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{{#Wiki_filter:CATEGORYREGULATOINFORMATIONDISTRIBUTIONTEM(RIDS)ACCESSIONNBR:9706050294DOC.DATE:97/05/30NOTARIZED:NODOCKETFACZL:50;315DonaldC.CookNuclearPowerPlant,Unit1,IndianaM05000315tAOTH.QAME'UTHORAFFILIATIONFINZSSZ,M.IndianaMichiganPowerCo.(formerlyIndiana&MichiganEleBLIND,A.A.IndianaMichiganPowerCo.(formerlyIndiana&MichiganEleRECIP.NAMERECIPIENTAFFILIATION
{{#Wiki_filter:CATEGORYREGULATOINFORMATION DISTRIBUTION TEM(RIDS)ACCESSION NBR:9706050294 DOC.DATE:
97/05/30NOTARIZED:
NODOCKETFACZL:50;315 DonaldC.CookNuclearPowerPlant,Unit1,IndianaM05000315tAOTH.QAME
'UTHORAFFILIATION FINZSSZ,M.
IndianaMichiganPowerCo.(formerly Indiana&MichiganEleBLIND,A.A.
IndianaMichiganPowerCo.(formerly Indiana&MichiganEleRECIP.NAME RECIPIENT AFFILIATION


==SUBJECT:==
==SUBJECT:==
LER97-006-01:on970327,equipmentincontainmentrenderedinoperableduetocrackedflooduptubeswasidentified.Causedbyworkpracticesthatresultedintwoseparatetypesoffailures.Criticalareasinspected.W/970530ltr.DISTRIBUTIONCODE:.IE22TCOPIESRECEIVED:LTRENCLSIZE:TITLE:50.73/50.9LicenseeEventReport(LER),IncidentRpt,etc.NOTES:EINTERNAL:RECIPIENTIDCODE/NAMEPD3-3PDFILECENTERNRR/DRCH/HHFBNRR/DRCH/HOLBNRR/DRPM/PECBNRR/DSSA/SRXBRGN3FILE01COPIESLTTRENCL112211111111111111RECIPIENTIDCODE/NAMEHICKMAN,JAEOD/SPD/RRABNRR/DE/ECGBNRR/DE/EMEBNRR/DRCH/HICBNRR/DRCH/HQMBNRR/DSSA/SPLBRES/DET/EIBCOPIESLTTRENCL11111111111111l,lDEXTERNAL:LSTLOBBYWARDNOACPOORE,W.NRCPDR1111~11LITCOBRYCE,JHNOACQUEENER,DSNUDOCSFULLTXT111111UNNOTETOALL"RIDS"RECIPIENTS:PLEASEHELPUSTOREDUCEWASTETHCONTACTTHEDOCUMENTCONTROLDESKiROOMOWFN5D-5(EXT.415-2083)TOELIMINATEYOURNAMEFROMDISTRIBUTIONLISTSFORDOCUMENTSYOUDON'TNEED!FULLTEXTCONVERSIONREQUIREDTOTALNUMBEROFCOPIESRF"ZRED:LTTR24ENC'4 IndianaMichiganPowerCompanyCookNuclearPianiOneCookPlaceBridgman,MI49106IMay30,1997UnitedStatesNuclearRegulatoryCommissionDocumentControlDeskWashington,DC20555OperatingLicensesDPR-58DocketNo.50-315DocumentControlManager:Inaccordancewiththecriteriaestablishedby10CFR50.73entitledLicenseeEvent~lhfI'gpibig1iltd.'7-006-01Sincerely,A.A.BlindSiteVicePresidentI(ImbdAttachmentc:A.B.Beach,RegionIIIE.E.FitzpatrickP.A.BarrettS.J.BrewerJ.R.PadgettD.HahnRecordsCenter,INPONRCResidentInspector9706050294970530PDRADQCK050003i58PDRllllllllllllllllllllllliilllillflillli
LER97-006-01:on 970327,equipment incontainment renderedinoperable duetocrackedflooduptubeswasidentified.
Causedbyworkpractices thatresultedintwoseparatetypesoffailures.
Criticalareasinspected.W/970530 ltr.DISTRIBUTION CODE:.IE22TCOPIESRECEIVED:LTR ENCLSIZE:TITLE:50.73/50.9 LicenseeEventReport(LER),IncidentRpt,etc.NOTES:EINTERNAL:
RECIPIENT IDCODE/NAME PD3-3PDFILECENTERNRR/DRCH/HHFB NRR/DRCH/HOLB NRR/DRPM/PECB NRR/DSSA/SRXB RGN3FILE01COPIESLTTRENCL112211111111111111RECIPIENT IDCODE/NAME HICKMAN,J AEOD/SPD/RRAB NRR/DE/ECGB NRR/DE/EMEB NRR/DRCH/HICB NRR/DRCH/HQMB NRR/DSSA/SPLB RES/DET/EIB COPIESLTTRENCL11111111111111l,lDEXTERNAL:
LSTLOBBYWARDNOACPOORE,W.NRCPDR1111~11LITCOBRYCE,JHNOACQUEENER,DS NUDOCSFULLTXT111111UNNOTETOALL"RIDS"RECIPIENTS:
PLEASEHELPUSTOREDUCEWASTETHCONTACTTHEDOCUMENTCONTROLDESKiROOMOWFN5D-5(EXT.
