ML17241A489

LER 99-004-00:on 990912,noted That MSSV Surveillance Was Outside of TS Requirements.Caused by Setpoint Drift.Subject MSSVs Are Being Refurbished & Retested Prior to Unit Startup from SL1-16 Refueling Outage.With 991007 Ltr

ML17241A489
Person / Time
Site:	Saint Lucie
Issue date:	10/07/1999
From:	FREHAFER K W, STALL J A FLORIDA POWER & LIGHT CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
L-99-219, LER-99-004-01, NUDOCS 9910140083
Download: ML17241A489 (10)

Text

MMJ;NVUlCY'~~~~REGULATORYINFORMATIONDISTRIBUTIONSYSTEM(RIDS)ACCESSIONNBR:9910140083DOC.DATE:99/10/07NOTARIZED:NOFACIL:50-335St.LuciePlant,Unit1,FloridaPower&LightCo.AUTH.NAME.'AUTHORAFFILIATIONFREHAFER,K.W.FloridaPower&LightCo.STALL,J.A.,FloridaPower&LightCo.RECIP.NAMERECIPIENTAFFILIATIONDOCKET¹05000335

SUBJECT:

LER99-004-00:on990912,notedthatMSSVsurveillancewasoutsideofTSrequirements.Causedbysetpointdrift.SubjectMSSVsarebeingrefurbished&retestedpriortounitstartupfromSLl-16refuelingoutage.With991007ltr.DISTRIBUTIONCODE:IE22TCOPIESRECEIVED:LTRIENCLISIZE:TITLE:50.73/50.9LicenseeEventReport(LER),IncidentRpt,etc.NOTES:'ECIPXENTIDCODE/NAMELPD2-2INTERNAL:ACRSNRR/DIPM/IOLBNRR/DSSA/SPLBRES/DRY/OERABCOPIESLTTRENCL1111111111RECIPIENTIDCODE/NAMEGLEAVES,WNRR/DRXP/REXBRES/DET/ERABRGN2FILE01'OPIESLTTRENCL1111111111EXTERNAL:LSTLOBBYWARDNOACPOORE,W.NRCPDR111111LMXTCOMARSHALLNOACQUEENER,DSNUDOCSFULLTXT111111NOTETOALL"RIDS"RECIPIENTS:PLEASEHELPUSTOREDUCEWASTE.TOHAVEYOURNAMEORORGANIZATIONREMOVEDFROMDISTRIBUTIONLISTORREDUCETHENUMBEROFCOPIESRECEIVEDBYYOUORYOURORGANIZATION,CONTACTTHEDOCUMENTDESK(DCD)ONEXTENSION415-2083TDOCUMENTCONTRCFULLTEXTCONVERSIONREQUIREDTOTAL,NUMBEROFCOPIESREQUIRED:LTTR16ENCL16 FloridaPowerStLightCompany,6351S.OceanDrive,JensenBeach,FL34957FPLOctober7,1999L-99-21910CFR$50.73U.S.NuclearRegulatoryCommissionAttn:DocumentControlDeskWashington,D.C.20555Re:St.LucieUnit1DocketNo.50-335ReportableEvent:1999-004-00DateofEvent:September12,1999MainSteamSafetyValvesSurveillanceOutsideTechnicalSecificationReuirementsTheattachedLicenseeEventReport1999-004isbeingsubmittedpursuanttotherequirementsof10CFRf50.73toprovidenotificationofthesubjectevent.Verytrulyyours,J.A.StallVicePresidentSt.LucieNuclearPlantJAS/EJW/KWFAttachmentcc:RegionalAdministrator,USNRC,RegionIISeniorResidentInspector,USNRC,St.LucieNuclearPlant99i0140083991007PDRADOCK05000335PDRanFPLGroupcompany