ML17264A556

LER 96-007-00:on 960612,CR Operators Identified Control Rods Misaligned & Not Moving in Proper Sequence.Caused by Faulty Firing Circuit Card in Rod Control Sys.Faulty Firing Circuit Card in 1BD Power Cabinet replaced.W/960712 Ltr

ML17264A556
Person / Time
Site:	Ginna
Issue date:	07/12/1996
From:	MARTIN J T, MECREDY R C ROCHESTER GAS & ELECTRIC CORP.
To:	VISSING G S NRC (Affiliation Not Assigned), NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
LER-96-007, LER-96-7, NUDOCS 9607180141
Download: ML17264A556 (10)

Text

~CA.TEGORY1gREGULATORYINFORMATIONDISTRIBUTIONSYSTEM(RIDS)ACCESSIONNBR:9607180141DOC.DATE:96/07/12NOTARIZED:NODOCKETtFACIL:5G-244RobertEmmetGinnaNuclearPlant,Unit1,RochesterG05000244AUTH.NAMEAUTHORAFFILIATIONMARTINsJ.T.RochesterGasaElectricCorp.MECREDY,R.C.RochesterGas&ElectricCorp.RECIP.NAMERECIPIENTAFFILIATIONVISSINGsG.S.

SUBJECT:

LER96-007-00:on960612,CRoperatorsidentifiedcontrolrodsmisaligned&notmovinginpropersequence.Causedbyfualtyfiringcircuitcardinrodcontrolsys.Faultyfiringcircuitcardin1BDpowercabinetreplaced.W/960712ltr.DZSTRZBUTZONCODE:ZE22TCOPZESRECEZVED:LTRiENCZlSZSE:TITLE:50.73/50.9LicenseeEventReport(LER),IncidentRpt,etc.NOTES:LicenseExpdateinaccordancewith10CFR2,2.109(9/19/72).05000244RECIPIENTIDCODE/NAMEPD1-1PDINTERNAL:OD/S'FILECENRDEEELBNRR/DRCH/HHFBNRR/DRCH/HOLBNRR/DRPM/PECBNRR/DSSA/SRXBRGN1FILE01EXTERNAL:LSTLOBBYWARDNOACMURPHYIGANRCPDRCOPIESLTTRENCL1'2211111111111111111111RECIPIENTIDCODE/NAMEVISSINGsG.AEOD/SPD/RRABNRR/DE/ECGBNRR/DE/EMEBNRR/DRCH/HICBNRR/DRCH/HQMBNRR/DSSA/SPLBRES/DSIR/EIBLITCOBRYCE,JHNOACPOORE,W.NUDOCSFULLTXTCOPIESLTTRENCL1111111111111111221111NOTETOALL"RIDS"RECIPIENTS:PLEASEHELPUSTOREDUCEWASTE!CONTACTTHEDOCUMENTCONTROLDESKSROOMOWFNSD-5(EXT.415-2083)TOELIMINATEYOURNAMEFROMDISTRIBUTIONLISTSFORDOCUMENTSYOUDON'TNEED!FULLTEXTCONVERSIONREQUIREDTOTALNUMBEROFCOPIESREQUIRED:LTTR25ENCL25 AenROCHESTERGASANDflfCTRICCORPORATION~89EASTAVFNUE,ROCHESTfR,NY.Id6498001AREACODE7/65Q-2200ROBERTC.MECREDY'licePresidentt4vc!earOperationsJuly12,1996U.S.NuclearRegulatoryCommissionDocumentControlDeskAttn:GuyS.VissingProjectDirectorateI-1Washington,D.C.20555

Subject:

LER96-007,ControlRodsMisaligned,DuetoRodSequencingProblem,ResultsinManualReactorTripR.E.GinnaNuclearPowerPlantDocketNo.50-244Inaccordancewith10CFR50.73,LicenseeEventReportSystem,item(a)(2)(iv),whichrequiresareportof,"Anyeventorconditionthatresultedinamanualorautomaticactuationofanyengineeredsafetyfeature(ESF),includingthereactorprotectionsystem(RPS)",theattachedLicenseeEventReportLER96-007isherebysubmitted.Thiseventhasinnowayaffectedthepublic'shealthandsafety.Verytrulyyours,RobertC.Mecredyxc:U.S.NuclearRegulatoryCommissionMr.GuyS.Vissing(MailStop14C7)PWRProjectDirectorateI-1Washington,D.C.20555U.S.NuclearRegulatoryCommissionRegionI475AllendaleRoadKingofPrussia,PA19406U.S.NRCGinnaSeniorResidentInspector9607i80i4i9607i2PDRADOCK05000244SPDR\