415-2083)
TOELIMINATE YOURNAMEFROMDISTRIBUTION LISTSFORDOCUMENTS YOUDON'TNEED!FULLTEXTCONVERSION REQUIREDTOTALNUMBEROFCOPIESRF"ZRED:LTTR24ENC'4 IndianaMichiganPowerCompanyCookNuclearPianiOneCookPlaceBridgman, MI49106IMay30,1997UnitedStatesNuclearRegulatory Commission DocumentControlDeskWashington, DC20555Operating LicensesDPR-58DocketNo.50-315DocumentControlManager:Inaccordance withthecriteriaestablished by10CFR50.73entitledLicenseeEvent~lhfI'gpibig1iltd.'7-006-01 Sincerely, A.A.BlindSiteVicePresident I(ImbdAttachment c:A.B.Beach,RegionIIIE.E.Fitzpatrick P.A.BarrettS.J.BrewerJ.R.PadgettD.HahnRecordsCenter,INPONRCResidentInspector 9706050294 970530PDRADQCK050003i58PDRllllllllllllllllllllllliilllill flillli


NRCFORM366(5-92)S.NUCLEARREGUULTORYCOMMISSIONLICENSEEEVIDENTREPORT(LER)ROVEDBYOHBNO.3150-0104EXPIRES5/31/95ESTIMATEDBURDENPERRESPONSETOCOMPLYlllTHTHIINFORMATION'COLLECTIOMREQUEST:50.0MRS.-FORNARCOMMENTSREGARDIHGBURDENESTIMATEToTHINFORMATIONANDRECORDSMANAGEMENTBRANCH(MMB7714),U.STNUCLEARREGULATORYCOMMISSIONNASHIMGTON,DC20555-0001,ANDTOTHEPAPERMORREDUCTIONPROJECT(3150.0104),OFFICE0MANAGEMENTANDBUDGETNASHINGTOHDC20503.'ACILITYNAME(1),OonaldC.CookNuclearPlant-Unit1DOCKETNUMBER(2)50.315Page1of10TITLE(4)EuimentinContainmentRenderedlnoerableDuetoCrackedFlooduTubesMONTHDAYYEAREVENTDATE5YEARLERNUMBER6SEQUENTIALMUHBERREVISIONNUMBERMOHTHDAYYEARREPORTDATE7FACILITYNAMECook-Unit2DOCKETNUHBER50-316OTHERFACILITIESINVOLVED8279700601053097FACILITYNAMEDOCKETNUMBEROPERATINGMODE(9)P(XJERLEVEL(10)0THISREPORTISSUBMITTEDPURSUANT20.2201(b)20.2203a120.2203(a)(2)(i)20.2203a2ii20.2203(a)(2)(iii)20.2203(a)(2)(iv)?0.2203(a)(2)(v)20.2203(a){3)(i)20.2203a3ii20.2203(a)(4)50.36c150.36(c)(2)50.73(a)(2)(i)50.73(a)(2)(ii)50.73(a)(2){iii)5073a)(2iv'0.73(a)(2)(v)50.73a2vii50.73(a)(2)(viii)(A)50.73(a)(2)(viii)(B)50.73(a)(2)(x)73.71(b)73.7toOTHER(SpecifyinAbstractbetouandinText,NRCForm366A)TOTHEREQUIREMENTSOFt0CFR:CheckoneormorettNAMELICENSEECONTACTFORTHISLER12Mr.MikeFinissi,SystemEngineering-ElectricalSupervisorTELEPHONENUMBER(IncludeAreaCode)616/465-5901,x2830COMPLETEONELINEFOREACHCOMPONENTFAILUREDESCRIBEDINTHISREPORT13CAUSESYSTEMCOMPOHEHTMANUFACTURERREPORTABLETONPRDSCAUSESYSTEHCOMPOHEHTMANUFACTURERREPORTABLETONPRDSSUPPLEMENTALREPORTEXPECTED14YES(Ifyes,completeEXPECTEDSUBMISSIOHDATE).XHOEXPECTEDSUBMISSIONDATE(15)MONTHDAYYEARABSTRACT(Limitto1400spaces,i.e.,approximately15single-spacedtypevrittentines)(16)ThisLERrevisionisbeingsubmittedtoprovideadditionalinformationregardingthesafetysignificanceandtherootcausedeterminationforcrackedilooduptubes(FUTS)foundinCookUnits1and2.Duringaninspectionoffiooduptubesformoistureintrusion,3FUTSwiththruwalldefectswereidentified.Asaresult,pro-activemeasuresweretakentoinspecttheremainingUnit1FUTS.ThisresultedlntheidentificationofsixadditionalthruwalldefectsinUnit1.Asaresult,Unit2FUTswereinspected,and2crackedtubeswerefound.Ofthe11totaldamagedtubes,Unit1contained7FUTSandUnit2contained1FUTwithanassociatedcircuitthatisneededforacddentmitigationorpostacddentmonitoring.OnMarch23theUnit2conditionwasreportedunder10CFR50.72(b)(1)(ii).OnMarch27Unit1conditionwasreportedunder10CFR50.72(b)(2)g.ENSnotificationsweremadeforboth.Thedamagehasbeenattributedtoworkpracticesthatresultedintwodifferenttypesoffailures-materialstresscracksandrandomarcstrikes,mostprobablyearlyinplantNe.AlldamagedUnit1EQFUTShavebeenreplacedandbothUnit2tubeshavebeenreplaced.Topreventthecracksduetoinstallationpracticesfromreoccurring,theCookPlantFUTInstallationWorkInstructionswillbemodifiedtocontainadditionalguidance.WeldingpracticeshavebeensuflidentlyenhancedsincetheearlyportionoftheplantlifetopredudearestrikesonFUTS.InspectionsoftheFUTSfordamagewillalsobeperformedatthebeginningandtheendoftherefuelingoutagesuntilassuranceisreachedthatnofurtherproblemswerefound.Postulatedfailuresthatcouldresultfromthecrackedflooduptubeswereevaluatedandfoundnottopresentasignificanriskwithregardtotheprotectionofthepublichealthandsafety.
NRCFORM366(5-92)S.NUCLEARREGUULTORY COMMISSION LICENSEEEVIDENTREPORT(LER)ROVEDBYOHBNO.3150-0104 EXPIRES5/31/95ESTIMATED BURDENPERRESPONSETOCOMPLYlllTHTHIINFORMATION'COLLECTIOM REQUEST:50.0MRS.-FORNARCOMMENTSREGARDIHG BURDENESTIMATE ToTHINFORMATION ANDRECORDSMANAGEMENT BRANCH(MMB7714),U.STNUCLEARREGULATORY COMMISSION NASHIMGTON, DC20555-0001, ANDTOTHEPAPERMORREDUCTION PROJECT(3150.0104),
NRCFORH366A~SNUCLEARREGULATORYC(mHISSIONLICENSEE&/ENTCONTINUATIONtPPROVEDBYOHB'O.3150.0104EXPIRES5/31/95ESTIHATEDBURDENPERRESPONSETOCOHPLY'WITHTHISIHFORHATIONCOLLECTIONREQUEST:50.0NRS.'ORNARDCOHHEHTSREGARDINGBURDENESTIHATETOTHEINFORHATIONANDRECORDSHANAGEHENT'RANCH'HNBB7714),U.S.NUCLEARREGULATORYCOHHISSION,NASHINGTON,DC20555-0001,ANDTOTHEPAPERIJORi(REDUCTIONPROJECT(3150-0104)~OFFICEOFHANAGEHENTANDBUDGETMASNINGTONDC20503.FACILITYNAÃE1CookNuclearPlant-Unit1TEXT(ifserespaceisrequired.useadditicnaliaCFora366A's)(17)50-315LERNUHBER6'EARSEQUENTIAL97-006REVISION01'PAGE32OF10ConditionsPriortoOccurrenceUnit1wasinMode6,RefuelingUnit2wasinMode1,PowerOperation,at100percentRatedThermalPowerDescritlonofEventElectricalpenetrationsattheD.C.CookNuclearplantarelocatedbelowthepredictedfloodinglevelinsidecontainmentfollowingalossofcoolantaccident.Asaresult,safetyrelatedcablesareroutedthroughstainlesssteeltubes,knownasflooduptubes,whichpreventthewaterinthecontainmentfromcontactingthecables.Thisprecautionisnecessarybecausetheelectricalcableshavenotbeenenvironmentallyqua1ifiedforsubmergenceinwater.AllKatponwiresbelowflooduplevelsneededforEQarecontainedinaflooduptube.ThereisnootherEQequipmentbelowflooduplevelwhichneedsflooduptubestomaintainitsqualification.AsaresultofLER316/96-006-00,whichwaswrittentodocumentthediscoveryofmoistureintrusionintoFUTsduringUnit2's1996refuelingoutage,onethirdofUnit1'sFUTswereinspectedformoistureintrusionduringits1997refuelingoutage.Duringtheflooduptubeinspection,ninetubesinUnit1werefoundtohavecrackswhichwouldallowwaterintrusionfollowingalossofcoolantaccident.AsaresultoftheUnit1findings,theflooduptubesinUnit2wereinspected,andtwocrackedtubeswerediscovered.ThecablesthatarecontainedinsidetheflooduptubesareKaptoninsulated,andareviewofpartialtestdataforKaptoninsulatedwiresinhighpHsolutionshasledtotheconclusionthatcablefailuresmayoccuraftertw'ohoursofsubmergenceinthehighpHsolution(9to10)thatwouldfloodthelowercontainmentfollowingalossofcoolantaccident.TheUnit1tubeswereinspectedduringtheperiodMarch16,1997throughMarch23,1997.Followingtheinspection,thefollowingequipmentwhichisrequiredforaccidentmitigationorpostaccidentmonitoringwasidentifiedasadverselyimpactedbytheexistenceofacrackedfiooduptube:1-8LP-1321-BLP-1421-NTR-1401-NTR-2401-HR-11-VMO-102SteamGeneratorthreenarrowrange(EIIS/IP-LT)leveltransmitterSteamGeneratorfournarrowrange(EIIS/IP-LT)leveltransmitterReactorcoolantloop4hotlegwide(EIIS/TR)rangetemperaturerecorderthermalsensorReactorcoolantloop4coldlegwide(EIIS/TR)rangetemperaturerecorderthermalsensorHydrogenRecombiner(EIIS/BB-RCB)ContainmentHydrogenSkimmer(EIIS/BB-IV)ventilationfanHV-CEQ-2suctionshutoffvalve  
OFFICE0MANAGEMENT ANDBUDGETNASHINGTOH DC20503.'ACILITY NAME(1),OonaldC.CookNuclearPlant-Unit1DOCKETNUMBER(2)50.315Page1of10TITLE(4)EuimentinContainmentRenderedlno erableDuetoCrackedFloodu TubesMONTHDAYYEAREVENTDATE5YEARLERNUMBER6SEQUENTIAL MUHBERREVISIONNUMBERMOHTHDAYYEARREPORTDATE7FACILITYNAMECook-Unit2DOCKETNUHBER50-316OTHERFACILITIES INVOLVED8279700601053097FACILITYNAMEDOCKETNUMBEROPERATING MODE(9)P(XJERLEVEL(10)0THISREPORTISSUBMITTED PURSUANT20.2201(b) 20.2203a120.2203(a)(2)(i) 20.2203a2ii20.2203(a)(2)(iii) 20.2203(a)(2)(iv)
?0.2203(a)(2)(v) 20.2203(a){3)(i) 20.2203a3ii20.2203(a)(4) 50.36c150.36(c)(2) 50.73(a)(2)(i) 50.73(a)(2)(ii) 50.73(a)(2){iii) 5073a)(2iv'0.73(a)(2)(v) 50.73a2vii50.73(a)(2)(viii)(A) 50.73(a)(2)(viii)(B) 50.73(a)(2)(x) 73.71(b)73.7toOTHER(SpecifyinAbstractbetouandinText,NRCForm366A)TOTHEREQUIREMENTS OFt0CFR:CheckoneormorettNAMELICENSEECONTACTFORTHISLER12Mr.MikeFinissi,SystemEngineering
-Electrical Supervisor TELEPHONE NUMBER(IncludeAreaCode)616/465-5901, x2830COMPLETEONELINEFOREACHCOMPONENT FAILUREDESCRIBED INTHISREPORT13CAUSESYSTEMCOMPOHEHT MANUFACTURER REPORTABLE TONPRDSCAUSESYSTEHCOMPOHEHT MANUFACTURER REPORTABLE TONPRDSSUPPLEMENTAL REPORTEXPECTED14YES(Ifyes,completeEXPECTEDSUBMISSIOH DATE).XHOEXPECTEDSUBMISSION DATE(15)MONTHDAYYEARABSTRACT(Limitto1400spaces,i.e.,approximately 15single-spaced typevritten tines)(16)ThisLERrevisionisbeingsubmitted toprovideadditional information regarding thesafetysignificance andtherootcausedetermination forcrackedilooduptubes(FUTS)foundinCookUnits1and2.Duringaninspection offiooduptubesformoistureintrusion, 3FUTSwiththruwalldefectswereidentified.
Asaresult,pro-activemeasuresweretakentoinspecttheremaining Unit1FUTS.Thisresultedlntheidentification ofsixadditional thruwalldefectsinUnit1.Asaresult,Unit2FUTswereinspected, and2crackedtubeswerefound.Ofthe11totaldamagedtubes,Unit1contained 7FUTSandUnit2contained 1FUTwithanassociated circuitthatisneededforacddentmitigation orpostacddentmonitoring.
OnMarch23theUnit2condition wasreportedunder10CFR50.72(b)(1)(ii).
OnMarch27Unit1condition wasreportedunder10CFR50.72(b)(2)g.
ENSnotifications weremadeforboth.Thedamagehasbeenattributed toworkpractices thatresultedintwodifferent typesoffailures-material stresscracksandrandomarcstrikes,mostprobablyearlyinplantNe.AlldamagedUnit1EQFUTShavebeenreplacedandbothUnit2tubeshavebeenreplaced.
Topreventthecracksduetoinstallation practices fromreoccurring, theCookPlantFUTInstallation WorkInstructions willbemodifiedtocontainadditional guidance.
Weldingpractices havebeensuflidently enhancedsincetheearlyportionoftheplantlife topredudearestrikesonFUTS.Inspections oftheFUTSfordamagewillalsobeperformed atthebeginning andtheendoftherefueling outagesuntilassurance isreachedthatnofurtherproblemswerefound.Postulated failuresthatcouldresultfromthecrackedflooduptubeswereevaluated andfoundnottopresentasignifican riskwithregardtotheprotection ofthepublichealthandsafety.
NRCFORH366A~SNUCLEARREGULATORY C(mHISSIONLICENSEE&/ENTCONTINUATION tPPROVEDBYOHB'O.3150.0104 EXPIRES5/31/95ESTIHATED BURDENPERRESPONSETOCOHPLY'WITHTHISIHFORHATION COLLECTION REQUEST:50.0NRS.'ORNARDCOHHEHTSREGARDING BURDENESTIHATETOTHEINFORHATION ANDRECORDSHANAGEHENT'RANCH'HNBB 7714),U.S.NUCLEARREGULATORY COHHISSION, NASHINGTON, DC20555-0001, ANDTOTHEPAPERIJORi(
REDUCTION PROJECT(3150-0104)
~OFFICEOFHANAGEHENT ANDBUDGETMASNINGTON DC20503.FACILITYNAÃE1CookNuclearPlant-Unit1TEXT(ifserespaceisrequired.
useadditicnal iaCFora366A's)(17)50-315LERNUHBER6'EARSEQUENTIAL 97-006REVISION01'PAGE32OF10Conditions PriortoOccurrence Unit1wasinMode6,Refueling Unit2wasinMode1,PowerOperation, at100percentRatedThermalPowerDescritlonofEventElectrical penetrations attheD.C.CookNuclearplantarelocatedbelowthepredicted floodinglevelinsidecontainment following alossofcoolantaccident.
Asaresult,safetyrelatedcablesareroutedthroughstainless steeltubes,knownasflooduptubes,whichpreventthewaterinthecontainment fromcontacting thecables.Thisprecaution isnecessary becausetheelectrical cableshavenotbeenenvironmentally qua1ified forsubmergence inwater.AllKatponwiresbelowflooduplevelsneededforEQarecontained inaflooduptube.ThereisnootherEQequipment belowflooduplevelwhichneedsflooduptubestomaintainitsqualification.
AsaresultofLER316/96-006-00, whichwaswrittentodocumentthediscovery ofmoistureintrusion intoFUTsduringUnit2's1996refueling outage,onethirdofUnit1'sFUTswereinspected formoistureintrusion duringits1997refueling outage.Duringtheflooduptubeinspection, ninetubesinUnit1werefoundtohavecrackswhichwouldallowwaterintrusion following alossofcoolantaccident.