NRCFORM366I6.1999)U.S.NUCLEARREGULATORYCOMMISSIONLICENSEEEVENTREPORT(LER)(Seereverseforrequirednumberofdigits/charactersforeachblock)APPROVEDBYOMBNO.3160-0104EXPIRES06/30/2001Estimatedburdenperresponsetocomplywiththismandatoryinformationcollectionrequest:50hrs.Reportedlessonsteamedareincorporatedintothelicensingprocessandfedbacktoindustry.ForwardcommentsregardingburdenestimatetotheRecord.TAanagementBranch{TWF33),U.S.NuclearRegulatoryCommission,Washington,Dc205554001,andtothePapenvorkReductionProject(31504104j,OfficeofManagementandBudget,Washington,DC20503.IfaninformationcollectiondoesnotdisplayacurrentlyvalidOMBcontrolnumber,theNRCmaynotconductorsponsor,andapersonisnotrequiredtorespondto,theInformationcollection.FACILITYNAME(1)St.LucieUnit1DOCKETNUMBER(2)05000335PAGE(3)Page1of5TITLE(4)MainSteamSafetyValvesSurveillanceOutsideTechnicalSpecification'equirementsMONTHDAYYEAREVENTDATE(6)LERNUMBER(6)YEARSEQUENTIALREVISIONNUMBERNUMBERREPORTDATE(7)MONTHDAYFACIUTYNAMEOTHERFACILITIESINVOLVED(8)DOCKETNUMBER091219991999-004-0010071999FACIUTYNAMEDOCKETNUMBEROPERATINGMODE(9)POWERLEVEL{10)07020.2201(b)20.2203(a){1)20.2203(a)(2)(i),20.2203(a)(2)(v)20.2203(a)(3){I)20.2203{a)(3)(ii)X50.73(a)(2)(i)50.73(a)(2)(ii)50.73(a)(2)(iii)THISREPORTISSUBMITTEDPURSUANTTOTHEREQUIREMENTSOF10CFR5:(Chockonoormore)(11)50.73{a)(2)(viii)50.73(a)(2)(x)73.7120.2203{a)(2)(ii)20.2203(a)(2)(iii)20.2203(a){2)(iv)20.2203(a)(4)50.36(c){1)50.36(c)(2)50.73(a){2)(iv)50.73(a)(2)(v)50.73(a)(2){vii)OTHERSpecifyInAbstractbeloworinNRCForm366ANAMELICENSEECONTACTFORTHISLER{12)TELEPHONENUMBERunaludaAraaCoda)KennethW.Frehafer,LicensingEngineer(561)467-7748COMPLETEONELINEFOREACHCOMPONENTFAILUREDESCRIBEDINTHISREPORT13)CAUSESYSTEMCOMPONENTMANUFACTURERREPORTABLEToEPIXCAUSESYSTEMCOMPONENTMANUFACTURERREPORTABLEToEPIXSUPPLEMENTALREPORTEXPECTED(14)YES(tfyes,c'ompleteEXPECTEDSUBMISSIONDATE).XNoEXPECTED,SUBMISSIONDATE(16)MONTHDAYABSTRACT/Limitto1400spaces,i.e.,approximately15singlewpacedtypewrittenlines/(16)OnSeptember12,1999,St.LucieUnit1wasinMode1andholdingat.approximately70percentreactorpowerfortesting'fthemainsteamsafetyvalves(MSSVs)inaccordancewithproceduze1-MSP-08.07,"MainSteamSa'fetySetpointSurveillance."ThreetrainAandonetrainBMSSVsliftedlow,outsideoftherequiredTechnicalSpecificationpressuresetpointrangeof+/-1percent.Priortotesting,thereactortripsetpointswerereducedtoallowcontinuedoperationwithtwoMSSVspertrainoutofservice.ThesetpressureofoneofthetrainAMSSVswasresettoallowcontinuedoperation.TheapparentcauseoftheMSSVsurveillancefailureswassetpointdrift.PerASMEcodeconsiderations,aformalrootcauseisnotrequired.Thesafetysignificanceofthelowas-foundMSSVsetpointswasevaluatedandfoundtobeinsignificant.ThesubjectMSSVsarebeingrefurbishedandretestedpriortounitstartupfromtheSL1-16refuelingoutage.FPLisconsideringwhetherachangetotheSt.LucieTechnicalSpecificationsorTSbasesisappropriatetoaddressthedifferencesbetweenNUREG-1432andtheSt.~LucieTechnicalSpecificationsconcerningas-foundandas-leftsafetyreliefsetpoints.NRCFORM3BBIB.1999)

