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{{#Wiki_filter:REGULATORYINFORMATIONDISTRIBUTIQl'JSYSTEM(RIDS)ACCESSIONNBR:8802230067DOC.DATE:88/02/18NOTARIZED:NODOCKET0FACIL:50-315DonaldC.CookNuclearPoeerPlant'nitiiIndiana505000315AUTH.NAMEAUTHORAFFILIATIONBEILMANiT.P.IndianaMichiganPowerCo.(formerlyIndiana8.MichiganEleSMITHiW.G.IndianaMichiganpowerCo.(formerlyIndiana5MichiganEleRECIP.NAMERECIPIENTAFFILIATION
{{#Wiki_filter:REGULATORY INFORMATION DISTRIBUTIQl'J SYSTEM(RIDS)ACCESSION NBR:8802230067 DOC.DATE:88/02/18NOTARIZED:
NODOCKET0FACIL:50-315DonaldC.CookNuclearPoeerPlant'nitiiIndiana505000315AUTH.NAMEAUTHORAFFILIATION BEILMANiT.P.IndianaMichiganPowerCo.(formerly Indiana8.MichiganEleSMITHiW.G.IndianaMichiganpowerCo.(formerly Indiana5MichiganEleRECIP.NAMERECIPIENT AFFILIATION


==SUBJECT:==
==SUBJECT:==
LER87-023-01:on871109problemdiscoveredrefusesrequiredforisolationbetweenlocalshutdoen8cindicationpanels.ProblemsconfiTmedon871222.Causedbgengineerdesignoversight.Designchangesmode.W/880218ltr.DISTRIBUTIONCODE:IE22DCOPIESRECEIVED:LTRENCLSIZE:TITLE:50.73LicenseeEventReport(LER>iIncidentRptietc.RECIPIENTIDCODE/NAMEPD3-3LAWIGGINGTQNiDCQPIESLTTRENCL11RECIPIENTIDCODE/NAMEPD3-3PDCQPIESLTTRENCL11INTERNAL:ACRSMICHELSONAEOD/DOAAEOD/DBP/ROABARM/DCTS/DABNRR/DEBT/ADSNRR/DEST/ELBNRR/DEST/MEBNRR/DEST/PSBNRR/DEBT/SGBNRR/DLPG/GABNRR/DREP/RABBREGFILE02IBRGN3FILE0111101111111111ACRSMOELLERAEOD/DSP/NASAEOD/DBP/TPABDEDRONRR/DEBT/CEBNRR/DEBT/ICSBNRR/DEBT/MTBNRR/DEST/RSBNRR/DLPG/HFBNRR/DOEA/E*BNRR/DREP/RPBNRR/PM*8/ILRBRESTELFORD>JRES/DRPSDIR221111111111111111122111111EXTERNAL:EG5GGROHiMHSTLOBBYWARDNRCPDRNSICMAYSiGFORDBLDGHOYiALPDRNSICHARRIS'111111TOTALNUMBEROFCOPIESREQUIRED:LTTR46ENCL45 IndianaMichiganPowerCompanyCookNuclearPlantP.O.Box458Bridgman,MI491066164655901ZINDUNANlCHtGAMPODFebruary18,1988UnitedStatesNuclearRegulatoryCommissionDocumentControlDeskWashington,D.C.20555OperatingLicenseDPR-58DocketNo.50-315DocumentControlManager:Inaccordancewiththecriteriaestablishedby10CFR50.73entitledLicenseeEventReortinSstem,thefollowingreportisbeingsubmitted:87-023-01Sincerely,W.G.Smith,Jr.PlantManagerWGS:afhAttachmentcc:D.H.Williams,Jr.A.B.Davis,RegionIIIM.P.AlexichR.F.KroegerH.B.BruggerR.W.JurgensenNRCResidentInspectorJ.F.Stang,NRCR.C.CallenG.Charnoff,Esq.DottieSherman,ANILibraryD.HahnINPOPNSRCA.A.BlindP.A.Barrett/P.LauzauM~pN NRCForm345(943)LICENSEEEVENTREPORT(LER)US.NUCLEARREOULATOAYCOMMISSIONAPPROVEDOMBNO.31500104EXPIRES:5/31/SBFACILITYNAME(I)D.C.CookNuclearPlant-Unit1DOCKETNUMBER(2)PAE305000315>OF05"'"""DeficientDesignResultsinFailuretoProvideElectricalIsolationBetweenLocalShutdownandIndicationPanelsMONTHOAYYEAREVENTDATE(5)LERNUMBER(5)YEARjPP~SEQUENTIALNUMBERREVISIONNUMBERREPORTDATE(7)MONTHOAYYEAROTHERFACILITIESINVOLVED(SlDOCKETNUMBERIS)050003FACILITYNAMESD.C.Cook-Unit21109878702301005000OPERATINQMODE(9)POWERLEVEL00)09020402(B)20AOS(e)(l)(I)20AOS(s)II)(S)20AOS(e)(1)(ill)20AOS(e)(1)(N)20AOS(~)(1)(v)20AOS(e)SOW(e)(I)50.35(el(2)50.73(e)(2)(I)50.73(e)(2)(5)50.73(e)(2)(llilLICENSEECONTACTFORTHISLER(12)50.73(e)(2)(N)50,73(sl(2)(v)50.73(el(2)(vill50.73(e)(2)(vllI)(AI50.73(e)(2)(vill)(BI50,73(el(2)(rr)THISREPORTISSUBMITTEDPURSUANTT0THEREQUIREMENTSOf10CFR(IrfCnecltoneormoreOfthrfollovfinPI(1173.71(B)73.71(c)OTHER(SpecifyInAbrtreetbelowenrfInTest,HRCForm3SEAINAMET.P.BeilmanInstrumentation&ControlDepartmentSuperintendentTELEPHONENUMBERAREACODE616465-5901COMPLETEONELINEFOREACHCOMPONENTFAILUREDESCRIBEDINTHISREPORT(13)CAUSESYSTEMCOMPONENTMANUFAC-TURERREPORTABLEIg+(p.'NoITO>>ROS:ROu%a.4@MID!gAPN'n......Sk4CAUSESYSTEMCOMPONENTMANUFAC.TUREREPORTABLETONPRDS'o&N"'Pno.-8oSUPPLEMENTALREPORTEXPFCTED(14)EXPECTEDSUBMISSIONDATE(15)MONTHOAYYEARYES(ifyrr,complereEXPECTEDSUSIeIISSIOHDATE)NOABSTRACTfLlmitto1400epecer,I.r.,rpprorrlmetrfyfiltrrnelnpleeprcrtypewrittenIlneel(IS)Theprimarypurposeofthissupplementalreportistoprovideadditionalinformationregardingthesequenceofevents.OnNovember9,1987,duringareviewofaninvestigationcon-cerningRegulatoryGuide1.97compliance,itwasdiscoveredthatapotentialproblemcouldexistinvolvingthefusesrequiredforisolationbetweenthevariousLocalShutdownandIndication(LSI)panels(improperlylocatedonUnit2andnotincorporatedintotheexistingdesignonUnit1).OnDecember22,1987itwasconfirmedthataconditionexistedthat,intheeventofafirelocaltoaLSIpanel,power(bothnormalandalternate)tosomeorallofthesameunits'emainingpanelscouldhavebeenlost.ThecauseoftheeventwasanoversightbydesignengineersinthedesignandverificationprocessassociatedwiththeinitialAppendixRmodifications.Firewatcheswereassignedtotourtheaffectedareas.Designchangeshavebeenimplementedwhichprovidethenecessaryisola-tionintheeventofafire.Topreventrecurrencetheappro-priateengineeringprocedureshavebeenprefacedtoaddressthisspecificelectricalisolationconcern.NRCForm355Nl8802230067880218PDRADOCK05000315SPDR