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{{#Wiki_filter:!+ACCELERATEDDISTRIBUTIONDEMONSTRATIONSYSTEMREGULATORINFORMATIONDISTRlBUTIONpTEM(RIDS)ACCESSIONNBR:9203110291DOC.DATE:92/03/04NOTARIZED:NODOCKET¹FACIL:50-244RobertEmmetGinnaNuclearPlant,Unit1,RochesterG05000244AUTH.NAMEAUTHORAFFILIATIONBACKUSiW.H.RochesterGas&ElectricCorp.MECREDY,R.C.RochesterGas&ElectricCorp.RECIP.NAMERECiPIENTAFFILIATION
{{#Wiki_filter:!+ACCELERATED DISTRIBUTION DEMONSTRATION SYSTEMREGULATOR INFORMATION DISTRlBUTION pTEM(RIDS)ACCESSION NBR:9203110291 DOC.DATE:
92/03/04NOTARIZED:
NODOCKET¹FACIL:50-244 RobertEmmetGinnaNuclearPlant,Unit1,Rochester G05000244AUTH.NAMEAUTHORAFFILIATION BACKUSiW.H.
Rochester Gas&ElectricCorp.MECREDY,R.C.
Rochester Gas&ElectricCorp.RECIP.NAME RECiPIENT AFFILIATION


==SUBJECT:==
==SUBJECT:==
LER92-002-00:on920203,reactortripoccurredw/reactoratapprox23%fullpowerjustsubsequenttoturbinetripwhileat47%power.CausedbylololevelinSGAduetodesignperturbations.Newsettingcalculated.W/920304ltr.DISTRIBUTIONCODE:IE22TCOPIESRECEIVED:LTRENCLSIZE:TITLE:50.73/50.9LicenseeEventReport(LER),IncidentRpt,etc.NOTES:LicenseExpdateinaccordancewith10CFR2,2.109(9/19/72).RD/05000244ARECIPIENTIDCODE/NAMEPDl-3LAJOHNSON,ACOPIESLTTRENCL1111RECIPIENTIDCODE/NAMEPD1-3PDCOPIESLTTRENCL11DDINTERNAL:ACNWAEOD/DSP/TPABNRR/DET/EMEB7ENRR/DLPQ/LPEB10NRR/DREP/PRPBllNRR/DST/SICB8H3NRR/DST/SRXB8ERES/DSIR/EIBEXTERNAL'G&GBRYCEiJ~HNRCPDRNSICPOOREiW.AEOD/DOAAEOD/ROAB/DSPNRR/DLPQ/LHFB10"NRR/DOEA/OEABNRR/DST/SELB8DgNR~D-.LB8Dl-G~02RGN1FILE0133LSTLOBBYWARD1111NSICMURPHYgG.A111.1NUDOCSFULLTXT112211112211111111221~1'111111111111DNOTETOALL"RIDS"RECIPIENTS:PLEASEHELPUSTOREDUCEWASTE!CONTACTTHEDOCUMENTCONTROLDESK,ROOMPl-37(EXT.20079)TOELIMINATEYOURNAMEFROMDISTRIBUTIONLISTSFORDOCUMENTSYOUDON'TNEED!ADDSFULL'TEXTCONVERSIONREQUIREDTOTALNUMBROFCOPIESREQUIRED:LTTR30ENCL30 I
LER92-002-00:on 920203,reactor tripoccurredw/reactor atapprox23%fullpowerjustsubsequent toturbinetripwhileat47%power.CausedbylololevelinSGAduetodesignperturbations.New settingcalculated.W/920304 ltr.DISTRIBUTION CODE:IE22TCOPIESRECEIVED:LTR ENCLSIZE:TITLE:50.73/50.9 LicenseeEventReport(LER),IncidentRpt,etc.NOTES:License Expdateinaccordance with10CFR2,2.109(9/19/72).
rrf~'I~zotrr.sT4MROCHESTERGASANDELECTRICCORPORATION489EASTAVENUE,ROCHESTERN.K-74649-0001ROBER't(,hlECRjtpYVrr<VresidenlCrnnaNo<lcmProdursrorrTELE&>0'MEARErrCOM716546'2700March4,1992U.S.NuclearRegulatoryCommissionDocumentControlDeskWashington,DC20555
RD/05000244ARECIPIENT IDCODE/NAME PDl-3LAJOHNSON,A COPIESLTTRENCL1111RECIPIENT IDCODE/NAME PD1-3PDCOPIESLTTRENCL11DDINTERNAL:
ACNWAEOD/DSP/TPAB NRR/DET/EMEB 7ENRR/DLPQ/LPEB10 NRR/DREP/PRPBll NRR/DST/SICB8H3 NRR/DST/SRXB 8ERES/DSIR/EIB EXTERNAL'G&GBRYCEiJ~HNRCPDRNSICPOOREiW.AEOD/DOAAEOD/ROAB/DSP NRR/DLPQ/LHFB10" NRR/DOEA/OEAB NRR/DST/SELB 8DgNR~D-.LB8Dl-G~02RGN1FILE0133LSTLOBBYWARD1111NSICMURPHYgG.A 111.1NUDOCSFULLTXT112211112211111111221~1'111111111111DNOTETOALL"RIDS"RECIPIENTS:
PLEASEHELPUSTOREDUCEWASTE!CONTACTTHEDOCUMENTCONTROLDESK,ROOMPl-37(EXT.20079)TOELIMINATE YOURNAMEFROMDISTRIBUTION LISTSFORDOCUMENTS YOUDON'TNEED!ADDSFULL'TEXTCONVERSION REQUIREDTOTALNUMBROFCOPIESREQUIRED:
LTTR30ENCL30 I
rrf~'I~zotrr.sT4MROCHESTER GASANDELECTRICCORPORATION 489EASTAVENUE,ROCHESTER N.K-74649-0001 ROBER't(,hlECRjtpY Vrr<Vresidenl CrnnaNo<lcmProdursrorr TELE&>0'ME ARErrCOM716546'2700March4,1992U.S.NuclearRegulatory Commission DocumentControlDeskWashington, DC20555


