCHXs.Themaximumopeningdifferentialpressureis269psid.PressureLockin:FornormalSDCsystemwarm-up(andforplacingteSDCsysteminoperation),thesevalvesareopenedpriortostartingtheLPSIpumpsandbeforetheSDCsystemisalignedtotheRCS.Thereisnorapiddepressurizationeventupstreamordownstreamofthesevalves(e.g.,duetoalinebreak)thatwouldrequirethesevalvestoopen.ForrestorationofSDCHXsevents,thesevalveswouldbeclosedandreopenedonalossofCCWtoaSDCHX.ThesevalveswouldbereopenedwithaLPSIpumprunning.Therefore,thereisnodepressurizationeventpostulatedinwhichthevalvesarereliedupontoopen.Inregardstothermal expansionoffluidtrappedinthebonnet,V-3456andV-3457arerequiredtoopenforwarminguptheSDCsystemandforrestoringtheSDCsystemtoservicefollowingisolationoftheSDCHXs.Forwarmup,thesevalvesareopenedpriortostartingtheassociatedLPSIpump.Therefore,thevalveswouldnotbeheatedpriortoopening.ForrestorationoftheSDCHXevent,thephysicallocationofthevalvespreventsthemfrombeingexposedtotemperatureincreasesinthesystem.ThermalBindin:ForalossofCCWtotheSDCHXs,thesevalvescouecosedhotandrequiredtoopenafterthesystemhascooledduetotherestorationofCCWorduetoambientconditions.However,forthefollowingreasons,thermalbindingisnotlikely:1)ItisexpectedthattherestorationofCCWtotheSDCHXswouldbeashortevolution(i.e.,<30minutes)andthesevalveswouldlikelynotexperiencesignificantcoolinginthistimeframe;2)V-3456andV-3457arecontrolledinthecloseddirectionbypositionlimitswitches(thislimitstheseatingforceofthediscintheseats);3)V-3456andV-3457haveSB-0actuatorsinstalledonthem.SBLimitorqueoperatorshavecompensatingspringpacksthatabsorbinertialclosingforcesandpreventexcessivewedgingofthediscintotheseat.Theinstallationofcompensatingspringpacksonmotoroperatorsreducesthevalveseatingloadsandthepotentialforthermalbinding;4)Thebodyanddiscareidenticalmaterials.Therefore,thermalexpansiondifferenceswouldbesmallandarewithinthecapabilityoftheactuators.Conclusion:V-3456andV-3457arenotsusceptibletopressuregd/h1b.V-34806V-3652"ShutdownCoolingIsolationValves"Descrition:Thesevalvesare10"Westinghouseflex-wedgegatevaveswitSMB-1actuators.Thevalvesarelocatedinthecontainmentbuilding,insidethesecondaryshieldwallatelevation39'0"(V-3480)and30'6"(V-3652),respectively.V-3480andV-3652arethein-board(totheRCS)isolationvalvesthatisolate2Aand2BtrainsofSDCfromtheRCS.Themaximumopeningdifferentialpressureis277psid.Thesafety-relatedfunctionforthesevalvesistoopentoaligntheRCStotheSDCsysteminordertocooltheRCSfromhotshutdown(Mode4)tocoldshutdown(Mode5).ThermalBindin:Typically,V-3480andV-3652areclosedunderhotconz.talons('F)whenisolatingtheSDCsystemduringheatupandopenedcold(<120'F)duetothevalvescoolingtoambientconditions.Inaddition,thesevalvescouldbeisolatedunderhotconditionsduetoaninadvertentisolationofSDC.Asaresult,thevalvescouldcoolifleftisolatedforasignificantperiodoftimeduetothedistanceofthevalvesfromtheRCS.Undertheseconditions,thermalbindingcouldoccur.However,itisimportanttonotethatthermalbindinghasnotbeenobservedinthesevalveswhenthevalvesareopenedtoaligntheSDCsystemtotheRCSduringaplantcooldown.

