ML17261B082

LER 90-008-00:on 900524,determined That Five of Eight Degraded Voltage Relays on 480-volt Safeguard Buses Calibr Outside of Tech Spec Limits.Caused by Use of Wrong Setpoint.Relays Recalibr & Returned to svc.W/900625 Ltr

ML17261B082
Person / Time
Site:	Ginna
Issue date:	06/25/1990
From:	BACKUS W H, MECREDY R C ROCHESTER GAS & ELECTRIC CORP.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
LER-90-008, LER-90-8, NUDOCS 9007050121
Download: ML17261B082 (12)

Text

ACCELERATEDlg>TRJBUTIONDEMONSATIONSYSTEMREGULATORYINFORMATION'DISTRIBUTIONSYSTEM(RIDS)ACCESSIONNBR:9007050121DOC.DATE:90/06/25NOTARIZED:NODOCKETFACIL:50-244RobertEmmetGinnaNuclearPlant,Unit1,RochesterG05000244AUTH.NAMEAUTHORAFFILIATIONBACKUS,W.H.RochesterGas&ElectricCorp.MECREDY,R.C.RochesterGas&ElectricCorp.RECIP.NAMERECIPIENTAFFILIATION05000244

SUBJECT:

LER90-008-00:on900524,safeguardsbusesdegradedvoltagerelaysmiscalibrateddetoprocedureinadequacy.W/9ltr.DISTRIBUTIONCODE:IE22TCOPIESRECEIVED:LTRENCLSIZE:TITLE:,.50.73/50.9LicenseeEventReport(LER),IncidentRpt,etc.NOTES:LicenseExpdateinaccordancevith10CFR2,2.109(9/19/72).RECIPIENTIDCODE/NAMEPD1-3LAJOHNSON,AINTERNALACNWAEOD/DSP/TPABDEDRONRR/DET/EMEB9H3NRR/DLPQ/LPEB10NRR/DREP/PRPB11NOR/DST/SICB7ENRR/DST/SRXB8ERES/DSIR/EIBEXTERNALEG&GSTUARTgVALPDRNSICMAYS,GNUDOCSFULLTXTCOPIESLTTRENCL111122111111112211111144111111RECIPIENTIDCODE/NAMEPD1-3PDAEOD/DOAAEOD/ROAB/DSP..NRR/DET/ECMB9HNRR/DLPQ/LHFB11NRR/DOEA/OEAB11NRR/DST/SELB8DB8D1EGILE02RG1FILE01LSTLOBBYWARDNRCPDRNSICMURPHY,G.ACOPIESLTTRENCL111122111111111111111.11111NOTETOALL"RIDS"RECIPIENTS:PLEASEHELPUSTOREDUCElVASTE!CONTACI'HEDOCUMENTCONTROLDESK,ROOMP1-37(EXT.20079)TOELIMINATEYOURNAMEFROMDISTRIBUTIONLISTSFORDOCUMENTSYOUDON'TNEED!DDFULLTEXTCONVERSIONREQUIREDTOTALNUMBEROFCOPIESREQUIRED:LTTR34ENCL34P+

ROCHESTERGASANDIWCer'.le/),".'STA1(ELECTRICCORPORATION~89EASTAVENUE,ROCHESTER,N.K146490001TELCPHO4Ciseicoot7ie5462700June25,1990U.S.NuclearRegulatoryCommissionDocumentControlDeskWashington,DC20555

Subject:

LER90-008,SafeguardsBusesDegradedVoltageRelaysMiscalibratedDueToProcedureInadequacyCausesaConditionProhibitedByPlantTechnicalSpecificationsR.E..GinnaNuclearPowerPlantDocketNo.50-244Inaccordancewith10CPR50;73,Licensee.EventReportSystem,Item(a)(2)(i)(B),whichrequiresareportof"anyoperationprohibitedbytheplant'sTechnicalSpecifications",theattachedLicenseeEventReportLER90-008isherebysubmitted.Thiseventhasinnowayaffectedthepublic'shealthandsafety.Verytrulyyours,RobertC.MecedyDivisionManaerNuclearProductionXC:U.S.NuclearRegulatoryCommissionRegionI475AllendaleRoadKingofPrussia,PA19406xc:GinnaUSNRCSeniorResidentInspector