==Subject:==
==Subject:==
LER92-002,FeedwaterTransient,DueToLossOfExcitationInducedTurbine/GeneratorTrip,CausesLoLoSteamGen'eratorLevelReactorTrip-R.E.GinnaNuclearPowerPlantDocketNo.50-244Inaccordancewith10CFR50.73,Licensee.EventReportSystem,item(a)(2)(iv),whichrequiresareportof,"anyeventorconditionthatresultedinmanualorautomaticactuationofanyEngineeredSafetyFeature(ESF),includingtheReactorProtectionSystem(RPS)",theattachedEventReportLER92-002isherebysubmitted.Thiseventhasinnowayaffectedthepublic'shealthandsafety.Verytrulyyours,RobertC.Mecredy.xcoU.S.NuclearRegulatoryCommissionRe'gionI475AllendaleRoadKingofPrussia,PA19406GinnaUSNRCSeniorResidentInspectorf)~g(4~(q'l92031i0291'720304PDRADOCK050002445PDR It'l  
LER92-002,Feedwater Transient, DueToLossOfExcitation InducedTurbine/Generator Trip,CausesLoLoSteamGen'erator LevelReactorTrip-R.E.GinnaNuclearPowerPlantDocketNo.50-244Inaccordance with10CFR50.73, Licensee.
<<ACcrea<<I4ASILICENSEEEVENTREPORTLER)Ug,IRILSARRIRVLATCATcoe>>e<<voceAeeaavlaOeetNO,$1<<.aiavISIIAISI/SQISeACILITYNAeelIllR.E.in'naNuclearPowerPlant:OOCRtTIA>>eOIRQlAo6ooo244>ot'"FeedwaterTransient,DuetoLossofExcitationnucedTurz.neGeneratorTrip,CausesLoLoSteamGeneratorLevelReactorTripIVINSOATSIIILtRNueettAIIIAIMRTOATIIIIOTHIAeACILITISIINVOLVIONlVO<<THOAYYIA1YIAR0239292~save<<ewe<<vee~IA002AevorceeIrueee~A0IIONTH03OAY04YIAR92eACIUTY<<AeeeeOOCAIT<<uee~SAISI0600O06000Oel1*TINOeeOOIItl~Oeel1LlvlL023THIS1leOATNSuteeITTIOeuAWANTI$Lea$4ISO.NQNlllIIISa.calleIIIIIIISt.eleIIIIIRI$OAOllelllIl<<lSO.OOSlelllllelSt.cellel~OMWIII~OMWQI~O.TSNIQIII~O.TtieIQIIIIIO.TSNIQIIVO~O.TSNIQII<<I~O.TSlalQ)lel~O.TSlalQlleOIIO.TIlelQlleraIAI~0.$SIeIQIleetlQISO.TSWQllel0THI1$ovl1tlelNTIOeItel1$."lceeeeerrercereeleeeeeeeree>>IlllM714ITLTllelOTHSRlteeeeVIeAeeeeeeererereeeTeeL<<RC/>>4<<AUILICINSIICONTACTMRTHQLSAllllTILteleONINVLQIAWesleyJI.BackusARIACOOlTechnicalAssist:anttotheOperationsManager31552444CCAVLSTIONSLINC>ORtACHCaeeMNINTOAILUAI0tlCAIllaIelTHISRIMATlltlCAUSISYSTINCOIIMNINTVA<<u>ACrTVAIAIMRTAILI'gent,~H<@tToNeRosr~P4;":~QjCVSISYSTSNcoeeMNINTHANVSA4TVAIRIMATAILTONOAOSXBTBW315g~NAN$3'.~e'rterr%g~rr3>vVjj~4~e:.II~I,>>~C.~,y;$$4SVTTLININT*LAIMATtteICTIOIIAIVIIIllTee.er<<e>>NSRJSCTSOSVINISSIO>>OATIIAJSTA*cTILeevl4Iecoeeeer.IA,eeereee<<e>>reAY>>eeree>>eeeeeeeoer<<I>>e<<eevlltlttetCTSOLVINISSIONOA'llll~IeeONTHCAYYIAROnFebruary3,1992withthereactoratapproximately23%fullpower,justsubsequenttoaturbinetripwhileat474reactorpower,areactortripoccurredduetoLoLoLevel(</=17%)inthe"A"SteamGenerator(S/G).TheControlRoomoperatorsimmediatelyperformedtheappropriateactionsofEmergencyOperatingProceduresE-0(ReactorTriporSafetyInjection)andES-0.1(ReactorTripResponse).BothMainSteamIsolationValves(MSIVs)weresubsequentlyclosedtolimitaReactorCoolantSystem(RCS)cooldownandtheplantwasstabil-izedathotshutdown.Theunderlyingcauseoftheeventwastheinabilitytocontrolthe"A"S/Glevelabovethereactortripsetpointduetodesignandtransientinducedperturbations.(ThiseventisNUREG-1022(x)CauseCode).CorrectiveactiontakenorplannedarediscussedinSectionVofthetext.<<ACe<<r<<I44$I If IIACtv'040ILICENSEEEVENTREPORTILER)TEXTCONTINUATIONVl.4VCLlAAAIOVLATOAVCeaWIllIISIA>>AOVlO0+14OIIQI~IQAl)et<AllII)I'lSSACILITYIIAIAlIII"OOCIIKZIIVIACCAIll%lAALlAIIIAAI~IIIllS~QMA4TIAL'VUAACVOIOHVIA~AOlIlIR.E.GinnaNuclearPowerPlanttlXTOr~aeOee~.~~~AAC~~'sIIlllosooo2449200200020F].PRE-L?V1?NTPLANTCONDITIONSTheplantwasatapproximately47%reactorpowerduetoaloadreductionearlierintheday.Partofthisload.reduction(i.e.toapproximately60%reactorpower)wasrequestedbytheRochesterGasandElectricCorporation(RG&E)PowerControlDispatchertoremoveamajortrans-missionlinefromservice(circuit908)forrepair.Theremainderofthisloadreduction(from60%to47%reactorpower)wasmadetoreducereactorpowerbelowpermissiveP-9(i.e.ReactorTripFromTurbineTripBlocked)toperformcondenserwaterboxmaintenanceandturbineon-linetriptestingandvalvetesting.ThemaingeneratorvoltagecontrolwasinthemanualmodeduetovoltageoscillationsexperiencedearlierintQeday.Thereactorcontrolrodswerealsointhemanualmodetomaintainthecoreaxialfluxwithinitsoperatingband.Turbineon-linetriptestingand'alvetestingwasinprogresswiththelasttest'sinitialconditionsbeingverifiedpriortoperformanceofthetest.IIDESCRIPTIONOFEVENTA.DATESANDAPPROXIMATETIMESOPMAZOROCCUEGU9iCES:oFebruary3,1992,2220EST:duetolossofexcitation.MainGenerator.Trip0February3,1992,2220EST:MainTurbinetripdue=tomaingeneratortrip.0February,3,1992,2224EST:Eventdateandtime.0February3,1992,2224EST:Discoverydateandtime.0February3,'992,2224EST:ControlRoomoperatorsverifybothreactortripbreakersopen,andallcontrolandshutdownrodsinserted.VAC~QALIlAAAIl4$I  
EventReportSystem,item(a)(2)(iv),
whichrequiresareportof,"anyeventorcondition thatresultedinmanualorautomatic actuation ofanyEngineered SafetyFeature(ESF),including theReactorProtection System(RPS)",theattachedEventReportLER92-002isherebysubmitted.
Thiseventhasinnowayaffectedthepublic'shealthandsafety.Verytrulyyours,RobertC.Mecredy.xcoU.S.NuclearRegulatory Commission Re'gionI475Allendale RoadKingofPrussia,PA19406GinnaUSNRCSeniorResidentInspector f)~g(4~(q'l92031i0291
'720304PDRADOCK050002445PDR It'l  
<<ACcrea<<I4ASILICENSEEEVENTREPORTLER)Ug,IRILSARRIRVLATCAT coe>>e<<voce AeeaavlaOeetNO,$1<<.aiavISIIAISI/SQISeACILITYNAeelIllR.E.in'naNuclearPowerPlant:OOCRtTIA>>eOIRQlAo6ooo244>ot
'"Feedwater Transient, DuetoLossofExcitation nucedTurz.neGenerator Trip,CausesLoLoSteamGenerator LevelReactorTripIVINSOATSIIILtRNueettAIIIAIMRTOATIIIIOTHIAeACILITISI INVOLVIONlVO<<THOAYYIA1YIAR0239292~save<<ewe<<vee~IA002AevorceeIrueee~A0IIONTH03OAY04YIAR92eACIUTY<<AeeeeOOCAIT<<uee~SAISI0600O06000Oel1*TINO eeOOIItl~Oeel1LlvlL023THIS1leOATNSuteeITTIO euAWANTI$Lea$4ISO.NQNlllIIISa.calleIIIIIIISt.eleIIIIIRI$OAOllelllIl<<lSO.OOSlelllllelSt.cellel~OMWIII~OMWQI~O.TSNIQIII~O.TtieIQIIIIIO.TSNIQIIVO
~O.TSNIQII<<I~O.TSlalQ)lel
~O.TSlalQlleOI IO.TIlelQlleraIAI~0.$SIeIQIleetl QISO.TSWQll el0THI1$ovl1tlelNTI OeItel1$."lceeeeerrercereeleeeeeeeree>>IlllM714ITLTllelOTHSRlteeeeVIeAeeeeeeererereeeTeeL<<RC/>>4<<AUILICINSIICONTACTMRTHQLSAllllTILteleONI NVLQIAWesleyJI.BackusARIACOOlTechnical Assist:ant totheOperations Manager31552444CCAVLSTIONSLINC>ORtACHCaeeMNINT OAILUAI0tlCAIllaIelTHISRIMATlltlCAUSISYSTINCOIIMNINT VA<<u>ACrTVAIAIMRTAILI'gent,~H<@tToNeRosr~P4;":~Qj CVSISYSTSNcoeeMNINTHANVSA4TVAIRIMATAILTONOAOSXBTBW315g~NAN$3'.~e'rterr%g~rr3>vVjj~4~e:
.II~I,>>~C.~,y;$$4SVTTLININT*L AIMATtteICTIOIIAIVIIIllTee.er<<e>>NSRJSCTSOSVINISSIO>>
OATIIAJSTA*cTILeevl4Iecoeeeer.IA,eeereee<<e>>re AY>>eeree>>eeeee eeoer<<I>>e
<<eevlltlttetCTSOLVINISSION OA'llll~IeeONTHCAYYIAROnFebruary3,1992withthereactoratapproximately 23%fullpower,justsubsequent toaturbinetripwhileat474reactorpower,areactortripoccurredduetoLoLoLevel(</=17%)inthe"A"SteamGenerator (S/G).TheControlRoomoperators immediately performed theappropriate actionsofEmergency Operating Procedures E-0(ReactorTriporSafetyInjection) andES-0.1(ReactorTripResponse).
BothMainSteamIsolation Valves(MSIVs)weresubsequently closedtolimitaReactorCoolantSystem(RCS)cooldownandtheplantwasstabil-izedathotshutdown.
Theunderlying causeoftheeventwastheinability tocontrolthe"A"S/Glevelabovethereactortripsetpointduetodesignandtransient inducedperturbations.
(ThiseventisNUREG-1022 (x)CauseCode).Corrective actiontakenorplannedarediscussed inSectionVofthetext.<<ACe<<r<<I44$I If IIACtv'040ILICENSEEEVENTREPORTILER)TEXTCONTINUATION Vl.4VCLlAAAIOVLATOAV CeaWIllIISI A>>AOVlO0+14OIIQI~IQAl)et<AllII)I'lSSACILITYIIAIAlIII"OOCIIKZIIVIACCAIll%lAALlAIIIAAI~IIIllS~QMA4TIAL'VUAACVOIOHVIA~AOlIlIR.E.GinnaNuclearPowerPlanttlXTOr~aeOee~.
~~~AAC~~'sIIlll osooo2449200200020F].PRE-L?V1?NT PLANTCONDITIONS Theplantwasatapproximately 47%reactorpowerduetoaloadreduction earlierintheday.Partofthisload.reduction (i.e.toapproximately 60%reactorpower)wasrequested bytheRochester GasandElectricCorporation (RG&E)PowerControlDispatcher toremoveamajortrans-missionlinefromservice(circuit908)forrepair.Theremainder ofthisloadreduction (from60%to47%reactorpower)wasmadetoreducereactorpowerbelowpermissive P-9(i.e.ReactorTripFromTurbineTripBlocked)toperformcondenser waterboxmaintenance andturbineon-linetriptestingandvalvetesting.Themaingenerator voltagecontrolwasinthemanualmodeduetovoltageoscillations experienced earlierintQeday.Thereactorcontrolrodswerealsointhemanualmodetomaintainthecoreaxialfluxwithinitsoperating band.Turbineon-linetriptestingand'alvetestingwasinprogresswiththelasttest'sinitialconditions beingverifiedpriortoperformance ofthetest.IIDESCRIPTION OFEVENTA.DATESANDAPPROXIMATE TIMESOPMAZOROCCUEGU9iCES:
oFebruary3,1992,2220EST:duetolossofexcitation.
MainGenerator.
Trip0February3,1992,2220EST:MainTurbinetripdue=tomaingenerator trip.0February,3, 1992,2224EST:Eventdateandtime.0February3,1992,2224EST:Discovery dateandtime.0February3,'992,2224EST:ControlRoomoperators verifybothreactortripbreakersopen,andallcontrolandshutdownrodsinserted.
VAC~QALIlAAAIl4$I  


IIACSvv~(041ILICENSEEEVENTREPORTILERITEXTCONTINUATIONUl,vUCLSAAAl<<ULATOAY<<OvvlllIOAISArrrovlOOvlvOIISO~IOsl)erirf5llII%$CSACILITYVAVlIllCO<<IICTIIUVClrl1ILlAlsUVCSAlll$I4vSr7IAI.rvASVISIOHV1~AOlIllR.E.GinnaNuclearPowerPlantosooo244TlxTIII~vSSSrrrsrvr.vvSrrrrAvIvrcsvrl~'llIITI92-002-00030>12oFebruary3,1992,2229EST:ControlRoomoperatorsclosebothMainSteamIsolationValves(MSIVs)tolimitaReactorCoolantSystem(RCS)cooldown.oFebruary3,1992,2307EST:Plantstabilizedathotshutdowncondition.B.EVENT:OnFebruary3,1992atapproximately2220EST,withthereactoratapproximately47%stablereactorpower,theControlRoomreceivedturbinetripfirstoutannunciatoralarmK-26(GeneratorLockoutRelay).Asreactorpowerwaslessthan50%fullpowerwiththemaincondenseravailable,(i.e.lessthanpermis-siveP-9),reactortripfromturbinetripwasautomaticallyblocked.TheControlRoomoperatorsimmediatelyentered-AbnormalProcedureAP-TURB.'1(TurbineTripWithoutReactorTripRequired)andperformeditsapplicableactions.TheresponsesoftheSteamGenerator(S/G)FeedwaterRegulatingValves(FRVs)fordifferentcontrolconfigurationsarenotedhereforclarityofsubsequentevents:oWhenallFRVs(MainandBypass)areintheautomaticmode,theywillgofullopenonaturbinetripwithRCSaveragetemperature(Tavg)greaterthan554F.Whentemperaturegoesbelow554F,thesevalveswillgofullclosed.0AllFRVs,bothmainandbypass,willfullycloseuponreceivingaHIS/GLevel()/=674)orsafetyinjectionsignalregardlessoftheirauto/manualstatus(feedwaterisolation).'WhentheMainFRVsareplacedinthe,manualmodefromtheaboveconfiguration,theywillassumethepositionabasedonthecurrentcontrollermanualdemandsignalandstaythereuntiladjustedbytheresponsibleoperator.AssumingthatthebypassFRVsareleftinauto,thebypassFRVswillcontinuetorespondtotheautomaticfeedwatercontroldemand.VACsOAvSCCA<l4$I tl HISCTerm~IMMIeLICENSEEEVENTREPORTILERITEXTCONTINUATIONU.S.HUclcAAitoUUAToircossssls$loi/ASSAOVCOOH$HO$1$OWIOS$Ilr<A$5IISI'$$AACIUI'TYHAMII1IOOCIICTHUMOIA111CliHUMOtiI~ISSOU~HTIAI,ASvlQIOrMrSA0$1$1R.E.GinnaNuclearPowerPlantRATlrmarMSrsrHssrsr.~srsrrrsAMHrcIlsrr~$111TIosooo24492--0.'2"-0'04osl2PriortotheturbinetripallFRVswereintheautomaticcontrolmodewiththebypassFRVsfullopenandthemainFRVscontrollingS/Glevelinsomemidposition.Subsequenttotheturbinetrip,thema'inFRVswentfullopenperdesign(thebypassFRVswerealreadyfullopen)andtheControlRoomoperatortransferredthemainFRVstomanualcontrolandadjustedthemtocontrolS/Glevels.ThebypassFRVswereleftintheautomaticcontrolmode.ThenarrowrangeS/Glevelswereatapproximately534andrapidlyincreasingwhenthemainFRVswereshiftedtothemanualmode.TheControlRoomoperatorclosed'ownthemainFRVstoapproximately10-134opentocontrolS/Glevels.Duringthistimethe"A"S/GFRVisolatedonHILevel(i.e.)/=67%narrowrangelevel).DuringapproximatelythissametimethefullopenbypassFRVsrapidlyclo".edbecausetheirautomaticcontrollingsetpointwasnow394S/Glevel.TheControlRoomoperator'continuedtomakeadjustmentstothemainFRVstocompensateforthetransientperturbations,butwasunsuccessful.At2224EST,February3,1992,withthereactoratapproximately234fullpowerareactortripoccurredduetoLoLoLevel((/=174)inthe"A"S/G.TheControlRoomoperatorsperformedtheimmediateactionsofEmergencyOperatingProcedureE-0(ReactorTripOrSafetyInjection)andtransitionedtoEmergencyOperatingProcedureES-O.l(ReactorTripResponse)whenitwasverifiedthatbothreactortripbreakerswereopen,allcontrolandshutdownrodswereinserted,andsafetyinjectionwasnotactuatedorrequired.BothMSIVsweresubsequentlyclosedat2229ESTtolimittheRCScooldown.TheclosingoftheMSIVssubsequentlymitigatedtheRCScooldownandtheplantwasstabilizedinhotshutdownat2307EST.MACsorvsAAAI$441 I