NRCFORM366A(6-1998)LlCENSEEEVENTREPORT(LER)TEXTCONTINUATIONU.S.NUCLEARREGULATORYCOMMISSIONFACILITYNAME(1)St.LucieUnit1DOCKETNUMBER(2)05000335LERNUMBER(6)SEQUENTIALREVISIONNUMBERNUMBER1999-004-00PAGE(3)Page2of5TEXT(Ifmorespaceisreriuired,useadditionalcopiesofIVRCForm366A)(17)DescriptionoftheEventOnSeptember12,1999,St.LucieUnit1wasinMode1andholdingatapproximately70percentreactorpowerfortestingofthemainsteamsafetyvalves(MSSVs)(EIIS)SB)RV)duringthedownpowexfortheSL1-16refuelingoutage.ThefollowingMSSVsliftedoutsideoftheirTechnicalSpecifications(TS)requiredpressurerange.AdditionallyV8213liftedoutsideofthe+/-3%ASMEcodeallowedrangeby0.6psiglow.ThissurveillancetestingoftheMSSVs'etpointswasperformedinaccordancewithprocedure1-HSP-08.07,"HainSteamSafetySetpointSurveillance."ValveSepointV8201V8202V8211V8213TrainMeasuredLiftPressure(psia)986.9982.91025.51008.7TSLimit1000+/-1%1000+/-1()1040+/-1()1040+/-1'hDeviationFromTSLimit(())1'1-1071-1.45-3013MSSVsV8201,V8211,and,V8213wereleftinoperableandoutofserviceatthecompletionoftesting.V8202wasrestoredtoOPERABLEstatsbysetpointadjustmentwithintheactiontimeofTechnicalSpecification3.7.1.1.PriortotestingtheMSSVs,thereactortripsetpointshadbeenreducedtoallowcontinuedoperationwithtwoMSSVspertrainoutofservicepexworkordex(WO)98023939-02.NomorethantwovalvespertrainwereoutofserviceandthereactortripsetpointswereproperlyadjustedinaccordancewithTe'chnicalSpecification3.7'.1,thereforetherewerenooperabilityconcerns.CauseoftheEventTheas-foundsetpressuredeviationswererelativelyminorandsimilartothosefoundinpastcycles.Theapparentcauseissetpointdriftand/ortheuseofthenewtestmethods.Asdescribedbelow,aformalrootcauseisnotrequiredbyASME/ANSIOM-1987,partl.PerASME/ANSIOM-1'tt1.3.3.1(e)(2)andCodeInterpretation92-8,aClass1pressurereliefvalvewithanas-foundsetpointoutsidetheacceptancerangeofthesetpointontheminussideisnotconsideredafailure.Asaconsequence,additi.onaltestingforvalvesfailingoutsidethenegativeacceptancecriteriaisnotrequiredbytheASMECode.FPLqualityinstruction(QI)11-PR/PSL-7,"ControlofCodeSafetyandReliefValves,"containsadditionalcriteriawithin95.5.3thatgenerallyrequiresadditionaltestingforvalvesfailingthenegativetolerancecriteria.TheQIcriteriaarebasedontheadversesystemfunctionalissuesresultingfromreliefvalveseatleakageandprematurelift.However,pertheQI,thecriteriaforadditionaltestingofvalvesfaili.ngthenegativetoleranceacceptancecriteriamaybewaivedoralteredbasedonanevaluationoftheas-foundtestpressure,valveinspection,systemrequirementsandhistori.calrecords.TheexpansionoftestingscopeduetothefailureofV8213waswaivedbasedonthesmallamountofdeviation(3.13%vs.3%),theacceptableresultsoftheother'alvetestswithrespecttoASMENRCFORM388A18.1898)