NACtsrrsNO%4SIUCENSEEEVENTREPORTtLER)IAS,SACLIAAASOVLATOA+COAAO~AttAOYIOOasoINLIINoloNlahASISISIIIStACILITYNASSIIIIR.E.GinnaNuclearPowerPlantOOCACTNVssOCAIllo6o0o244Tos08.SafeguardsBusesDegradedVoltageReysz.scaxraeoureInadacCausesACondxtionProhibitedByPlantTechnicalSpecificationsIVCNTOATCISILIANVasOCAillAltOATOATSmOTlllAtACILITIISNrvOLVIOISIaSOSrTrrOAYYCAAYCAA~I0VIrsrsAaslvss~~A~soNTrs~srssaS1OAYYCAAtAOLITY>>ArsisOOCtlTNVQCCAISI0600052490900080006259006000OtIAATIlrOasoolilltOrrl1LIVIL098Io.soslalSl.sOS4ll1II~N.SNlslllllllSO.AN4111IIN)SSANlsllll(lrlSO.SCSlaIllIlrlSl.sOCI~INJllslllINMWIIIN.TS4I0IIIN.TI4IIIIIIIN.lIllI0lIAOLICCNSISCONTACTtOATIIIILCAllllN.lllsIISIVrlN.TSNIISIIllN.TSlaIillItalNTS4IISIIrrAIIAIN.llitIISIIYNIISIIO.TSlslilllsITIIISAlt01TISSvasslTTCOtvASVANTTOTill1IOVI1CNCNTSOt'llCt1fr10srssssssrr>>ssrairSrtrasNIIIITS.TISITL714lOTlll1IStss~rsrssossTssl,>>ACtssasJOCAIWesleyH.BackusTechnicalAssistanttotherationsManaerTILltNONCNVSSSIAAAIACOOl3155-24-44COastLSTIONILINItOIIACNCOastONINTtAILVAIOISCAIIIOiNTlrll1ltOATIIIICAvSIIYSTCNCOastONINTisAsrvtACTVAIAIsOATASLITONtAOISYSTIIICOQtONINTssANvtACTVAIAltOATASLTONtAOSNrrrpr.>I~sr.rg$(vc')rrsrs~rC)gSVttLIISINTAL1ltOATIAtlCTIOII%ssONTNCAYYIAAIatlCTIOLvlasilllo1OA'TIIIIITCIlit~.~SitCCTCOSVSSSISSO>>OArCIOLSSTA*CTIassvrssI%XIrtsr>>,Ia,stsrassrrs>>rtrrrrssNstssstsrsrttsrrsrrssassssllllOnMay24,1990at1604EDSTwiththereactoratapproximately984fullpower,anevaluationofundervoltagerelaytestdatarevealedthatfive(5)oftheeight(8)DegradedVoltageRelayson480volt'afeguardbuseswerecalibratedsuchthatrelayactuationwouldnotoccurwithinthelimitsofTechnicalSpecifi-cations.Asthiswasasetpointproblemwiththedegradedvoltagerelays,noimmediateplantoroperatorresponseswerenecessary.Theunderlyingcauseoftheeventwasattributedtothewrongsetpointandsetpointtolerancebeingspecifiedinacalibrationprocedure.ImmediatecorrectiveactionwastocalibratetheDegradedVoltageRelaystoasetpointontheconservativesideofthetolerance.Subsequenttothecalibration,thedegradedvoltagerelaysweretestedsatisfactorilyandreturnedtoservice.NACteaSN NACSodom444AI945ILICENSEEEVENTREPORTILER)TEXTCONTINUATIONU,4.NUCLCAAATOULATOAYCOMMI94IONASSAOYTOOM4NO1I50&10I5)ISIA4$4I5I/45SACILITYNAM4IllOOCKTTNUM44AITILTANUM44A19I94OUTNTIALNUMATVCKINNUM~AO4I4IR.E.GinnaNuclearPowerPlantTEXT(ISmarMSSSNnatured.sMOdOeenVNIICfenn445AYIIltlosooo24490-0080002op0PRE-EVENTPLANTCONDITIONSTheunitwasatapproximately98%reactorpower.TheResultsandTestDepartmentandanElectricalEngineeringrepresentativewereobservingtheRelayDepartmentperformingprotectiverelaycalibrationprocedurePR-1.1(480VoltUndervoltageAndGroundAlarmSchemeForBuses14,16,17and18.)II.DESCRIPTIONOFEVENTA.DATESANDAPPROXIMATETIMESOFMAJOROCCURRENCES:oModificationinstallationin1982:EventdateoMay24,1990,1115EDST:Discoverydateandtimeofthefirstoffiverelaysfound-belowthelimitofTechnicalSpecifications.oMay24,1990,1604EDST:Allaffectedrelaysrecalibrated,testedsatisfactorilyandrestoredtoservice.B.EVENT:OnMay24,1990at1604EDST,withthereactoratapproximately.98%fullpowerPR-l.lwascompleted.EvaluationofthePR-l.ldatarevealedthatfive(5)oftheeight(8)DegradedVoltageRelayson480voltsafeguardsbuses14,16,17,and18hadbeencalibratedsuchthatrelayactuationwouldnotoccurwithinthelimitsofTechnicalSpecifications,page2.3-10,Figure2.3-1.Therelaysaffectedwereasfollows:relays27/14onBus14,27B/16onBus16,27/17and27B/17onBus17and27/18onBus18.Thisdeterminationoccur-redafterevaluationandanalysisoftestdataandTechnicalSpecificationreiui:rementsasfollows:~tACSCAM544A<945I NIICScenSSSA~W491LICENSEEEVENTREPORT(LERITEXTCONTINUATIONU.S.NUCLSANASOULATOAYCOMMISSIONAttROYSOOMSNOSI90&10c/SICItASS91914$SACILITYNAMK111OOCKSTNUMSSAITILSIINUMSKIII~ItAOSISIR.E.GinnaNuclearPowerPlantSAASIOUSHTcALHUMosooo2440-08A9V4IQHNVCC9A00030FO8TSICTlllmCnNMCC~CCevnd,WcaAkxntNACf<<rnAKI'llIITI00Thecurrent.480voltsafeguardsbusundervoltagesystemwasfirstputinservicein1982.SetpointswerespecifiedbyCorporateElectricalEngineering,andthese'etpoints(withtolerancesestablishedbytheRelayandTestDepartment)wereusedtocalibratetheserelaysoverthepasteightyears.OnApril4,1990thenormalannualcalibrationwasperformedonthe480voltsafeguardsbusesDegradedVoltageRelays,perPR-l.l.Thisprocedurechecksandcalibratesthedropoutvoltageoftherelays.Theprocedurespecifieda+54calibrationtoler-anceonthedropoutsetpointwitha"desired"specifiedsetpointof103.5volts.AllDegradedVoltageRelayswerecalibratedtothesespecifica-tions.Becauseofthe+toleranceallowedbytheproceduresomeoftherelayswerecalibratedtolessthanthe"desired"103.5voltswhichwasconsideredacceptable.00OnApril12,1990thenormalpostcalibrationtestwasperformedonthe480voltsafeguardsbusesDegradedVoltageRelaysperperiodictestprocedurePT-9.1(UndervoltageProtection-480VoltSafeguardBuses).Thisprocedurecheckstheresetvoltageoftherelaysandalsothedropoutresponsetime,butdoesnotcheckthedropoutvoltage.AllDegradedVoltageRelayswerefoundtobewithinthespecificationsoftheprocedure.PriortoApril26,1990areviewofthecalibrationdatafromApril4,1990andareviewofplantTechnicalSpecificationswasperformedbytheISI/ISTCoordinatorandanElectricalEngineeringrepresentative.Followingthisreview,thesein-dividualsrequestedthatallDegradedVoltage'cACcOAM99CAi9491 