IIACSvv~(041ILICENSEEEVENTREPORTILERITEXTCONTINUATION Ul,vUCLSAAAl<<ULATOA Y<<OvvlllIOAI SArrrovlOOvlvOIISO~IOsl)erirf5llII%$CSACILITYVAVlIllCO<<IICTIIUVClrl1ILlAlsUVCSAlll$I4vSr7IAI.rvASVISIOHV1~AOlIllR.E.GinnaNuclearPowerPlantosooo244TlxTIII~vSSSrrrsrvr.vvSrrrrAvIvrcsvrl~'llIITI92-002-00030>12oFebruary3,1992,2229EST:ControlRoomoperators closebothMainSteamIsolation Valves(MSIVs)tolimitaReactorCoolantSystem(RCS)cooldown.
IIACSoew%CAI%45>LICENSEEEVENTREPORT{LER)TEXTCONTINUATIONy,l,IIUCLSAAAlOULATOAVCOSSMISCIOII/ASSAOVlOOulIOTISO&104l~>AllSINAI1$SACILITVIIASStIIIOOCKttIIUI&lAITIvSAALlllIIUSSCIAISIS~4USatiALU1SAOlISIR.E.GinnaNuclearPowerPlantTlXTIIT~~e~.WeeerCeW+ACArmWSSIUTIosooo244920200050vl2Equipmentproblemsthatoccurredduringtheeventwereasfollows:0'he"ALTSteamGeneratorMSIVMainControlBoardindicationshowedthevalvetobenotfullyclosed.Anauxiliaryoperatorwasimmediatelysentouttocheckandreportedthevalveclosedbasedonviewingthevalveexternalindicator.Subsequently,theMainControlBoardindicatedthevalvefullyclosedapproximately23minutesaftersignalreceipt.00FollowingthestartoftheTurbine,DrivenAuxiliaryFeedwater(TDAFW)pumponLoLoS/GLevels,itexhibitedsomeoscillationsinflow,howevertotalflowremainedabovetherequired400gallonsperminute(GPM)asrecordedonthePlantProcessComputerSystem(PPCS).TheIntermediateRangeNuclearInstrumentation,ChannelN-35,aftertrackingconsistantwithChannelN-36down'toapproximately10E-10amps,haditsindicationcontinuetodropbelow10E-11amps.TheN-35-channelreturnedtonormal(10E-11amps)approximatelytenhoursfollowingthetrip.C.INOPERABLESTRUCTURESgCOMPONENTSlORSYSTEMSTHATCONTRIBUTEDTOTHEKG9iT:D.None.OWNERSYSTEMSORSECONDARYFUNCTIONSAFFECTED:~None.E.METHODOFDISCOVERY:TheeventwasimmediatelyapparentduetoalarmsandindicationsintheControlRoom.hACSOAISSASAISASI 0~~1 HACSoreMI$4$ILICENSEEEVENTREPORTILERITEXTCONTINUATIONvt.IIUCLEA+AtOULATCAYcoooorlttrorrAssAOYEOOvtHO$I$0aIOo-t)eOIAEStrtI1$SACILITYHAlttIllOOCKETIIUoottAItlLt1HUOSOEAIII$$4v~rrYIOLMootveOI<o~AOEIEIR.E.GinnaNuclearPowerPlantTEXTlrsrrreoHIOoo~rotreoS.reoroorrorHPCAHe~$IIITIosooo24492-002-060F12OPERATORACTION:Afterthereactortrip,theControlRoomoperatorsperformedtheactionsofEmergencyOperatingProceduresE-O,(ReactorTripOrSafetyInjection)andES-0.1,(ReactorTripResponse).TheMSIVsweremanuallyactuatedclosedapproximatelyfour(4)minutesafterthetriptopreventfurtherplantcooldown.Theplantwassubsequentlystabilizedathotshutdown..Subsequently,theControlRoomoperatorsnotifiedhighersupervisionandtheNuclearRegulatoryCom-missionper10CFR50.72,non-emergency,4hournotification.G.SAFETXSXSTEMRESPONSES:The"A"S/GFRVsclosedautomaticallyfromafeedwatdrisolationsignal.III.CAUSEOFKGDFZA.IMMEDIATECAUSE:Thereactortripwasdueto"AttS/GLoLoLevel(</=>>4)B.ROOTCAUSE:Theunderlyingcauseofshe"A"S/GLoLoLevel~(</=174)wasdeterminedtobetheControlRoomoperator'sinabilitytocontrolthe"A"S/Glevelaboveitsreactortripsetpointduetothefollowingcontributingfactors:Thetransientperturbationsthatwereoccurringduetodesign(i.e.thedesignoftheFRVstogofullopen,wheninautomaticmode,followingaturbinetrip,andthedesignofhavingthebypassFRVsopenatthehigherpowerlevels).0TheshrinkandswellphenomenonoftheS/Gwaterlevelsduetotheabovedesigninducedperturba-tionsandthetransientinducedperturbations.HACSoaksttAArtttl 44 IINCNotes~I$4$I0LICENSEEEVENTREPORTILER)TEXTCONTINUATIONVl.1VCLlAA1$OVLATO1YCOMMI$$IO1NANNAOVlOOVNAO$I$O~IONlNNI1$$$I$I1$NACILITYIIANltIllOOCIIlZIIVINCCAIllLl1IIINNC$1I~IslavlseviALMalv+IO<I>AOlI$IR.E.GinnaNuclearPowerPlantTEXTIN'1INNN1~.vNNOeeeaWIYNC/erat~$IIITI05IO0024492-002-00070'2,ANALYSISOFEV19iTThiseventisreportableinaccordancewith10CFR50.73,LicenseeEventReportsystem,item(a)(2)(iv),whichrequiresreportingof,"anyeventorconditionthatresultedinmanualorautomaticactuationofanyEngineeredSafetyFeature(ESF)includingtheReactor'rotectionSystem(RPS)".The"A"S/GLoLoLevelreactortripwasanautomaticactuationoftheRPS.Anassessmentwasperformedconsideringboththesafetyconsequences.andimplicationsofthiseventwiththefollowingresultsandconclusions:Therewerenosafetyconsequencesorimplicationsattributedtothereactortripbecause:oThetworeactortripbreakersopenedasrequired.oAllcontrolandshutdownrodsinsertedasdesigned.oTheplantwasstabilizedathotshutdown.TheGinnaUpdatedFinalSafetyAnalysisReport(UFSAR)Chapter15.2.2,"LossofExternalElectricalLoad",wasreviewedandcomparedtotheplantresponseforthisevent.Theplantisdesignedtoaccepta50%lossofelectricalloadwhileoperatingatfullpoweroracompletelossofelectricalloadwhileoperatingbelow50%,withoutinitiatingareactortrip.Althoughplantdesigncanaccepta50%lossofload,pastexperiencehas'hownavulnerabilitytoS/Gshrinkandswell.SincetheS/GmainFRVsareplacedinmanual,actualplantresponsewillbedependentuponoperatorresponsetoindicatedS/Glevel.GinnaUFSARChapter15.2.2evaluatestheplantbehaviorforacompletelossofloadfromfullpowerwithoutadirectreactortrip,primarilytoshowtheadequacyofthepressure-relievingdevicesandalsotoshowthatnocoredamageoccurs.CompletelossofloadanalysisshowsthatDNBRdoesnotdropbelow2.0andpressurizerpressuredoesnotexceed2500psia.Onlyasmallpressurespike(approxi-mately30psig)andasmalltemperaturespike(2.5F)wasencounteredduringthistransient.wACNOAIN$NAAI$44I  
oFebruary3,1992,2307EST:Plantstabilized athotshutdowncondition.
B.EVENT:OnFebruary3,1992atapproximately 2220EST,withthereactoratapproximately 47%stablereactorpower,theControlRoomreceivedturbinetripfirstoutannunciator alarmK-26(Generator LockoutRelay).Asreactorpowerwaslessthan50%fullpowerwiththemaincondenser available, (i.e.lessthanpermis-siveP-9),reactortripfromturbinetripwasautomatically blocked.TheControlRoomoperators immediately entered-AbnormalProcedure AP-TURB.'1 (TurbineTripWithoutReactorTripRequired) andperformed itsapplicable actions.Theresponses oftheSteamGenerator (S/G)Feedwater Regulating Valves(FRVs)fordifferent controlconfigurations arenotedhereforclarityofsubsequent events:oWhenallFRVs(MainandBypass)areintheautomatic mode,theywillgofullopenonaturbinetripwithRCSaveragetemperature (Tavg)greaterthan554F.Whentemperature goesbelow554F,thesevalveswillgofullclosed.0AllFRVs,bothmainandbypass,willfullycloseuponreceiving aHIS/GLevel()/=674)orsafetyinjection signalregardless oftheirauto/manual status(feedwater isolation).
'WhentheMainFRVsareplacedinthe,manualmodefromtheaboveconfiguration, theywillassumethepositionabasedonthecurrentcontroller manualdemandsignalandstaythereuntiladjustedbytheresponsible operator.
AssumingthatthebypassFRVsareleftinauto,thebypassFRVswillcontinuetorespondtotheautomatic feedwater controldemand.VACsOAvSCCA<l4$I tl HISCTerm~IMMIeLICENSEEEVENTREPORTILERITEXTCONTINUATION U.S.HUclcAAitoUUAToir cossssls$
loi/ASSAOVCOOH$HO$1$OWIOS$Ilr<A$5IISI'$$AACIUI'TY HAMII1IOOCIICTHUMOIA111CliHUMOtiI~ISSOU~HTIAI,ASvlQIOrMrSA0$1$1R.E.GinnaNuclearPowerPlantRATlrmarMSrsrHssrsr.~srsrrrsAMHrcIlsrr~$111TIosooo24492--0.'2"-0'04osl2PriortotheturbinetripallFRVswereintheautomatic controlmodewiththebypassFRVsfullopenandthemainFRVscontrolling S/Glevelinsomemidposition.
Subsequent totheturbinetrip,thema'inFRVswentfullopenperdesign(thebypassFRVswerealreadyfullopen)andtheControlRoomoperatortransferred themainFRVstomanualcontrolandadjustedthemtocontrolS/Glevels.ThebypassFRVswereleftintheautomatic controlmode.ThenarrowrangeS/Glevelswereatapproximately 534andrapidlyincreasing whenthemainFRVswereshiftedtothemanualmode.TheControlRoomoperatorclosed'own themainFRVstoapproximately 10-134opentocontrolS/Glevels.Duringthistimethe"A"S/GFRVisolatedonHILevel(i.e.)/=67%narrowrangelevel).Duringapproximately thissametimethefullopenbypassFRVsrapidlyclo".edbecausetheirautomatic controlling setpointwasnow394S/Glevel.TheControlRoomoperator'continued tomakeadjustments tothemainFRVstocompensate forthetransient perturbations, butwasunsuccessful.
At2224EST,February3,1992,withthereactoratapproximately 234fullpowerareactortripoccurredduetoLoLoLevel((/=174)inthe"A"S/G.TheControlRoomoperators performed theimmediate actionsofEmergency Operating Procedure E-0(ReactorTripOrSafetyInjection) andtransitioned toEmergency Operating Procedure ES-O.l(ReactorTripResponse) whenitwasverifiedthatbothreactortripbreakerswereopen,allcontrolandshutdownrodswereinserted, andsafetyinjection wasnotactuatedorrequired.
BothMSIVsweresubsequently closedat2229ESTtolimittheRCScooldown.
TheclosingoftheMSIVssubsequently mitigated theRCScooldownandtheplantwasstabilized inhotshutdownat2307EST.MACsorvsAAAI$441 I
IIACSoew%CAI%45>LICENSEEEVENTREPORT{LER)TEXTCONTINUATION y,l,IIUCLSAAAlOULATOA VCOSSMISCIOII
/ASSAOVlOOulIOTISO&104l~>AllSINAI1$SACILITVIIASStIIIOOCKttIIUI&lAITIvSAALlllIIUSSCIAISIS~4USatiALU1SAOlISIR.E.GinnaNuclearPowerPlantTlXTIIT~~e~.WeeerCeW+ACArmWSSIUTIosooo244920200050vl2Equipment problemsthatoccurredduringtheeventwereasfollows:0'he"ALTSteamGenerator MSIVMainControlBoardindication showedthevalvetobenotfullyclosed.Anauxiliary operatorwasimmediately sentouttocheckandreportedthevalveclosedbasedonviewingthevalveexternalindicator.
Subsequently, theMainControlBoardindicated thevalvefullyclosedapproximately 23minutesaftersignalreceipt.00Following thestartoftheTurbine,DrivenAuxiliary Feedwater (TDAFW)pumponLoLoS/GLevels,itexhibited someoscillations inflow,howevertotalflowremainedabovetherequired400gallonsperminute(GPM)asrecordedonthePlantProcessComputerSystem(PPCS).TheIntermediate RangeNuclearInstrumentation, ChannelN-35,aftertrackingconsistant withChannelN-36down'toapproximately 10E-10amps,haditsindication continuetodropbelow10E-11amps.TheN-35-channelreturnedtonormal(10E-11amps)approximately tenhoursfollowing thetrip.C.INOPERABLE STRUCTURES gCOMPONENTS lORSYSTEMSTHATCONTRIBUTED TOTHEKG9iT:D.None.OWNERSYSTEMSORSECONDARY FUNCTIONS AFFECTED:
~None.E.METHODOFDISCOVERY:
Theeventwasimmediately apparentduetoalarmsandindications intheControlRoom.hACSOAISSASAISASI 0~~1 HACSoreMI$4$ILICENSEEEVENTREPORTILERITEXTCONTINUATION vt.IIUCLEA+AtOULATCAY coooorlttrorr AssAOYEOOvtHO$I$0aIOo-t)eOIAEStrtI1$SACILITYHAlttIllOOCKETIIUoottAItlLt1HUOSOEAIII$$4v~rrYIOLMootveOI<o~AOEIEIR.E.GinnaNuclearPowerPlantTEXTlrsrrreoHIOoo~rotreoS.reoroorrorHPCAHe~$IIITIosooo24492-002-060F12OPERATORACTION:Afterthereactortrip,theControlRoomoperators performed theactionsofEmergency Operating Procedures E-O,(ReactorTripOrSafetyInjection) andES-0.1,(ReactorTripResponse).
TheMSIVsweremanuallyactuatedclosedapproximately four(4)minutesafterthetriptopreventfurtherplantcooldown.
Theplantwassubsequently stabilized athotshutdown.
.Subsequently, theControlRoomoperators notifiedhighersupervision andtheNuclearRegulatory Com-missionper10CFR50.72,non-emergency, 4hournotification.
G.SAFETXSXSTEMRESPONSES:
The"A"S/GFRVsclosedautomatically fromafeedwatdr isolation signal.III.CAUSEOFKGDFZA.IMMEDIATE CAUSE:Thereactortripwasdueto"AttS/GLoLoLevel(</=>>4)B.ROOTCAUSE:Theunderlying causeofshe"A"S/GLoLoLevel~(</=174)wasdetermined tobetheControlRoomoperator's inability tocontrolthe"A"S/Glevelaboveitsreactortripsetpointduetothefollowing contributing factors:Thetransient perturbations thatwereoccurring duetodesign(i.e.thedesignoftheFRVstogofullopen,wheninautomatic mode,following aturbinetrip,andthedesignofhavingthebypassFRVsopenatthehigherpowerlevels).0Theshrinkandswellphenomenon oftheS/Gwaterlevelsduetotheabovedesigninducedperturba-tionsandthetransient inducedperturbations.