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NRCFORM366AI496)LICENSEEEVENTREPORT(LER)TEXTCONTINUATIONU.S.NUCLEARREGULATORYCOMMISSIONFACILITYNAMEI1)R.E.GinnaNuclearPowerPlantDOCKET05000244LERNUMBERIB)TEARSEQUENTIALREVISIONNUMBERNUMBER96-007-00PAGEI3)2OF6TEXTiifmorespaceisrequired,useadditionalcopiesofPVRCForm366A/{17)PRE-EVENTPLANTCONDITIONS:OnJune12,1996,atapproximately1432EDST,theplantwasinMode2butnotcritical.Areactorstartupwasinprogress.Thereactorcoolantsystem(RCS)wasbeingmaintainedatatemperatureofapproximately547degreesFandapressurizer(PRZR)pressureofapproximately2235PSIG.Thereactorstartupwasinterruptedbyaconcernwiththeauxiliaryfeedwater(AFW)system.Atthistime,thereactorwassubcritical,BanksAandBwerefullywithdrawn,BankCwasat140steps,andBankDwasat10steps.Byapproximately1509EDST,thestartupwasresumedafterresolutionoftheAFWconcerns.Assoonasthecontrolrodswerepulledtwomorestepsout(to12stepsonBankD),MainControlBoardAnnunciatorC-5(PPCSRodSequenceorRodDeviation)alarmed,causedbythepositionoftworodsinControlBand"D"(rodsC-7andK-7)deviatingfromthebankpositionby12stepsormore.TheControlRoomoperatorsobservedthatrodsC-7andK-7deviatedfromtheres'tofthebank(rodsG-3andG-11).RodsC-7andK-7hadnottransitionedoffthebottomofthefirstMicroprocessorRodPositionIndication(MRPI)transition.TheControlRoomoperatorsimmediatelystoppedallrodmovement.TheControlRoomoperatorsimmediatelyenteredAbnormalOperatingProcedureAP-RCC.2(RCC/RPIMalfunction)andperformedtheappropriateactions.RodsC-7andK-7areinBankD,Group1,andarepoweredfromthe1BDPowerCabinet.InstrumentandControl(IKC)techniciansinspectedthe1BDPowerCabinetforanyobviousfaultsorblownfuses.Therewereno"RodControlUrgent"alarmsor"MRPIUrgentFailure"alarms,andtherewasnolocalindicationofRegulationFailureontheassociatedFailureDetectioncards.AfterconsultingwiththeIhCgroupandhighersupervision,itwasdeterminedthat,sincetheplantwasestimatedtobenearcriticality,rodswouldbemanuallyinsertedtoshutdowntoMode3inacontrolledmanner,ratherthanattemptingtocorrecttherodcontrolproblemwhileinMode2.TheControlRoomoperatorsexitedprocedure0-1.2,andinitiatedrodinsertiontoshutdownthereactortoMode3.Afterrodshadbeeninsertedsixteen(16)stepsfromthepreviouspositions,AnnunciatorC-5alarmedagain.BankCrodswereat126/125steps,andtwoBank8rodshadalreadytransitionedoffthetopofthereactorcorebyMRPIindications.{TheBankBrodsshouldnothavestartedtomoveuntilBankCwasat100steps).TheC-5AnnunciatoralarmwasduetotworodsinBankB(E-7andI-7)deviatingfromthebankpositionby12stepsormore.TheControlRoomoperatorsimmediatelystoppedallrodmovementandenteredprocedureAP-RCC.2atapproximately1531EDST.II.DESCRIPTIONOFEVENT:A.DATESANDAPPROXIMATETIMESOFMAJOROCCURRENCES:June12,1996,1540EDST:ControlRoomoperatorsmanuallytripthereactor,verifybothreactortripbreakersop'n,andverifyallcontrolandshutdownrodsarefullyinserted.Eventtimeanddiscoverytime.0,June12,1996,1548EDST:PlantisstabilizedinMode3.INRCFORM366AI4.95l lhF