NRCForm366A(943)LICENSEEEVENTREPORT(LER)TEXTCONTINUATIONU.S.NUCLEARREGULATORYCOMMISSIONAPPROVEOOMBNO.3150-0104EXPIRES:8/31/85FACILITYNAME(I)'OCKETNUMBER(2)LERNUMBER(6)PAGE(3)YEAR~@@SEOUENTIALNUMBERREVISIONNUMBERD.C.CookNuclearPlant-Unit1TEXT/lfmorospsso/sisr)eked,ososddilions///RCForm366A's/(I2)0500031587023010OF05Theprimarypurposeofthissupplementalreportistoprovideadditionalinformationregardingthesequenceofeventsleadinguptothedeterminationthattheeventwasreportable.ConditionsPriortoOccurrence(Conditionsdateofdiscovery)Unit1-Mode1(poweroperation)-90percentReactorThermalPowerUnit2-Mode1(poweroperation)-80percentReactorThermalPowerDescritionofEventOnNovember9,1987,duringaninvestigationintothefeasibilityofusingexistingReactorCoolantSystemWideRangeT-HotandT-Coldindications(EIIS/AB-TI)forRegulatoryGuide1.97com-pliance,itwasdiscoveredthatapotentialproblemcouldexistinvolvingthefuses(EIIS/FU)requiredforisolationbetweenthevariousLocalShutdownandIndication(LSI)panels(EIIS/PL)(improperlylocatedonUnit2andnotincludedintheexistingdesignonUnit1).OnDecember22,1987itwasconfirmedthataconditionexistedthat,intheeventofafirelocaltoanLSIpanel,power(bothnormalandalternate)tosomeorallofthesameunits'emainingLSIpanelscouldbelost.Ifpowerwaslosttoallpanels,thoseindicationsavailablelocallywouldbelost.Inaddition,allWideRangeT-HotandT-Coldindications,1of4channelsofpressurizerlevelindication(EIIS/AB-LI),andbothtrainsoftheReactorVesselLevelIndicationSystem(EIIS/AB-LI)wouldbelostinthecontrolroom.Thisconditionisnotconsistentwiththerequirementsof10CFR50,AppendixRandhasexistedsinceinitialinstallationoftheAppendixRmodifications(Unit1-September,1985;Unit2-June,1986)'.Withtheexceptionofthesub'jectLSIpanels,therewerenoinoperablecomponents,systemsorstructuresthatcontributedtothisevent.Thefollowingprovidesthereasonfortimebetween(1)thedate(November9,1987)thattheconfiguration(i.e.,apotentialproblemwiththeelectricalisolationbetweenpowerfeedstoNRCFORM3ddA(983)
LER87-023-01:
NRCForm366Au(94)3)LICENSEEEVENTREPORT(LER)TEXTCONTINUATIONU.S.NUCLEARREGULATORYCOMMISSIONAPPROVEOOMBNO.3150-0104EXPIRES:6/31/95FACILITYNAME(I)'OCKETNUMBER(2)LERNUMBER(6)jSISEGUENTIALAIPieoREVISIONNUMBER66'ONUMBERPAGE(3)D.C.CookNuclearPlant-Unit105000315TEXTillmorespsoeisrequired,usesddicionslllRCForm3654's)(17)87-023-0103QF05DescritionofEvent-(Continued)LocalShutdownIndicationpanels)wasinitiallyquestionedand(2)thedate(December22,1987)whentheknownproblemwasre-ported.Specifically,onNovember9,1987theengineerwhoiden-tifiedtheconcerninitiatedaProblemReport.ProblemReportsareusedtodocumenteitherknownnonconformancesorpotentialnonconformancesandtoassureproperinvestigationintothedocumentedconcern.ForthecasereportedinthisLER,theengineerlaterconcluded,onNovember9,1987,thattheconcernidentifiedontheProblemReportwasnotaproblem(i.e.,aconditionwhichwascontrarytoregulatoryrequirementswasnotidentified).Therefore,theengineerdidnotforwardtheProblemReporttomanagement.Approximatelyseventoninedayslater,theengineer'ssupervisorquestionedtheengineeraboutthestatusoftheconcern.Atthattime(approximately,November18,1987)thesupervisorconcludedthattheelectricalisolationconcernmayhaveanimpactonregulatory(10CFR50,AppendixR)compliance.Therefore,thesupervisorhadtheProblemReportforwardedtotheappropriatemanagement(ProblemAssessmentGroup),sothataninvestigationwouldbeconductedpursuanttotheproceduralrequirementswhichgovernsuchaninvestigation.OnDecember21,1987engineeringandlicensingreviewsconcludedthateventhoughcertainprocessvariablesrequiredby10CFR50,AppendixRcouldbelostincertainfirescenarios,sufficientalternativeinformationwasstillavailable.Therefore,itwasconcludedthataregulatorycomplianceproblemdidnotexist.However,onDecember22,1987itwasconcludedthataproblemdidexist.Specifically,asinglefiremighteliminatetheredundantAlternativeShutdownCapabilityinstrumentationrequiredby10CFR50AppendixR,SectionIII.L.Atthistime(December22,1987),whenthisproblemwasfirstidentifiedasreportable:(1)therequirementsof10CFR50.72werefulfilled(1650hours)and(2)areportper10CFR50.73wasinitiated.Insummary,onNovember9,1987,theengineerwhohadfirstquestionedtheLSIpanelelectricalisolation,concludedthataproblemdidnotexist.OnapproximatelyNovember18,1987,theengineer'ssupervisor,throughconsultationwithherassistantsupervisorandalicensingengineer,concludedthattheconcernwarrantedformalinvestigation.OnDecember21,1987engineeringandlicensingconcludedthattherequirementsofAppendixRwerebeingfulfilled,inspiteofelectricalisolationconcerns.OnDecember22,1987,theconclusionwasreachedthatcertainconcernspost-fireprocessvariables(e.g.,T-HOTandT-COLD)couldnotbeassured.Therefore,appropriatereportabilityactionswereinitiated.NRCFORM366A0)63I