NACform99SA19411LICENSEEEVENTREPORT(LER)TEXTCONTINUATIONV.E.NVCI.EAIIIIEQVLATOIIYCOMMISSIONAfflIOVEOOMENO1150MIOA/EII91AEE.Efllr95fACILIYYNAME111R.E.GinnaNuclearPowerPlantSEXYllfrrroroAoocoNrooMrof.oooANoooenorHIICforrrr~'IIIIIIOOCKEZNVMEEN11105000244LEIINVMEEIIIEIrEAA-SEQvsrrzrAL'svolorr~rvMSANMMSA90-008-0004oF0Relaysthatwerefoundatorbelow103.5voltsbeadjustedtogreaterthan103.5volts.Thegreaterthan103.5voltswasrequestedtoensurethatallrelayswerewithintheTechnicalSpecificationlimitof103.5voltspriortoenteringtheplantmodeforwhichtheserelaysarerequiredtobeoperable.FiveDegradedVoltageRelayswereadjustedonApril26,1990.OnMay11,1990thenormalmonthlyPT-9.1wasperformedonall480voltsafeguardsbusesDegradedVoltageRelays.ThistestwaswitnessedbyanElectricalEngineeringrepresentative.Afterreviewofthetestdata,theElectricalEngineeringrepresentativeexpressedaconcernthat,basedonthetestresetdata,'actualdropoutvoltageof5oftheDegradedVoltageRelaysmaybebelowtheTechnicalSpecification103.5voltlimit.OnMay24,1990PR-l.lwasreperformedonthe5DegradedVoltageRelaystoverifytheirdropoutvoltagesetpoint.At1115EDST,thedropoutvoltageofthefirstrelaywascheckedandfoundbelowtheTechnicalSpecificationlimitof103.5volts.Subsequently,thedropoutvoltagesoftheother4relayswerealsofoundbelowtheTechnicalSpecificationlimitof103.5volts.Theaffectedrelayswererecalibratedtogreaterthan103.5voltsandPT-9.1wasperformedoneachrelayasitwasrestoredtoservicefollowingcalibration.Allrelayssubsequentlytestedsatisfactorily.0OnMay29,1990PT-9.1wasreperformedonall480voltsafeguardsbusesDegradedVoltageRelaystocheckforpossiblesetpointdrift.Allrelaystestedsatisfactorily.NACA0AMSOOAI9411 NIICTMmSSSA19431LICENSEEEVENTREPORTILER)TEXTCONTINUATIONV.S.NVCLSAIIIISOULATOIIYCOMMISSIONA99AOVSOOMSNO>190&105IS)c9111SS'919149SACILITYNAMSIIIR.E.GinnaNuclearPowerPlantOOCKSTNUMSSIIITILSANVI5SSIII~I<<5*A550>>5>>TIALMVM5A85<<I@IONMM'51~AOSISITEXTlllmooN>>55>>leoveaf.<<55@dao>>A5lNACArm~9lIITIosooo24490-008-0005OFO8C.INOPERABLESTRUCTURESTCOMPONENTSTORSYSTEMSTHATCONTRIBUTED.TOTHEEVENT:D.E.None.OTHERSYSTEMSORSECONDARYFUNCTIONSAFFECTED:None.METHODOFDISCOVERY:TheeventwasmadeapparentduringtheperformanceofPR-l.lonMay24,1990.F.OPERATORACTION:AsthiswasasetpointproblemwiththeDegradedVoltageRelays,noimmediate'peratoractionwasnecessary.G.SAFETYSYSTEMRESPONSES:None.III.CAUSEOFEVENTA.IMMEDIATECAUSE:Theimmediatecauseoftheeventwasdueto5of8DegradedVoltageRelayson480voltsafeguardbuses14,16,17,and18beingcalibratedsuchthatrelayactuationwouldnotoccurwithinthelimitsofTechnicalSpecifi-cations.B.ROOTCAUSE:TherootcauseoftheeventdiscoveredonMay24,1990,wasattributedtothecalibrationconditionsthatexistedonApril26,1990,duringthepreviouscalibra-tionofthefiveDegradedVoltageRelays.TheunderlyingNAC501M555k<9431 