ML17228B230

LER 95-003-00:on 950708,automatic Reactor Trip Occurred During Turbine Overspeed Surveillance Testing Due to Personnel Error.Personnel Involved in Event Counseled & Procedure Changes Being made.W/950803 Ltr

ML17228B230
Person / Time
Site:	Saint Lucie
Issue date:	08/03/1995
From:	BENKEN E J, SAGER D A FLORIDA POWER & LIGHT CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
L-95-218, LER-95-003-02, LER-95-3-2, NUDOCS 9508080069
Download: ML17228B230 (7)

Text

jpRIORITY.1e,(ACCELERATEDRIDSPROCESSING)REGULATORYINFORMATIONDISTRIBUTIONSYSTEM(RIDS)ACCESSIONNBR:9508080069DOC.DATE:95/08/03NOTARIZED:NOFACIL:50-335St.LuciePlant,Unit1,FloridaPower&LightCo.AUTH.NAMEAUTHORAFFILIATIONBENKEN,E.J.FloridaPower&LightCo.SAGER,D.A.FloridaPower&LightCo.RECIP.NAMERECIPIENTAFFILIATIONDOCKETg05000335

SUBJECT:

LER95-003-00:on950708,automaticreactortripoccurredduringturbineoverspeedsurveillancetestingduetopersonnelerror.Personnelinvolvedineventcounseled&procedurechangesbeingmade.W/950803ltr.DISTRIBUTIONCODE:IE22TCOPIESRECEIVED:LTRENCLSIZE:TITLE:50.73/50.9LicenseeEventReport(LER),IncidentRpt,etc.NOTESRECIPIENTIDCODE/NAMEPD2-1PDINTERNAL:ACRSAEOD/SPD/RRABNRR/DE/ECGBNRR/DE/EMEBNRR/DOPS/OECBNRR/DRCH/HICBNRR/DSSA/SPLBNRR/DSSA/SRXBRGN2FILE01EXTERNAL:LSTLOBBYWARDNOACMURPHY,G.ANRCPDRCOPIESLTTRENCL11111111111111111111111111RECIPIENTIDCODE/NAMENORRIS,J-EHZE~RNRR/DE/EELBNRR/DISP/PIPBNRR/DRCH/HHFBNRR/DRCH/HOLBNRR/DSSA/SPSB/BRES/DSIR/EIBLITCOBRYCE,JHNOACPOOREiWNUDOCSFULLTXTCOPIESLTTRENCL112211111111111111221111NOTETOALL"RZDS"RECZPZENTS:PLEASEHELPUSTOREDUCEWASTE!CONTACTTHEDOCUMENTCONTROLDESK,ROOMOWFN5D8(415-2083)TOELIMINATEYOURNAMEFROMDISTRIBUTIONLISTSFORDOCUMENTSYOUDON'TNEED!FULLTEXTCONVERSIONREQUIREDTOTALNUMBEROFCOPIESREQUIRED:LTTR27ENCL27 FloridaPower&LightCompany,P.O.Box128,FortPierce,FL34954.0128August3,1995L-95-21810CFR50.73U.S.NuclearRegulatoryCommissionAttn:DocumentControlDeskWashington,D.C.20555Re:St.LucieUnit1DocketNo.50-335ReportableEvent:95-003DateofEvent:July8,1995AutomaticReactorTiDuriTesiduetPesoelErroTurb'0esedSureillaceTheattachedLicenseeEventReportisbeingsubmittedpursuanttotherequirementsof10CFR50.73toprovidenotificationofthesubjectevent.Verytrulyyours,D.A..gerVicersidentSt.LuiePlantDAS/EJBAttachmentcc:StewartD.Ebneter,RegionalAdministrator,USNRCRegionIISeniorResidentInspector,USNRC,St.LuciePlant9508080069950803PDRADOCK050003358PDR