NRCForm366A(643)LICENSEEEVENREPORT(LER)TEXTCONTINUATIONU.S.NUCLEARREOULATORYCOMMISSIONAPPROVEDOMBNO.3150M(04EXPIRES:6/31/85FACILITYNAME(I)DOCKETNUMBER(3)LERNUMBER(6)y6ARQM;560U6NTIAL~W~i<5R5VI5I0NNUMSERi&rrNUMBERPACE(3)D.C.CookNuclearPlant-Unit1TEXT///moreepeee/IrequIred,ueeeddir)rrur//VRCForm3564'5/()7)0500031587-023-0104QF05CauseofEventThecauseoftheeventwasanoversightbydesignengineersinthedesignandverificationprocessassociatedwiththeinitialAppendixRmodifications.AnalsisofEventTheconditionisnotconsistentwiththerequirementsof10CFR50,AppendixR,andassuch,isnotconsistentwithourdesignbasis.Theeventhasbeendeterminedreportableper10CFR50.73,(a)(2)(ii)(B).AppendixRrequiresthatadequateinstrumentationbeavailabletoensuresafeshutdowninthecaseofasinglefire.IfafireatoneoftheLSIpanelshadledtothelossofpowertoallofoneUnits'SIpanels,WideRangeT-HotandT-Coldindicationswouldhavebeenlost(bothlocalandcontrolroom).AccordingtoIEInformationNotice84-09,theseprocessvariablesarerequ'iredforsafeshutdown.However,sufficientinformationwouldhavebeenavailabletotheoperatorforachievingsafeshutdownintheuseofthein-corethermocoupleindicationsand/ortheuseofmainsteampressureandsaturationtemperaturecurves.IfpowerwaslosttoallLSIpanelsduetoafireatanyLSIpanellocation,allindicationsonallLSIpanelswouldbelost.However,withtheexceptionofWideRangeT-HotandT-Cold,alloftheprocessvariablesindicatedlocallyattheLSIpanelswouldnotberequiredlocallyduetotheiravailabilityinthecontrolroomandthefactthatafireatanyLSIpanellocationwouldnotrequireremoteshutdown.Therefore,forthereasonsdetailedabove,ithasbeenconcludedthattheconditionreportedinthisLERrepresentsneitherasignificantrisktopublichealthandsafety,norasignificantdegradationofourAppendixRsafeshutdowncapability.CorrectiveActionsRovingfirewatcheswereassignedtotourtheaffectedareasonDecember22,1987(LSIpanellocationswithinbothunits).TherovingfirewatcheswereupgradedtocontinuousfirewatchesonDecember24,1987.Thesestepsweretakentoserveasaninterimcompensatoryactionuntilthenecessarydesignchangescouldbeimplemented.ForUnit2,designchangeswereimplementedDecember30,1987thatremovedtheimproperlylocatedfusesandinstalledreplacementstoremedytheinadequacy.ForUnit1,fuseswereinstalledonNRCFORM35@A(963)
on871109problemdiscovered refusesrequiredforisolation betweenlocalshutdoen8cindication panels.ProblemsconfiTmedon871222.Causedbgengineerdesignoversight.
NRCForm366A(94)3)LICENSEEEVENTREPORT(LER)TEXTCONTINUATIONU.S.NUCLEARREGULATORYCOMMISSIONAPPROVEDOMBNO.3(50-0I04EXPIRES:6/31i65FACILITYNAME('I)'OCKETNUMBER(3)LERNUMBER(6)YEARoSs'EGUENTIALNUMBERio.REVISIONNUMBERPAGE(3)D.C.CookNuclearPlant-Unit1TEXTilfmorespeosisseqoired,useeddirionelNRCForm3654's)(17)0500031587-0230105OF05CorrectiveActions-(Continued)December29,1987.Theexistingconfigurationnowprovidestheelectricalisolationnecessaryintheeventofafire.Webelievethatthisconditionisanisolatedevent.Althoughconsiderationof10CFR50,AppendixRelectricalisolationcriteriaintheengineeringanddesignprocessisrequired,additionalemphasiswillbeplacedontheseelectricalisolationrequirements.Theappropriateengineeringprocedures,dealingwithAppendixRdesigndetails,havebeenprefaced(viaaletter)toincludethiselectricalisolationconcern.Theletterwasreviewedduringamonthlytrainingsession(01/21/88)attendedbyelectricalengineeringpersonnel.FailedComonentIdentificationNonePreviousSimilarEventsNoneNRCFORM366A(993I}}
Designchangesmode.W/880218ltr.DISTRIBUTION CODE:IE22DCOPIESRECEIVED:
LTRENCLSIZE:TITLE:50.73LicenseeEventReport(LER>iIncidentRptietc.RECIPIENTIDCODE/NAME PD3-3LAWIGGINGTQNi DCQPIESLTTRENCL11RECIPIENTIDCODE/NAME PD3-3PDCQPIESLTTRENCL11INTERNAL:
ACRSMICHELSON AEOD/DOAAEOD/DBP/ROAB ARM/DCTS/DAB NRR/DEBT/ADS NRR/DEST/ELB NRR/DEST/MEB NRR/DEST/PSB NRR/DEBT/SGB NRR/DLPG/GAB NRR/DREP/RAB BREGFILE02IBRGN3FILE0111101111111111ACRSMOELLERAEOD/DSP/NAS AEOD/DBP/TPAB DEDRONRR/DEBT/CEB NRR/DEBT/
ICSBNRR/DEBT/MTB NRR/DEST/RSB NRR/DLPG/HFB NRR/DOEA/E*B NRR/DREP/RPB NRR/PM*8/
ILRBRESTELFORD>JRES/DRPSDIR221111111111111111122111111EXTERNAL:
EG5GGROHiMHSTLOBBYWARDNRCPDRNSICMAYSiGFORDBLDGHOYiALPDRNSICHARRIS'111111TOTALNUMBEROFCOPIESREQUIRED:
LTTR46ENCL45 IndianaMichiganPowerCompanyCookNuclearPlantP.O.Box458Bridgman, MI491066164655901ZINDUNANlCHtGAMPODFebruary18,1988UnitedStatesNuclearRegulatory Commission DocumentControlDeskWashington, D.C.20555Operating LicenseDPR-58DocketNo.50-315DocumentControlManager:Inaccordance withthecriteriaestablished by10CFR50.73entitledLicenseeEventReortinSstem,thefollowing reportisbeingsubmitted:
87-023-01 Sincerely, W.G.Smith,Jr.PlantManagerWGS:afhAttachment cc:D.H.Williams, Jr.A.B.Davis,RegionIIIM.P.AlexichR.F.KroegerH.B.BruggerR.W.Jurgensen NRCResidentInspector J.F.Stang,NRCR.C.CallenG.Charnoff, Esq.DottieSherman,ANILibraryD.HahnINPOPNSRCA.A.BlindP.A.Barrett/P.
LauzauM~pN NRCForm345(943)LICENSEEEVENTREPORT(LER)US.NUCLEARREOULATOAY COMMISSION APPROVEDOMBNO.31500104EXPIRES:5/31/SBFACILITYNAME(I)D.C.CookNuclearPlant-Unit1DOCKETNUMBER(2)PAE305000315>OF05
"'"""Deficient DesignResultsinFailuretoProvideElectrical Isolation BetweenLocalShutdownandIndication PanelsMONTHOAYYEAREVENTDATE(5)LERNUMBER(5)YEARjPP~SEQUENTIAL NUMBERREVISIONNUMBERREPORTDATE(7)MONTHOAYYEAROTHERFACILITIES INVOLVED(SlDOCKETNUMBERIS) 050003FACILITYNAMESD.C.Cook-Unit21109878702301005000OPERATINQ MODE(9)POWERLEVEL00)09020402(B)20AOS(e)(l
)(I)20AOS(s)II)(S) 20AOS(e)(1)(ill) 20AOS(e)(1)(N)20AOS(~)(1)(v)20AOS(e)SOW(e)(I) 50.35(el(2) 50.73(e)(2)(I)50.73(e)(2)(5)50.73(e)(2)(llilLICENSEECONTACTFORTHISLER(12)50.73(e)(2)(N)50,73(sl(2)(v) 50.73(el(2)(vill 50.73(e)(2)(vllI)(AI50.73(e)(2)(vill)(BI 50,73(el(2)(rr)
