ML17263A225

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LER 93-001-00:on 930312,both Source Range Detectors Found Inoperable During Energization.Caused by Center Electrode Degradation Due to Gamma Corrosion.Failed Detectors Replaced W/Qualified spares.W/930412 Ltr
ML17263A225
Person / Time
Site: Ginna Constellation icon.png
Issue date: 04/12/1993
From: BACKUS W H, MECREDY R C
ROCHESTER GAS & ELECTRIC CORP.
To:
NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
LER-93-001, LER-93-1, NUDOCS 9304160043
Download: ML17263A225 (26)


Text

ACCEI.EEDDOCUMENTDISOBVTIONSYSTEMREGULAORYINFORMATIONDISTRIBUT8SYSTEM(RIDS)ACCESSIONNBR:9304160043DOC.DATE:93/04/12NOTARIZED:NOFACIL:50-244RobertEmmetGinnaNuclearPlant,Unit1,RochesterGAUTH.NAMEAUTHORAFFILIATIONBACKUSgWHERochesterGas&ElectricCorp.MECREDY,R.C.RochesterGas&ElectricCorp.RECIP.NAMERECIPIENTAFFILIATIONDOCKET05000244

SUBJECT:

LER93-001-00:on930312,bothsourcerangedetectorsfoundinoperableduringenergization.Causedbycenterelectrodedegradationduetogammacorrosion.Faileddetectorsreplacedw/qualifiedspares.W/930412ltr.DISTRIBUTIONCODE:IE22TCOPIESRECEIVED:LTRENCLSIZE:TITLE:50.73/50.9LicenseeEventReport(LER),ncidentRpt,etc.NOTES:LicenseExpdateinaccordancewith10CFR2,2.109(9/19/72).05000244RECIPIENTIDCODE/NAMEPD1-3LAJOHNSONiAINTERNAL:ACNWAEOD/DSP/TPABNRR/DE/EELBNRR/DORS/OEABNRR/DRCH/HICBNRR/DRIL/RPEBRR7'DSSA/PLBGFILE02RGNE01EXTERNAL'G&GBRYCEgJ~HNRCPDRNSICPOOREiW.COPIESLTTRENCL1111221111111111111111221111RECIPIENTIDCODE/NAMEPD1-3PDAEOD/DOAAEOD/ROAB/DSPNRR/DE/EMEBNRR/DRCH/HHFBNRR/DRCH/HOLBNRR/DRSS/PRPBNRR/DSSA/SRXBRES/DSIR/EIBLSTLOBBYWARDNSICMURPHY,G.ANUDOCSFULLTXTCOPIESLTTRENCL111122111111221111111111f'2374pQgc5NOTETOALL"RIDS"RECIPIENTS:$0-tPLEASEHELPUSTOREDUCEWASTE!CONTACTTHEDOCUMENTCONTROLDESK,ROOMPI-37(EXT.504-2065)TOELIMINATEYOURNAMEFROMDISTRIBUTIONLISTSFORDOCUMENTSYOUDON'TNEED!FULLTEXTCONVERSIONREQUIREDTOTALNUMBEROFCOPIESREQUIRED:LTTR30ENCL30

JJrROCHESTERGASANDELECTRICCORPORATION,r'~".'rOarrtEt~jStJlf489EASTAVENUE,ROCHESTERN.K14649-0001ROBERTC.h1ECREDYVicePresidentCrnnJNucteJrProductionTELEPHONEAREACODE7i65462700April12,1993U.S.NuclearRegulatoryCommissionDocumentControlDeskNashington,DC20555

Subject:

LER93-001,LossofSourceRangeDetectorIndicationDuringEnergization,DuetoFaultyDetectors,CausesaConditionProhibitedbyPlantTechnicalSpecifica-tions.R.E.GinnaNuclearPowerPlantDocketNo.50-244Inaccordancewith10CFR50.73,LicenseeEventReportSystem,item(a)(2)(i)(B),whichrequiresareportof,"anyoperationprohibitedbytheplant'sTechnicalSpecifications",theattachedLicenseeEventReportLER93-001isherebysubmitted.Thiseventhasinnowayaffectedthepublic'shealthandsafety.Verytrulyyours,XCJRobertC.MeredyU.S.NuclearRegulatoryCommissionRegionI475AllendaleRoadKingofPrussia,PA19406GinnaUSNRCSeniorResidentInspectorIGG030'9304160043930412PDRADOCK05000244S'PDR~'I>]gdIf