~~NRCFORH366(5-92)U.S.IN)CLEARREGUULTORYC(NITSSIONAPPROVEDBYQSNO.3150-0104EXPIRES5/31/95LICENSEEEVENTREPORT(LER)(Seereverseforrequirednumberofdigits/charactersforeachblock)ESTIHATEDBURDENPERRESPONSETOC(WPLYlllTHTHISINFORHAT10NCOLLECTIONREQUEST:50.0HRS.FORMARDCOHHENTSREGARDINGBURDENESTIHATETOTHEINFORHATIONANDRECORDSHANAGEHENTBRANCH(HNBB7714),U.S.NUCLEARREGULATORYCOHHISSIONgMASHINGTON,OC20555-0001ANDTOTHEPAPERNORKREDUCTIONPROJECT(3140-0104),OFFICEOFHANAGEKENTANDBUDGETMASHINGTONOC20503.FACILITYIWK(1)St.LucieUnit1DOCKETIRWBER(2)05000335PAGE(3)1OF5TITLE(4)AutomaticReactorTripDuringTurbineOverspeedSurveillanceTestingduetoPersonnelError.EVENTDATE5HONTHDAYYEAR070895YEAR95LERNNBER6SEQUENTIALNUHBER003REVISIONNOSER0REPORTDATE7HONTHDAY0803OTHERFACILITIESINVOLVED8FACILITYNAHEYEARN/AFACILITYNAHEN/ADOCKETNUHBERDOCKETNUHBEROPERATINGaIRmE(9)LEVEL(10)100THISREPORTISSUSHITTEDPURSUANT20.402(b)20.405(a)(1)(i)20.405(a)(1)(ii)20.405(a)(1)(iii)20.405(a)(1)(iv)20.405(a)(1)(v)20.405(c)50.36(c)(1)50.36(c)(2)50.73(a)(2)(i)50.73(a)(2)(ii)50.73(a)(2)(iii)50.73(a)(2)(iv)50.73(a)(2)(v)50.73(a)(2)(vii)50.73(a)(2)(viii)(A)50.73(a)(2)(viii)(B)50.73(a)(2)(x)73.71(b)73.71(c)OTHER(SpecifyinAbstractbelowandinText,NRCForm366AToTHEREQUIREHENTSOF10CFR:Checkoneormore11LICENSEECONTACTFORTHISLER12NAHEEdwinJ.Benken,LicensingEngineerTELEPHONENUHBER(IncludeAreaCode)(407)468-4248COMPLETEONELINEFOREACHC(NPONENTFAILUREDESCRIBEDINTHISREPORI'3CAUSESYSTEHCOHPONENTHANUFACTURERREPORTABLETONPRDSCAUSESYS'IEHCOHPONENTHANUFACTURERREPORTABLETONPRDSSUPPLEHENTALREPORTEXPECTED14YES(Ifyes,coagulateEXPECTEDSUBHISSIONDATE).XNoEXPECTEDSUBHISSIONDATE(15)HONTHDAYYEARABSTRACT(Limitto1400spaces,i.e.,approximately15single-spacedtypewrittenlines)(16)OnJuly8,1995,Unit1wasoperatingat100percentreactorpower.OperationspersonnelwereconductingascheduledTurbineoverspeedtripsurveillanceperanapprovedplantprocedure.DuringtheportionofthesurveillancethattestsasolenoidvalveforOverspeedProtectionControl(20-1OPC)autilitynon-licensedOperatorfailedtocloseanisolationvalveasdirectedbytheprocedure.Failuretoclosethisvalveallowedelectro-hydraulic(EH)fluidfromtheGovernorvalves(GV)andInterceptvalves(IV)todrainwhenthesolenoidvalvewasopenedinasubsequentstep.DrainingoftheEHfluidcausedclosureoftheMainTurbineGovernorandInterceptvalveswhichresultedinanautomaticreactortrip.Therootcauseofthiseventwascognitivepersonnelerroronthepartofautilitynon-licensedoperatorwhofailedtoproperlyimplementaproceduralstepduringperformanceofasurveillance.Correctiveactionsforthisevent:1)Operationspersonnelinvolvedwiththeeventwerecounselled.2)Procedurechangesarebeingmadetoincorporatehumanfactorsimprovementsandadditionalstepverifications.3)Otherloadthreateningsurveillancesarebeingreviewedtodetermineifgenericchangesarewarranted.4)Atechnicalsubcommitteeisevaluatingthiseventforadditionalcorrectiveactionstopreventreoccurrence.5)Sitemanagementheldatripreviewmeetingopentoalldisciplinesforlessonslearnedfromthisevent.NRCFORH()