THISREPORTISSUBMITTED PURSUANTT0THEREQUIREMENTS Of10CFR(IrfCnecltoneormoreOfthrfollovfinPI (1173.71(B)73.71(c)OTHER(SpecifyInAbrtreetbelowenrfInTest,HRCForm3SEAINAMET.P.BeilmanInstrumentation
&ControlDepartment Superintendent TELEPHONE NUMBERAREACODE616465-5901 COMPLETEONELINEFOREACHCOMPONENT FAILUREDESCRIBED INTHISREPORT(13)CAUSESYSTEMCOMPONENT MANUFAC-TURERREPORTABLE Ig+(p.'NoITO>>ROS:ROu%a.4@MID!gAPN'n......
Sk4CAUSESYSTEMCOMPONENT MANUFAC.TUREREPORTABLE TONPRDS'o&N"'Pno.-8oSUPPLEMENTAL REPORTEXPFCTED(14)EXPECTEDSUBMISSION DATE(15)MONTHOAYYEARYES(ifyrr,complereEXPECTEDSUSIeIISSIOH DATE)NOABSTRACTfLlmitto1400epecer,I.r.,rpprorrlmetrfy filtrrnelnpleeprcr typewritten Ilneel(IS)Theprimarypurposeofthissupplemental reportistoprovideadditional information regarding thesequenceofevents.OnNovember9,1987,duringareviewofaninvestigation con-cerningRegulatory Guide1.97compliance, itwasdiscovered thatapotential problemcouldexistinvolving thefusesrequiredforisolation betweenthevariousLocalShutdownandIndication (LSI)panels(improperly locatedonUnit2andnotincorporated intotheexistingdesignonUnit1).OnDecember22,1987itwasconfirmed thatacondition existedthat,intheeventofafirelocaltoaLSIpanel,power(bothnormalandalternate) tosomeorallofthesameunits'emaining panelscouldhavebeenlost.Thecauseoftheeventwasanoversight bydesignengineers inthedesignandverification processassociated withtheinitialAppendixRmodifications.
Firewatcheswereassignedtotourtheaffectedareas.Designchangeshavebeenimplemented whichprovidethenecessary isola-tionintheeventofafire.Topreventrecurrence theappro-priateengineering procedures havebeenprefacedtoaddressthisspecificelectrical isolation concern.NRCForm355Nl8802230067 880218PDRADOCK05000315SPDR NRCForm366A(943)LICENSEEEVENTREPORT(LER)TEXTCONTINUATION U.S.NUCLEARREGULATORY COMMISSION APPROVEOOMBNO.3150-0104 EXPIRES:8/31/85FACILITYNAME(I)'OCKETNUMBER(2)LERNUMBER(6)PAGE(3)YEAR~@@SEOUENTIAL NUMBERREVISIONNUMBERD.C.CookNuclearPlant-Unit1TEXT/lfmorospsso/sisr)eked, ososddilions///RCForm366A's/(I2)0500031587023010OF05Theprimarypurposeofthissupplemental reportistoprovideadditional information regarding thesequenceofeventsleadinguptothedetermination thattheeventwasreportable.
Conditions PriortoOccurrence (Conditions dateofdiscovery)
Unit1-Mode1(poweroperation)
-90percentReactorThermalPowerUnit2-Mode1(poweroperation)
-80percentReactorThermalPowerDescritionofEventOnNovember9,1987,duringaninvestigation intothefeasibility ofusingexistingReactorCoolantSystemWideRangeT-HotandT-Coldindications (EIIS/AB-TI) forRegulatory Guide1.97com-pliance,it wasdiscovered thatapotential problemcouldexistinvolving thefuses(EIIS/FU) requiredforisolation betweenthevariousLocalShutdownandIndication (LSI)panels(EIIS/PL)
(improperly locatedonUnit2andnotincludedintheexistingdesignonUnit1).OnDecember22,1987itwasconfirmed thatacondition existedthat,intheeventofafirelocaltoanLSIpanel,power(bothnormalandalternate) tosomeorallofthesameunits'emaining LSIpanelscouldbelost.Ifpowerwaslosttoallpanels,thoseindications available locallywouldbelost.Inaddition, allWideRangeT-HotandT-Coldindications, 1of4channelsofpressurizer levelindication (EIIS/AB-LI),
andbothtrainsoftheReactorVesselLevelIndication System(EIIS/AB-LI) wouldbelostinthecontrolroom.Thiscondition isnotconsistent withtherequirements of10CFR50,AppendixRandhasexistedsinceinitialinstallation oftheAppendixRmodifications (Unit1-September, 1985;Unit2-June,1986)'.Withtheexception ofthesub'jectLSIpanels,therewerenoinoperable components, systemsorstructures thatcontributed tothisevent.Thefollowing providesthereasonfortimebetween(1)thedate(November 9,1987)thattheconfiguration(i.e.,
apotential problemwiththeelectrical isolation betweenpowerfeedstoNRCFORM3ddA(983)
NRCForm366Au(94)3)LICENSEEEVENTREPORT(LER)TEXTCONTINUATION U.S.NUCLEARREGULATORY COMMISSION APPROVEOOMBNO.3150-0104 EXPIRES:6/31/95FACILITYNAME(I)'OCKETNUMBER(2)LERNUMBER(6)jSISEGUENTIAL AIPieoREVISIONNUMBER66'ONUMBERPAGE(3)D.C.CookNuclearPlant-Unit105000315TEXTillmorespsoeisrequired, usesddicionsl llRCForm3654's)(17)87-023-0103QF05DescritionofEvent-(Continued)
LocalShutdownIndication panels)wasinitially questioned and(2)thedate(December 22,1987)whentheknownproblemwasre-ported.Specifically, onNovember9,1987theengineerwhoiden-tifiedtheconcerninitiated aProblemReport.ProblemReportsareusedtodocumenteitherknownnonconformances orpotential nonconformances andtoassureproperinvestigation intothedocumented concern.ForthecasereportedinthisLER,theengineerlaterconcluded, onNovember9,1987,thattheconcernidentified ontheProblemReportwasnotaproblem(i.e.,acondition whichwascontrarytoregulatory requirements wasnotidentified).
Therefore, theengineerdidnotforwardtheProblemReporttomanagement.