NRCFORM366A(496ILICENSEEEVENTREPORT(LER)TEXTCONTINUATIONU.S.NUCLEARREGULATORYCOMMISSIONFACILITYNAME(1)R.E.GinnaNuclearPowerPlantDOCKET05000244LERNUMBER(6)TEARSEQUENTIAI.REVISIONNUMBERNUMBER96-007-00PAGE(3)3OF6TEXTilfmorespeceisrequired,useeddirionelcopiesofNRCForm388Ai(17)EVENT:OnJune12,1996,duetoproblemswithcontrolrodsequencing,theShiftSupervisorhadconsultedwiththel&Cgroupandhighersupervision.TheI&Cgroupadvisedthattroubleshootingtoidentifyandresolvetheproblemwithrodsequencingcouldpotentiallybeextensive.Aconservativedecisionwasmadetomanuallytripthereactorandthenproceedwithtroubleshooting.TheShiftSupervisororderedamanualreactortrip.Therefore,atapproximately1540EDST,theControlRoomoperatorsmanuallytrippedthereactorandperformedtheimmediateactionsofEmergencyOperatingProcedureE-0(ReactorTriporSafetyInjection).TheytransitionedtoEmergencyOperatingProcedureES-0.1(ReactorTripResponse)whenitwasverifiedthatbothreactortripbreakerswereopen,allcontrolandshutdownrodswerefullyinserted,andsafetyinjectionwasnotactuatedorrequired.TheytransitionedtoNormalOperatingProcedure0-3(HotShutdownwithXenonPresent)atapproximately1548EDST,andtheplantwasstabilizedinMode3.Thel&CgroupperformedtroubleshootingoftheRodControlsystemanddeterminedthattherewasamultiplexingerrorinthe1BDPowerCabinet.I&CobservedthatBankB,Group1wasbeingselectedinthe1BDcabinet,andBankD,Group2wasbeingselectedinthe2BDcabinet.TestpointsmeasuredintheRodControlLogicCabinetindicatedthatthecorrectbankwasbeingselectedbytheBankOverlapcircuit,butwasnotbeingproperlyselectedbythe1BDPowerCabinet.Theproblemwasisolatedtothestationary"B"firingcircuitcard,whichreceivesthemultiplexingsignal.tThefaultyfiringcircuitcardwasreplaced.Afterthecompletionofmaintenance,theControlRoomoperatorsperformedpost-maintenancetestingandthencommencedareactorstartup.Thereactorwastakencriticalatapproximately2148EDSTonJune12,1996.C.INOPERABLESTRUCTURES,COMPONENTS,ORSYSTEMSTHATCONTRIBUTEDTOTHEEVENT:NoneD.OTHERSYSTEMSORSECONDARYFUNCTIONSAFFECTED:NoneE.METHODOFDISCOVERY'ThecontrolrodmisalignmentscausedMainControlBoardAnnunciatorC-5toalarm,alertingtheControlRoomoperatorstothiscondition.Thereactortripwasmanuallyinitiatedandwasconfirmedbyplantresponse,alarms,andindicationsintheControlRoom.NAGfORM366A(485l NRCFORM366Ai@96)LICENSEEEVENTREPORT(LER)TEXTCONTINUATIONU.S.NUCLEARREGULATORYCOMMISSIONFACILITYNAME(1)R.E.GinnaNuclearPowerPlantDOCKET05000244LERNUMBER(6)TEARSEQUENTIALREYISIONNUMBERNUMBER96-007-00PAGE(3)4'F6TEXTllfmorespaceisrequired,useadditionalcopiesofNRCForm388A/(17)F.OPERATORACTION:TheControlRoomoperatorspromptlyidentifiedthecontrolrodmisalignmentandperformedtheappropriateactionsofprocedureAP-RCC.2.TheShiftSupervisorconservativelyorderedamanualreactortripwhenasecondbankofrodsbecamemisalignedduetoinsertingoutofsequence.Afterthereactortrip,theControlRoomoperatorsperformedtheappropriateactionsofproceduresE-0andES-0.1.TheplantwasstabilizedinMode3.Subsequently,theControlRoomoperatorsnotifiedtheNRCper10CFR50.72(b)(2)(ii),non-emergencyfourhournotification,atapproximately1811EDSTonJune12,1996.G.SAFETYSYSTEMRESPONSES:NoneIII.CAUSEOFEVENT:A.IMMEDIATECAUSE:Theimmediatecauseofthereactortripwasmanualtripinitiation,orderedbytheShiftSupervisorasaconservativedecisionwhentwobanksofcontrolrodshadmovedoutofsequence.B.INTERMEDIATECAUSE:Theintermediatecauseoftherodsequencingproblemwasamultiplexingerrorinthe1BDRodControlcabinet.ThecorrectbankwasbeingselectedbytheBankOverlapcircuit,butwasnotbeingproperlyselectedbythe1BDPowerCabinet.C.ROOTCAUSE:TheISCgroupperformedtroubleshootingintheLogicCabinetand1BDPowerCabinet.TestpointsmeasuredintheLogicCabinetindicatedthatthecorrectbankwasbeingselectedbytheBankOverlapcircuit,butwasnotbeingproperlyselectedbythe1BDPowerCabinet.IRCdeterminedthatthestationary"B"firingcircuitcard,whichreceivesthemultiplexingsignalfromtheLogicCabinet,wasfaulty.ThiseventisNUREG-1022CauseCode(8),"Design,Manufacturing,Construction/Installation".TheproblemwiththeRodControlcircuitsdoesnotmeettheNUMARC93-01,"IndustryGuidelineforMonitoringtheEffectivenessofMaintenanceatNuclearPowerPlants",definitionofa"MaintenancePreventableFunctionalFailure".NRCFORM366Ale NRCFORM366AI4SQLICENSEEEVENTREPORT(LER)TEXTCONTINUATIONU.S.NUCLEARREGULATORYCOMMISSIONFACILITYNAME(1)R.E.GinnaNuclearPowerPlantDOCKET05000244LERNUMBER(6IyEARSEQUENTIALREVISIONNUMBERNUMBER96-007-00PAGE(3I5OF6TEXTflfmorespaceisrequired,useaddidonalcopiesofNRCForm366AJ(17)IV.ANALYSISOFEVENT:Thiseventisreportableinaccordancewith10CFR50.73,LicenseeEventReportSystem,item(a)(2)(iv),whichrequiresareportof,"Anyeventorconditionthatresultedinamanualorautomatic'actuationofanyengineeredsafetyfeature(ESF),includingthereactorprotectionsystem(RPS)".ThemanualreactortripisanactuationoftheRPS.Anassessmentwasperformedconsideringboththesafetyconsequencesandimplicationsofthiseventwiththefollowingresultsandconclusions:Therewerenooperationalorsafetyconsequencesorimplicationsattributedtocontrolrodmisalignmentsandsubsequentmanualreactortripbecause:oTheimpropersequencingandmisalignmentofthecontrolrodswiththereactorsubcriticalisboundedbythesafetyanalysiswhichassumesaminimummisalignmentwithrespecttopowerdistributionandshutdownmargin(SDM)of25stepsandtotalmisalignment(i.e.,stuckrod)forthecontrolrodmisalignmentaccident.Eachofthesecasesisevaluatedforcriticalconditionsonly,sinceSDMismaintainedthroughtheuseofchemicalmeansinplaceofthecontrolrodswhensubcriticat.Sincethereactorwassubcritical,rodswerenotmisalignedby25steps,andtheSDMrequirementsoftheGinnaStationImprovedTechnicalSpecifications(ITS),LimitingConditionforOperation(LCO)3.1.1werestillmet,therearenosafetyimplications.oThetworeactortripbreakersopenedasrequired.oAllcontrolandshutdownrodsfullyinsertedasdesigned.oTheplantwasstabilizedinMode3.Basedontheabove,itcanbeconcludedthatthepublic'shealthandsafetywasassuredatailtimes.V.CORRECTIVEACTION:A.ACTIONTAKENTORETURNAFFECTEDSYSTEMSTOPRE-EVENTNORMALSTATUS:Thefaultyfiringcircuitcardinthe1BDpowercabinetwasreplaced.ThemultiplexingsignalwastestedforcontrolBank8andcontrolBankDinBankIndividual.Theproperlocalindicationsofgroupselectionwasalsoverified.SurveillanceTestProcedurePT-1(RodControlSystem)wasperformedtoverifyproperrodmovementandsequencing.NIICFORM366AII-9Q

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