ML17265A666

LER 99-009-00:on 990503,instrumentation Declared Inoperable in Multiple Channels Resulted in Condition Prohibited by Ts. Caused by Unanticipated High Frequency AC Voltage Ripple. Entered TS LCO 3.0.3.With 990602 Ltr

ML17265A666
Person / Time
Site:	Ginna
Issue date:	06/02/1999
From:	MECREDY R C, ST MARTIN J T ROCHESTER GAS & ELECTRIC CORP.
To:	VISSING G S NRC (Affiliation Not Assigned), NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
LER-99-009, LER-99-9, NUDOCS 9906080307
Download: ML17265A666 (13)

Text

REGULATORYINFORMATIONDISTRIBUTIONSYSTEM(RXDS)ACCESSZONNBR:9906080307DOC.DATE:99/06/02NOTARIZED:NODOCKETIPACZL:50-244RobertEmmetGinnaNuclearPlant,Unit1,RochesterGterG05000244AUTH.NAMEAUTHORAFFILIATIONSTMARTIN,J.T.RochesterGas&.ElectricCorp.MECREDY,R.C.~RochesterGas&.ElectricCorp.RECIP.NAME,RECIPIENTAFFILIATIONVISSXNG,G.S.

SUBJECT:

LER99-009-00:on990503,instrumentationdeclaredinoperableinmultiplechannelsresultedinconditionprohibitedbyTS.CausedbyunanticipatedhighfrequencyACvoltagerippe.EnteredTSLCO3.0.3.With990602ltr.DISTRIBUTIONCODEXE22TCOPIESRECEIVEDeLTRgENCL(SIZEaTITLE:50.73/50.9LicenseeEventReport(LER),XncidentRpt,etc.NOTES:LicenseExpdateinaccordancewith10CPR2,2.109(9/19/72).G050002440RECIPIENTZDCODE/NAMELPD1-1PDINTERNAL:AEOD/SPD/RRABNRR/DZPM/IOLBNRR/DRIP/REXBRES/DET/EIBEXTERNAL:LSTLOBBYWARDNOACPOORE,W.NRCPDRCOPIESLTTRENCL11111'1111111.111RECIPIENTXDCODE/NAMEVZSSXNG,G.FILECENTERR/DXPM/XQMBNRR/DSSA/SPLBRGN1PILE01LMXTCOMARSHALLNOACQUEENER,DSNUDOCSFULLTXTCOPIESLTTRENCL1111111111111111NOTETOALL"RIDS"RECIPIENTS:PLEASEHELPUSTOREDUCEWASTE.TOHAVEYOURNAMEORORGANIZATIONREMOVEDFROMDISTRIBUTIONLISTSORREDUCETHENUMBEROFCOPIESRECEIVEDBYYOUORYOURORGANIZATION<CONTACTTHEDOCUMENTCONTROLDESK(DCD)ONEXTENSION41S-2083FULLTEXTCONVERSIONREQUIREDTOTALNUMBEROFCOPIESREQUIRED:LTTR16ENCL16 4HDROCHESTfRGASANDE'ELECTRICCORFORATION~89EASTAVENUE,ROCHfSTER,N,YI46d9.000IAREACODE216586-27MRosERTc.MEcREDYVicePresislenlt4uc!eorOperosionsJune2,1999U.S.NuclearRegulatoryCommissionDocumentControlDeskAttn:GuyS.VissingProjectDirectorateI-1Washington,D.C.20555

Subject:

.LER1999-009,InstrumentationDeclaredInoperableinMultipleChannelsResultsinConditionProhibitedbyTechnicalSpecificationsR.E.GinnaNuclearPowerPlantDocketNo.50-244

DearMr.Vissing:

TheattachedLicenseeEventReportLER1999-009issubmittedinaccordancewith10CFR50.73,LicenseeEventReportSystem,item(a)(2)(i)(B),"Anyoperationorconditionprohibitedbytheplant'sTechnicalSpecifications".Veryrulyyours,XC:Mr.GuyS.Vissing(MailStop8C2)ProjectDirectorateI-1DivisionofReactorProjects-I/IIOfficeofNuclearReactorRegulationU.S.NuclearRegulatoryCommissionWashington,D.C.20555RegionalAdministrator,RegionIU.S.NuclearRegulatoryCommission475AllendaleRoadKingofPrussia,PA19406U.S.NRCGinnaSeniorResidentInspector+t990b080307'll's!0602PDRADQCK05000244SPDR NRCFORM866IBI%BIU.S.NUCLEARREGULATORYCOMMISSIONLICENSEEEYENTREPORT(LER)fSoereverseforrequirednumberof'digitslcharactersforeachb(ocklM5QIkrNpNIIsp@eigA'P%88Sy'nformationcoBoctP)arortuost:50hrs.ReportedlessonslearnedarencorporatedkrtotheBcenskrgprocessandfodbacktohdustry.ForwardcommentsregardingburdenestimatetotheRecordsMsnagernontBranchp4F33),U.S.NudearRegulatoryCommfssbn,Wasfsngton,DC205554001~andtothePaperworkReductionProject(31500104),OfreeofManagementandBudget,WasNngton,DC20503.Ifaninformationcoeect'ondoesnotdisplayacurrendyvsMOMB,controlnumber,theNRCmaynotconductorsponsor.andaFACILITYNAMEI11R.E.GinnaNuc(earPowerPlantIDOCKETNUMBERI2)05000244PAGEI3)1OF7TITLEte)InstrumentationDeclaredInoperableinMultipleChannelsResultsinConditionProhibitedbyTechnicalSpecifications05031999,EVENTDATE(5)OAYLERNUMBER(6)SEOUFNTIALRENSIONNUMBERNUMBER1999",009-00MONTHON06021999REPORTDATE(7)DOCKETNUMSER05000OOCKETNUMSER05000FACfLITYNAMEFACILrTYNAMEOTHERFACILITIESINVOLVED(6)OPERATINGMODE(9)POWERLEVEL(10)090URSUANTTOTHEREQUIREMENTHISREPORTISSUBMITTFDP20.2203(a)(2)(v)20.2203(a)(3)(i)20.2201(b)20.2203(a)(1)20.2203(a)(3)(ii)20.2203(a)(2)(i)20.2203(a}(4)50.36(cl(1)20.2203(a)(2)(ii)20.2203(a)(2)(iii}50.36(c)(2)20.2203(a)(2)(iv)LICENSEECONTACTFORTHISLER(12)TSOF10CFRB:(Checkoneormore)(11)50.73(a)(2)(viii)50.73(a}(2}(x)X50.73(a)(2)(i)(B)50.73(a)(2)(ii)73.7150.73(a}(2l(iii)OTHER50.73(a)(2wiv)50.73(a)(2)(v)SpecifymAbstractbeloworinNRCForm355A50.73(a)(2)(vii)TELEPMONENUMSER(InrrudeAresCode)JohnT.St.Martin-TechnicalAssistant(716)771-3641CAUSESYSTEMCOMPONOITMANUFACTURERREPORTABLETOEPOSCAUSESYS'fEMMANUFACTURERREPORTABLETOEPIXSUPPLEMENTALREPORTEXPECTED(l4)YES(Ifyes,completeEXPECTEDSUBMISSIONDATE).NOXEXPECTEDSUBMISSIONDATER5)IlONTHOAYABSTRACT(Limitto1400spaces,i.e.,approximately15single.spacedtypewrittenlines}(16)OnMay3,1999,theplantwasinMode1atapproximately90%steadystatereactorpower.IthadpreviouslybeendeterminedthatOvertemperatureDeltaTandOverpowerDeltaTbistabletripsetpointswerepotentiallynon-conservativeonthreeoutoffourreactorprotectionsystemchannels,andanevaluationwasinprogress.Atapproximately2330EDST,instrumentationforthesethreechannelswasdeclaredinoperable.ImmediatecorrectiveactionwastoenteiTechnicalSpecificationLimitingConditionforOperation3.0.3,andtakeactionstorestorethechannelstooperablestatus.Followingreplacementoftheaffectedbistableswithbistab(esofadifferentdesign,thebistabletripsetpointswererecalibratedandthreeoffourchannelsweredeclaredoperable.TheplantexitedLimitingConditionforOperation3.0.3.TheunderlyingcauseoftheeventwasanunanticipatedhighfrequencyACvoltagerippleontheDeltaTsignalsthatadverselyaffectedthetripsetpointsforthebistables.CorrectiveactiontopreventrecurrenceisoutlinedinSectionV.B.