Approximately seventoninedayslater,theengineer's supervisor questioned theengineeraboutthestatusoftheconcern.Atthattime(approximately, November18,1987)thesupervisor concluded thattheelectrical isolation concernmayhaveanimpactonregulatory (10CFR50,AppendixR)compliance.
Therefore, thesupervisor hadtheProblemReportforwarded totheappropriate management (ProblemAssessment Group),sothataninvestigation wouldbeconducted pursuanttotheprocedural requirements whichgovernsuchaninvestigation.
OnDecember21,1987engineering andlicensing reviewsconcluded thateventhoughcertainprocessvariables requiredby10CFR50,AppendixRcouldbelostincertainfirescenarios, sufficient alternative information wasstillavailable.
Therefore, itwasconcluded thataregulatory compliance problemdidnotexist.However,onDecember22,1987itwasconcluded thataproblemdidexist.Specifically, asinglefiremighteliminate theredundant Alternative ShutdownCapability instrumentation requiredby10CFR50AppendixR,SectionIII.L.Atthistime(December 22,1987),whenthisproblemwasfirstidentified asreportable:
(1)therequirements of10CFR50.72werefulfilled (1650hours)and(2)areportper10CFR50.73wasinitiated.
Insummary,onNovember9,1987,theengineerwhohadfirstquestioned theLSIpanelelectrical isolation, concluded thataproblemdidnotexist.Onapproximately November18,1987,theengineer's supervisor, throughconsultation withherassistant supervisor andalicensing
: engineer, concluded thattheconcernwarranted formalinvestigation.
OnDecember21,1987engineering andlicensing concluded thattherequirements ofAppendixRwerebeingfulfilled, inspiteofelectrical isolation concerns.
OnDecember22,1987,theconclusion wasreachedthatcertainconcernspost-fire processvariables (e.g.,T-HOTandT-COLD)couldnotbeassured.Therefore, appropriate reportability actionswereinitiated.
NRCFORM366A0)63I NRCForm366A(643)LICENSEEEVENREPORT(LER)TEXTCONTINUATION U.S.NUCLEARREOULATORY COMMISSION APPROVEDOMBNO.3150M(04EXPIRES:6/31/85FACILITYNAME(I)DOCKETNUMBER(3)LERNUMBER(6)y6ARQM;560U6NTIAL~W~i<5R5VI5I0NNUMSERi&rrNUMBERPACE(3)D.C.CookNuclearPlant-Unit1TEXT///moreepeee/IrequIred, ueeeddir)rrur//VRC Form3564'5/()7)0500031587-023-0104QF05CauseofEventThecauseoftheeventwasanoversight bydesignengineers inthedesignandverification processassociated withtheinitialAppendixRmodifications.
AnalsisofEventThecondition isnotconsistent withtherequirements of10CFR50,AppendixR,andassuch,isnotconsistent withourdesignbasis.Theeventhasbeendetermined reportable per10CFR50.73,(a)(2)(ii)(B).
AppendixRrequiresthatadequateinstrumentation beavailable toensuresafeshutdowninthecaseofasinglefire.IfafireatoneoftheLSIpanelshadledtothelossofpowertoallofoneUnits'SIpanels,WideRangeT-HotandT-Coldindications wouldhavebeenlost(bothlocalandcontrolroom).According toIEInformation Notice84-09,theseprocessvariables arerequ'ired forsafeshutdown.
However,sufficient information wouldhavebeenavailable totheoperatorforachieving safeshutdownintheuseofthein-corethermocouple indications and/ortheuseofmainsteampressureandsaturation temperature curves.IfpowerwaslosttoallLSIpanelsduetoafireatanyLSIpanellocation, allindications onallLSIpanelswouldbelost.However,withtheexception ofWideRangeT-HotandT-Cold,alloftheprocessvariables indicated locallyattheLSIpanelswouldnotberequiredlocallyduetotheiravailability inthecontrolroomandthefactthatafireatanyLSIpanellocationwouldnotrequireremoteshutdown.
Therefore, forthereasonsdetailedabove,ithasbeenconcluded thatthecondition reportedinthisLERrepresents neitherasignificant risktopublichealthandsafety,norasignificant degradation ofourAppendixRsafeshutdowncapability.
Corrective ActionsRovingfirewatcheswereassignedtotourtheaffectedareasonDecember22,1987(LSIpanellocations withinbothunits).Therovingfirewatcheswereupgradedtocontinuous firewatchesonDecember24,1987.Thesestepsweretakentoserveasaninterimcompensatory actionuntilthenecessary designchangescouldbeimplemented.
ForUnit2,designchangeswereimplemented December30,1987thatremovedtheimproperly locatedfusesandinstalled replacements toremedytheinadequacy.
ForUnit1,fuseswereinstalled onNRCFORM35@A(963)
NRCForm366A(94)3)LICENSEEEVENTREPORT(LER)TEXTCONTINUATION U.S.NUCLEARREGULATORY COMMISSION APPROVEDOMBNO.3(50-0I04EXPIRES:6/31i65FACILITYNAME('I)'OCKETNUMBER(3)LERNUMBER(6)YEARoSs'EGUENTIAL NUMBERio.REVISIONNUMBERPAGE(3)D.C.CookNuclearPlant-Unit1TEXTilfmorespeosisseqoired, useeddirionel NRCForm3654's)(17)0500031587-0230105OF05Corrective Actions-(Continued)
December29,1987.Theexistingconfiguration nowprovidestheelectrical isolation necessary intheeventofafire.Webelievethatthiscondition isanisolatedevent.Althoughconsideration of10CFR50,AppendixRelectrical isolation criteriaintheengineering anddesignprocessisrequired, additional emphasiswillbeplacedontheseelectrical isolation requirements.
Theappropriate engineering procedures, dealingwithAppendixRdesigndetails,havebeenprefaced(viaaletter)toincludethiselectrical isolation concern.Theletterwasreviewedduringamonthlytrainingsession(01/21/88) attendedbyelectrical engineering personnel.
FailedComonentIdentification NonePreviousSimilarEventsNoneNRCFORM366A(993I}}