~(,KRCFORH366A(5-92)U.SNUCLEARREGULATORYCQKISSI(NILICENSEEEVENTREPORT(LER)TEXTCONTINUATIONAPPROVEDBYCHBNO3150-0104EXPIRES5/31/95ESTIHATEDBURDENPERRESPONSETOCOMPLYNITHTHISINFORHATIONCOLLECTIONREQUEST:50.0HRS.FORNARDCOHHENTSREGARDINGBURDENESTIHATETOTHEINFORMATIONANDRECORDSHANAGEHENTBRANCH(HNBB7714),U.S.NUCLEARREGULATORYCOHHISSION,MASHINGTOM,DC20555-0001(ANDTOTHEPAPERNNKREDUCTIOMPROJECT(31/0-0104),OFFICEOFHAMAGEHEMTANDBUDGETMASHIMGTONDC20503.FACILITYMAHE1St.LucieUnit10500033595LERMINBER6SEQUEHTIAL003REVISIONPAGE32OF5TEXTIfmoesceisrireduseadditionalcoiesofMCForm3(17)DESCRIPTIONOPTHEEVENTOnJuly8,1995,St.LucieUnit1wasoperatingat100percentReactorpower.Autilitynon-licensedOperatorwasperformingthemonthlyturbineoverspeedtripte"tinaccordancewithanapprovedplantprocedure.Thenon-licensedoperatorwasperformingthestepsoftheprocedurewhileautilitylicensedOperatormaintainedradiocommunicationwiththecontrolroom.DuringtheportionofthetestwhichcheckstheoperabilityofanOverspeedProtectionControl(OPC)solenoidvalve,SE22138(EIIS:TG),theproceduredirectedtheoperatortounlockandcloseV22482(EIIS:TG),"EHTestHeaderto20-1/OPCIsolation."Thisistheelectro-hydraulic(EH)fluidinletisolationtotheOPCsolenoidvalve.ThisstepensuresthattheOPCsolenoidvalveisisolatedfromtheactualEHfluidsystem(EIIS:TG)supplyingtheturbineGovernor(GV)andInterceptvalves(IV)(EIIS:SB)priortotestingthesolenoid.TheNPOremovedthelockingdevicefromisolationvalveV22482,butwasmomentarilydistractedbyplacingthelockingdeviceinasecureposition,andfailedtoclosethevalveasdirectedbytheprocedure.Whenthenextstepoftheprocedurewasexecuted(theactualstroketestingofsolenoidvalveSE22138)EHfluidwasdrainedfromtheGVsandIVscausingtheGVsandIVstorapidlyclose.Closureoftheturbinevalvesquicklyreducedsteamflowthroughtheturbinewhichresultedinareactortripfromhighpressurizerpressureat1122hours.EmergencyOperatingProcedure(EOP)-1,"StandardPostTripActions"wasimmediatelyimplemented.TheReactorCoolantSystem(RCS)PowerOperatedReliefValves(PORV)(EIIS:AB)actuatedasdesignedduringthetimethehighPressurizerpressuresignalwaspresent(lessthan4seconds),andthenreclosed.ThemaximumRCSpressurereachedduringthiseventwas2430psia.Themaximumsecondarypressurereachedwas1023psia.Operatorsobservedincreasinglevelinthe1ASGafterthetripandclosedthe15percentfeedwaterbypassvalve.LevelcontinuedtoincreaseandtheControlRoomOperatorsclosedtheisolationvalveforthe1AFeedwaterRegulatingValve(EIIS:JB).The1BMainFeedwaterPump(MFW)(EIIS:SJ)subsequentlytrippedfromalowflowcondition,andthe1AMFWPumptrippedduetohighlevelinthe1ASG.The1BMFWPumpwasrestartedandSGlevelswerethencontrolledwithinthenormalband.AreliefvalveintheLetdownLevelControlSystem(EIIS:CB)openedduringtheeventduetothesystemtransient,andsubsequentlyclosedwhenControlRoomoperatorsreducedtheletdownpressurecontroller(EIIS:CB)setpoint.TheSteamGeneratorSafetyValves(EIIS:SB)functionedasdesignedtolimitSGpressureduringtheinitialtransient.TheSteamBypassControlSystem(SBCS)(EIIS:Jl)functionedproperlytocontrolRCStemperatureduringthisevent.NRC-FORH366A(5-92)