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NRCFORM366A$1999)LICENSEEEVENTREPORT(LER)TEXTCONTINUATIONU.S.NUCLEARREGULATORYCOMMISSIONFACILITYNAME(1)DOCKET(2)LERNUMBER(6)PAGE(3)..R.E.GinnaNuclearPowerPlant05000244SEOUEMTIA(8EVSIOIIIIUMBNImMBN1999-009-003OF7TEXTIifmorespaceisrequired,useadditionalcopiesofNRCForm366'17)ThePlantOperationsReviewCommittee(PORC)wasconvenedatapproximately1900EDSTtoreviewthissituation.PORCconcurredthatreducingpowerto90%wasaprudentmeasure.Channel2bistables,inserviceformorethan18months,werenotaffectedbythiscondition.Channel2wasprovenfullyoperableandchannel1wascurrentlyinthetrippedmode.Thus,continuedplantoperationwaspermissible,whilebistableoperabilitywasassessedbyNESpersonnel.PreliminarycalculationsweresubsequentlyperformedbyNESstaff.ThesecalculationsindicatedthatRPSchannel1bistabletripsetpointswerewithindesignlimits.ThemarginforOTDTandOPDTwerelow,butthebistableswereconsideredoperable.II.DESCRIPTIONOFEVENT:A.DATESANDAPPROXIMATETIMESOFMAJOROCCURRENCES'ay3,1999,0820EDST:RPSchannel1isremovedfromserviceanddeclaredinoperabletoperformtroubleshooting((perCPI-TRIP-TEST-5.10)).May3,1999,dayshift:ACrippleisdiscoveredinRPSchannel1.Later,ACrippleisdiscoveredinRPSchannels3and4.May3,1999,2330EDST:EventDateandTimeandDiscoveryDateandTime.May3,1999,2347EDST:Plantshutdowninitiated.May4,1999,0136EDST:RPSchannel1isdeclaredoperable.May4,1999,0428EDST:RPSchannel3isdeclaredoperable.May4,1999,0428EDST:ITSLCO3.0.3isexited.Plantshutdownisstoppedat21%power.May4,1999,2121EDST:RPSchannel4isdeclaredoperable.EVENT:OnMay3,1999,theplantwasinMode1atapproximately90%steadystatereactorpowerafterthepowerdecreasefromfullpower,whichwasstartedatapproximately1840EDSTandcompletedatapproximately2000EDST.NESpersonnelcompletedthecalculations,whichnowindicatedthatRPSchannel1bistableswerenotoperable.TheShiftSupervisorandplantmanagementwereimmediatelynotified.Atapproximately2330EDST,basedontherevisedcalculationaldata,itwasdeterminedthatthreeaffectedchannelsofRPS(channels1,3and4)bedeclaredinoperable.