NRCFORM366AI6-1888)LICENSEEEVENTREPORT(LER)TEXTCONTINUATIONU.S.NUCLEARREGULATORYCOMMISSIONFACILITYNAME(1)St.LucieUnit1DOCKETNUMBER(2)05000335LERNUMBER(6)SEQUENTIALREVISIONNUMBERNUMBER1999-004-00PAGE(3)Page3of5TEXTllfmorespecsisrequired,useadditionelcopiesofNRCForm366A)(17)CauseoftheEvent(cont'd)criteria,theabsenceofrecentproblemswithMSSVseatleakageandprematurelift,andtheinsignificanteffectofasmallnegativesetpressuredeviationinahighbankMSSVreliefvalve.TheMSSVsarebeingrefurbishedandretested.AnalysisoftheEventThiseventisreportableunder10CFR50.72(a)(2)(i)(B)as"anyoperationorconditionprohibitedtheplant'sTechnicalSpecifications."TheSt.LucieUnit1TechnicalSpecificationsdifferfromNUREG-1432r"StandardTechnicalSpecificationCombustionEngineeringPlants,"inthatanas-foundMSSVsetpointtoleranceisnotincludedintheSt.LucieTechnicalSpecifications.FPLisconsideringwhetherachangetotheSt.LucieTechnicalSpecificationsozTSbasesisappropriatetoaddressthisTechnicalSpecificationdifference.AnalysisofSafetySignificanceTheMSSVsmustopentoprovideoverpressureprotectionforthesteamgeneratorsandreliefcapacitytoremovedecayheat.TheMSSVsareclassifiedasSafety-Related,QualityGroupBcomponents.PerTStable3.7-1themaximumallowablepowerlevelhightripsetpointwithtwoinoperablesteamlinesafetyvalvesoneitheroperatingsteamgeneratoris79.8%EffectonSafetAnalsesValvesV8201,V8202,V8211andV8213liftedoutsidetheTSliftsettingtolerancelimitof+/-1percent.However,theseliftsettingfailuresweregreaterthanthe-1percentlimit.ValvesV8205andV8216liftedwithinthetolerancelimitspecifiedintheTS.Itwillbeassumedforthepurposeofthisevaluation*thatalltheremainingvalveswouldhaveliftedwithintheirtolerancelimits.TheonlyFSARanalyzedeventsthatcouldpotentiallybeaffectedbythedeviationsintheMSSVsetpointsarethelossofexterhalload(LOEL)andthesmallbreak,LOCA(SBLOCA).Theloss.ofexternalloadevent,includingthecaseofinoperableMSSVs,reliesontheMSSVstoreleasethesystemenergysoastopreventtheprimaryandthesecondarysidepressuresfromexceedingtheoverpzessurizationcriteria.TheanalysisofthiseventassumesconservativelythattheMSSVsbegintoopenattheTSallowedmaximumliftpressurecorrespondingtoatoleranceof+1percent.OpeningofthevalvesatapressurelowerthanthatassumedinthesafetyanalysiswouldbebeneficialforthistransientandtheresultswouldremainboundedbytheFSARresults.IntheanalysisofthesmallbreakLOCAevent,itis-assumedthattheMSSVsbegintoopenataliftpressurecorrespondingtoatoleranceof+3percent.Theas-foundsetpressuresthereforewould,nothaveanyadverse'impactonthesmallbreakLOCAanalysisresults,aspresentedintheFSAR.OtherFSAReventsincludingthesteamgeneratortuberupture(SGTR)eventarenotimpactedbythevariationsintheMSSVliftpressure.TheSGTReventanalyzedintheFSARconservativelyassumestheopeningoftheatmosphericdumpvalves(ADVs)toNRCFORM3BBA(6-1888)