==

Conclusion:==

V-3480andV-3652arepotentiallysusceptibletopCk'bh1b.dd'.h1maybesusceptibletoanincreaseinbonnetpressuresabovemaximumRCSpressureduetoambienttemperatureincreaseassociatedwithaMSLBinsidecontainmentafterthevalveshavebecomepressurized.Thesevalvesrequiredaphase3review,the'detailedvalvespecificanalysisdescribedinAttachment1(seepage1-4),inordertodetermineifsufficientheatinputfromcontainmentisavailabletoincreasethevalvebonnettemperature.V-3481,V-3651&V-3545"ShutdownCoolingIsolationValves"Descrition:Thesevalvesare10"Westinghouseflex-wedgegatevaveswitSMB-1actuators.Thevalvesarelocatedinthecontainmentbuilding,insidethesecondaryshieldwallatelevation39'0"(V-3481),30'6"(V-3651)and36'3"(V-3545),respectively.V-3481andV-3651aretheoutboard(totheRCS)isolationvalvesthatisolate2Aand2BtrainsofSDCsystemfromtheRCS.V-3545istheSDCsuctioncross-tieisolationvalve.Themaximumopeningdifferentialpressureis277psid(V-3481&V-3651)and275psid(V-3545).Theshutdowncoolingsuctionlinesareconfiguredsuchthatoneofthetwoisolationvalvesineachlineispoweredfromthe2Atrain,whilethesecondisolationvalve,ispoweredfromthe2Btrain.Thecross-tievalve(V-3545)ispoweredfromthe480Vmotorcontrolcenter(MCC)2AB,whichcanbealignedtoeitherthe2Aor2Belectricaltrain.ThisconfigurationwasrequiredtoensurethattheSDCsystemcouldbealignedtotheRCSintheeventofalossofeither2Aor2Btrainpower.Therefore,thesafety-relatedfunctionforthesevalvesistoaligntheRCStotheSDCsysteminordertocooltheRCSfromhotshutdown(Mode4)tocoldshutdown(Mode5).ForV-3545,thesafetyfunctionisrequiredasaredundantdesignfeatureforalossofelectricalpower"tooneoftheelectricaltrains.ThermalBindin:Typically,V-3481,V-3651andV-3545areclosedunerotconitions(>300'F)whenisolatingtheSDCsystemduringheatupandopenedcold((120'F)duetothevalvescoolingtoambientconditions.Inaddition,thesevalvescouldbeisolatedunderhotconditionsduetoaninadvertentisolationofSDC.Asaresult,thevalvescouldcoolifleftisolatedforasignificantperiodoftimeduetothedistanceofthevalvesfromtheRCS.Undertheseconditions,thermalbindingcouldoccur.However,itisimportanttonotethatthermalbindinghasnotbeenobservedinthesevalveswhenthevalvesareopenedtoaligntheSDCsystemtotheRCSduringaplantcooldown.Conclusion:V-3481,V-3651,andV-3545arepotentiallysusceptibletopressurelockingbutnotthermalbinding.Inaddition,thesevalvesmaybesusceptibletoanincreaseinbonnetpressuresabovemaximumRCSpressureduetoambienttemperatureincreaseassociatedwithaMSLBinsidecontainmentafterthevalveshavebecomepressurized.Thesevalvesrequiredaphase3review,thedetailed IK' valvespecificanalysisdescribedinAttachment1(seepage1-4),inordertodetermineifsufficientheatinputfromcontainmentisavailabletoincreasethevalvebonnettemperature.V-3517andV-3658"ShutdownCoolingHeatExchangerInletIsolationValves"-3517d-355511"*'ggl-dggatevalveswithSB-Oactuators.Thevalvesarelocatedoutsidethecontainmentbuilding,insidethereactorauxiliarybuilding,inthe2Aand2Bsafeguardsroomsatelevations-7'10"(V-3517)and-2'8'/,"(V-3658).ThesevalvesarenormallylockedclosedisolationvalvesthatservetodisolatetheSDCheatexchangersfromtheLPSIsystemwhentheSDCHXsarenotinuse.Thesafety-relatedfunctionforthesevalvesistoopentoallowwarmupandoperationoftheSDCHXs.Themaximumopeningdifferentialpressureis162psid.PressureLockin:FornormalSDCsystemwarm-upandforplacingteSDCsysteminoperation,thesevalvesareopenedafterstartingtheLPSIpumpsandbeforetheSDCsystemisalignedtotheRCS.Thereisnorapiddepressurizationeventupstreamordownstreamofthesevalves(e.g.,duetoalinebreak)thatwouldrequirethesevalvestoopen-.Inregardstothermalexpansionoffluidtrappedinthebonnet,V-3517andV-3658arerequiredtoopenforwarminguptheSDCsystem.Forwarmup,thesevalvesareopenedafterstartingtheassociatedLPSIpumpandpriortoopeningtheSDCHXflowcontrolvalve.FlowisroutedthroughtheSDCHXuntilthesystemheatsup.Therefore,thevalveswouldnotbeexposedtotemperatureincreasespriortoopening.ThermalBindin:ThemostlimitingscenarioisisolationofV-3517anV-uetore-alignmentoftheSafetyInjectionsystemafterheatup.InthisscenariothevalvesareclosedafterrecirculatingtheSDCto150'F.DuringwarmuptoplacetheSDCinservice,thevalveswouldberequiredtoopenatatemperature<150'F.ThermalbindingisnotlikelybecausethechangeintemperaturefromremovaloftheSDCsystemfromservicetowarmingthesystemupisrelativelysmall,andthebodyanddiscarecomposedofthesamematerial.Therefore,thermalexpansiondifferenceswouldbesmall.Inaddition,thesevalveshaveoperatorswhichhavecompensatingspringpacksthatabsorbinertialclosingforcesandpreventexcessivewedgingofthediscintotheseat.Theinstallationofcompensatingspringpacksonmotoroperatorsreducesthevalveseatingloadsandthepotentialforthermalbinding.Conclusion:V-3517andV-3658arenotsusceptibletopressuregd/515.V-36646V-3665"ShutdownCoolingIsolationValves"Descrition:Thesevalvesare10"Westinghouseflex-wedgegatevaveswa.tSB-0actuators.Thevalvesarelocatedoutsidethecontainmentbuilding,insidetheRABatelevation24'7"(V-3664) 00 and25'0"(V-3665),respectively.V-3664andV-3665arethecontainmentisolationvalvesthatisolate2Aand2BtrainsofSDC.Themaximumopeningdifferentialpressureis269psid.Thesafety-relatedfunctionsforthesevalvesistoprovidecontainmentisolationandtoopentoaligntheRCStotheSDCsysteminordertocooltheRCSfromhotshutdown(Mode4)tocoldshutdown(Mode5).PressureLockin:V-3664&V-3665aresubjectedtoupstreampressurefromtheRCSduringalignmentforshutdowncooling.ThisscenarioassumesthatV-3664&V-3665areopenedfollowingtheopeningoftheupstreamshutdowncoolingisolationvalves.Thereisnorapiddepressurizationassociatedwiththisscenario.However,ifitisassumedthatthereisleakagepastupstreamisolationvalvesV-3664&V-3665thelinecouldbepressurizedto335psig(theSDCreliefvalvesetpoint).However,forthedepressurizationoftheRCSfrom350psiato275psia(thepermissivesetpointforaligningtheRCStoSDC),forMSLBorsmallbreakLOCAscenarios,thedepressurizationisnotsignificantlydifferentfromthenormalPlantCooldownscenario.Therefore,itisreasonabletoconcludethatthesevalvesarenotsusceptibletopressurelockingbasedthecapabilityofthesevalvestoopenforanormalplantshutdown.Inregardstothermalexpansionoffluidtrappedinthebonnet,V-3664andV-3665remainclosedwhentheSDCsystemiswarmed-up.However,V-3664andV-3665arephysicallyisolatedfromtheflowpathforSDCwarm-up.ThermalBindin:Thesevalvescouldbeclosedunderhotconditions(i.e.,SDCcoolingisolatedwhiletheRCSisstillhotorinadvertentisolationofSDC),andthevalvecouldcoolifleftisolatedforasignificantperiodoftimeduetothedistanceofthevalvefromtheRCS.Undertheseconditions,thermalbindingcoul'doccur.However,thesevalve'shaveoperatorswhichhavecompensatingspringpacksthatabsorbinertialclosingforcesandpreventexcessivewedgingofthediscintotheseat.Theinstallationofcompensatingspringpacksonmotoroperatorshasbeenidentifiedasonemethodforpreventingthermalbinding.Therefore,V-3664andV-3665arenotconsideredtobesusceptibletothermalbinding.Conclusion:V-3664andV-3665arenotsusceptibletopressuregh11.MV-08-12&MV-08-13"2CAuxiliaryFeedWater(AFW)PumpSteamAdmissionValves"DESCRIPTION:Thesevalvesare4"Pacificdoublediscgatevalves.1d'y.hdifferentialpressureis1015psid.Thesevalvesarenormallyclosedandopenathightemperature(i.e.,operatingtemperature=532'F).Thesevalvesopenuponreceiptofanauxiliaryfeedwateractuationsignal(AFAS)andprovideaflowpathfrommainsteamtothe2CAFWpumpturbine.Inaddition,thevalvesmustbecapableofoperatingondemandtoinitiate2CAFWflowtothesteamgenerators toreduceRCStemperaturetotheentrytemperatureforinitiatingtheSDC.PressureLockin:MV-08-12andMV-08-13couldexperiencerapidepressurxzationupstreamofthevalve(e.g.,MSLB,feedwater,linebreak).However,sincethesevalvesaresteamvalves,thecompressibilityofthesteaminthebonnetprecludesthisscenariofromcausingapressurelockedcondition.Pressurelockingofsteamvalvesoccursduetoconfigurationsthatpermitcondensatetocollectanddrainintothevalvebonnet(e.g.,verticalpiperuns)withasubsequenttemperatureincreaseofthevalvebonnet.MV-08-12andMV-08-13areinstalledinhorizontalpiperunswiththeactuatorsmountedabovethecenterlineofthepipe.BasedupontheconfigurationofMV-08-12andMV-08-13,itisunlikelythatcondensatewouldcollectintheirbonnets.ThermalBindin:Doublediscgatevalvesarenotconsideredsusceptxetothermalbinding.Conclusion:MV-08-12andMV-08-13arenotsusceptibletopressureg1gh.1B-9

St.LucieUnits1and2DocketNo.50-335and50-389GenericLetter95-07-180-DaResonseATTACHMENT2ST.LUCIEUNIT2SUMMARYOFTHEOPERABILITYASSESSMENTFORPRESSURELOCKINGOFSHUTDOWNCOOLINGPOWEROPERATEDGATEVALVESV-.3480,V-3651,ANDV-36522-1 EVALUATIONAlthoughtheNRCGL95-07doesnotpermitavalvetobeexcludedfromconsiderationofpressurelockingduetolackofoccurrenceatthespecificplant,orvalveleakagerate,FPLconsidersthattheactualvalveseatleakageandvalvehistoricalperformanceareacceptablefordeterminingvalveoperabilityuntilthefinalcorrectivemeasuresareimplemented.DuringtheevaluationoftheUnit2SDCisolationvalves(V-3480,V-3651andV-3652)forthepurposesofdemonstratingoperability,theactualvalveseatleakageperformancewasutilized.TheNRCGLdidnotdiscusstheexclusionofseatleakagefordeterminingvalveoperabilityandthisapproachdoesnotexcludethevalvesfromfurtherconsiderationofpressurelocking.Additionally,apressurelockingeventhasnotbeenidentifiedforthisWestinghousevalvedesign(1500psiclassflexwedgegate)oneitherSt.Lucieunit,andnonewereidentifiedinthereviewofNUREG-1275',Volume9,Supplement6toNRCGL89-10',NRCIN92-26'rINPOSOER84-074.ValveLeakaeReuiredandSurveillanceDataFPLhasconservativeycacuatetatvaveseateaage>.004gpmforV-3480andV-3652,andthatseatleakage>0.011gpmforV-3651wouldreducepressureinthevalvebonnetsandthepipingbetweentheSDCisolationvalvestoshutdowncoolingentryconditions(-250psig)within3hoursfollowingthemostlimitingpressurelockingscenario.ThemostlimitingscenarioforpressurelockingisaMSLBinsidecontainment.AlargebreakLOCAisnotconsideredlimitingbecausethecontainmentsumprecirculationwouldprovidefordecayheatremoval,andtheshutdowncoolingisolationvalveswouldnotberequired.AsmallbreakLOCAwouldresultinrapiddepressurization,butwouldnotsignificantlyheatupcontainment.ValveseatleakagesurveillancerequirementsspecifiedinSt.LucieUnit2TechnicalSpecification,(TS)4.4.6.2.3aresatisfiedbyperformingAdministrativeProcedure2-0010125Aat>leastonceevery18months.ThesurveillancetestisalsorequirediftheunitentersMode5andthetesthasnotbeenperformedinthepreceding9months.Thetestisperformedwithadifferentialpressuregreaterthan200psidacrossthevalve.Areviewofthecompleteddatasheetsfortheperiodfrom1990to1995showedthat,NUREG-1275,Volume9,"OperatingExperienceFeedbackReport-PressureLockingandThermalBindingofGateValves"GenericLetter89-10,Supplement6,"InformationonScheduleandGrouping,andStaffResponsestoAdditionalPublicQuestions"'NRCInformationNotice92-26,"PressureLockingofMotorOperatedFlexibleWedgeGateValves"INPOSOERNumber84-07,"PressureLockingandThermalBindingofGateValves"2-2

historically,theobservedseatleakageforthesevalveshasbeen>0.011gpm.ThisexceedstheminimumrequiredleakagetoreducebonnetpressurepriortoopeningtheisolationvalvesfollowingapostulatedMSLB.BasisforUtilizinTestSeatLeakaeThevalveflex-wedgehasagapetweenitsupstreamanownstreamdiscs;thefluidinthisgapishydraulicallyconnectedtothebonnet.FortheobservedseatleakagetooccurduringtheTSsurveillancetest,thedownstreamdiscmustleakthroughtheseat.Seatleakagethroughthisdiscallowsthebonnettodepressurizeduringanormalplantcooldownevolution,priortoopeningthevalvesforshutdowncoolingoperation.Theconditioninthevalvesduringnormalheatup,operationandcooldownarepredictedtobeasfollows:1)Duringthe18-monthTSsurveillancetest,thevalvesareseatleakagetestedwiththeRCSatapproximately250psiatoobtainavalvedifferentialpressuregreaterthan200psid.Theobservedseatleakagerequiresthatthedownstreamdischavesomeleakage.2)DuringRCSheatup,thevalvesareclosedwiththeRCSandshutdowncoolingfluidat270psigand300'F.NotethatthedownstreamisolationvalvesV-3664andV-3665onthesamepipinglinebutoutsidecontainmentarealsoclosedatthistime.3)DuringRCSheatupandsteadystateoperation,thevalvescooltoambienttemperature,andthedifferentialpressurebetweentheRCSfluid(2250psia)andbonnetfluidforcestheupstreamdiscwedgeawayfromitsseat.ThebonnetfluidmaypressurizetoRCSpressure,eitherduetothediscwedgebeingforcedawayfromitsseat,orduetoleakagethroughthematingsurfacesoftheseatanddiscwedge.Theupstreamvalvediscwedgewillre-seatwhenthedifferentialpressureforceacrosstheupstreamdiscisminimized;thisoccurswhenbonnetpressureapproachesRCSpressure.Iftheoutboardisolationvalves(V-3481andV-3651)havealowerseatleakageratethantheupstreamisolationvalves(V-