HACSoaksttAArtttl 44 IINCNotes~I$4$I0LICENSEEEVENTREPORTILER)TEXTCONTINUATION Vl.1VCLlAA1$OVLATO1YCOMMI$$IO1NANNAOVlOOVNAO$I$O~IONlNNI1$$$I$I1$NACILITYIIANltIllOOCIIlZIIVINCCAIllLl1IIINNC$1I~IslavlseviAL Malv+IO<I>AOlI$IR.E.GinnaNuclearPowerPlantTEXTIN'1INNN1~.vNNOeeeaWIYNC/erat~$IIITI05IO0024492-002-00070'2,ANALYSISOFEV19iTThiseventisreportable inaccordance with10CFR50.73, LicenseeEventReportsystem,item(a)(2)(iv),
whichrequiresreporting of,"anyeventorcondition thatresultedinmanualorautomatic actuation ofanyEngineered SafetyFeature(ESF)including theReactor'rotection System(RPS)".The"A"S/GLoLoLevelreactortripwasanautomatic actuation oftheRPS.Anassessment wasperformed considering boththesafetyconsequences.
andimplications ofthiseventwiththefollowing resultsandconclusions:
Therewerenosafetyconsequences orimplications attributed tothereactortripbecause:oThetworeactortripbreakersopenedasrequired.
oAllcontrolandshutdownrodsinsertedasdesigned.
oTheplantwasstabilized athotshutdown.
TheGinnaUpdatedFinalSafetyAnalysisReport(UFSAR)Chapter15.2.2,"LossofExternalElectrical Load",wasreviewedandcomparedtotheplantresponseforthisevent.Theplantisdesignedtoaccepta50%lossofelectrical loadwhileoperating atfullpoweroracompletelossofelectrical loadwhileoperating below50%,withoutinitiating areactortrip.Althoughplantdesigncanaccepta50%lossofload,pastexperience has'hownavulnerability toS/Gshrinkandswell.SincetheS/GmainFRVsareplacedinmanual,actualplantresponsewillbedependent uponoperatorresponsetoindicated S/Glevel.GinnaUFSARChapter15.2.2evaluates theplantbehaviorforacompletelossofloadfromfullpowerwithoutadirectreactortrip,primarily toshowtheadequacyofthepressure-relieving devicesandalsotoshowthatnocoredamageoccurs.CompletelossofloadanalysisshowsthatDNBRdoesnotdropbelow2.0andpressurizer pressuredoesnotexceed2500psia.Onlyasmallpressurespike(approxi-mately30psig)andasmalltemperature spike(2.5F)wasencountered duringthistransient.
wACNOAIN$NAAI$44I  


ISACTens444AI4431LICENSEEEVENTREPORTILER)TEXTCONTINUATIONU.S.HUCLSAAASOULATOAYCO>>>>ISSIOSIASSAOYSOOU4'SO)ISO~IOs4)ctiA4$41SISSFACILITYIIA>>4IllOOCIISTHUIS44AISIT~AALSAKUSA44AISISSQUSNT<ALUAASYhlORUSASAO4ISIR.E.GinnaNuclearPowerPlantTSXT/IT~>>S>>h>>SUse4.v>>>>h>>On>>hfISCA>>>>~'S11171I050002492002-0OF12Followingthereactortrip,pressurizer'leveldecreasedtoapproximately54levelasaresultofthecooldown.Thisisanexpectedobserved'ransient.TheS/Glevelsbothdecreasedtothenarrowrangetaps.ThisisanexpectedtransientbasedupontheencounteredshrinkintheS/Gs.Aslowcooldownresultedduringtheposttriprecoveryperiod.Thiscooldownisboundedbytheplantaccident'nalysisanddoesnotexceedtheTechnicalSpecificationlimitof100Fperhour.AdditionalprotectionwasprovidedbyclosureoftheMSIVs.Basedontheaboveandareviewofposttripdataandpastplanttransients,itcanbeconcludedthattheplanthasoperatedasdesignedandthatthere'asnounreviewedsafetyquestionsandthatthepublic'shealthandsafetywasassuredatalltimes.CORRECTIVEACTIONA.ACTIONTAKENTORRKZJBNAFFECTEDSYSTEMSTOPRE-&TENTNORMALSTATUS:0TheS/GlevelswerereturnedtotheirnormaloperatinglevelsbyadditionofAuxiliaryFeedwater,subsequenttothereactortrip.0The"A"MSIV,manufacturedbyAtwoodandMorrill,isa30inchairoperatedswingcheckvalve,installedinthereversedirectiontouseS/Gsteamflowtoensureproperclosure.Aswithanyswingcheckvalve,theclosingmomentmustbelargeenoughtoovercomethefrictiononthevalveshaftduetothevalvepacking-..Completeclosureisaccomplishedbytheforceofthefluidflowonthevalvedisc.The"A"MSIVwassubsequentlystrokedseveraltimessuccessfullytoensureoperabilityandadequateclosurecapability.Resultsofthesetestssupporttheconclusionthatfailureofthe"A"MSIVtofullyseatduringthereactortripwasnotduetointernalvalvedistortionandbending,butwastheresultofalackofflowacrossthevalvedisc.Failuretocloseisattributedtotheclosureoperationoccurringinaquiescentenvironment.'eACAOASI444AiSWI Lh 0IIACtovv%CA104llUCENSEEEVENTREPORT{LER)TEXTCONTINUATIONVl.IIVCLtAAAlCULATCAYCISALIIQQCII/AitAOVEOOVIW)ISOWIOCE)ctiACS~ITI%SS*CILITYIIANIIIIDOCKCTIIVINIAITIL41IILNNI1IIIvTAASICVINTiALVIVOS<V1V~ACEIelR.E.GinnaNuclearP'owerPlant0s00o24492-pp2ppftXTW~~1~vmeeeaaeVIIACAVVI~'llIITl090~12Valveclosureisdependentupontwofactors:Themoment,developedbytheweightofthevalvediscandthespringprovidedtoassistinvalve.closure,plussufficientsteamflowacrossthevalvedisc,withoutwhichthevalvewasnotcapableofcompletingitsclcgoperation.WhenthedemandsignalforMSI~=oclosewasger.atedd/pacrosstheAMSIVwaslowerthanth-.d/pacrosstheBMSIV.Thed/pacrosstheB=.IVwasenoughtofullyseatthevalvewhilethed/pacrosstheAMSIVdidnotprovideenoughforcetoovercomeshaftpackingfrictionalforces.Approximately23minuteslater,thed/pacrosstheAMSIVincreasedapproximately2psidwhichresultedincompleteclosureofthevalve.Foralldesignbasisaccidents,whereMSIVclosureisrequired,the=-accidenttransientswoulddevelopalargeenoughdifferentialpressuretoobtaincompletevalveclosure.RG&Eiscontinuingtoevaluatevariouspackingmaterialswhichhavealowfrictioncoefficientandcanperformtherequiredsealingfunction.oTheTDAFWpumpwassubsequentlytestedtodeterminethecauseoftheflowoscillations,butthetesthadtobeabortedduetoasteamleakonthegovernorvalve.Thegovernorvalvewasdisassembled,inspectedandplacedbackinservice.Thesteamleakwastheresultofgasketleak(probablycausedduetoexcessivetravelofthegovernorvalve).Thegasketwasreplacedwithaqualifiedspare.Thecauseoftheflowoscillationswasduetothe"hunting"ofthegovernorvalve.Thehuntingofthegovernorvalvewascausedbyafeedbacknutbeingoutofproperposition.,ThepositionofthefeedbacknutwascorrectedandtheTDAFWpumpwassubsequentlytestedsuccessfullyandreturnedtoservice.11CPCAIv~IIABI  
ISACTens444AI4431LICENSEEEVENTREPORTILER)TEXTCONTINUATION U.S.HUCLSAAASOULATOAY CO>>>>ISSIOSI ASSAOYSOOU4'SO)ISO~IOs4)ctiA4$41SISSFACILITYIIA>>4IllOOCIISTHUIS44AISIT~AALSAKUSA44AISISSQUSNT<AL UAASYhlORUSASAO4ISIR.E.GinnaNuclearPowerPlantTSXT/IT~>>S>>h>>SUse4.v>>>>h>>On>>hfISCA>>>>~'S11171I050002492002-0OF12Following thereactortrip,pressurizer'level decreased toapproximately 54levelasaresultofthecooldown.
Thisisanexpectedobserved'ransient.
TheS/Glevelsbothdecreased tothenarrowrangetaps.Thisisanexpectedtransient basedupontheencountered shrinkintheS/Gs.Aslowcooldownresultedduringtheposttriprecoveryperiod.Thiscooldownisboundedbytheplantaccident'nalysisanddoesnotexceedtheTechnical Specification limitof100Fperhour.Additional protection wasprovidedbyclosureoftheMSIVs.Basedontheaboveandareviewofposttripdataandpastplanttransients, itcanbeconcluded thattheplanthasoperatedasdesignedandthatthere'asnounreviewed safetyquestions andthatthepublic'shealthandsafetywasassuredatalltimes.CORRECTIVE ACTIONA.ACTIONTAKENTORRKZJBNAFFECTEDSYSTEMSTOPRE-&TENT NORMALSTATUS:0TheS/Glevelswerereturnedtotheirnormaloperating levelsbyadditionofAuxiliary Feedwater, subsequent tothereactortrip.0The"A"MSIV,manufactured byAtwoodandMorrill,isa30inchairoperatedswingcheckvalve,installed inthereversedirection touseS/Gsteamflowtoensureproperclosure.Aswithanyswingcheckvalve,theclosingmomentmustbelargeenoughtoovercomethefrictiononthevalveshaftduetothevalvepacking-.
.Completeclosureisaccomplished bytheforceofthefluidflowonthevalvedisc.The"A"MSIVwassubsequently strokedseveraltimessuccessfully toensureoperability andadequateclosurecapability.
Resultsofthesetestssupporttheconclusion thatfailureofthe"A"MSIVtofullyseatduringthereactortripwasnotduetointernalvalvedistortion andbending,butwastheresultofalackofflowacrossthevalvedisc.Failuretocloseisattributed totheclosureoperation occurring inaquiescent environment.
'eACAOASI444AiSWI Lh 0IIACtovv%CA104llUCENSEEEVENTREPORT{LER)TEXTCONTINUATION Vl.IIVCLtAAAlCULATCAY CISALIIQQCII
/AitAOVEOOVIW)ISOWIOCE)ctiACS~ITI%SS*CILITYIIANIIIIDOCKCTIIVINIAITIL41IILNNI1IIIvTAASICVINTiAL VIVOS<V1V~ACEIelR.E.GinnaNuclearP'owerPlant0s00o24492-pp2ppftXTW~~1~vmeeeaaeVIIACAVVI~'llIITl090~12Valveclosureisdependent upontwofactors:Themoment,developed bytheweightofthevalvediscandthespringprovidedtoassistinvalve.closure, plussufficient steamflowacrossthevalvedisc,withoutwhichthevalvewasnotcapableofcompleting itsclcgoperation.
WhenthedemandsignalforMSI~=oclosewasger.atedd/pacrosstheAMSIVwaslowerthanth-.d/pacrosstheBMSIV.Thed/pacrosstheB=.IVwasenoughtofullyseatthevalvewhilethed/pacrosstheAMSIVdidnotprovideenoughforcetoovercomeshaftpackingfrictional forces.Approximately 23minuteslater,thed/pacrosstheAMSIVincreased approximately 2psidwhichresultedincompleteclosureofthevalve.Foralldesignbasisaccidents, whereMSIVclosureisrequired, the=-accidenttransients woulddevelopalargeenoughdifferential pressuretoobtaincompletevalveclosure.RG&Eiscontinuing toevaluatevariouspackingmaterials whichhavealowfrictioncoefficient andcanperformtherequiredsealingfunction.
oTheTDAFWpumpwassubsequently testedtodetermine thecauseoftheflowoscillations, butthetesthadtobeabortedduetoasteamleakonthegovernorvalve.Thegovernorvalvewasdisassembled, inspected andplacedbackinservice.Thesteamleakwastheresultofgasketleak(probably causedduetoexcessive travelofthegovernorvalve).Thegasketwasreplacedwithaqualified spare.Thecauseoftheflowoscillations wasduetothe"hunting" ofthegovernorvalve.Thehuntingofthegovernorvalvewascausedbyafeedbacknutbeingoutofproperposition.,
Thepositionofthefeedbacknutwascorrected andtheTDAFWpumpwassubsequently testedsuccessfully andreturnedtoservice.11CPCAIv~IIABI  


IIACt<<<<~IS45ILICENSEEEVENTREPORTILER)TEXTCONTINUATIONM5,~IICLSAAAlauLASOAVCO<<AIISSIOIIAlt1OVSOOUINOSISO~IO45)cttII55SISI'SSFACILITYHAAISI'lOOCIIS7HUIAllAISILlllNIIIASSIII~ISSQMSleTILL~U8'IYCIOR<<SAAAOlISIR.E.GinnaNuclearPowerPlantosooo24492p2ppraXtW~eeaee~.v<<~+ACA<<~'iIIm1poi:1200AstheIntermediateRange"NISChannelN-35trackedNISChannelN-36for,itsnormaloperatingrange.andreturnedtonormalapproximatelyten(10)hoursafterthetrip,noimmediateactionwasdeemednecessary.ThisabnormalityhasbeenobservedandresearchedextensivelyinthepastincooperationwiththeNSSSvendor,Westinghouse.Notechnicalbasishasbeenidentifiedastowhythe10E-11idlecurrentdoesnotmaintainindicationat10E-11amps;RG&EandWestinghouseconcurredthatthechannelwasoperableandcapableofperformingallintendedfunctions.Furtherevaluationsoftheresponsecharacteris-ticsofNISchannelN-35willbeperformedduringthe1992AnnualRefuelingandMaintenanceOutage.Thiseventwasinitiatedbyamaingeneratortripduetolossofexcitation.Extensiveexamination,evaluationandtestingwasperformedonthemaingeneratorvoltagecontrolsystem,withthefollowingresultsandconclusions:Theautomaticandmanualvoltagecontrolunitswereextensivelytestedandfoundtooperatesatisfactorily.TheMinimumExcitationLimiter(MEL)datatakenduringthetestingindicatedthatthesettingwastooclosetonormaloperatingpointsofthegenerator.AnewMELsettingwascalculated,reviewedby.Westinghouse(thevendor)andimplemented.Therevisedsettingwillallowoperationtoapproximately190MVARunderexcitedat500MW.h1CBOA<<SASAil4$I l4 IIACIVnXWIS@)ILICENSEEEVENTREPORT(LERITEXTCONTINUATIONV,l.HVCLSAAASOULATOISYCOWHISSIOIIJAttrOvlOOUSeO)ISOMI04SIctirlSSI)I'ISAACILITYHAAISIIIOOCIIltHUUl1111LlrIIUMOlrI~I~AOlI)IR.E.GinnaNuclearPowerPlant05o0o2449tt)ITIItrrn~rnever.vnrrreenrrrCAttn~sIImS~Ovlrt<ALev-002-00110'2Theunitwassynchronizedtothesystemwiththe-voltageregulatorinmanualandnounusualeventswerenoted.Whenthevoltageregulatorwasplacedinthe-automaticmode,theloopwithinthevoltageregulatorsystemwasunstableandthevoltageregulatorwasreturnedtothemanualmode.Theoperationofthevoltageregulatordampingmodulewasverifiedandthegainwasreducedfrommaximumsettingtothemidpointonthepotentiometer.Thevoltageregulatorwasreturnedtotheautomaticmodeandoperatedsatisfactorily.Theplanthasnowoperatedatapproximatelyfullpowerandhasgonethroughseveralnormalvoltageadjustmentssuchasloweringthevoltaqeintheeveningandraisingthevoltageinthemorningasrequiredbysystemload.Noabnormalities.havebeenencountered.B.ACTIONTAKENORPLANNEDTOPREVENTRECURRENCE:AstheunderlyingcauseoftheeventwasdeterminedtobetheinabilityoftheControlRoomoperatortocontrolthe"A"S/Gleve~aboveitsreactortripsetpointduetodesignandtransientinducedlevelperturbation,thefollowingactionshavebeentakenorarebeingplanned:0ApplicableoperatingprocedureshavebeenchangedtorequirethatthebypassFRVsbeplacedinmanualclosedwhenincreasingaboveapproximately304reactorpower.0ApplicableoperatingprocedureshavebeenchangedtorequirereturningthebypassFRVstoautomaticcontrolwhendecreasingbelow304reactorpower.eACJOAN)SAAil4)1  