Revision as of 09:24, 29 June 2018

LER 87-023-01:on 871109 Problem Discovered Re Fuses Required for Isolation Between Local Shutdown & Indication Panels. Problems Confirmed on 871222.Caused by Engineer Design Oversight.Design Changes made.W/880218 Ltr
ML17325A621
Person / Time
Site: Cook American Electric Power icon.png
Issue date: 02/18/1988
From: BEILMAN T P, SMITH W G
INDIANA MICHIGAN POWER CO. (FORMERLY INDIANA & MICHIG
To:
NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
References
RTR-REGGD-01.097, RTR-REGGD-1.097 IEIN-84-09, IEIN-84-9, LER-87-023-01, LER-87-23-1, NUDOCS 8802230067
Download: ML17325A621 (7)
v • d • e


Text

REGULATORY INFORMATION DISTRIBUTIQl'J SYSTEM(RIDS)ACCESSION NBR:8802230067 DOC.DATE:88/02/18NOTARIZED:

NODOCKET0FACIL:50-315DonaldC.CookNuclearPoeerPlant'nitiiIndiana505000315AUTH.NAMEAUTHORAFFILIATION BEILMANiT.P.IndianaMichiganPowerCo.(formerly Indiana8.MichiganEleSMITHiW.G.IndianaMichiganpowerCo.(formerly Indiana5MichiganEleRECIP.NAMERECIPIENT AFFILIATION

SUBJECT:

LER87-023-01:

on871109problemdiscovered refusesrequiredforisolation betweenlocalshutdoen8cindication panels.ProblemsconfiTmedon871222.Causedbgengineerdesignoversight.

Designchangesmode.W/880218ltr.DISTRIBUTION CODE:IE22DCOPIESRECEIVED:

LTRENCLSIZE:TITLE:50.73LicenseeEventReport(LER>iIncidentRptietc.RECIPIENTIDCODE/NAME PD3-3LAWIGGINGTQNi DCQPIESLTTRENCL11RECIPIENTIDCODE/NAME PD3-3PDCQPIESLTTRENCL11INTERNAL:

ACRSMICHELSON AEOD/DOAAEOD/DBP/ROAB ARM/DCTS/DAB NRR/DEBT/ADS NRR/DEST/ELB NRR/DEST/MEB NRR/DEST/PSB NRR/DEBT/SGB NRR/DLPG/GAB NRR/DREP/RAB BREGFILE02IBRGN3FILE0111101111111111ACRSMOELLERAEOD/DSP/NAS AEOD/DBP/TPAB DEDRONRR/DEBT/CEB NRR/DEBT/

ICSBNRR/DEBT/MTB NRR/DEST/RSB NRR/DLPG/HFB NRR/DOEA/E*B NRR/DREP/RPB NRR/PM*8/

ILRBRESTELFORD>JRES/DRPSDIR221111111111111111122111111EXTERNAL:

EG5GGROHiMHSTLOBBYWARDNRCPDRNSICMAYSiGFORDBLDGHOYiALPDRNSICHARRIS'111111TOTALNUMBEROFCOPIESREQUIRED:

LTTR46ENCL45 IndianaMichiganPowerCompanyCookNuclearPlantP.O.Box458Bridgman, MI491066164655901ZINDUNANlCHtGAMPODFebruary18,1988UnitedStatesNuclearRegulatory Commission DocumentControlDeskWashington, D.C.20555Operating LicenseDPR-58DocketNo.50-315DocumentControlManager:Inaccordance withthecriteriaestablished by10CFR50.73entitledLicenseeEventReortinSstem,thefollowing reportisbeingsubmitted:

87-023-01 Sincerely, W.G.Smith,Jr.PlantManagerWGS:afhAttachment cc:D.H.Williams, Jr.A.B.Davis,RegionIIIM.P.AlexichR.F.KroegerH.B.BruggerR.W.Jurgensen NRCResidentInspector J.F.Stang,NRCR.C.CallenG.Charnoff, Esq.DottieSherman,ANILibraryD.HahnINPOPNSRCA.A.BlindP.A.Barrett/P.