NACFORM300(Se)9)US.NUCLEARREGULATORYCOMMISSIAPPAOVEDOMBNO.3)500(OCEXPIRF5:C/30/92ESTIMATEDBURDENPERRFSPONSETOCOMPLYWTHTHISINFORMATIOAICOLLKCTIONAEOUESTI50.0HAS.FORWARDCOMMENTSREGARDINGBUADENESTIMATETOTHERECORDSANDRFPORTSMANAGEMENTBRANCH(F030).U.S.NUCLEARREGULATORYCOMMISSION,WASHINGTON.DC20555,ANDTOTHEPAPEAWORKABDUCTIONPROiECT(31500'IOe).OFFICEOFMANAGEMENTANDBUDGET.WASHINGTON,DC20503.LICENSEEEVENTREPORT(LER)DOCKETNUMBER(2)PA'FACILITYNAME(1)R.E.GinnaNuclearPowerPlanto5ooo244ioFllTITLE(e)LossofSourceRangeDetectorIndicationDuringEnergization,DuetoFaultyDetectorsCausesaConditionProhibitedvTechnicalSnecificaio~yCC~'VENTDATE(SlLEANUMBER(0)REPORTDATE(7OTHERFACILITIESINVOLVED(0)MONTHOAYYEARYEARIg@SEQUENTIALNUMSERREVISIONMONTHOAYYEARFACILITYNAMESDOCKETNUMBFRISI050000312939300100041293~~05000OPERATINGMODE(0)NPOWERLEVELppp20.I02(0)20.e00(~)IIIIII20A05(el(1)(9)20.005(e)ll1(ill)20A054)ll)Grl20.405(~Ill)4)20.e05(~)BOM(c)(I)50.30(cl(2)50.73(eI(2IIII50.73(e)(2)IIII50.734)(2)(III)LICENSFECONTACTFOATHISLER(12)50,73leI(2)IIr)50.73(el(2)4l50.73(e)(2)lrQ)50.73(e)(2)(rljj)(A)50.73(el(2)(r(QI(~)50.73(e)(2)(el0THEREDUIREMENTSOF10CFR():(Checkonrormoreofthefo//owindi(11)THISREPORTISSUBMITTEDPURSUANTT73.71(III73.71(c)OTHERISptcifycnAtjttrectOrrowrot/lnyrrt,/j/RCForm300AINAMEWes1eyH.BackusTechnicalAssistanttotheOoerationsManaerTELEPHONENUMBERAREACODE315524-4446COMPLETEONELINEFOREACHCOMPONENTFAILUREOKSCRIBEDINTHISREPORTll3)CCAUSESYSTEMCOMPONENTMANUFAC.TURERREPORTABLETONPADSj~jPN~QQcAUsESYSTEMCOMPONENTMANUFAC.TURKREPOATABLE(cTONPRDSQtMY.'NUwY,IGDTW12pSUPPLEMKNTALREPORl'XPECTED(IC)EXPECTEDSUBMISSIONDATK(15)kklk)MI.QjtKiPyX~(MONTHOAYYEARYESIIIyrt,complrttEXPECTEDSt/der/SSIONDATEINOABSTRACTILlmlttoIrddtpecrt,I,r.,rppror/mrtrfyIifttenrindle.eptcrtyprwrittrn/inrdI10)OnMarch12,1993,at1425EST,viththereactorsubcriticalduringaplannedshutdown,bothsourcerangedetectorsverefoundinoperablewiththereactortripbreakersclosed.TheControlRoomoperatorsimmediatelyenteredandperformedtheapplicableactionsofequipmentrestorationprocedureER-NZSe1(SRMalfunction).Thereactortripbreakersvereopenedvithinfive(5)minutesoftheevent.Themostlikelycauseofthesourcerangedetectorfailureswascenterelectrodedegradationduetogammacorrosionofthebaretungstencenter~e"trode(centerwire).(ThiseventisNUREG--1022(B)causecode).Correctiveactionwastoreplacethefaileddetectorsvithqualifiedspares.CorrectiveactiontopreventrecurrenceisoutlinedinsectionV(B).NRCForm300(509)