NRCFORN366A(592)U.S.NUCLEARREGUIATOIYCOBIISSIOILICENSEEEVENTREPORT(LER)TEXTCONTINUATIONAPPROVEDBYOSNO.3150-0104EXPIRES5/31/95ESTIHATEDBURDENPERRESPONSETOCONPLYMITHTHISINFORHATIONCOLLECTIONREQUEST:50.0HRS.FORMARDCONHENTSREGARDINGBURDENESTIHATETOTHEINFORHATIONANDRECORDSHANAGEHENTBRANCH(HHBB7714),U.S~NUCLEARREGULATORYCOHIISSIOI,'MASHINGTOH,DC20555.0001(ANDTOTHEPAPERMDRKREDUCTIOIPROJECT(3140.0104),OFFICEOFIIANAGEHENTANDBUDGETMASHINGTONDC20503.FACILITYNANE1St.LucieUnit1DOXETNNBER2LERNWBER6YEARSEQUENTIALREVISIOIPAGE305000335TEXTlfaerosceisrireduseedditiooeIcoiesofNRCFo366A(17)95003030F5DESCRXPTXONOFTHEEVENTcontiuedTheControlRoomcrewcompletedtheactionsofEOP-01,StandardPostTripActions",andimplementedEOP-02,"ReactorTripRecovery"afterdiagnosinganuncomplicatedtrip.UponcompletionoftheReactorTripRecoveryprocedure,theunitwasmaintainedinastable,Mode3conditionforposttripreviewandeventinvestigation.CAUSEOFTHEEVENTThecauseofthiseventwascognitivepersonnelerrorbyautilitynon-licensedoperatorwhofailedtocorrectlyimplementaproceduralstepduringperformanceofaturbineoverspeedtripsurveillance.Theoperatorwasmomentarilydistractedbyplacingavalvelockingdeviceinasecureposition,anddidnotclosethevalveasdirectedbytheprocedure.YSXSOFTHEEVENTThiseventisreportableundertherequirementsof10CFR50.73.a.2.iv,as"anyeventthatresultedinamanualorautomaticactionofanyEngineeredSafetyFeature."TheclosureoftheMainTurbineGovernorandInterceptvalvescausedarapidreductioninsecondarysteamflow.TheeffectofthereductioninsecondarysteamdemandwasanincreaseinSGpressureandtemperature,andRCStemperatureandpressure.IncreasingRCSpressureresultedinanuncomplicatedReactortriponhighpressurizerpressureasdesigned.Aninvestigationperformedaftertheeventrevealedthatthecalibrationonthe1AMainFeedwaterRegulatingValve(FCV-9011)electro-pneumatictransducer(E/P)haddrifted,sothatthefeedwaterflowcontrolvalvedidnotclosefullyasexpectedontheplanttrip.Thiscausedthe1ASteamGeneratorleveltoincreaseabovethenormalvaluetothehighleveltripsetpointfortheMainFeedwaterPump.ClosingtheMainFeedwaterBlockvalvesecuredtheflowtothe1ASGfromFCV-9011,stabilizingSGlevel.Thiseventisboundedbysection15.2.7oftheSt.LucieUnit1UpdatedFinalSafetyAnalysisReport(UFSAR)"LossofExternalElectricalLoadorTurbineStopValveClosure."Thissectiondescribesarapid,largereductionofpowerdemandonthereactorwhileoperatingatfullpower.TheUFSARstates,"Whentheturbinestop/controlvalvecloses,thesteamflowisterminated,causingthesecondarysystemtemperatureandpressuretoincrease.Theprimary-to-secondaryheattransferdecreasesassecondarysystemtemperatureincreases.Ifthereactorisnottrippedwhentheturbineistripped,.~.thereactorwilltriponhighpressurizerpressure,reducingtheprimaryheatsource."NRCFORII366A(5-92)