AsaresultoftheUnit1findings, theflooduptubesinUnit2wereinspected, andtwocrackedtubeswerediscovered.
Thecablesthatarecontained insidetheflooduptubesareKaptoninsulated, andareviewofpartialtestdataforKaptoninsulated wiresinhighpHsolutions hasledtotheconclusion thatcablefailuresmayoccuraftertw'ohoursofsubmergence inthehighpHsolution(9to10)thatwouldfloodthelowercontainment following alossofcoolantaccident.
TheUnit1tubeswereinspected duringtheperiodMarch16,1997throughMarch23,1997.Following theinspection, thefollowing equipment whichisrequiredforaccidentmitigation orpostaccidentmonitoring wasidentified asadversely impactedbytheexistence ofacrackedfiooduptube:1-8LP-1321-BLP-142 1-NTR-140 1-NTR-240 1-HR-11-VMO-102SteamGenerator threenarrowrange(EIIS/IP-LT) leveltransmitter SteamGenerator fournarrowrange(EIIS/IP-LT) leveltransmitter Reactorcoolantloop4hotlegwide(EIIS/TR) rangetemperature recorderthermalsensorReactorcoolantloop4coldlegwide(EIIS/TR) rangetemperature recorderthermalsensorHydrogenRecombiner (EIIS/BB-RCB)
Containment HydrogenSkimmer(EIIS/BB-IV) ventilation fanHV-CEQ-2suctionshutoffvalve  


HRCFORH366A.S.NUCLEARREGULATORYCOXHISSIOHLICENSEEZWHNTCONTINUATION&PROVEDBYQS'NO.3150-0104EXPIRES5/31/95ESTIHATEDBURDENPERRESPONSE'TOCOHPLYMITHTHISINFORHATIONCOLLECTIONREQUEST:50.0HRS.FORMARDCOHHEHTSREGARDIHGBURDENESTIMATETOTHEIHFORHATIOHAHDRECORDSHANAGEHEHT.BRANCH(HHBB7714),U.S.NUCLEARREGULATORYCOHHISSIOHgMASHINGTON,DC20555-0001,AND-TOTHEPAPERMORKREDUCTIONPROJECt(3150-0104),OFFICEOFHANAGEHENTANDBUDGETMASHIHGTOHDC20503;,FACILITYMAKE1CookNuclearPlant-Unit150-315LERHUHBER6YEARSEQUEHTIAL97-006REVISION01~I~t4rraua3OF10TEXT((fcerespaceisrequ(red.useaddit(onalNRCForm366A's)(17)DescritionofEventcont'd1-NSO-021ReactorCoolantSystempost-accident(EIIS/AB-VTV)venttrainAsolenoidvalve1-IMO-315EastRHRandNorthSafetyInjectionto(EIIS/BO-INV)reactorcoolantloops1and4hotlegsshutoffvalve1-IMO-316EastRHRandNorthSafetyInjectionto(EIIS/BO-INV)reactorcoolantloops1and4coldlegsshutoffvalve1-IMO-325WestRHRandsouthsafetyinjectionto(EIIS/BO-INV)reactorcoolantloops2and3hotlegsshutoffvalve1-NMO-151PressurizerreliefvalveNRV-151(EIIS/AB-ISV)upstreamshutoffvalve1-33-NRV-153PressurizertrainApressurereliefvalveNRV-153closelimitswitchTheUnit2flooduptubeswereinspectedonMarch23,1997.Atthattime,acrackwasfoundintheflooduptube2-IP3-3.Thisflooduptubecontainsacablewhichsuppliespowertooneoftwocontainmentrecirculation(CEQ)fans(EIIS/BB-FAN).TheCEQfansoperatelongtermfollowingalossofcoolantaccident,andabsentqualificationdataforwatersubmergence,continuedoperationoftheimpactedCEQfancouldnotbeguaranteed.CauseoftheEventThetubedamagehasbeenattributedtoworkpracticesthatresultedintwoseparatetypesoffailures-materialstresscracksandrandomarcstrikes,mostprobablyearlyintheplantlife.Inthreeisolatedinstances,unrelatedtothematerialstresscracks,thetubeexhibitedholesinthetubeapproximately1/8"-1/4"wide.Theseholeshadaburnedappearancesuchthattheymayhavebeencausedbyweldingactivitiesinthevicinityoftheflooduptubes.Theothercauseisduetolocalizedstressestothematerialatthepointwherethetubetransitionsfromflexibletoarigidconfiguration.Thecausalanalysisevaluatedthebasictubeconstruction,inspecteddamagedtubes,andperformedaninspectionontheinstallationintheannulus.Theflooduptubeconstructionisastandardsingle-plyhelicalcorrugatedbellowsthatisconstructedfromaType321stainlesssteel.BothendsoftheflooduptubeareweldedtoaType304stainlesssteelfittingwithmalethreads.Thefittingsconstitutearigidpointwhilethebellowsthemselvesareaflexiblemember.Thistypeofconstructionallowsthetubetoflexuniformlythroughoutitsentirelengthexceptatthepointwhereitconnectstothefittings.
HRCFORH366A.S.NUCLEARREGULATORY COXHISSIOHLICENSEEZWHNTCONTINUATION
HRCFORN366A.S.NUCLEARREGUULTORYCOXNISSIOMLICENSEELWENTCONTINUATIONROVEDBYONBNO.3150-01,04EXPIRES5/31/95ESTINATEDBURDENPERRESPOHSETO'COHPLYMITHTHISIHFORHATIOHCOLLECTIOHREQUEST:50.0NRS;FORNARDCONHEHTSREGARDINGBURDENESTINATETOTHEINFORNATIONANDRECORDSNANAGEHEHTBRANCH"(NHBB7714),U.S.NUCLEARREGULATORYCOHHISSION,IIASHIHGTON,DC20555-0001,AHDTOTHEPAPERHORKREDUCTIONPROJECT(3150-0104),OFFICEOFHANAGEHEHTANDBUDGETMASHINGTOHDC20503.FACILITYMANE1CookNuclearPlant-Unit1TEXT(ifsorespaceisrequired.useadditionalHRCFore366A's)(17)CauseoftheEventcont'dDOCKETNU)IBER250-315YEAR97LERNIGER6SEQUENTIALREVISICH01PAGE34OF10AnexaminationoftwocrackedtubeswhichhadthissecondtypeoffailurewasperformedbyDCCNPmetallurgicalengineers.Aportionoftheirinvestigationfollows:"Anexaminationoftwotypicallycrackedtubesrevealeda3/4"longlinearindicationorientedparalleltothecorrugationattherootofaconvolution.Thecrackwaslocatedadistanceoftwoconvolutionsfromtheweldattachingthebellowstothethreadedfitting.Oneendofthecrack,hadaY-patterncrackthatisindicativeofacrackinitiationpointduetoexcessivebendingstressinthethinmaterial.Duetothecrack'slocation,thedefectisnotweldingrelated.Althoughnotusedinthisapplication,thecorrugatedbellowsiscapableofwithstandingmotion,lateraloffset,angularrotation,aswellasaxialextensionandcompressionovertheentirelengthoftheflooduptube.However,withinalocalizedregion,suchaswherethebellowsareattachedtothethreadedfitting,thebellowstransitionsfromflexibletorigid.Atthislocation,thethinbellowsmaterialwillnotwithstandanybendingortorsionalrotationloading."Theflooduptubeinstallationintheannuluswasreviewedtodeterminewhichconfigurationwasmorepronetofailure.Itwasfoundthatallthoseflooduptubesthathavethistypeofdefectwereinthoseinstallationswherethereisaminimumofseventubesperpenetration.Thisisattributedtothefactthatthosepenetration"installationswithmoreflooduptubesalsohavemorestringentbendingrestrictionsduetospacerestrictions.Thefactthatallthesecrackswerenearthefittingendoftheflooduptubeandinthoseinstallationswhichrequiresmallerbendingradiiconfirmthatthecrackswereduetolocalizedstress.Duetothetype,location,orientationofthedefectandlackofloadingduringservice,thesedefectsweremostprobablyinitiatedinthebellowsduringinstallationorsubsequentrework.AnalsisoftheEventTheseeventsarereportableundertheprovisionsof10CFR50.73(a)(2)()l.(8),operationprohibitedbytheplant'stechnicalspecifications,10CFR50.73(a)(2)(ii),anyeventorconditionthatresultedintheconditionofthenuclearpowerplant,includingitsprincipalsafetybarriers,beingseriouslydegraded,and10CFR50.73(a)(2)(ii)(B),aconditionwhichisoutsideofthedesignbasisoftheplant.Thecablesarerequiredtobeenvironmentallyqualifiedper10CFR50.49.However,theenvironmentalqualificationtestingdidnotincludesubmergingthecableinwater.PartialtestdataforKaptoninsulatedcableshowsthatonetestsamplefailedaftertwohours,andasecondtestsamplefailedafterfortyeighthours.Onthisbasis,itwasdeterminedthatKaptoninsulatedcablewasnotsuitableforlongtermusesubmergedinasumpsolutionhavingapHof9-10.  