NRCFORM3SSA(649)US,NUCLEARREGULATORYCOMMISSIONLlCENSEEEVENTREPORT(LER)TEXTCONTINUATlONAPPROVEDOMBNO,3150010SEXPIRES:4/30/92ESTIMATEDBURDENPERRESPONSETOCOMPLYIYTHTHISINFORMATIONCOLLECTIONREOUEST:500HRS.FORWARDCOMMENTSREGARDINGBURDENESTIMATETOTHERECORDSANDREPORTSMANAGEMENTBRANCH(F430),U.S.NUCLEARREGULATORYCOMMISSION,WASHINGTON,DC20555,ANDTOSHEPAPERWORKREDUCTIONPROJECT(31500)04),OFFICEOFMANAGEMENTANDBUDGET,WASHINGTON.DC20503.FACILITYNAME(1)DOCKETNUMBER(2)YEARLERNUMBER(8)??oSEOUCNTIAL>5~REVrdr0N?.'/1/NUMddASP/r)NUMEAPAGE(3)R.E.GlnnaNuclearPowerPlantTEXT///mored/rdee/d//r/rer/ude/(r)roe/ir//ICForm3//S42/(12)osooo24493-0010002oFl1PRE-PMNTCONDITONSAplantshutdownwasinprogressperoperatingprocedure0-2.1(NormalShutdowntoHotShutdown)fortheannualrefuelingandmaintenanceoutage.Theturbinegeneratorhadgust.beentakenoffthelineandControlRoomoperators'wereintheprocessofshuttingthereactordownandinsertingallcontrolandshutdownrods.DESCRIPTIONOFEVENTDATESANDAPPROXIMATETIMESOFMAZOROCCURRENCESoMarch12,1993,1425EST:EventdateandtimeoMarch12,1993,1425,EST:EventdiscoverydateandtimeoMarch12,1993,1430EST:ControlRoomoperatorscompleteinsertingallcontrolandshutdownrodsandopenthereactortripbreakers.oMarch12,1993,1435EST:Plantstabilizedathotshutdown.oMarch12,1993,1501EST:SourceRangeNISN-31andNISN-32declaredinoperable.oMarch12,1993,1730EST:SourceRangeNISN-32declaredoperableusingtheinstalledsparesourcerangedetector.oMarch16,1993,1747EST:SourceRangeNISN-31declaredoperable.oMarch17,1993,2040EST:SourceRangeNISN-32declaredoperable,usingitsnormalsourcerangedetector.NRCPenn388A(589)

NRCFORM366A(689)U.S.NUCLEARREGULATORYCOMMISSIONLICENSEEEVENTREPORT(LER)TEXTCONTINUATIONAPPROVEDOM6NO.31500106EXPIRES:6/30/92ESTIMATEDBURDENPERRESPONSETOCOMPLYWTHTHISLNFORMATIONCOLLECTIONREGUEST:50.0HRS.FORWARDCOMMENTSREGARDINGBURDENESTIMATEToTHERECORDSANDREPORTSMANAGEMENTSRANCH(PJ)30).U.S.NUCLEARREGULATORYCOMMISSION,WASHINGTON,DC20555,ANDTO1HEPAPERWORKREDUCTIONPROJECT(3)500106),OFFICEOFMANAGEMENTANOBUDGET,WASHINGTON.DC20503.FACILITYNAME(I)DOCKETNUMBER(2)LERNUMBER(6)YEARO~>:SSOUSNTIAIv~4'EVISIONNVM66R'&-NUMFSAI'AGEI3)R.E.GinnaNuclearPaverPlantTEXTlllmototptcoitttquia/,uttAt//oont/P/RC%%dmt36SA't/(IT)0s0002~~93p010003DF11B.EVENT-OnMarch12,1993atapproximately1425ESTwiththereactorsubcriticalduringaplannedshutdown,sourcerange(SR)NuclearInstrumentationSystem(NIS)ChannelN-31andChannelN-32automaticallyenergizedatthenormalsetpointof</=5E-11ampsonthetwointermediaterange(IR)NISchannels.TheControl.Roomoperatorswerecloselymonitoringthedecayoftheintermediaterangecurrents,andwereanticipatingthe'resetlevelforthe.sourceranges.Atthetimeofautomaticenergizationofthesourcerangedetec-tors,therewasnocountrateindicationonChannelN-31orChannelN-32.Seeingnoindicationofcountrate,theControlRoomoperators,inaccordancewithplantproceduresandtrainingguidance,immediatelyattemptedtomanually.energizethesourcerangedetectorsusingtheP-6defeatpushbuttons.Thesourcerangedetectorsstilldidnotindicatecounts.TheControlRoomoperatorscontinuedtoexpeditiouslyinsertcontrolandshutdownrodsper0-2.1andatapproximately1430ESTthereactortripbreakerswereopened.Theplant,wassubsequentlystabilizedinhotshutdownatapproximately1435EST.NRCForm366A(649)