3480andV-3652),thepipingbetweenthevalvesmayalsopressurizetoapproximatelyRCSpressure.Ifavalve'sdownstreamseatleakageisgreaterthantheupstreamvalvewedgeleakage,thebonnetmaynotpressurizesignificantly;thiscouldpressurizedownstreampipingandcausepressurereliefvalvesV-3666orV-3667(335psigsetpoint)toliftanddischargeintothecontainmentsump.Reliefvalvedischargecouldbeobservedbychangesinthecontainmentsumplevel,bytheRCSleakagedetectionsystem,orasRCSleakage.DuringRCScooldownthevalvebonnetandpipingbetweenthevalveswilldepressurize,duetothemeasuredseatleakagethroughthedownstreamvalvewedge.Thetimefromreactortriptoenteringshutdowncoolingistypically8hours.2-3 0

4)IfadesignbasisMSLBoccurs,theRCSwoulddepressurizeto500psiainapproximately80seconds.Plantoperatorsmaycommencearapidcooldowntoshutdowncoolingentryconditionsin3hours.Sincethevalveshaveahistoryofminorseatleakagethroughtheupstreamanddownstreamwedgesandseatsatlowdifferentialpressure,itisexpectedthatvalveseatleakagewouldoccurunderpost-MSLBconditionstoreducebonnetpressure.However,thedifferencebetweenaMSLBcooldownandanormalcooldownisthatthereisonlya3hourversus8hourcooldownperiod,andthevalvesandpipingwillheatupandpressurizebecausecontainmentambienttemperaturewillincreaserapidly.Undertheseconditions,therequiredvalveseatleakageraterequiredtoreducethepressureinthevalvebonnetandpipingfromRCSpressuretotheshutdowncoolingsystemdesignpressurein3hoursis0.0011gpmforvalveV-3651and0.004gpmforvalvesV-3480andV-3652.TherequiredvalveseatleakagetotheshutdowncoolingsystemismuchlessthantheobservedseatleakageratedeterminedbytheTSsurveillancetest.ToensurethecontinuedoperabilityoftheshutdowncoolingisolationvalvesafterFall1995St.LucieUnit2refuelingoutage(SL2-9),plantpersonnelverifiedthattheobservedseatleakagewasatleast0.01gpmforV-3480andV-3652,andatleast0.015gpmforV-3651.Thisleakagerateprovidesa35%marginbetweenmeasuredandrequiredseatleakage.BasisforExtendinCorrectiveActionUntil1997RefuelinOutaeTeparmedcorrectiveactionwastriaimpementeonV-48duringtheFall1995SL2-9refuelingoutageandwillbereplicatedontheremainingthreevalvesduringthenextrefuelingoutage.Inaddition,theplannedcorrectiveactionsforV-3480andV-3652willrequireafreezesealand/orafullcoreoffload.Topermitbetterintegrationofthemodificationsintotherefuelingoutageactivities,theremainingmodificationsweredelayeduntiltheSpring1997St.LucieUnit2refuelingoutage(SL2-10).Deferringcorrectiveactionuntilthenextoutageisnotasafetyissueforthefollowingreasons:Theshutdowncoolingisolationvalvesarenotrequireduntil3hoursafterapostulatedaccident.Bythattime,thebonnetpressureandpipingpressurewilldecaytoanacceptablevalue,basedontheactualobservedvalveseatleakage;2)NoincidenceofthesevalvesfailingtoopenhaseverbeenidentifiedoneitherSt.Lucieunit.Noincidenceofpressurelockinghasbeenreportedtothevalvevendor,orlistedinthereviewedindustrydata;and2-4 0

TheaffectedvalveswouldbeprioritizedasmediumpriorityusingNRCGL89-10guidelines.FormediumpriorityMOVs,theNuclearEnergyInstitute(NEI)guidancerecommendsthattheresourcesareappropriatelyappliedrelativetosafetysignificanceandpriorityoftheMOV.2-5 l~0'0