&PROVEDBYQS'NO.3150-0104 EXPIRES5/31/95ESTIHATED BURDENPERRESPONSE'TO COHPLYMITHTHISINFORHATION COLLECTION REQUEST:50.0HRS.FORMARDCOHHEHTSREGARDIHG BURDENESTIMATETOTHEIHFORHATIOH AHDRECORDSHANAGEHEHT.
BRANCH(HHBB7714),U.S.NUCLEARREGULATORY COHHISSIOHg MASHINGTON, DC20555-0001, AND-TOTHEPAPERMORK REDUCTION PROJECt(3150-0104),
OFFICEOFHANAGEHENT ANDBUDGETMASHIHGTOH DC20503;,FACILITYMAKE1CookNuclearPlant-Unit150-315LERHUHBER6YEARSEQUEHTIAL 97-006REVISION01~I~t4rraua3OF10TEXT((fcerespaceisrequ(red.
useaddit(onal NRCForm366A's)(17)DescritionofEventcont'd1-NSO-021 ReactorCoolantSystempost-accident (EIIS/AB-VTV) venttrainAsolenoidvalve1-IMO-315 EastRHRandNorthSafetyInjection to(EIIS/BO-INV) reactorcoolantloops1and4hotlegsshutoffvalve1-IMO-316 EastRHRandNorthSafetyInjection to(EIIS/BO-INV) reactorcoolantloops1and4coldlegsshutoffvalve1-IMO-325 WestRHRandsouthsafetyinjection to(EIIS/BO-INV) reactorcoolantloops2and3hotlegsshutoffvalve1-NMO-151Pressurizer reliefvalveNRV-151(EIIS/AB-ISV) upstreamshutoffvalve1-33-NRV-153 Pressurizer trainApressurereliefvalveNRV-153closelimitswitchTheUnit2flooduptubeswereinspected onMarch23,1997.Atthattime,acrackwasfoundintheflooduptube2-IP3-3.Thisflooduptubecontainsacablewhichsuppliespowertooneoftwocontainment recirculation (CEQ)fans(EIIS/BB-FAN).
TheCEQfansoperatelongtermfollowing alossofcoolantaccident, andabsentqualification dataforwatersubmergence, continued operation oftheimpactedCEQfancouldnotbeguaranteed.
CauseoftheEventThetubedamagehasbeenattributed toworkpractices thatresultedintwoseparatetypesoffailures-material stresscracksandrandomarcstrikes,mostprobablyearlyintheplantlife.Inthreeisolatedinstances, unrelated tothematerialstresscracks,thetubeexhibited holesinthetubeapproximately 1/8"-1/4" wide.Theseholeshadaburnedappearance suchthattheymayhavebeencausedbyweldingactivities inthevicinityoftheflooduptubes.Theothercauseisduetolocalized stressestothematerialatthepointwherethetubetransitions fromflexibletoarigidconfiguration.
Thecausalanalysisevaluated thebasictubeconstruction, inspected damagedtubes,andperformed aninspection ontheinstallation intheannulus.Theflooduptubeconstruction isastandardsingle-ply helicalcorrugated bellowsthatisconstructed fromaType321stainless steel.BothendsoftheflooduptubeareweldedtoaType304stainless steelfittingwithmalethreads.Thefittingsconstitute arigidpointwhilethebellowsthemselves areaflexiblemember.Thistypeofconstruction allowsthetubetoflexuniformly throughout itsentirelengthexceptatthepointwhereitconnectstothefittings.
HRCFORN366A.S.NUCLEARREGUULTORY COXNISSIOM LICENSEELWENTCONTINUATION ROVEDBYONBNO.3150-01,04 EXPIRES5/31/95ESTINATED BURDENPERRESPOHSETO'COHPLY MITHTHISIHFORHATIOH COLLECTIOH REQUEST:50.0NRS;FORNARDCONHEHTSREGARDING BURDENESTINATETOTHEINFORNATION ANDRECORDSNANAGEHEHT BRANCH"(NHBB7714),U.S.NUCLEARREGULATORY COHHISSION, IIASHIHGTON, DC20555-0001, AHDTOTHEPAPERHORK REDUCTION PROJECT(3150-0104),
OFFICEOFHANAGEHEHT ANDBUDGETMASHINGTOH DC20503.FACILITYMANE1CookNuclearPlant-Unit1TEXT(ifsorespaceisrequired.
useadditional HRCFore366A's)(17)CauseoftheEventcont'dDOCKETNU)IBER250-315YEAR97LERNIGER6SEQUENTIAL REVISICH01PAGE34OF10Anexamination oftwocrackedtubeswhichhadthissecondtypeoffailurewasperformed byDCCNPmetallurgical engineers
.Aportionoftheirinvestigation follows:"Anexamination oftwotypically crackedtubesrevealeda3/4"longlinearindication orientedparalleltothecorrugation attherootofaconvolution.
Thecrackwaslocatedadistanceoftwoconvolutions fromtheweldattaching thebellowstothethreadedfitting.Oneendofthecrack,hadaY-pattern crackthatisindicative ofacrackinitiation pointduetoexcessive bendingstressinthethinmaterial.
Duetothecrack'slocation, thedefectisnotweldingrelated.Althoughnotusedinthisapplication, thecorrugated bellowsiscapableofwithstanding motion,lateraloffset,angularrotation, aswellasaxialextension andcompression overtheentirelengthoftheflooduptube.However,withinalocalized region,suchaswherethebellowsareattachedtothethreadedfitting,thebellowstransitions fromflexibletorigid.Atthislocation, thethinbellowsmaterialwillnotwithstand anybendingortorsional rotationloading."
Theflooduptubeinstallation intheannuluswasreviewedtodetermine whichconfiguration wasmorepronetofailure.Itwasfoundthatallthoseflooduptubesthathavethistypeofdefectwereinthoseinstallations wherethereisaminimumofseventubesperpenetration.