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'I NRCFORM366A(CISSS)LlCENSEEEVENTREPORT(LER)TEXTCONTINUATIONU.S.NUCLEARREGULATORYCOMMISSION~FACILITYNAMEI1)R.E.GinnaNuclearPowerPlantDOCKETI2)05000244LERNUMBERIe)YEARSEQUENTIALREYISIONNUMSERNUMSER1999-009-00PAGEI3)6OF7TEXT(Ifmorespaceisrequired,useadditionalcopiesofitiRCForm366AJI17)IV.ANALYSISOFEVENT:Thiseventisreportableinaccordancewith10CFR50.73,LicenseeEventReportSystem,item(a)(2)(i)(B),"Anyoperationorconditionprohibitedbytheplant'sTechnicalSpecifications"~TheentryintoITSLCO3.0.3asaresultofdeclaringmorethanoneFunctioninITSTable3.3.1-1inoperableisconsideredtobeaconditionprohibitedbyTechnicalSpecifications.Anassessmentwasperformedconsideringboththesafetyconsequencesandimplicationsofthiseventwiththefollowingresultsandconclusions:TherewerenooperationalorsafetyconsequencesattributedtothreeRPSchannelsforOTDTandOPDTbeinginoperable.Amoredetailedpost-eventreviewwasperformed.Ithassubsequentlybeendeterminedthatonlyonetripfunction(RPSchannel3OPDT)wasactuallyinoperable.Thisdeterminationisbasedontheas-founddataandamorerigorousanalysisoftheassociatedinstrumentuncertainties.AllfourOTDTchannelswerefoundtobewithinaccidentanalysisassumptions,afteraccountingfortheas-foundmargintotripsetpointandincorporatingtheappropriateinstrumentuncertainties.Hence,theonlyfunctionthatwouldnothaveactuatedwithintheboundsoftheGinnaStationaccidentanalysiswasonechannelofOPDT.Withthreeoperablechannelsavailableanda2outof4logictoprovidetherequiredtripfunction,thereisadequateassurancethatthereactorprotectionsystemwouldhaveperformedwithinitsrequiredenvelopeasassumedintheaccidentanalysis.Basedontheabove,itcanbeconcludedthatthepublic'shealthandsafetywasassuredatalltimes.V.CORRECTIVEACTION:A.ACTIONTAKENTORETURNAFFECTEDSYSTEMSTOPRE-EVENTNORMALSTATUS:FollowingreplacementofbistablesandcalibrationofthebistablesinRPSchannels1and3,threechannels(channels1and3andpreviouslyunaffectedchannel2)weredeclaredoperable.ACTIONTAKENORPLANNEDTOPREVENTRECURRENCE:NUSindicatedthattheywillbeupdatingthepartslisttoremovetheincorrectlysizedcomponent.NESpersonneldesignedamodificationtothemathmodulestoeliminatetheeffectsofACrippleontheOPDTandOTDTbistabletripsetpoints.Thismodificationhasbeenimplemented.

NRCFORM366AgIBBBILICENSEEEVENTREPORT(LER)TEXTCONTINUATIONU.S.NUCLEARREGULATORYCOMMISSION~FACILITYNAMEI1)R.E.GinnaNuclearPowerPlantDOCKETI2)05000244LERNUMBERI6)SB)UalTIAlRSNSIOHIIUMBIAIIUMBBI1999-003-00PAGEI3)7OF7TEXTllfmorespaceisrequired,useadditionalcopiesofNRCForm866AJI17)oThiseventisbeingreviewedforanypotentiallessonstobelearnedandappliedtotheappropriatepartsoftheGinnamodificationprocess:design,procurement,installation,testing.TheindustrywillbenotifiedofthiseventviaanentryintheNuclearNETWORKsystem.VI~ADDITIONALINFORMATION:A.FAILEDCOMPONENTS:NoneB.PREVIOUSLERsONSIMILAREVENTS:AsimilarLEReventhistoricalsearchwasconductedwiththefollowingresults:NodocumentationofsimilarLEReventswiththesamerootcauseatGinnaNuclearPowerPlantcouldbeidentified.C.SPECIALCOMMENTS:None