IIACt<<<<~IS45ILICENSEEEVENTREPORTILER)TEXTCONTINUATION M5,~IICLSAAAlauLASOA VCO<<AIISSIOII Alt1OVSOOUINOSISO~IO45)cttII55 SISI'SSFACILITYHAAISI'lOOCIIS7HUIAllAISILlllNIIIASSII I~ISSQMSleTILL~U8'IYCIOR<<SAAAOlISIR.E.GinnaNuclearPowerPlantosooo24492p2ppraXtW~eeaee~.v<<~+ACA<<~'iIIm1poi:1200AstheIntermediate Range"NISChannelN-35trackedNISChannelN-36for,itsnormaloperating range.andreturnedtonormalapproximately ten(10)hoursafterthetrip,noimmediate actionwasdeemednecessary.
Thisabnormality hasbeenobservedandresearched extensively inthepastincooperation withtheNSSSvendor,Westinghouse.
Notechnical basishasbeenidentified astowhythe10E-11idlecurrentdoesnotmaintainindication at10E-11amps;RG&EandWestinghouse concurred thatthechannelwasoperableandcapableofperforming allintendedfunctions.
Furtherevaluations oftheresponsecharacteris-ticsofNISchannelN-35willbeperformed duringthe1992AnnualRefueling andMaintenance Outage.Thiseventwasinitiated byamaingenerator tripduetolossofexcitation.
Extensive examination, evaluation andtestingwasperformed onthemaingenerator voltagecontrolsystem,withthefollowing resultsandconclusions:
Theautomatic andmanualvoltagecontrolunitswereextensively testedandfoundtooperatesatisfactorily.
TheMinimumExcitation Limiter(MEL)datatakenduringthetestingindicated thatthesettingwastooclosetonormaloperating pointsofthegenerator.
AnewMELsettingwascalculated, reviewedby.Westinghouse (thevendor)andimplemented.
Therevisedsettingwillallowoperation toapproximately 190MVARunderexcited at500MW.h1CBOA<<SASAil4$I l4 IIACIVnXWIS@)ILICENSEEEVENTREPORT(LERITEXTCONTINUATION V,l.HVCLSAAASOULATOISY COWHISSIOII JAttrOvlOOUSeO)ISOMI04SIctirlSSI)I'ISAACILITYHAAISIIIOOCIIltHUUl1111LlrIIUMOlrI~I~AOlI)IR.E.GinnaNuclearPowerPlant05o0o2449tt)ITIItrrn~rnever.vnrrreenrrrCAttn~sIImS~Ovlrt<ALev-002-00110'2Theunitwassynchronized tothesystemwiththe-voltageregulator inmanualandnounusualeventswerenoted.Whenthevoltageregulator wasplacedinthe-automatic mode,theloopwithinthevoltageregulator systemwasunstableandthevoltageregulator wasreturnedtothemanualmode.Theoperation ofthevoltageregulator dampingmodulewasverifiedandthegainwasreducedfrommaximumsettingtothemidpointonthepotentiometer.
Thevoltageregulator wasreturnedtotheautomatic modeandoperatedsatisfactorily.
Theplanthasnowoperatedatapproximately fullpowerandhasgonethroughseveralnormalvoltageadjustments suchasloweringthevoltaqeintheeveningandraisingthevoltageinthemorningasrequiredbysystemload.Noabnormalities.
havebeenencountered.
B.ACTIONTAKENORPLANNEDTOPREVENTRECURRENCE:
Astheunderlying causeoftheeventwasdetermined tobetheinability oftheControlRoomoperatortocontrolthe"A"S/Gleve~aboveitsreactortripsetpointduetodesignandtransient inducedlevelperturbation, thefollowing actionshavebeentakenorarebeingplanned:0Applicable operating procedures havebeenchangedtorequirethatthebypassFRVsbeplacedinmanualclosedwhenincreasing aboveapproximately 304reactorpower.0Applicable operating procedures havebeenchangedtorequirereturning thebypassFRVstoautomatic controlwhendecreasing below304reactorpower.eACJOAN)SAAil4)1  


IIACIsrselAAA104lILICENSEEEVENTREPORTILER)TEXTCONTINUATIONvl.eevCLlAIIAlOULATCAYcoseseeClloee/AASSOvloOvleeoIISOWIOel>eseAl5~rlITSI'ACILITYIIAIIlIIIOOCIIKTeeULQlA111LlAIIUAOlAI~IvTAASloulreveALSAVes~areverU~s~AolIQR.E.GinnaNuclearPower.Plant06<<o244TKXTrrrrsrers~r~.vmeseseeeerrrreCArse~'grIITI92-002-12o~12oAmodificationisplannedforthe1993AnnualRefuelingandMaintenanceOutagethatwouldmodifytheexistingfeedwaterisolationlogicforfail-openorfail-closedofthemainandbypassFRVsuponturbinetripwithmainFRVsinautomaticcontrolmode.Theplannedmodificationwilldeletetheexistingfail-openlogicandreplacethefail-closedlogicwithactuationuponreactortripasopposedtoturbinetrip.AstheeventwasinitiatedbytheMainGeneratortripduetolossofexcitation,thefollowingactionsareplannedtopreventrecurrence'.00RG&Eisplanningtopurchaseandinstallareplacementvoltageregulatorunit.IRoutinetestingandmaintenancewillbeperformedontheexistingvoltageregulatorunitduringthe1992AnnualRefuelingandMaintenanceOutagetoattainahighdegreeofconfidencethattheunitwilloperatewithoutincidentfortheentirefuelcycle.ADDITIONALINFORMATIONA.FAILEDCOMPONENTS:TheTDAFWpumpturbineisa465horsepowernoncondensingsteamturbine,serialnumber26635,manufacturedbytheWorthingtonCorporation.B.PREVIOUSLERsONSIMILAREVENTS:AsimilarLEReventhistoricalsearchwasconductedwiththefollowingresults:NodocumentationofsimilarLEReventswiththesameunderlyingcauseatGinnaStationcouldbeidentified.C.SPECIALCOMMENTS:None.~eACSOAee1AAArl4lI}}
IIACIsrselAAA104lILICENSEEEVENTREPORTILER)TEXTCONTINUATION vl.eevCLlAII AlOULATCAY coseseeClloee
/AASSOvloOvleeoIISOWIOel>eseAl5~rlITSI'ACILITY IIAIIlIIIOOCIIKTeeULQlA111LlAIIUAOlAI~IvTAASloulreveAL SAVes~are verU~s~AolIQR.E.GinnaNuclearPower.Plant06<<o244TKXTrrrrsrers~r~.vmeseseeeerrrreCArse~'grIITI92-002-12o~12oAmodification isplannedforthe1993AnnualRefueling andMaintenance Outagethatwouldmodifytheexistingfeedwater isolation logicforfail-open orfail-closed ofthemainandbypassFRVsuponturbinetripwithmainFRVsinautomatic controlmode.Theplannedmodification willdeletetheexistingfail-open logicandreplacethefail-closed logicwithactuation uponreactortripasopposedtoturbinetrip.Astheeventwasinitiated bytheMainGenerator tripduetolossofexcitation, thefollowing actionsareplannedtopreventrecurrence'.
00RG&Eisplanningtopurchaseandinstallareplacement voltageregulator unit.IRoutinetestingandmaintenance willbeperformed ontheexistingvoltageregulator unitduringthe1992AnnualRefueling andMaintenance Outagetoattainahighdegreeofconfidence thattheunitwilloperatewithoutincidentfortheentirefuelcycle.ADDITIONAL INFORMATION A.FAILEDCOMPONENTS:
TheTDAFWpumpturbineisa465horsepower noncondensing steamturbine,serialnumber26635,manufactured bytheWorthington Corporation.
B.PREVIOUSLERsONSIMILAREVENTS:AsimilarLEReventhistorical searchwasconducted withthefollowing results:Nodocumentation ofsimilarLEReventswiththesameunderlying causeatGinnaStationcouldbeidentified.
C.SPECIALCOMMENTS:
None.~eACSOAee1AAArl4lI}}

Revision as of 13:09, 29 June 2018

LER 92-002-00:on 920203,reactor Trip Occurred W/Reactor at Approx 23% Full Power Just Subsequent to Turbine Trip While at 47% Power.Caused by Lo Lo Level in SG a Due to Design Perturbations.New Setting calculated.W/920304 Ltr
ML17262A758
Person / Time
Site: Ginna Constellation icon.png
Issue date: 03/04/1992
From: BACKUS W H, MECREDY R C
ROCHESTER GAS & ELECTRIC CORP.
To:
NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
LER-92-002, LER-92-2, NUDOCS 9203110291
Download: ML17262A758 (28)
v • d • e


Text

!+ACCELERATED DISTRIBUTION DEMONSTRATION SYSTEMREGULATOR INFORMATION DISTRlBUTION pTEM(RIDS)ACCESSION NBR:9203110291 DOC.DATE:

92/03/04NOTARIZED:

NODOCKET¹FACIL:50-244 RobertEmmetGinnaNuclearPlant,Unit1,Rochester G05000244AUTH.NAMEAUTHORAFFILIATION BACKUSiW.H.

Rochester Gas&ElectricCorp.MECREDY,R.C.

Rochester Gas&ElectricCorp.RECIP.NAME RECiPIENT AFFILIATION

SUBJECT:

LER92-002-00:on 920203,reactor tripoccurredw/reactor atapprox23%fullpowerjustsubsequent toturbinetripwhileat47%power.CausedbylololevelinSGAduetodesignperturbations.New settingcalculated.W/920304 ltr.DISTRIBUTION CODE:IE22TCOPIESRECEIVED:LTR ENCLSIZE:TITLE:50.73/50.9 LicenseeEventReport(LER),IncidentRpt,etc.NOTES:License Expdateinaccordance with10CFR2,2.109(9/19/72).

RD/05000244ARECIPIENT IDCODE/NAME PDl-3LAJOHNSON,A COPIESLTTRENCL1111RECIPIENT IDCODE/NAME PD1-3PDCOPIESLTTRENCL11DDINTERNAL:

ACNWAEOD/DSP/TPAB NRR/DET/EMEB 7ENRR/DLPQ/LPEB10 NRR/DREP/PRPBll NRR/DST/SICB8H3 NRR/DST/SRXB 8ERES/DSIR/EIB EXTERNAL'G&GBRYCEiJ~HNRCPDRNSICPOOREiW.AEOD/DOAAEOD/ROAB/DSP NRR/DLPQ/LHFB10" NRR/DOEA/OEAB NRR/DST/SELB 8DgNR~D-.LB8Dl-G~02RGN1FILE0133LSTLOBBYWARD1111NSICMURPHYgG.A 111.1NUDOCSFULLTXT112211112211111111221~1'111111111111DNOTETOALL"RIDS"RECIPIENTS:

PLEASEHELPUSTOREDUCEWASTE!CONTACTTHEDOCUMENTCONTROLDESK,ROOMPl-37(EXT.20079)TOELIMINATE YOURNAMEFROMDISTRIBUTION LISTSFORDOCUMENTS YOUDON'TNEED!ADDSFULL'TEXTCONVERSION REQUIREDTOTALNUMBROFCOPIESREQUIRED:

LTTR30ENCL30 I

rrf~'I~zotrr.sT4MROCHESTER GASANDELECTRICCORPORATION 489EASTAVENUE,ROCHESTER N.K-74649-0001 ROBER't(,hlECRjtpY Vrr<Vresidenl CrnnaNo<lcmProdursrorr TELE&>0'ME ARErrCOM716546'2700March4,1992U.S.NuclearRegulatory Commission DocumentControlDeskWashington, DC20555

Subject:

LER92-002,Feedwater Transient, DueToLossOfExcitation InducedTurbine/Generator Trip,CausesLoLoSteamGen'erator LevelReactorTrip-R.E.GinnaNuclearPowerPlantDocketNo.50-244Inaccordance with10CFR50.73, Licensee.

EventReportSystem,item(a)(2)(iv),

whichrequiresareportof,"anyeventorcondition thatresultedinmanualorautomatic actuation ofanyEngineered SafetyFeature(ESF),including theReactorProtection System(RPS)",theattachedEventReportLER92-002isherebysubmitted.

Thiseventhasinnowayaffectedthepublic'shealthandsafety.Verytrulyyours,RobertC.Mecredy.xcoU.S.NuclearRegulatory Commission Re'gionI475Allendale RoadKingofPrussia,PA19406GinnaUSNRCSeniorResidentInspector f)~g(4~(q'l92031i0291

'720304PDRADOCK050002445PDR It'l

<<ACcrea<<I4ASILICENSEEEVENTREPORTLER)Ug,IRILSARRIRVLATCAT coe>>e<<voce AeeaavlaOeetNO,$1<<.aiavISIIAISI/SQISeACILITYNAeelIllR.E.in'naNuclearPowerPlant:OOCRtTIA>>eOIRQlAo6ooo244>ot

'"Feedwater Transient, DuetoLossofExcitation nucedTurz.neGenerator Trip,CausesLoLoSteamGenerator LevelReactorTripIVINSOATSIIILtRNueettAIIIAIMRTOATIIIIOTHIAeACILITISI INVOLVIONlVO<<THOAYYIA1YIAR0239292~save<<ewe<<vee~IA002AevorceeIrueee~A0IIONTH03OAY04YIAR92eACIUTY<<AeeeeOOCAIT<<uee~SAISI0600O06000Oel1*TINO eeOOIItl~Oeel1LlvlL023THIS1leOATNSuteeITTIO euAWANTI$Lea$4ISO.NQNlllIIISa.calleIIIIIIISt.eleIIIIIRI$OAOllelllIl<<lSO.OOSlelllllelSt.cellel~OMWIII~OMWQI~O.TSNIQIII~O.TtieIQIIIIIO.TSNIQIIVO

~O.TSNIQII<<I~O.TSlalQ)lel

~O.TSlalQlleOI IO.TIlelQlleraIAI~0.$SIeIQIleetl QISO.TSWQll el0THI1$ovl1tlelNTI OeItel1$."lceeeeerrercereeleeeeeeeree>>IlllM714ITLTllelOTHSRlteeeeVIeAeeeeeeererereeeTeeL<<RC/>>4<<AUILICINSIICONTACTMRTHQLSAllllTILteleONI NVLQIAWesleyJI.BackusARIACOOlTechnical Assist:ant totheOperations Manager31552444CCAVLSTIONSLINC>ORtACHCaeeMNINT OAILUAI0tlCAIllaIelTHISRIMATlltlCAUSISYSTINCOIIMNINT VA<ACrTVAIAIMRTAILI'gent,~H<@tToNeRosr~P4;":~Qj CVSISYSTSNcoeeMNINTHANVSA4TVAIRIMATAILTONOAOSXBTBW315g~NAN$3'.~e'rterr%g~rr3>vVjj~4~e:

.II~I,>>~C.~,y;$$4SVTTLININT*L AIMATtteICTIOIIAIVIIIllTee.er<<e>>NSRJSCTSOSVINISSIO>>

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<<eevlltlttetCTSOLVINISSION OA'llll~IeeONTHCAYYIAROnFebruary3,1992withthereactoratapproximately 23%fullpower,justsubsequent toaturbinetripwhileat474reactorpower,areactortripoccurredduetoLoLoLevel(</=17%)inthe"A"SteamGenerator (S/G).TheControlRoomoperators immediately performed theappropriate actionsofEmergency Operating Procedures E-0(ReactorTriporSafetyInjection) andES-0.1(ReactorTripResponse).

BothMainSteamIsolation Valves(MSIVs)weresubsequently closedtolimitaReactorCoolantSystem(RCS)cooldownandtheplantwasstabil-izedathotshutdown.

Theunderlying causeoftheeventwastheinability tocontrolthe"A"S/Glevelabovethereactortripsetpointduetodesignandtransient inducedperturbations.

(ThiseventisNUREG-1022 (x)CauseCode).Corrective actiontakenorplannedarediscussed inSectionVofthetext.<<ACe<<r<<I44$I If IIACtv'040ILICENSEEEVENTREPORTILER)TEXTCONTINUATION Vl.4VCLlAAAIOVLATOAV CeaWIllIISI A>>AOVlO0+14OIIQI~IQAl)et<AllII)I'lSSACILITYIIAIAlIII"OOCIIKZIIVIACCAIll%lAALlAIIIAAI~IIIllS~QMA4TIAL'VUAACVOIOHVIA~AOlIlIR.E.GinnaNuclearPowerPlanttlXTOr~aeOee~.