Thisisattributed tothefactthatthosepenetration" installations withmoreflooduptubesalsohavemorestringent bendingrestrictions duetospacerestrictions.
Thefactthatallthesecrackswerenearthefittingendoftheflooduptubeandinthoseinstallations whichrequiresmallerbendingradiiconfirmthatthecrackswereduetolocalized stress.Duetothetype,location, orientation ofthedefectandlackofloadingduringservice,thesedefectsweremostprobablyinitiated inthebellowsduringinstallation orsubsequent rework.AnalsisoftheEventTheseeventsarereportable undertheprovisions of10CFR50.73(a)(2)()l.
(8),operation prohibited bytheplant'stechnical specifications, 10CFR50.73(a)(2)(ii),
anyeventorcondition thatresultedinthecondition ofthenuclearpowerplant,including itsprincipal safetybarriers, beingseriously
: degraded, and10CFR50.73(a)(2)(ii)(B),
acondition whichisoutsideofthedesignbasisoftheplant.Thecablesarerequiredtobeenvironmentally qualified per10CFR50.49.
However,theenvironmental qualification testingdidnotincludesubmerging thecableinwater.PartialtestdataforKaptoninsulated cableshowsthatonetestsamplefailedaftertwohours,andasecondtestsamplefailedafterfortyeighthours.Onthisbasis,itwasdetermined thatKaptoninsulated cablewasnotsuitableforlongtermusesubmerged inasumpsolutionhavingapHof9-10.  


iiRCFORH366AU.S.NUCLEARREGULATORYCOO)ISSIONLICENSEEEVENTCONTINUATIONAPPROVEDBYO)IBNO.3150-0104EXPIRES5i31/95ESTINATEOBURDENPERRESPONSETOCOHPLYMITHTHISlNFORHATIONCOLLECTIONREaUESTs50.0.HRS.FORMAROCOHHENTSREGARDIHG'BURDENESTIHATETO'HEINFORNATIONANDRECORDSHANAGEHENTBRANCH(HNBB7714),U.S.NUCLEARREGULATORYCOHHISSIONgMASHINGTOH,DC20555.0001,ANDTOTHEPAPERMORKREDUCTIONPROJECT(3150-0104)~OFFICEOFHANAGEXENTANDBUDGETMASHINGTONDC20503.FACILITYNAKE1CookNuclearPlant-Unit1TEXT(ifcerespaceisrequired,useadditionalHRCFora366A's)(17)AnalsisoftheEventcont'dDOCKETaRJÃBER250-315YEAR97LERNURSER6SEOUENTIALREVISION01PAGE35OF10Becausethecracksinfiooduptubesarelocatedbelowthecontainmentflooduplevel,water,couldenterthetubeandthecablewouldbesubmergedinasodiumhydroxidesolutionhavingapHof9to10.Submergenceinthis.solutionwoulddegradetheKaptoninsulation,anditwouldeventuallyfail.Asthetimetofailure.cannotbeaccuratelypredicted,anyequipmentrequiredforIongtermaccidentmitigationwasconsideredtobeinoperable.EquipmentwhichcouldcompleteitssafetyfunctionwithintwohoursfollowingtheaccidentwasconsideredoperableforthepurposeoftheanalysispresentedinthisLER.iltisnotpossibletotellwhenthetubesbecamecracked.However,theapparentcauseofthecracks,weldingarcstrikesandstresscracking,indicatesthattheyexistedpriortodiscovery.Therefore,itisassumedthattheunitwasinT/S3.0.3,whichisreportableasaconditionwhichisoutsidethedesignbasisoftheplantandasoperationprohibitedbytheplant'stechnicalspecifications.Theresultoftheevaluationisthat,althoughthepotentialforequipmentfailureplacedtheplantoutsideofitslicensingbasisinmanyinstances,therewasnopostulatedfailurethatisconsideredtohaveamajorimpactwithregardtoprotectingthepublichealthandsafety.Also,inmanycasestheequipmentwasbackedupbyunaffectedredundantequipmentand/orequipmentwhichco'uldperformasimilarsafetyfunction.Unit1NarrowRaneSteamGeneratorLevelTransmittersThenarrowrangesteamgeneratorleveltransmitters(1-BLP-132,-142)provideasignaltothereactorprotectionsystem,andtheyareusedforpostaccidentmonitoringofthesteamgeneratorlevel(Technicalspecification3.3.3.8requiresoneoperablechannelpersteamgenerator).Theprotectionsystemfunctionwouldbeaccomplishedpriortothecable'sbecomingsubmerged.Therearethreenarrowrangesteamgeneratorleveltransmitterspersteamgenerator,andthepostaccidentmonitoringfunctioncouldbeaccomplishedbyeithertheremainingtwonarrowrangetransmitters.HotLeWideRaneTemeratureRecorderThehotlegwiderangetemperaturerecorder(1-NTR-140,-240)signalisrequiredasinputtotheRCSIsubcoolingmonitor,andthesubcoolingmonitoringsystemwouldbelesseffectivesinceinputtemperaturesfromanentireRCSloopwouldbelost.Theoperatoralsohasavailablesubcoolingindicationusingthecoreexitthermocouples.Thisisactuallythepreferredmethodofdeterminingsubcoolingsinceitprovidesconservativeresults.Thusthelossof1-NTR-140and1-NTR-240wouldnothavesignificantlyimpactedplantoperationsandisjudgedtohavehadnoadverseimpactonpublichealthandsafety.  
iiRCFORH366AU.S.NUCLEARREGULATORY COO)ISSIONLICENSEEEVENTCONTINUATION APPROVEDBYO)IBNO.3150-0104 EXPIRES5i31/95ESTINATEO BURDENPERRESPONSETOCOHPLYMITHTHISlNFORHATION COLLECTION REaUESTs50.0.HRS.FORMAROCOHHENTSREGARDIHG'BURDEN ESTIHATETO'HEINFORNATION ANDRECORDSHANAGEHENT BRANCH(HNBB7714),U.S.NUCLEARREGULATORY COHHISSIONg MASHINGTOH, DC20555.0001, ANDTOTHEPAPERMORK REDUCTION PROJECT(3150-0104)
~OFFICEOFHANAGEXENT ANDBUDGETMASHINGTON DC20503.FACILITYNAKE1CookNuclearPlant-Unit1TEXT(ifcerespaceisrequired, useadditional HRCFora366A's)(17)AnalsisoftheEventcont'dDOCKETaRJÃBER250-315YEAR97LERNURSER6SEOUENTIAL REVISION01PAGE35OF10Becausethecracksinfiooduptubesarelocatedbelowthecontainment flooduplevel,water,couldenterthetubeandthecablewouldbesubmerged inasodiumhydroxide solutionhavingapHof9to10.Submergence inthis.solutionwoulddegradetheKaptoninsulation, anditwouldeventually fail.Asthetimetofailure.cannotbeaccurately predicted, anyequipment requiredforIongtermaccidentmitigation wasconsidered tobeinoperable.
Equipment whichcouldcompleteitssafetyfunctionwithintwohoursfollowing theaccidentwasconsidered operableforthepurposeoftheanalysispresented inthisLER.iltisnotpossibletotellwhenthetubesbecamecracked.However,theapparentcauseofthecracks,weldingarcstrikesandstresscracking, indicates thattheyexistedpriortodiscovery.