NRCFORM366A(64)9)US.NUCLEARREGULATORYCOMMISSIONLICENSEEEVENTREPORT(LER)TEXTCONTINUATIONAPPROVEDOMBNO.3ISOOI04EXPIRESI4/30/92ESTIMATEDBURDENPERRESPONSETOCOMPLYWTHTHISINFORMATIONCOLLECTIONREOUEST:50.0HRS.FORWARDCOMMENTSREGARDINGBURDENESTIMATETOTHERECORDSANDREPORTSMANAGEMENTBRANCH(P4)30),U.S.NUCLEARREGULATORYCOMMISSION,WASHINGTON,DC20555,ANDTOTHEPAPERWORKREDUCTIONPROJECT(31504)104).OFFICEOFMANAGEMFNTANDBUDGET,WASHINGTON,OC20503.FACILITYNAME(1)DOCKETNUMBER(2)YEARLERNUMBER(6)SEOUENZIAL,Oi)iNUMB%4AEVISIONNUMO64PAGE(3)R.E.GlnnaNuclearPowerPlantTEXT///mom4/>>ooJF~os,uood/d/ooo/NRCFomI35549/()7)osooo24493-00100040F~SubsequentlytheControlRoomoperatorsnotifiedhighersupervisionandtheInstrument&Control(I&C)Departmentoftheeventandatapproximately1501ESTdeclaredsourcerangeNISN-31andN-32inoperable.ThePlantOperationReviewCommittee(PORC)wasconvenedtoreviewtheactionstaken,conformancetoTechnicalSpecifications,eventclassificationandreportability.PORCdirectedthataccesstotheContainmentBuilding(CNMT)beprohibiteduntilonesourcerangechannelwasrestoredtooperablestatus.InadditionPORCconfirmedthatactionsweretakentoensureplantcooldownwouldnotoccur,andthatdilutionofboronconcentrationwouldnotoccur.TheControlRoomoperatorsenteredandperformedtheapplicableactionsofequipment,restorationprocedureER-NIS.1(SRMalfunction)includingcontinuedborationtogreaterthan54shutdownmargin.andsamplingtheReactorCoolantSystem(RCS).forboronconcentrationonaperiodicbasisduringtheboration.C.INOPERABLESTRUCTUEUKSFCOMPONENTS,ORSYSTEMSTHATCONTRIBUTEDTOTHE15TENT:D.None.OTE&RSYSTEMSORSECONDARYFUNCTIONSAFFECTED:None.EMETHODOPDISCOVERYTheeventwasimmediatelyapparentduetoindicationsintheControlRoom.NRCFoIm366A(64)9)