~~~AAC~~'sIIlll osooo2449200200020F].PRE-L?V1?NT PLANTCONDITIONS Theplantwasatapproximately 47%reactorpowerduetoaloadreduction earlierintheday.Partofthisload.reduction (i.e.toapproximately 60%reactorpower)wasrequested bytheRochester GasandElectricCorporation (RG&E)PowerControlDispatcher toremoveamajortrans-missionlinefromservice(circuit908)forrepair.Theremainder ofthisloadreduction (from60%to47%reactorpower)wasmadetoreducereactorpowerbelowpermissive P-9(i.e.ReactorTripFromTurbineTripBlocked)toperformcondenser waterboxmaintenance andturbineon-linetriptestingandvalvetesting.Themaingenerator voltagecontrolwasinthemanualmodeduetovoltageoscillations experienced earlierintQeday.Thereactorcontrolrodswerealsointhemanualmodetomaintainthecoreaxialfluxwithinitsoperating band.Turbineon-linetriptestingand'alvetestingwasinprogresswiththelasttest'sinitialconditions beingverifiedpriortoperformance ofthetest.IIDESCRIPTION OFEVENTA.DATESANDAPPROXIMATE TIMESOPMAZOROCCUEGU9iCES:

oFebruary3,1992,2220EST:duetolossofexcitation.