Therefore, itisassumedthattheunitwasinT/S3.0.3,whichisreportable asacondition whichisoutsidethedesignbasisoftheplantandasoperation prohibited bytheplant'stechnical specifications.
Theresultoftheevaluation isthat,althoughthepotential forequipment failureplacedtheplantoutsideofitslicensing basisinmanyinstances, therewasnopostulated failurethatisconsidered tohaveamajorimpactwithregardtoprotecting thepublichealthandsafety.Also,inmanycasestheequipment wasbackedupbyunaffected redundant equipment and/orequipment whichco'uldperformasimilarsafetyfunction.
Unit1NarrowRaneSteamGenerator LevelTransmitters Thenarrowrangesteamgenerator leveltransmitters (1-BLP-132,
-142)provideasignaltothereactorprotection system,andtheyareusedforpostaccidentmonitoring ofthesteamgenerator level(Technical specification 3.3.3.8requiresoneoperablechannelpersteamgenerator).
Theprotection systemfunctionwouldbeaccomplished priortothecable'sbecomingsubmerged.
Therearethreenarrowrangesteamgenerator leveltransmitters persteamgenerator, andthepostaccidentmonitoring functioncouldbeaccomplished byeithertheremaining twonarrowrangetransmitters.
HotLeWideRaneTemeratureRecorderThehotlegwiderangetemperature recorder(1-NTR-140,
-240)signalisrequiredasinputtotheRCSIsubcooling monitor,andthesubcooling monitoring systemwouldbelesseffective sinceinputtemperatures fromanentireRCSloopwouldbelost.Theoperatoralsohasavailable subcooling indication usingthecoreexitthermocouples.
Thisisactuallythepreferred methodofdetermining subcooling sinceitprovidesconservative results.Thusthelossof1-NTR-140and1-NTR-240 wouldnothavesignificantly impactedplantoperations andisjudgedtohavehadnoadverseimpactonpublichealthandsafety.  


MRCFORM366AS.N)CLEARREGULATORYCOMMISSIONLICENSEE'TTENTCONTlNUATION(NBMO-3150-0104EXPIRES5/3'I/95ESTIMATEDBURDENPERRESPONSETOCOMPLYWITHTHISINFORMATIONCOLLECTIONREQUEST:50.0HRS.FORWARDCOMMENTSREGARDINGBURDENESTIMATETOTHEINFORMATIONANORECORDSMANAGEMEHTBRANCH(MNBB7714),U.S.NUCLEARREGULATORYCOMHISSIOH~WASHINGTON,OC20555-0001,ANOTOTHEPAPERWORKREDUCTIONPROJECT(31500104)gOFFICEOFMANAGEMENTANDBUDGETWASHINGTONDC20503.FACILITYNAMECookNuclearPlant-Unit1TEXTitfNorespaceisrequired.useadditionalMICFons3664's)(I7),AnalslsoftheEventcont'd50-31597LERMINBER6SEQUENTIALREVISION01PAGE36OF10HdroenRecombinerTheCookNuclearPlanthastwohydrogenrecombinersofwhichonlyoneisrequiredforaccidentmitigation.Onlyoneofthetworecombiners(1-HR-1)wasadverselyimpactedbyacrackedflooduptube.Thehydrogenrecombinerisusedtomaintainthelong-termhydrogenconcentrationinsidecontainmentbelow4volumepercent.Althoughtheprincipalmeansofhydrogencontrolthatisincludedfntheplantdesignbasisaretwoelectrichydrogenrecombinerscombinedwithtwocontainmentairrecirculationfans,additionalmeansofhydrogencontrol,hydrogenigniters,wereaddedtoaddressthepossibilityofexcessivehydrogenconcentrationsthatmayexistfollowingasevereaccident.Ananalysishasbeenperformedtoshowthattheignitersarecapableofpreventinghydrogenignitionfromendangeringthepublichealthandsafetywhenhydrogenconcentrationsareexcessivelyhigh.Therefore,intheeventthatbothrecombinersweretofail,andthehydrogenconcentrationsweretobuilduptoexcessiveamounts,itisbelievedthatthehydrogenigniterswouldpreventtheensuingproblemswithhydrogenignitionfromadverselyimpactingpublichealthandsafety.Althoughtheignitersdonothavethedatatosupportlongevityofoperation,theyarecapableofsupportingoperationforatleastoneweek.Itisbelievedthattheigniterswouldlastforperiodsconsiderablebeyondthattime.Duringthetimethattherewastotalrelianceonthehydrogenigniters,itmaybepossibletorepairtheunaffectedelectrichydrogenrecombiner(iftherepaircouldbeperformedoutsidethecontainment)orestablishsomeothermeansoflongtermhydrogencontrol,ifitwerenecessary.Basedonthecombinationoftheunlikelihoodoffailureoftheredundanthydrogenrecombiner,combinedwiththeavailabilityofthehydrogenigniters,itisconcludedthattherewouldbeanalmostnegligiblechancethatthecracksinthefiooduptubesservicingelectricalcablesto1-HR-1wouldhaveresultedinsignificantproblemsassociatedwithhydrogenignitionshouldadesignbasisLOCAhaveoccurredattheplant.Itisthereforeconcludedthatthecrackintheflooduptubeassociatedwith1-HR-1didnotrepresentasignificanthazardwithregardtotheprotectionofthepublichealthandsafety.ContainmentRecirculationFanValveTheCookNuclearPlanthastworecirculationfans,onlyoneofwhichisrequiredforaccidentmitigation.Onlyoneoftherecirculationfanswasimpactedbythecrackedflooduptubecontainingthecableassociatedwithvalve1-VMO-102.Thecontainmentairrecirculationsystemvalveisactivated10minutesaftertheaccidentoccurs.BasedonpartialtestdatawhichdemonstratethataminimumoftwohoursisrequiredbeforeKaptoninsulationisdegradedtothepointwhereitisnolongereffective,itisconcludedthatthisvalvewouldhaveperformeditsfunctionpriortotheinsulation'sbeingsignificantlydegraded.