NRCFORM366A(689)US.NUCLEARREGULATORYCOMMISSIONLICENSEEEVENTREPORT(LER)TEXTCONTINUATION~APPROVEDOMBNO,315001065XPIRES:6/30/92ESTIMATEDBURDENPERRESPONSETOCOMPLYWTHTHISINFOAMATIONCOLLECTIONREQUEST:500HRS.FORWARDCOMMENTSREGARDINGBUAOENESTIMATETOTHERECORDSANDREPORTSMANAGEMENTBRANCH(P430),U.S.NUCLEARREGULATORYCOMMISSION,WASHINGTON.DC20555,ANDTOTHEPAPERWORKREDUCTIONPROJECT(31500106).OFFICEOFMANAGEMENTANDBUDGET.WASHINGTON,OC20503.FACILITYNAMEn)DOCKETNUMBER(2)LERNUMBER(6)YEARLPNLSEQUENTIAI.+WC:REVISIONI+I:NUMEER4.'UMERPAGED))R.E.GinnaNuclearPoT6erPlantJEXT///6NKEEpecris>>6U9od.u>>>>M/6'one/N/ICForm35569)nl)osooo24493-010005OFPOPERATORACTIONTheControlRoomoperators,afterrecognizingthattherewerenoindicatedcountratesoneitherofthesourcerangedetectors,immediatelyattemptedtomanuallyenergizethe-sourcerangedetectorsusingtheP-6defeatpushbuttons.TheoperatorsenteredER-NIS.1andperformedtheapplicableactions,includingpullingthefusesforInstrumentPower,inanotherattempttoreinstate,thesource'anges.Subsequently,theControlRoomoperatorsnotifiedhighersupervision'andtheI&CDepartmentanddeclaredsourcerangeNISN-31andN-32inoperable.G.SAFETYSYSTEMRESPONSESNone.III.CAUSEOFOSTENTA.IMMEDIATECAUSEThecauseofthefailureofsourcerangedetectorsN-31andN-32toindicatecountswasdetectorfailureduetocenterelectrodedegradation.SpecificmeasurementsindicatethatthecenterelectrodetoshieldhadbecomeshortcircuitedonsourcerangedetectorN-31,most,likelyduetotheelectrodebreakingatthebottomofthedetector.SourcerangedetectorN-32wasfoundtobeopencircuited,possiblyduetotheelectrodebreakingatthetopofthedetector.NACForm366A(689)

NRCFORM366AISS9)US.NUCLEARREGULATORYCOMMISSIONLICENSEEEVENTREPORT(LER)TEXTCONTINUATIONAPPROVEDOMSNO.31600104EXPIRES:E/30/92ESTIMATEDBURDENPERRESPONSETOCOMPLYWTHTHISINFORMATIONCOLLECTIONREOUESTI603)HRS.FORWARDCOMMENTSREGARDINGBURDENESTIMATETOTHERECORDSANDREPORTSMANAGEMENTBRANCHIF@30),U,S.NUCLEARREGULATORYCOMMISSION,WASHINGTON,DC20655,ANDTO1HEPAPERWORKREDUCTIONPROJECT131600)04),OFFICEOFMANAGEMENTANDBUDGET,WASHINGTON,DC20603.FACILITYNAME11)DOCKETNUMBER12)YEARLERNUMBERIS)X6%SEOUENTIAI.NUMBERREVISIONNUMSERPAGE13)R.E.GonnaNuclearPowerPlantTEXTillmoroEPocolrrorlrr/rod,IrwoddldorM/ll/ICForrrr366AS/)17)osooo24493-0010006OFBROOTCAUSE:AfterconsultingwithWestinghouseElectricCorporation(themanufacturerandvendorforthesedetectors),itwasconcludedthattheunderlyingcauseofthecenterelectrodedegradationofsourcerangedetectorsN-31andN-32ismostlikelyduetogammacorrosionofthebaretungstencenterelectrode(centerwire).Thiseffectoccurswheneverthesourcerangedetectorisenergized.ANALYSISOpEVENTTheeventisreportableinaccordancewith10CFR50.73,LicenseeEventReportSystem,item(a)(2)(i)(B),whichrequiresareportof,"anyoperationprohibitedbytheplant'sTechnicalSpecification",inthatthefailureofsourcerangedetectorsN-31andN-32toindicatecountsat</=1E-10ampsonthetwointermediaterangeNISchannelswasanoperationprohibitedbytheplantTechnicalSpecificationsasfollows:oSpecification3.5.1.1states,"TheProtectionSystemInstrumentationshownonTable3.5-1shallbeoperablewhenevertheconditionsspecifiedinColumn6areexceeded".Forthesourcerangeinstruments,column6referstoNote2,whichstates,"Channelsshouldbeoperableatallmodesbelowthebypassconditionwiththereactortripsystembreakersintheclosedpositionandcontrolroddrivesystemcapableofrodwithdrawal".Contrarytotheabove,sourcerangechannelsN-31andN-32wereinoperablebelowthebypassconditionof</=1E-10onbothIRNISchannelswiththereactortripbreakersclosedandthecontrolroddrivesystemcapableofrodwithdrawal.Thisconditionexistedforapproximatelyfive(5)minutesuntilthereactortripbreakerswereopened.WhileanActionStatementexistsforonesourcedetectorinoperable,thereisnostatedactionrequirementfortwo,detectorsinoperablewiththeReactorTripbreakersclosed.Therefore,aconditionprohibitedbytheplant'sTechnicalSpecificationsexisted.NRCForm366A)689)