MainGenerator.

Trip0February3,1992,2220EST:MainTurbinetripdue=tomaingenerator trip.0February,3, 1992,2224EST:Eventdateandtime.0February3,1992,2224EST:Discovery dateandtime.0February3,'992,2224EST:ControlRoomoperators verifybothreactortripbreakersopen,andallcontrolandshutdownrodsinserted.

VAC~QALIlAAAIl4$I

IIACSvv~(041ILICENSEEEVENTREPORTILERITEXTCONTINUATION Ul,vUCLSAAAl<<ULATOA Y<<OvvlllIOAI SArrrovlOOvlvOIISO~IOsl)erirf5llII%$CSACILITYVAVlIllCO<<IICTIIUVClrl1ILlAlsUVCSAlll$I4vSr7IAI.rvASVISIOHV1~AOlIllR.E.GinnaNuclearPowerPlantosooo244TlxTIII~vSSSrrrsrvr.vvSrrrrAvIvrcsvrl~'llIITI92-002-00030>12oFebruary3,1992,2229EST:ControlRoomoperators closebothMainSteamIsolation Valves(MSIVs)tolimitaReactorCoolantSystem(RCS)cooldown.

oFebruary3,1992,2307EST:Plantstabilized athotshutdowncondition.

B.EVENT:OnFebruary3,1992atapproximately 2220EST,withthereactoratapproximately 47%stablereactorpower,theControlRoomreceivedturbinetripfirstoutannunciator alarmK-26(Generator LockoutRelay).Asreactorpowerwaslessthan50%fullpowerwiththemaincondenser available, (i.e.lessthanpermis-siveP-9),reactortripfromturbinetripwasautomatically blocked.TheControlRoomoperators immediately entered-AbnormalProcedure AP-TURB.'1 (TurbineTripWithoutReactorTripRequired) andperformed itsapplicable actions.Theresponses oftheSteamGenerator (S/G)Feedwater Regulating Valves(FRVs)fordifferent controlconfigurations arenotedhereforclarityofsubsequent events:oWhenallFRVs(MainandBypass)areintheautomatic mode,theywillgofullopenonaturbinetripwithRCSaveragetemperature (Tavg)greaterthan554F.Whentemperature goesbelow554F,thesevalveswillgofullclosed.0AllFRVs,bothmainandbypass,willfullycloseuponreceiving aHIS/GLevel()/=674)orsafetyinjection signalregardless oftheirauto/manual status(feedwater isolation).

'WhentheMainFRVsareplacedinthe,manualmodefromtheaboveconfiguration, theywillassumethepositionabasedonthecurrentcontroller manualdemandsignalandstaythereuntiladjustedbytheresponsible operator.

AssumingthatthebypassFRVsareleftinauto,thebypassFRVswillcontinuetorespondtotheautomatic feedwater controldemand.VACsOAvSCCA<l4$I tl HISCTerm~IMMIeLICENSEEEVENTREPORTILERITEXTCONTINUATION U.S.HUclcAAitoUUAToir cossssls$

loi/ASSAOVCOOH$HO$1$OWIOS$Ilr<A$5IISI'$$AACIUI'TY HAMII1IOOCIICTHUMOIA111CliHUMOtiI~ISSOU~HTIAI,ASvlQIOrMrSA0$1$1R.E.GinnaNuclearPowerPlantRATlrmarMSrsrHssrsr.~srsrrrsAMHrcIlsrr~$111TIosooo24492--0.'2"-0'04osl2PriortotheturbinetripallFRVswereintheautomatic controlmodewiththebypassFRVsfullopenandthemainFRVscontrolling S/Glevelinsomemidposition.

Subsequent totheturbinetrip,thema'inFRVswentfullopenperdesign(thebypassFRVswerealreadyfullopen)andtheControlRoomoperatortransferred themainFRVstomanualcontrolandadjustedthemtocontrolS/Glevels.ThebypassFRVswereleftintheautomatic controlmode.ThenarrowrangeS/Glevelswereatapproximately 534andrapidlyincreasing whenthemainFRVswereshiftedtothemanualmode.TheControlRoomoperatorclosed'own themainFRVstoapproximately 10-134opentocontrolS/Glevels.Duringthistimethe"A"S/GFRVisolatedonHILevel(i.e.)/=67%narrowrangelevel).Duringapproximately thissametimethefullopenbypassFRVsrapidlyclo".edbecausetheirautomatic controlling setpointwasnow394S/Glevel.TheControlRoomoperator'continued tomakeadjustments tothemainFRVstocompensate forthetransient perturbations, butwasunsuccessful.

At2224EST,February3,1992,withthereactoratapproximately 234fullpowerareactortripoccurredduetoLoLoLevel((/=174)inthe"A"S/G.TheControlRoomoperators performed theimmediate actionsofEmergency Operating Procedure E-0(ReactorTripOrSafetyInjection) andtransitioned toEmergency Operating Procedure ES-O.l(ReactorTripResponse) whenitwasverifiedthatbothreactortripbreakerswereopen,allcontrolandshutdownrodswereinserted, andsafetyinjection wasnotactuatedorrequired.

BothMSIVsweresubsequently closedat2229ESTtolimittheRCScooldown.

TheclosingoftheMSIVssubsequently mitigated theRCScooldownandtheplantwasstabilized inhotshutdownat2307EST.MACsorvsAAAI$441 I

IIACSoew%CAI%45>LICENSEEEVENTREPORT{LER)TEXTCONTINUATION y,l,IIUCLSAAAlOULATOA VCOSSMISCIOII

/ASSAOVlOOulIOTISO&104l~>AllSINAI1$SACILITVIIASStIIIOOCKttIIUI&lAITIvSAALlllIIUSSCIAISIS~4USatiALU1SAOlISIR.E.GinnaNuclearPowerPlantTlXTIIT~~e~.WeeerCeW+ACArmWSSIUTIosooo244920200050vl2Equipment problemsthatoccurredduringtheeventwereasfollows:0'he"ALTSteamGenerator MSIVMainControlBoardindication showedthevalvetobenotfullyclosed.Anauxiliary operatorwasimmediately sentouttocheckandreportedthevalveclosedbasedonviewingthevalveexternalindicator.

Subsequently, theMainControlBoardindicated thevalvefullyclosedapproximately 23minutesaftersignalreceipt.00Following thestartoftheTurbine,DrivenAuxiliary Feedwater (TDAFW)pumponLoLoS/GLevels,itexhibited someoscillations inflow,howevertotalflowremainedabovetherequired400gallonsperminute(GPM)asrecordedonthePlantProcessComputerSystem(PPCS).TheIntermediate RangeNuclearInstrumentation, ChannelN-35,aftertrackingconsistant withChannelN-36down'toapproximately 10E-10amps,haditsindication continuetodropbelow10E-11amps.TheN-35-channelreturnedtonormal(10E-11amps)approximately tenhoursfollowing thetrip.C.INOPERABLE STRUCTURES gCOMPONENTS lORSYSTEMSTHATCONTRIBUTED TOTHEKG9iT:D.None.OWNERSYSTEMSORSECONDARY FUNCTIONS AFFECTED:

~None.E.METHODOFDISCOVERY:

Theeventwasimmediately apparentduetoalarmsandindications intheControlRoom.hACSOAISSASAISASI 0~~1 HACSoreMI$4$ILICENSEEEVENTREPORTILERITEXTCONTINUATION vt.IIUCLEA+AtOULATCAY coooorlttrorr AssAOYEOOvtHO$I$0aIOo-t)eOIAEStrtI1$SACILITYHAlttIllOOCKETIIUoottAItlLt1HUOSOEAIII$$4v~rrYIOLMootveOI<o~AOEIEIR.E.GinnaNuclearPowerPlantTEXTlrsrrreoHIOoo~rotreoS.reoroorrorHPCAHe~$IIITIosooo24492-002-060F12OPERATORACTION:Afterthereactortrip,theControlRoomoperators performed theactionsofEmergency Operating Procedures E-O,(ReactorTripOrSafetyInjection) andES-0.1,(ReactorTripResponse).

TheMSIVsweremanuallyactuatedclosedapproximately four(4)minutesafterthetriptopreventfurtherplantcooldown.

Theplantwassubsequently stabilized athotshutdown.

.Subsequently, theControlRoomoperators notifiedhighersupervision andtheNuclearRegulatory Com-missionper10CFR50.72,non-emergency, 4hournotification.

G.SAFETXSXSTEMRESPONSES:

The"A"S/GFRVsclosedautomatically fromafeedwatdr isolation signal.III.CAUSEOFKGDFZA.IMMEDIATE CAUSE:Thereactortripwasdueto"AttS/GLoLoLevel(</=>>4)B.ROOTCAUSE:Theunderlying causeofshe"A"S/GLoLoLevel~(</=174)wasdetermined tobetheControlRoomoperator's inability tocontrolthe"A"S/Glevelaboveitsreactortripsetpointduetothefollowing contributing factors:Thetransient perturbations thatwereoccurring duetodesign(i.e.thedesignoftheFRVstogofullopen,wheninautomatic mode,following aturbinetrip,andthedesignofhavingthebypassFRVsopenatthehigherpowerlevels).0Theshrinkandswellphenomenon oftheS/Gwaterlevelsduetotheabovedesigninducedperturba-tionsandthetransient inducedperturbations.

HACSoaksttAArtttl 44 IINCNotes~I$4$I0LICENSEEEVENTREPORTILER)TEXTCONTINUATION Vl.1VCLlAA1$OVLATO1YCOMMI$$IO1NANNAOVlOOVNAO$I$O~IONlNNI1$$$I$I1$NACILITYIIANltIllOOCIIlZIIVINCCAIllLl1IIINNC$1I~IslavlseviAL Malv+IOAOlI$IR.E.GinnaNuclearPowerPlantTEXTIN'1INNN1~.vNNOeeeaWIYNC/erat~$IIITI05IO0024492-002-00070'2,ANALYSISOFEV19iTThiseventisreportable inaccordance with10CFR50.73, LicenseeEventReportsystem,item(a)(2)(iv),

whichrequiresreporting of,"anyeventorcondition thatresultedinmanualorautomatic actuation ofanyEngineered SafetyFeature(ESF)including theReactor'rotection System(RPS)".The"A"S/GLoLoLevelreactortripwasanautomatic actuation oftheRPS.Anassessment wasperformed considering boththesafetyconsequences.

andimplications ofthiseventwiththefollowing resultsandconclusions:

Therewerenosafetyconsequences orimplications attributed tothereactortripbecause:oThetworeactortripbreakersopenedasrequired.

oAllcontrolandshutdownrodsinsertedasdesigned.

oTheplantwasstabilized athotshutdown.