NACtermSCCA$451LICENSEEEVENTREPORTILERITEXTCONTINUATIONU.d.NVCLEAIIAEOULATOIIYCOMMISSIONAttllOVEOOMSNOSI50&IOCEAtllIES5/5II55tACILITYNAMEIIIR.E.GinnaNuclearPowerPlantTEXTlitrereeMece~reee>>AC.eeeerAM>>r>>INIICterIASELCOlIITIOOCKETNVMEEIILTIosooo244LEIINVMOEIIIdl5CQIICNTIALNVMCA90-008ACVICIQNNIIMCA00tAOEISI060FO8causeoffindingsetpointsbelowlimits(inthepast)isnowevidentandisduetothewrongsetpointandsetpointtolerancebeingspecifiedinacalibrationprocedure.ThecalibrationprocedureforthesafeguardbusDegradedVoltageRelays(PR-1.1)specifiedanacceptancecriteriaof103.5volts+5%.GinnaTechnicalSpecificationfigure2.3-1requiresthe'DegradedVoltageRelaystoactuatewhentherelayvoltagesdropto103.5volts(AC)whichcorrespondsto414voltsonthe480voltsafeguardbus.Therelaysetpointof103.5voltswasdeterminedbyRG&ECorporateEngineeringandprovidedtoRelay.andTestDepartmentforuseinthecalibrationoftheserelays.However,nodefinitivetolerancebandwasprovidedwiththedesiredsetpoint.Normalvendorrecommendedtoleranceswereappliedupondevelopmentofthecalibrationprocedure.Thisresultedintheactualsetpointoftheserelaystobeacceptablewhenleftbelowtherequiredminimumdropoutvoltageof103.5volts.IV.ANALYSISOFEVENTThiseventisreportableinaccordancewith10CFR50.73,LicenseeEvent,ReportSystem,item(a)(2)(i)(B)twhichrequiresareportof,"anyoperationprohibitedbytheplant'sTechnicalSpecifications."The5outof8DegradedVoltageRelaysbeingcalibratedsuchthatrelayactuationwouldnotoccurwithinthelimitsofTechnicalSpecificationswasanoperationprohibitedbytheplantTechnicalSpecifica-tions.Anassessmentwasperformedconsideringboththesafetyconsequencesandimplicationsofthiseventwiththefollowingresultsandconclusions:NACAOAUSCCAIdddl

NIICfarm444A1945ILICENSEEEVENTREPORT(LER)TEXTCONTINUATIONU.s.51UCLEAAAECULATOATCOMM144IOMAtfIIOVEOOM4IIO5150&104/EllfIIIES'4ITIl45fACILITYIIAMEIIIR.E.GinnaNuclearPowerPlantTExTIlfmoreaoaoeoeerraerI.rraeooaeoorvIrtlICfarmSMA'llII1)OOCIIETIIUM4511111osooo24LEIIIIUM4511IEI55QVCMTIAL.,'EVrelOrrrrVrrea'rVMea9000800~ACEI4107Op08Therewerenooperationalorsafetyconsequencesorimplica-tionsattributedtothe5of8DegradedVoltageRelayson480voltsafeguardbuses14,16,17,and18beingcalibratedsuchthatrelayactuationwouldnotoccurwithinthelimitsofTechnicalSpecificationsbecauseofdesigne'drelayredundancyandrequiredoperatoractions.EachsafeguardbusisprovidedwithtwoDegradedVoltageRelaysandtwolossofvoltagerelays.Anyoneoftheserelayswillstartthecorrespondingemergencydieselgenera-tor.TwooutoftwoofeithertheDegradedVoltageRelaysortheLossofVoltageRelayswillstripthesafeguardsbusandclosethedieseltiebreakerontothesafeguardsbus.ThemiscalibrationoftheDegradedVoltageRelayswouldnothavepreventedthedieselgeneratorfromsupplyingemergencypowertothesafeguardsbusuponalossofvoltage.GinnaabnormaloperatingprocedureAP-ELEC.2,(Safe'guardsBusesLowVoltageorSystemLowFrequency),requiresbothemergencydieselgeneratorstobestartedmanuallyifanysafeguardsbusvoltagefallsbelow420volts.Inaddition,ifanysafeguardsbusvoltagedecreasesto414volts,theoperatorisdirectedtotransferallsafeguardbuspowersuppliestotheemergencydieselgenerators.SinceTechnicalSpecifica-tionFigure2.3-1allowsapproximately20minutesofcontinuedoperationatthelowestmiscalibratedrelaysetpoint,ampletimewasallottedforoperatorstoperformrequiredactionofAP-ELEC.2.Basedontheabove,itcanbeconcludedthatthepublic'shealthandsafetywasassuredatalltimes.V.CORRECTIVEACTIONA.ACTIONTAKENTORETURNAFFECTEDSYSTEMSTOPRE-EVENTNORMALSTATUS:oTheaffectedrelayswererecalibratedtogreaterthanthe103.5voltsTechnicalSpecificationlimit,testedsatisfactorilyandrestoredtoservice.'rAC501M5aear94)l RRC/oem494A1944ILICENSEEEVENTREPORTILER)TEXTCONTINUATIONV.4.NVCLEARRECULATORYCOMMIEEIOIIASSROVEOOMEHO3140&IOS/E)IPIRESEIEI/49IEACILITYIIAMEIIICOCKETHUMEER111LERIIUMEERIElvEAASSQVCNTIALAVMASVtSIOHI"RMSA~AOE141R.E.GinnaNuclearPowerPlantTEXTIlt~MS'~.uSs~IYIICa~'S>IITIo5ooo244900080008Dp08B.ACTIONTAKENORPLANNEDTOPREVENTRECURRENCE:oThetestconditionsthatexistedonApril26,1990,willbeevaluated.Asaresultofthisevaluation,itisexpectedthatimprovementswillberecommended.AnyrelayscalibratedafterApril25,1990,willbeidentified.Theresultsofthesecalibrationswillbereviewedforgenericconcernswithtestconditions.00Ananalysiswillbe.performedtoobtaintheoptimumsetpointandsetpointtolerance'fortheDegradedVoltage-Relays.CalibrationprocedurePR-1.1willberevisedtoincorporatethesenewsetpointsandsetpointtolerances.AnewmethodologyfortestingtheserelayswillbeincorporatedintoPeriodicTestprocedurePT-9.1.VI.ADDITIONALINFORMATIONA.AFFECTEDCOMPONENTS:TheDegradedVoltageRelaysareaModel211B1175DTypeITE-27relaymanufacturedbyITECorporation.B.PREVIOUSLER'SONSIMILAREVENTS:AsimilarLEReventhistoricalsearchwasconductedwiththefollowingresults:nodocumentationofsimilarLEReventswiththesamerootcauseatGinnaStationcouldbeidentified.C.SPECIALCOMMENTS:None.~%ACSORMSSSAl94SI