NRCFORM366A(669)U.S.NUCLEARREGULATORYCOMMISSION2~LICENSEEEVENTREPORT(LER)TEXTCONTINUATIONAPPROVEDOMBNO.3(600104EXPIRES:A/30/92ESTIMATEDBURDENPERRESPONSETOCOMPLYWTHTHISINFORMATIONCOLLECTIONREOUESTI500HRS.FORWARDCOMMENTSREGARDINGBURDENESTIMATEToTHERECORDSANDREPORTSMANAGEMENTBRANCH(P430),U.S.NUCLEARREGULATORYCOMMISSION,WASHINGTON,DC20555,ANDTo1HEPAPERWORKREDUCTIONPROJECT(3150010I),OFFICEOFMANAGEMENTANDBUDGET,WASHINGTON,DC20503.FACILITYNAME(11DOCKETNUMBER(2)LERNUMBER(6)PAGE(3)R.E.GinnaNuclearPowerPlantTEXT/I/momH>>ce/t>>I)r/irer/Ir>>pr/r//I/orN/HRCForm366AB/(17)YEAR~rA0s00024493SEOUENTIALNUMSER001<~~REVISION..IH:NUMER00070F11Oncethetripbreakersareopen,theminimumoperablechannelsrequiredreducestoone(1)insteadoftwo(2)andtheactionstatementstatesinpartasfollows:Withthenumberofoperablechannelsonelessthantheminimumoperablechannelsrequirement,suspendalloperationsinvolvingpositivereactivitychanges.Anassessmentwasperformedconsideringboththesafetyconsequencesandimplicationsofthiseventwiththefollowingresultsandconclusions:Thesafetysignificanceofthefailureofbothsourcerangechannelsisthelossofdetectionofsubcriticalneutronfluxinthecoreandthefunctionthosechannelsprovideforbothautomaticactuationofthereactorprotectionsystemandthepromptingofoperatoractiontoprotectshutdownmargin.However,thissignificanceisminimizedinthisinstanceforthefollowingreasons:0Thefailureoccurredcompletelywithinthesequenceofshuttingdownthe-reactorinaccordancewithplantprocedure0-2.1inthattheoperatorswerecloselymonitoringthedecayoftheintermediaterangecurrentsandwereanticipatingtheresetlevelforthesourceranges.lnaccordancewith0-2.1theoperatorswereex-peditiouslyinsertingthecontrolandshutdownrodstofivestepspriortomanuallyopeningthereactortripbreakers.Thissequence,simultaneouswithinjectingboricacidtoachievetherequiredRCScoldshutdownboronconcentrationinsuredthatshutdownmarginwasmaintainedgreaterthantherequirementsofTechnicalSpecifications,andthatshutdownmargindidnotdecreaseduringthisevent.NRCForm366A(BJ)9)