NRCFORll366A(5-92)U.S.NUCLEARREGULATORYCQHIISSION'LICENSEEEVENTREPORT(LER)TEXTCONTINUATIONAPPROVEDBZQNINO.3150-0104EXPIRES5/31/95ESTIHATEDBURDENPERRESPOHSETOCONPLYMITHTHISIHFORNATIONCOLLECTIONREQUEST:50.0HRS.FORMARDCOHHENTSREGARDINGBURDENESTIHATETOTHEINFORHATIONANDRECORDSNANAGENEHTBRANCH(HHBB7714),U.S.NUCLEARREGULATORYCONHISSION,MASHINGTQI,DC20555-0001ANDTOTHEPAPERMORKREDUCTIOHPROJECT(3140-0104),OFFICEOFHANAGEHENTANDBlmGETMASHINGTQlDC20503.FACILITYlUWE1St.LucieUnit1DOCKETNQIBER205000335YEAR95LERNWBER6SEQUENTIALREVISION003PAGE34OF5TEXTIfmorscisrireduseadditionscoiesofNCForm366(17)ANALYSISOPTHEEVENTcont,iuedInadditiontotheabove,UFSARsection15.2.7,statesthat,"Themitigativefeaturesofthepressurizerspray,pressurizerreliefvalves(PORV),andtheSteamBypassSystemareassumednottofunctionsoastoexacerbatethecalculatedpressurizationoftheprimarysystem.Thepurpose,...istodemonstratethattheprimarysafetyreliefcapabilityissufficienttolimitprimarypressuretolessthan110%ofthedesignpressure(2750psia),andtodemonstratethatthesecondarysafetyreliefcapacityissufficienttolimitsecondarypressuretolessthan110/ofthedesignpressure(1100psia)."Duringthisevent,thePORVs(EIIS:AB)functionedproperlytolimitprimarypressureto2430psia,sothatthePressurizercodesafetyvalves(EIIS:AB)werenotchallenged.TheSGcodesafeties(EIIS:SB)limitedSGpressureto1023psiaandSBCSfunctionedasdesigned.ThiseventislesslimitingthanthatdescribedinUFSARsection15.2.7.Thehealthandsafetyofthepublicwerenotaffectedbythisevent.CORRECTIVEACTIONS1)Operationspersonnelinvolvedwiththiseventwerecounseledontheimportanceofapplyingself-checkingprinciples.2)Thesurveillanceprocedureforconductingthistest,OP1/2-0030150,"SecondaryPlantOperatingChecksandTests"willbechangedtoincorporateformatimprovements,andtoincludeadditionalverificationthatcriticalstepshavebeencompleted,3)PlantStaffwillreviewotherloadthreateningsurveillancestodetermineifadditionalproceduralchangesorprecautionsarenecessarytominimizethepotentialforpersonnelerror.4)Atechnicalsubcommitteewasformedtoevaluatethiseventforgenericimplicationsandprovideadditionalcorrectiveactionstopreventreoccurrence.5)Sitemanagementheldatripreviewmeeting,attendedbypersonnelfromOperations,Maintenance,Training,Engineering,Technicalstaff,andseniorNuclearDivisionmanagementtoexaminethisevent.ThemeetingwasvideotapedtoassurethatlessonslearnedareavailabletoallOperationspersonnel.6)InstrumentandControl(I/C)andSystemEngineerscalibratedthe1AMainFeedwaterRegulatingValveE/Ptransducerpriortounitstartup.TheMainFeedwaterRegUlatingvalvepositioningcomponentsaffectingthiseventarebeingevaluatedforadditionalcorrectiveactions.7)ThisEventwillbeincludedintoOperationstrainingforbothlicensedandnon-licensedOperationspersonnel.HRC-FORH366A(5-92)

NRCFORM366A5-92)U.S.NUCLENIREGULATORYCQHIISSIQILICENSEEEVENTREPORT(LER)TEXTCONTINUATIONAPPROVEDBYQSNO.3150-0104EXPIRES5/31/95ESTINATEDBURDENPERRESPONSETOCQ(PLYMITHTHISINFORHAT10NCOLLECTIONREQUEST:50.0KRS.FORMARDCQINENTSREGARDINGBURDENESTIMATETOTHEINFORMATIONAMDRECORDSMANAGEMENTBRANCH(HMBB7714),U.S.HUCLEARREGULATORYCQBIISSION,llASHINGTON,DC20555-0001~ANDTOTHEPAPERMORkREDUCTIONPROJECT(3140-0104)~OFFICEOFHANAGEHEMTAMDBIIGET,MASHINGTON,DC20503.FACILITYNU%1DO(XETNMBER2LERNNBER6YEARSEQUENTIALREVISIOHPAGE3St.LucieUnit10500033595pp3p5OF5EXTIfmorsceisireduseedditionecoiesofMRCForm366A(17)ADDITIONALNPORMATIONil'nInifitiNocomponentfailureswereidentifiedforthisevent.PrvimilrEvnLER389/86-002describesaReactortripinitiatedbylossofloadduringTurbineoverspeedtestingduetocognitivepersonnelerror.HRCFORM