TheGinnaUpdatedFinalSafetyAnalysisReport(UFSAR)Chapter15.2.2,"LossofExternalElectrical Load",wasreviewedandcomparedtotheplantresponseforthisevent.Theplantisdesignedtoaccepta50%lossofelectrical loadwhileoperating atfullpoweroracompletelossofelectrical loadwhileoperating below50%,withoutinitiating areactortrip.Althoughplantdesigncanaccepta50%lossofload,pastexperience has'hownavulnerability toS/Gshrinkandswell.SincetheS/GmainFRVsareplacedinmanual,actualplantresponsewillbedependent uponoperatorresponsetoindicated S/Glevel.GinnaUFSARChapter15.2.2evaluates theplantbehaviorforacompletelossofloadfromfullpowerwithoutadirectreactortrip,primarily toshowtheadequacyofthepressure-relieving devicesandalsotoshowthatnocoredamageoccurs.CompletelossofloadanalysisshowsthatDNBRdoesnotdropbelow2.0andpressurizer pressuredoesnotexceed2500psia.Onlyasmallpressurespike(approxi-mately30psig)andasmalltemperature spike(2.5F)wasencountered duringthistransient.

wACNOAIN$NAAI$44I

ISACTens444AI4431LICENSEEEVENTREPORTILER)TEXTCONTINUATION U.S.HUCLSAAASOULATOAY CO>>>>ISSIOSI ASSAOYSOOU4'SO)ISO~IOs4)ctiA4$41SISSFACILITYIIA>>4IllOOCIISTHUIS44AISIT~AALSAKUSA44AISISSQUSNT<AL UAASYhlORUSASAO4ISIR.E.GinnaNuclearPowerPlantTSXT/IT~>>S>>h>>SUse4.v>>>>h>>On>>hfISCA>>>>~'S11171I050002492002-0OF12Following thereactortrip,pressurizer'level decreased toapproximately 54levelasaresultofthecooldown.

Thisisanexpectedobserved'ransient.

TheS/Glevelsbothdecreased tothenarrowrangetaps.Thisisanexpectedtransient basedupontheencountered shrinkintheS/Gs.Aslowcooldownresultedduringtheposttriprecoveryperiod.Thiscooldownisboundedbytheplantaccident'nalysisanddoesnotexceedtheTechnical Specification limitof100Fperhour.Additional protection wasprovidedbyclosureoftheMSIVs.Basedontheaboveandareviewofposttripdataandpastplanttransients, itcanbeconcluded thattheplanthasoperatedasdesignedandthatthere'asnounreviewed safetyquestions andthatthepublic'shealthandsafetywasassuredatalltimes.CORRECTIVE ACTIONA.ACTIONTAKENTORRKZJBNAFFECTEDSYSTEMSTOPRE-&TENT NORMALSTATUS:0TheS/Glevelswerereturnedtotheirnormaloperating levelsbyadditionofAuxiliary Feedwater, subsequent tothereactortrip.0The"A"MSIV,manufactured byAtwoodandMorrill,isa30inchairoperatedswingcheckvalve,installed inthereversedirection touseS/Gsteamflowtoensureproperclosure.Aswithanyswingcheckvalve,theclosingmomentmustbelargeenoughtoovercomethefrictiononthevalveshaftduetothevalvepacking-.

.Completeclosureisaccomplished bytheforceofthefluidflowonthevalvedisc.The"A"MSIVwassubsequently strokedseveraltimessuccessfully toensureoperability andadequateclosurecapability.

Resultsofthesetestssupporttheconclusion thatfailureofthe"A"MSIVtofullyseatduringthereactortripwasnotduetointernalvalvedistortion andbending,butwastheresultofalackofflowacrossthevalvedisc.Failuretocloseisattributed totheclosureoperation occurring inaquiescent environment.

'eACAOASI444AiSWI Lh 0IIACtovv%CA104llUCENSEEEVENTREPORT{LER)TEXTCONTINUATION Vl.IIVCLtAAAlCULATCAY CISALIIQQCII

/AitAOVEOOVIW)ISOWIOCE)ctiACS~ITI%SS*CILITYIIANIIIIDOCKCTIIVINIAITIL41IILNNI1IIIvTAASICVINTiAL VIVOS<V1V~ACEIelR.E.GinnaNuclearP'owerPlant0s00o24492-pp2ppftXTW~~1~vmeeeaaeVIIACAVVI~'llIITl090~12Valveclosureisdependent upontwofactors:Themoment,developed bytheweightofthevalvediscandthespringprovidedtoassistinvalve.closure, plussufficient steamflowacrossthevalvedisc,withoutwhichthevalvewasnotcapableofcompleting itsclcgoperation.

WhenthedemandsignalforMSI~=oclosewasger.atedd/pacrosstheAMSIVwaslowerthanth-.d/pacrosstheBMSIV.Thed/pacrosstheB=.IVwasenoughtofullyseatthevalvewhilethed/pacrosstheAMSIVdidnotprovideenoughforcetoovercomeshaftpackingfrictional forces.Approximately 23minuteslater,thed/pacrosstheAMSIVincreased approximately 2psidwhichresultedincompleteclosureofthevalve.Foralldesignbasisaccidents, whereMSIVclosureisrequired, the=-accidenttransients woulddevelopalargeenoughdifferential pressuretoobtaincompletevalveclosure.RG&Eiscontinuing toevaluatevariouspackingmaterials whichhavealowfrictioncoefficient andcanperformtherequiredsealingfunction.

oTheTDAFWpumpwassubsequently testedtodetermine thecauseoftheflowoscillations, butthetesthadtobeabortedduetoasteamleakonthegovernorvalve.Thegovernorvalvewasdisassembled, inspected andplacedbackinservice.Thesteamleakwastheresultofgasketleak(probably causedduetoexcessive travelofthegovernorvalve).Thegasketwasreplacedwithaqualified spare.Thecauseoftheflowoscillations wasduetothe"hunting" ofthegovernorvalve.Thehuntingofthegovernorvalvewascausedbyafeedbacknutbeingoutofproperposition.,

Thepositionofthefeedbacknutwascorrected andtheTDAFWpumpwassubsequently testedsuccessfully andreturnedtoservice.11CPCAIv~IIABI

IIACt<<<<~IS45ILICENSEEEVENTREPORTILER)TEXTCONTINUATION M5,~IICLSAAAlauLASOA VCO<<AIISSIOII Alt1OVSOOUINOSISO~IO45)cttII55 SISI'SSFACILITYHAAISI'lOOCIIS7HUIAllAISILlllNIIIASSII I~ISSQMSleTILL~U8'IYCIOR<<SAAAOlISIR.E.GinnaNuclearPowerPlantosooo24492p2ppraXtW~eeaee~.v<<~+ACA<<~'iIIm1poi:1200AstheIntermediate Range"NISChannelN-35trackedNISChannelN-36for,itsnormaloperating range.andreturnedtonormalapproximately ten(10)hoursafterthetrip,noimmediate actionwasdeemednecessary.

Thisabnormality hasbeenobservedandresearched extensively inthepastincooperation withtheNSSSvendor,Westinghouse.

Notechnical basishasbeenidentified astowhythe10E-11idlecurrentdoesnotmaintainindication at10E-11amps;RG&EandWestinghouse concurred thatthechannelwasoperableandcapableofperforming allintendedfunctions.

Furtherevaluations oftheresponsecharacteris-ticsofNISchannelN-35willbeperformed duringthe1992AnnualRefueling andMaintenance Outage.Thiseventwasinitiated byamaingenerator tripduetolossofexcitation.

Extensive examination, evaluation andtestingwasperformed onthemaingenerator voltagecontrolsystem,withthefollowing resultsandconclusions:

Theautomatic andmanualvoltagecontrolunitswereextensively testedandfoundtooperatesatisfactorily.

TheMinimumExcitation Limiter(MEL)datatakenduringthetestingindicated thatthesettingwastooclosetonormaloperating pointsofthegenerator.

AnewMELsettingwascalculated, reviewedby.Westinghouse (thevendor)andimplemented.

Therevisedsettingwillallowoperation toapproximately 190MVARunderexcited at500MW.h1CBOA<<SASAil4$I l4 IIACIVnXWIS@)ILICENSEEEVENTREPORT(LERITEXTCONTINUATION V,l.HVCLSAAASOULATOISY COWHISSIOII JAttrOvlOOUSeO)ISOMI04SIctirlSSI)I'ISAACILITYHAAISIIIOOCIIltHUUl1111LlrIIUMOlrI~I~AOlI)IR.E.GinnaNuclearPowerPlant05o0o2449tt)ITIItrrn~rnever.vnrrreenrrrCAttn~sIImS~Ovlrt<ALev-002-00110'2Theunitwassynchronized tothesystemwiththe-voltageregulator inmanualandnounusualeventswerenoted.Whenthevoltageregulator wasplacedinthe-automatic mode,theloopwithinthevoltageregulator systemwasunstableandthevoltageregulator wasreturnedtothemanualmode.Theoperation ofthevoltageregulator dampingmodulewasverifiedandthegainwasreducedfrommaximumsettingtothemidpointonthepotentiometer.

Thevoltageregulator wasreturnedtotheautomatic modeandoperatedsatisfactorily.

Theplanthasnowoperatedatapproximately fullpowerandhasgonethroughseveralnormalvoltageadjustments suchasloweringthevoltaqeintheeveningandraisingthevoltageinthemorningasrequiredbysystemload.Noabnormalities.

havebeenencountered.

B.ACTIONTAKENORPLANNEDTOPREVENTRECURRENCE:

Astheunderlying causeoftheeventwasdetermined tobetheinability oftheControlRoomoperatortocontrolthe"A"S/Gleve~aboveitsreactortripsetpointduetodesignandtransient inducedlevelperturbation, thefollowing actionshavebeentakenorarebeingplanned:0Applicable operating procedures havebeenchangedtorequirethatthebypassFRVsbeplacedinmanualclosedwhenincreasing aboveapproximately 304reactorpower.0Applicable operating procedures havebeenchangedtorequirereturning thebypassFRVstoautomatic controlwhendecreasing below304reactorpower.eACJOAN)SAAil4)1

IIACIsrselAAA104lILICENSEEEVENTREPORTILER)TEXTCONTINUATION vl.eevCLlAII AlOULATCAY coseseeClloee

/AASSOvloOvleeoIISOWIOel>eseAl5~rlITSI'ACILITY IIAIIlIIIOOCIIKTeeULQlA111LlAIIUAOlAI~IvTAASloulreveAL SAVes~are verU~s~AolIQR.E.GinnaNuclearPower.Plant06<<o244TKXTrrrrsrers~r~.vmeseseeeerrrreCArse~'grIITI92-002-12o~12oAmodification isplannedforthe1993AnnualRefueling andMaintenance Outagethatwouldmodifytheexistingfeedwater isolation logicforfail-open orfail-closed ofthemainandbypassFRVsuponturbinetripwithmainFRVsinautomatic controlmode.Theplannedmodification willdeletetheexistingfail-open logicandreplacethefail-closed logicwithactuation uponreactortripasopposedtoturbinetrip.Astheeventwasinitiated bytheMainGenerator tripduetolossofexcitation, thefollowing actionsareplannedtopreventrecurrence'.

00RG&Eisplanningtopurchaseandinstallareplacement voltageregulator unit.IRoutinetestingandmaintenance willbeperformed ontheexistingvoltageregulator unitduringthe1992AnnualRefueling andMaintenance Outagetoattainahighdegreeofconfidence thattheunitwilloperatewithoutincidentfortheentirefuelcycle.ADDITIONAL INFORMATION A.FAILEDCOMPONENTS:

TheTDAFWpumpturbineisa465horsepower noncondensing steamturbine,serialnumber26635,manufactured bytheWorthington Corporation.

B.PREVIOUSLERsONSIMILAREVENTS:AsimilarLEReventhistorical searchwasconducted withthefollowing results:Nodocumentation ofsimilarLEReventswiththesameunderlying causeatGinnaStationcouldbeidentified.

C.SPECIALCOMMENTS:

None.~eACSOAee1AAArl4lI

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