LauzauM~pN NRCForm345(943)LICENSEEEVENTREPORT(LER)US.NUCLEARREOULATOAY COMMISSION APPROVEDOMBNO.31500104EXPIRES:5/31/SBFACILITYNAME(I)D.C.CookNuclearPlant-Unit1DOCKETNUMBER(2)PAE305000315>OF05

"'"""Deficient DesignResultsinFailuretoProvideElectrical Isolation BetweenLocalShutdownandIndication PanelsMONTHOAYYEAREVENTDATE(5)LERNUMBER(5)YEARjPP~SEQUENTIAL NUMBERREVISIONNUMBERREPORTDATE(7)MONTHOAYYEAROTHERFACILITIES INVOLVED(SlDOCKETNUMBERIS) 050003FACILITYNAMESD.C.Cook-Unit21109878702301005000OPERATINQ MODE(9)POWERLEVEL00)09020402(B)20AOS(e)(l

)(I)20AOS(s)II)(S) 20AOS(e)(1)(ill) 20AOS(e)(1)(N)20AOS(~)(1)(v)20AOS(e)SOW(e)(I) 50.35(el(2) 50.73(e)(2)(I)50.73(e)(2)(5)50.73(e)(2)(llilLICENSEECONTACTFORTHISLER(12)50.73(e)(2)(N)50,73(sl(2)(v) 50.73(el(2)(vill 50.73(e)(2)(vllI)(AI50.73(e)(2)(vill)(BI 50,73(el(2)(rr)

THISREPORTISSUBMITTED PURSUANTT0THEREQUIREMENTS Of10CFR(IrfCnecltoneormoreOfthrfollovfinPI (1173.71(B)73.71(c)OTHER(SpecifyInAbrtreetbelowenrfInTest,HRCForm3SEAINAMET.P.BeilmanInstrumentation

&ControlDepartment Superintendent TELEPHONE NUMBERAREACODE616465-5901 COMPLETEONELINEFOREACHCOMPONENT FAILUREDESCRIBED INTHISREPORT(13)CAUSESYSTEMCOMPONENT MANUFAC-TURERREPORTABLE Ig+(p.'NoITO>>ROS:ROu%a.4@MID!gAPN'n......

Sk4CAUSESYSTEMCOMPONENT MANUFAC.TUREREPORTABLE TONPRDS'o&N"'Pno.-8oSUPPLEMENTAL REPORTEXPFCTED(14)EXPECTEDSUBMISSION DATE(15)MONTHOAYYEARYES(ifyrr,complereEXPECTEDSUSIeIISSIOH DATE)NOABSTRACTfLlmitto1400epecer,I.r.,rpprorrlmetrfy filtrrnelnpleeprcr typewritten Ilneel(IS)Theprimarypurposeofthissupplemental reportistoprovideadditional information regarding thesequenceofevents.OnNovember9,1987,duringareviewofaninvestigation con-cerningRegulatory Guide1.97compliance, itwasdiscovered thatapotential problemcouldexistinvolving thefusesrequiredforisolation betweenthevariousLocalShutdownandIndication (LSI)panels(improperly locatedonUnit2andnotincorporated intotheexistingdesignonUnit1).OnDecember22,1987itwasconfirmed thatacondition existedthat,intheeventofafirelocaltoaLSIpanel,power(bothnormalandalternate) tosomeorallofthesameunits'emaining panelscouldhavebeenlost.Thecauseoftheeventwasanoversight bydesignengineers inthedesignandverification processassociated withtheinitialAppendixRmodifications.

Firewatcheswereassignedtotourtheaffectedareas.Designchangeshavebeenimplemented whichprovidethenecessary isola-tionintheeventofafire.Topreventrecurrence theappro-priateengineering procedures havebeenprefacedtoaddressthisspecificelectrical isolation concern.NRCForm355Nl8802230067 880218PDRADOCK05000315SPDR NRCForm366A(943)LICENSEEEVENTREPORT(LER)TEXTCONTINUATION U.S.NUCLEARREGULATORY COMMISSION APPROVEOOMBNO.3150-0104 EXPIRES:8/31/85FACILITYNAME(I)'OCKETNUMBER(2)LERNUMBER(6)PAGE(3)YEAR~@@SEOUENTIAL NUMBERREVISIONNUMBERD.C.CookNuclearPlant-Unit1TEXT/lfmorospsso/sisr)eked, ososddilions///RCForm366A's/(I2)0500031587023010OF05Theprimarypurposeofthissupplemental reportistoprovideadditional information regarding thesequenceofeventsleadinguptothedetermination thattheeventwasreportable.

Conditions PriortoOccurrence (Conditions dateofdiscovery)

Unit1-Mode1(poweroperation)

-90percentReactorThermalPowerUnit2-Mode1(poweroperation)

-80percentReactorThermalPowerDescritionofEventOnNovember9,1987,duringaninvestigation intothefeasibility ofusingexistingReactorCoolantSystemWideRangeT-HotandT-Coldindications (EIIS/AB-TI) forRegulatory Guide1.97com-pliance,it wasdiscovered thatapotential problemcouldexistinvolving thefuses(EIIS/FU) requiredforisolation betweenthevariousLocalShutdownandIndication (LSI)panels(EIIS/PL)

(improperly locatedonUnit2andnotincludedintheexistingdesignonUnit1).OnDecember22,1987itwasconfirmed thatacondition existedthat,intheeventofafirelocaltoanLSIpanel,power(bothnormalandalternate) tosomeorallofthesameunits'emaining LSIpanelscouldbelost.Ifpowerwaslosttoallpanels,thoseindications available locallywouldbelost.Inaddition, allWideRangeT-HotandT-Coldindications, 1of4channelsofpressurizer levelindication (EIIS/AB-LI),

andbothtrainsoftheReactorVesselLevelIndication System(EIIS/AB-LI) wouldbelostinthecontrolroom.Thiscondition isnotconsistent withtherequirements of10CFR50,AppendixRandhasexistedsinceinitialinstallation oftheAppendixRmodifications (Unit1-September, 1985;Unit2-June,1986)'.Withtheexception ofthesub'jectLSIpanels,therewerenoinoperable components, systemsorstructures thatcontributed tothisevent.Thefollowing providesthereasonfortimebetween(1)thedate(November 9,1987)thattheconfiguration(i.e.,

apotential problemwiththeelectrical isolation betweenpowerfeedstoNRCFORM3ddA(983)

NRCForm366Au(94)3)LICENSEEEVENTREPORT(LER)TEXTCONTINUATION U.S.NUCLEARREGULATORY COMMISSION APPROVEOOMBNO.3150-0104 EXPIRES:6/31/95FACILITYNAME(I)'OCKETNUMBER(2)LERNUMBER(6)jSISEGUENTIAL AIPieoREVISIONNUMBER66'ONUMBERPAGE(3)D.C.CookNuclearPlant-Unit105000315TEXTillmorespsoeisrequired, usesddicionsl llRCForm3654's)(17)87-023-0103QF05DescritionofEvent-(Continued)

LocalShutdownIndication panels)wasinitially questioned and(2)thedate(December 22,1987)whentheknownproblemwasre-ported.Specifically, onNovember9,1987theengineerwhoiden-tifiedtheconcerninitiated aProblemReport.ProblemReportsareusedtodocumenteitherknownnonconformances orpotential nonconformances andtoassureproperinvestigation intothedocumented concern.ForthecasereportedinthisLER,theengineerlaterconcluded, onNovember9,1987,thattheconcernidentified ontheProblemReportwasnotaproblem(i.e.,acondition whichwascontrarytoregulatory requirements wasnotidentified).