J NRCFORM355A(689)U.S.NUCLEARREGULATORYCOMMISSIONLICENSEEEYENTREPORTILER)TEXTCONTINUATIONAPPROVEDOMBNO.31600104EXPIRES:4/30JS2ESTIMATEDBURDENPERRESPONSETOCOMPLYWTHTHISINFORMATIONCOLLECTIONREQUESTI50.0HRS.FORWARDCOMMENTSREGARDINGBURDENESTIMATETOTHERECORDSANDREPORTSMANAGEMENTBRANCH(P430),U.S.NUCLEARREGULATORYCOMMISSION,WASHINGTON,DC20555,ANDTO1HEPAPERWORKREDUCTIONPROJECT(31504104).OFFICEOFMANAGEMENTANDBUDGET,WASHINGTON,OC20503.FACILITYNAME(1)DOCKETNUMBER(21LERNUMBER(5)YEAR(PSEQUENTIALS)I(REVISIONM3NUMSEA'P..:NUMBERPAGE(3)R.E.GinnaNuclearPowerPlantTEXTFITmo>>~JJ>>ookod,u>>aktJNealHRCAnn35543)(IT)osooo24493-0010008OioAfterimmediatelyrecognizingthatthesourcerangechannelsdidnotindicatecountsattheintermediaterangeresetpoint,theoperatorstookappropriateactionsinattempting-toreinstate-sourcerangedetectors.Theycontinuedtoexpeditiouslyinsertcontrolandshutdownrods,andwithinfiveminutes,openedthereactortripbreakers.Theoperatorcontinuedborationtothecoldshutdown,xenonfreeconcentrationrequiredbyprocedureforRCScooldownbelow500degrees.Therewasnodecreaseinshutdownmargin,fromthetime'offailureofbothsourcerangechannelsuntilthetimethesparesourcerangedetectorwasusedtodeclareChannelN-32operable.Alloperationsinvolvingpositivereactivitychangesweresuspendersuntilafterthesparesourcerangedetectorwasdeclaredoperable.Basedontheabove,itcanbeconcludedthatthepublic'shealthandsafetywasassuredatalltimes.VCORRECTIVEACTIONAACTIONTAKENTORETURNAFFECTEDSYST1963TOPRE-EVENTNORMALSTATUS:0,ThedetectorinstalledinsourcerangechannelN-32wasdisconnectedandthepreviouslyinstalledsparesourcerangedetectorwasconnectedtosourcerangechannelN-32.NISN-32highvoltagesettingandthepulseheightdiscriminator(PHD)biassettingweread)ustedtoconformtothedataforthesparedetector.Atapproxi-mately1730ESTonMarch12,1993,sourcerangeChannelN-32wasdeclaredoperable.NRCForm365A(SSS)

NRCFORM366A(669)U.S.NUCLEARREGULATORYCOMMISSIONLICENSEEEVENTREPORT(LER)TEXTCONTINUATIONAPPROVED0MBNO.31500)04EXPIRES:6/30)92ESTIMATEDBURDENPERRESPONSETOCOMPLYWTHTHISINFORMATIONCOLLECTIONREQUEST:500HRS.FORWARDCOMMENTSREGARDINGBURDENESTIMATETOTHERECORDSANDREPORTSMANAGEMENTBRANCH(P630),U.S.NUCLEARREGULATORYCOMMISSION,WASHINGTON,OC20555,ANDTO1'HEPAPERWORKREDUCTIONPROJECT(31500106),OFFICEOFMANAGEMENTANDBUDGET,WASHINGTON,DC20503,FACILITYNAME(I)DOCKETNUMBER(2)LERNUMBER(6)YEARS~ySEQVSNTIAL:~2NUMSSIIREVISIONNUMSAPAGE(3)R.E.GonnaNuclearPowerPlantTEXTNmonJIMcels~,VJP~HRCForm35663)(IT)ppppp24430010009oF11ThedetectorinstalledinsourcerangechannelN-31wasreplacedwithadetectorwithdrawnfromstock.Subsequently,forsourcerangechannelN-31thehighvoltagepowersupplywasreplaced.Thedetectoranodevoltagecurve(alsoreferredtoastheplateaucurve).wasobtained,andthePHDbiassettingwasadjusted.Atapproximately1747ESTonMarch16,1993,sourcerangeChannelN-31wasdeclaredoperable.oThedetectorinstalledinsourcerangechannelN-32wasreplacedwithadetectorwithdrawnfromstock.Forthisnewlyinstalleddetector,theplateaucurvewasobtainedandthePHDbiassettingwasadjusted.TheinstalledsparesourcerangedetectorwasthendisconnectedfromsourcerangechannelN-32andthisnewlyinstalledsourcerangedetectorwasconnectedtosourcerangechannelN-32..Thechanneloperabilitytestwascompleted,andatapproximately2040ESTonMarch17,1993sourcerangeChannelN-32wasdeclaredoperable,usingitsnormalsourcerangedetector.BACTIONTAKENORPLANN19)TONUGENTREC&tRENCE:Tominimizefuturesourcerangedetectorfailures,thefollowingactionsarebeingplanned:0AperiodicreplacementintervalforBF~filledsourcerangedetectorswillbeestablished,basedupontimeinserviceornumberofener-gizationsofthedetectors.NRCForm366A(689)