NRCFORM366AIs-1998)LICENSEEEVENTREPORT(LER)TEXTCONTINUATIONU.S.I'IUCLEARREGULATORYCOMMISSIONFACILITYNAME(1)St.LucieUnit1DOCKETNUMBER(2)05000335LERNUMBER(6)SEQUENTIALREVISIONNUMBERNUMBER1999-004-00PAGE(3)Page4of5TEXT(Ifmorespeceisrequired,useedditionelcopiesofNRCForm366AJ(17)AnalysisofSafetySignificance(cont'd)releasethesteamfromtherupturedsteamgenerators.TheidentifiedMSSVs'etpointpressuredeviationsthuswouldnotimpacttheFSARconclusionsforthisevent.'heopeningofMSSVsatpressureslowerthantheliftpressurecorzespondingto-1percenttoleranceisthusdeterminedto'havenoadverseimpactonthesafetyanalysis,includingdeviationsoutside-3.percent.Amuchlowernegativevalve'tolerancelimit,althoughacceptablefromsafetyanalysisconsiderations,mayhaveoperationalimpactasthemargintooperatingpressuregetsreduced.TheMSSVs's-foundsetpressurevalues(specifiedabove)wereoutsidethetolerancelimitsspecifiedintheSt.LucieUnit1TechnicalSpecification3.7.1.1.Thisdegradedconditionhoweverdidnotcompromiseplantsafety.Theevaluationperformedusingtheas-foundsetpointsconcludesthat,Cycle15operationhadremainedwithinthedesignbasisoftheplantforallanalyzedFSARevents.NosafetycriteriawouldhavebeenviolatedduetotheidentifiedconditionoftheMSSVs.SeointDriftConsiderationsThebelowchartshowstheMSSVtestsinthelast3cyclesforunit1.Not'allofthevalvesweretestedduringthesecycles.TheAs-Found()Failurecolumnisshownforthecyclesthatwereevaluated.Theyrepresentthepercentagefromnameplatesetpointthatthevalvewasoutoftolerance.Thenoneinthecolumnmeans,thatthetestwassatisfactory.ThepercentDriftbetweenCycles.columnisthepercentagechangethatthevalveexperiencedoveronecycletakenfromthe2"eas-leftsetpointtestandthenextas-foundtestofthevalve.IValveS/NUnit1N55128-00-0001N55128-00-0002N55128-00-0003N55128-00-0004N55128-00-0005N55128-00-0006N55128-00-0007N55128-00-0008N55128-00-0009N55128-00-0010N55128-00-0011N55128-00-0011N55128-00-0012N55128-00-0013N55128-00-0014N55128-00-0015N55128-00-0016Date19961996199619961996199619961996-199619961995199919961996199619961996As-Pound%'ailurenonenone1.4none-1.52~1.831.932.54nonenonenone-1.45none1.951.271.17noneDate1999199919971999199719971997199619971999199719971999As-Pound%Pailure-1.71-1.31-1.03none1.62nonenone1.37none-3.13nonenonenone%Driftbetweencles-1.62-1.93-1.12-0.201.52-.50-.191.17-2.13-~68-3.50-1.35.10-0.87 NRCFORM366A(8-1998)LICENSEEEVENTREPORT(LER)TEXTCONTINUATIONU.S:NUCLEARREGULATORYCOMMISSIONFACILITYNAME{1)St.LucieUnit1DOCKETNUMBERI205000335LERNUMBERI6)SEQUENTIALREVISIONNUMBERNUMBER1999-004-00PAGEI3)Page5of5TEXT(Ifmorespaceisrequired,useadditionalcopiesofNRCForm3MAJ(17)AnalysisofSafetySignificance(cont'd)ThesedataarefromtheReliefValveDatabase.Thisevaluationdoesnottakeintoaccounttheinstrumentinaccuraciesorthedifferenceinreadingsbetween'the1"and2""testsdonetoacceptthevalves.ThetestmethodologywaschangedforUnit1forthe1999testing.Theplantstartedusingcomputeroperatedtestmachinevs.thepreviousmanualtestmethod.Bothtesttechniquesusealiftingdevicebutthenewersystem'sramprateandsetpointinterpretationarelesssubjectiveandoperatordependentwhichprovideformoreconsistentandaccuratereadings.FPLconcludedthatthereliefvalvessetpointdriftismostlyscattereddatawithnodominanttrendingsetpointdriftforanyvalveoverthecyclesanalyzed.Therefore,thereisnoconcernpertainingtothedownwarddriftoftheMSSVsetpoints.Basedontheabove,thiseventhadnoimpactonthehealthandsafetyofthepublic,CorrectiveActions1.ThesubjectMSSVsarebeingrefurbishedbyWyleLabsviaWO98018487.2.ThesubjectMSSVswillbereworkedandretestedperWO98018488.3.FPLisconsideringachangetotheSt.LucieTechnicalSpecificationstoaddressthedifferencesbetweenNUREG-1432andtheSt.LucieTechnicalSpecificationsconcerningas-foundandas-leftsafetyreliefvalvesetpoints.AdditionalInformationFailedComonentsIdentifiedBasedonASMEcodeconsiderations,therewerenoMSSVtestfailures.SimilarEventsLER50-389/1999-004-00and50-389/1999-004-01,"AsFoundCycle10PressurizerSafetyValveSetpointsOutsideTechnicalSpecificationLimits,"wasissuedforUnit2pressurizercodesafetysurveillancefailures.NRCFORM3BBAIB.1898) r~