Therefore, theengineerdidnotforwardtheProblemReporttomanagement.

Approximately seventoninedayslater,theengineer's supervisor questioned theengineeraboutthestatusoftheconcern.Atthattime(approximately, November18,1987)thesupervisor concluded thattheelectrical isolation concernmayhaveanimpactonregulatory (10CFR50,AppendixR)compliance.

Therefore, thesupervisor hadtheProblemReportforwarded totheappropriate management (ProblemAssessment Group),sothataninvestigation wouldbeconducted pursuanttotheprocedural requirements whichgovernsuchaninvestigation.

OnDecember21,1987engineering andlicensing reviewsconcluded thateventhoughcertainprocessvariables requiredby10CFR50,AppendixRcouldbelostincertainfirescenarios, sufficient alternative information wasstillavailable.

Therefore, itwasconcluded thataregulatory compliance problemdidnotexist.However,onDecember22,1987itwasconcluded thataproblemdidexist.Specifically, asinglefiremighteliminate theredundant Alternative ShutdownCapability instrumentation requiredby10CFR50AppendixR,SectionIII.L.Atthistime(December 22,1987),whenthisproblemwasfirstidentified asreportable:

(1)therequirements of10CFR50.72werefulfilled (1650hours)and(2)areportper10CFR50.73wasinitiated.

Insummary,onNovember9,1987,theengineerwhohadfirstquestioned theLSIpanelelectrical isolation, concluded thataproblemdidnotexist.Onapproximately November18,1987,theengineer's supervisor, throughconsultation withherassistant supervisor andalicensing

engineer, concluded thattheconcernwarranted formalinvestigation.

OnDecember21,1987engineering andlicensing concluded thattherequirements ofAppendixRwerebeingfulfilled, inspiteofelectrical isolation concerns.

OnDecember22,1987,theconclusion wasreachedthatcertainconcernspost-fire processvariables (e.g.,T-HOTandT-COLD)couldnotbeassured.Therefore, appropriate reportability actionswereinitiated.

NRCFORM366A0)63I NRCForm366A(643)LICENSEEEVENREPORT(LER)TEXTCONTINUATION U.S.NUCLEARREOULATORY COMMISSION APPROVEDOMBNO.3150M(04EXPIRES:6/31/85FACILITYNAME(I)DOCKETNUMBER(3)LERNUMBER(6)y6ARQM;560U6NTIAL~W~i<5R5VI5I0NNUMSERi&rrNUMBERPACE(3)D.C.CookNuclearPlant-Unit1TEXT///moreepeee/IrequIred, ueeeddir)rrur//VRC Form3564'5/()7)0500031587-023-0104QF05CauseofEventThecauseoftheeventwasanoversight bydesignengineers inthedesignandverification processassociated withtheinitialAppendixRmodifications.

AnalsisofEventThecondition isnotconsistent withtherequirements of10CFR50,AppendixR,andassuch,isnotconsistent withourdesignbasis.Theeventhasbeendetermined reportable per10CFR50.73,(a)(2)(ii)(B).

AppendixRrequiresthatadequateinstrumentation beavailable toensuresafeshutdowninthecaseofasinglefire.IfafireatoneoftheLSIpanelshadledtothelossofpowertoallofoneUnits'SIpanels,WideRangeT-HotandT-Coldindications wouldhavebeenlost(bothlocalandcontrolroom).According toIEInformation Notice84-09,theseprocessvariables arerequ'ired forsafeshutdown.

However,sufficient information wouldhavebeenavailable totheoperatorforachieving safeshutdownintheuseofthein-corethermocouple indications and/ortheuseofmainsteampressureandsaturation temperature curves.IfpowerwaslosttoallLSIpanelsduetoafireatanyLSIpanellocation, allindications onallLSIpanelswouldbelost.However,withtheexception ofWideRangeT-HotandT-Cold,alloftheprocessvariables indicated locallyattheLSIpanelswouldnotberequiredlocallyduetotheiravailability inthecontrolroomandthefactthatafireatanyLSIpanellocationwouldnotrequireremoteshutdown.

Therefore, forthereasonsdetailedabove,ithasbeenconcluded thatthecondition reportedinthisLERrepresents neitherasignificant risktopublichealthandsafety,norasignificant degradation ofourAppendixRsafeshutdowncapability.

Corrective ActionsRovingfirewatcheswereassignedtotourtheaffectedareasonDecember22,1987(LSIpanellocations withinbothunits).Therovingfirewatcheswereupgradedtocontinuous firewatchesonDecember24,1987.Thesestepsweretakentoserveasaninterimcompensatory actionuntilthenecessary designchangescouldbeimplemented.

ForUnit2,designchangeswereimplemented December30,1987thatremovedtheimproperly locatedfusesandinstalled replacements toremedytheinadequacy.

ForUnit1,fuseswereinstalled onNRCFORM35@A(963)

NRCForm366A(94)3)LICENSEEEVENTREPORT(LER)TEXTCONTINUATION U.S.NUCLEARREGULATORY COMMISSION APPROVEDOMBNO.3(50-0I04EXPIRES:6/31i65FACILITYNAME('I)'OCKETNUMBER(3)LERNUMBER(6)YEARoSs'EGUENTIAL NUMBERio.REVISIONNUMBERPAGE(3)D.C.CookNuclearPlant-Unit1TEXTilfmorespeosisseqoired, useeddirionel NRCForm3654's)(17)0500031587-0230105OF05Corrective Actions-(Continued)

December29,1987.Theexistingconfiguration nowprovidestheelectrical isolation necessary intheeventofafire.Webelievethatthiscondition isanisolatedevent.Althoughconsideration of10CFR50,AppendixRelectrical isolation criteriaintheengineering anddesignprocessisrequired, additional emphasiswillbeplacedontheseelectrical isolation requirements.

Theappropriate engineering procedures, dealingwithAppendixRdesigndetails,havebeenprefaced(viaaletter)toincludethiselectrical isolation concern.Theletterwasreviewedduringamonthlytrainingsession(01/21/88) attendedbyelectrical engineering personnel.

FailedComonentIdentification NonePreviousSimilarEventsNoneNRCFORM366A(993I

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