NRCFORM366A(689)FACILITYNAME(1)UE.NUCLEARREGULATORYCOMMISSIONLICENSEEEVENTREPORTtLER)TEXTCONTINUATIONDOCKETNUMBER(2)APPROVEDOM8NO.31600104EXPIRES:4/30/92ESTIMATEDBURDENPERRESPONSETOCOMPLYWTHTHISINFORMATIONCOLLECTIONREQUEST:50/)HRS.FORWARDCOMMENTSREGARDINGBURDENESTIMATETOTHERECORDSANDREPORTSMANAGEMENTBRANCH(P830),U.S.NUCLEARREGULATORYCOMMISSION,WASHINGTON,DC20555,ANDTOTHEPAPERWORKREDUCTIONPROJECT(31500104).OFFICEOFMANAGEMENTANDBUDGET,WASHINGTON,DC20503.PAGE(3)LERNUMBER(8)YEARP444SEQUENTIAL.AyNUMSERREVISIONNUMSSRR.E.GonnaNuclearPowerPlaneTEXT///mareS>>ceJIre/Ir/red,Ireeedd/dar>>/N/IC%%drm38642/((7)psppp244930010010OFoAnewWestinghousedesignfortheseBF3filledsourcerangedetectorsincorporateslowvoltagesourcerangedetectorswithgold-platedtungstencenterwireconductormaterial.Detectorsofthisnewdesignwillbeprocured.Whendetectorsofthisnewdesignareinstalled,aspartofaplanneddetectorupgradeschedule,asreplace-mentsforexistingdetectors,theperiodicreplacementintervalwillbere-evaluated.0Existingcalibrationprocedureswillberevised,"ornewproceduresdeveloped,toincludestepstoperformtimedomainreflectometry(TDR)measure-mentsonN-31,N-32andsparedetector,priortoscheduledrefuelingoutages.(TDRmeasurementscandetermineifthedetectorcenterelectrodewireisbroken,shortedoutorifithashighorlowresistance).0Atrendingprogramtodetectpotentialdegradationofsourcerangedetectorswillbeestablished,forthefollowingdata:1)Detectorplateaucurvedatawillbetrended.AstheBF3gasinthedetectordissociatesovertime,thehighvoltagewillbeadjustedhighereachtimeuntilitcannolongerbesetontheplateau.2)PHDbiascurveswillbetrended.RMATONAPAXLEDCOMPONENTS:ThefaultydetectorswereBF3filled,sourcerangedetectorproportionalcounters,PartNo.WL-24182manufacturedbyWestinghouseElectricCorporation.NRCForm388A(889)

NRCFORM366A(SJ)9)tUS.NUCLEARREGULATORYCOMMISSIONLICENSEEEVENTREPORT(LER)TEXTCONTINUATIONAPPROVEOOMBNO,31500104EXPIRES:EI30(92ESTIMATEDBURDENPERRESPONSETOCOMPLYWTHTHISINFORMATIONCOLLECTIONREQUEST:500HRS.FORWARDCOMMENTSREGARDINGBURDENESTIMATETOTHERECORDSANDREPORTSMANAGEMENTBRANCH(F430).U.S.NUCLEARREGULATORYCOMMISSION,WASHINGTON.OC20555,ANDTO1HEPAPERWORKREDUCTIONPROJECT(31500104).OFFICEOFMANAGEMENTANDBUDGET,WASHINGTON,DC20503.FACILITYNAME(1IDOCKETNUMBER(2)YEARLERNUMBER(SISEQUENTIALNVMSERREVISIONNVMSERI'AGE(3)R.E.GinnaNuclearPowerPlantRJOOOOPooo(ssoSs(INLgoooddlooIMIHRC%%dmI36643)(17)osooo244930010011OFB.PREVXOUSLERsONSIMILARKGFNTS.AsimilarLEReventhistoricalsearchwasconductedwiththefollowingresults:LER90-003(HigherThanNormalCountRateonSourceRangeNIS,DuetoaFaultyDetector,CausesaReactorTripDuringSourceRangeRe-energization)wasasimilareventwiththesamerootcause.Thecorrectiveactiontopreventrecur-rence,oftheeventdescribedinLER90-003,wastoinitiateaevaluationwhichwillultimatelyresultinprocurementandinstallationofdetectors,ofanewWestinghousedesign.Itshouldbenotedthateveniftheevaluationhadbeencompleted,anddetectorsofanewdesignhadbeenprocuredandwereinstock,thesedetectorswouldnothavebeeninstalledpriortothe1993outage.CSPECIALCOMMENTSNone.NRCFoIm366A(SJ)9)