MRCFORM366AS.N)CLEARREGULATORY COMMISSION LICENSEE'TTENTCONTlNUATION (NBMO-3150-0104 EXPIRES5/3'I/95ESTIMATED BURDENPERRESPONSETOCOMPLYWITHTHISINFORMATION COLLECTION REQUEST:50.0HRS.FORWARDCOMMENTSREGARDING BURDENESTIMATETOTHEINFORMATION ANORECORDSMANAGEMEHT BRANCH(MNBB7714),U.S.NUCLEARREGULATORY COMHISSIOH
MRCFORM366ASN)CI.EARREGULATORYCOOIISSIONLICENSEEEVENTCONTINUATIONBY(NBMO.3150-0104EXPIRES5/31/95ESTIMATEDBURDENPERRESPONSETOCOMPLYMITHTHISINFORMATIONCOLLECTIONREQUEST:50.0HRS.FORNARDCOMMENTSREGARDINGBURDENESTIMATETOTHEINFORMATIONAHDRECORDSMANAGEMEHTBRANCH(MHBB7714),U.S.NUCLEARREGULATORYCOMMISSION/MASHIHGTOH,DC20555-0001,ANDTOTHEPAPERNORKREDUCTIONPROJECT(3150-0104),OFFICEOFMANAGEMENTANDBUDGETllASHIHGTOHDC'20503.FACILITYMANE1CookNuclearPlant-Unit1TEXT(ifserespaceisrequired.useadditionalNRCFons36Q's)(17)AnalslsoftheEventcont'dDO(XETNIGER250-315.YEAR97LERNIGER6SEQUENTIAL006REVISION01PAGE37OF10ReactorVesselHeadVentValveTheCookNuclearPlanthastwoheadventvalves,onlyoneofwhichisrequiredbythetechnicalspecificationstobeoperable.Onlyoneoftheheadventvalveswasimpactedbyacrackedflooduptube.Thereactorvesselheadventsystem(1-NSO-021)isaseries/parallelarrangementwherefourvalvesaresuppliedbytwoseparatepowertrains.Anidenticalarrangementexistsforthepressurizerheadvent.NocreditistakenforthereactorheadventsintheFSARdesignbasisaccidentanalysis.Theyarestrictlyacontingencytobeusedforsevereaccidents.ThereactorheadventswereinstalledintheCookNuclearPlantinresponseto10CFR50.44(c)(3)(iii)toventahydrogenbubbleinthereactorheadintheeventofadegradedcoreaccidentwithsignificanthydrogengeneration.ThisheadventisalsousedintheEmergencyOperatingProcedurestoaidinvesseldepressurizationafterallothermechanismshavefailed,includingboththeprimaryandsecondarypoweroperatedreliefvalves.ColdLetoHotLeIn'ectionValvesValves1-IMO-315,1-IMO-316and1-IMO-325arerequiredtofunctionwhenswitchingfromcoldlegtohotleginjectionfollowingalossofcoolantaccident.Valves1-IMO-315and1-IMO-325arerequiredtoopentoprovideahotlegflowpathtoloops1,2,3,and4.Valve1-IMO-316isrequiredtoclosetoblockthecoldlegflowpathtoloops1and4.Usingthecurrentlicensedmethodology,theinabilitytoswitchtohotlegrecirculationwouldresultinboronprecipitationinthecoreandpossibleheattransferdegradation,potentiallyleadingtoacladdingtemperatureheatup.However,Westinghousehasdevelopedanewmethodologywhich,iflicensedandimplemented,wouldeliminatetheneedtoswitchtohotlegrecirculation.Thismethodologymodelstheflowthroughthegapbetweenthehotlegnozzleandthebarrelasamechanismfortransportingboratedvesselwatertothesump.TheWestinghouseWCAPpresentsthemethodologyanddocumentsagenericanalysisthatisapplicabletomostWestinghouse3and4loopplant,includingCook.AmongtheconclusionsdrawnfromthegenericanalysisisthattheECCSdoesnotneedtobealignedtotheRCShotlegspost-LOCAinordertolimitthebuildupofboron.Assuch,thehotIegnozzlegapwouldhavelimitedthebuildupofboronaftertheLOCA,eveniftheECCScouldnothavealignedtothehotlegs.Thiswouldhavepreventedboronprecipitationinthecore,maintainingtheheattransfercapability.ThustheinabilitytoaligntheECCStothehotlegswouldnothaveresultedinaviolationofanyofthe10CFR50.46criteria.Power0cratedReliefValveBlockValve1-NMO-151isanormallyopenblockvalveforapressurizerpoweroperatedreliefvalve(PORV),andistheonlyoneofthethreePORVblockvalvesthatwasimpactedbyacrackedflooduptube.TheCookNuclearPlantpressurizerhasthreePORVswhichlimitreactorcoolantsystempressure.ThePORVs,whicharespringclosedandair-openuponactuationoftheirassociatedsolenoidvalve,operateautomaticallyorbyremotemanualcontrol.RemotelyoperatedblockvalvesareprovidedtoisolatethePORVs.  
~WASHINGTON, OC20555-0001, ANOTOTHEPAPERWORK REDUCTION PROJECT(31500104)gOFFICEOFMANAGEMENT ANDBUDGETWASHINGTON DC20503.FACILITYNAMECookNuclearPlant-Unit1TEXTitfNorespaceisrequired.
useadditional MICFons3664's)(I7),AnalslsoftheEventcont'd50-31597LERMINBER6SEQUENTIAL REVISION01PAGE36OF10HdroenRecombiner TheCookNuclearPlanthastwohydrogenrecombiners ofwhichonlyoneisrequiredforaccidentmitigation.
Onlyoneofthetworecombiners (1-HR-1)wasadversely impactedbyacrackedflooduptube.Thehydrogenrecombiner isusedtomaintainthelong-term hydrogenconcentration insidecontainment below4volumepercent.Althoughtheprincipal meansofhydrogencontrolthatisincludedfntheplantdesignbasisaretwoelectrichydrogenrecombiners combinedwithtwocontainment airrecirculation fans,additional meansofhydrogencontrol,hydrogenigniters, wereaddedtoaddressthepossibility ofexcessive hydrogenconcentrations thatmayexistfollowing asevereaccident.
Ananalysishasbeenperformed toshowthattheignitersarecapableofpreventing hydrogenignitionfromendangering thepublichealthandsafetywhenhydrogenconcentrations areexcessively high.Therefore, intheeventthatbothrecombiners weretofail,andthehydrogenconcentrations weretobuilduptoexcessive amounts,itisbelievedthatthehydrogenigniterswouldpreventtheensuingproblemswithhydrogenignitionfromadversely impacting publichealthandsafety.Althoughtheignitersdonothavethedatatosupportlongevity ofoperation, theyarecapableofsupporting operation foratleastoneweek.Itisbelievedthattheigniterswouldlastforperiodsconsiderable beyondthattime.Duringthetimethattherewastotalrelianceonthehydrogenigniters, itmaybepossibletorepairtheunaffected electrichydrogenrecombiner (iftherepaircouldbeperformed outsidethecontainment) orestablish someothermeansoflongtermhydrogencontrol,ifitwerenecessary.
Basedonthecombination oftheunlikelihood offailureoftheredundant hydrogenrecombiner, combinedwiththeavailability ofthehydrogenigniters, itisconcluded thattherewouldbeanalmostnegligible chancethatthecracksinthefiooduptubesservicing electrical cablesto1-HR-1wouldhaveresultedinsignificant problemsassociated withhydrogenignitionshouldadesignbasisLOCAhaveoccurredattheplant.Itistherefore concluded thatthecrackintheflooduptubeassociated with1-HR-1didnotrepresent asignificant hazardwithregardtotheprotection ofthepublichealthandsafety.Containment Recirculation FanValveTheCookNuclearPlanthastworecirculation fans,onlyoneofwhichisrequiredforaccidentmitigation.
Onlyoneoftherecirculation fanswasimpactedbythecrackedflooduptubecontaining thecableassociated withvalve1-VMO-102.
Thecontainment airrecirculation systemvalveisactivated 10minutesaftertheaccidentoccurs.Basedonpartialtestdatawhichdemonstrate thataminimumoftwohoursisrequiredbeforeKaptoninsulation isdegradedtothepointwhereitisnolongereffective, itisconcluded thatthisvalvewouldhaveperformed itsfunctionpriortotheinsulation's beingsignificantly degraded.
MRCFORM366ASN)CI.EARREGULATORY COOIISSIONLICENSEEEVENTCONTINUATION BY(NBMO.3150-0104 EXPIRES5/31/95ESTIMATED BURDENPERRESPONSETOCOMPLYMITHTHISINFORMATION COLLECTION REQUEST:50.0HRS.FORNARDCOMMENTSREGARDING BURDENESTIMATETOTHEINFORMATION AHDRECORDSMANAGEMEHT BRANCH(MHBB7714),U.S.NUCLEARREGULATORY COMMISSION/
MASHIHGTOH, DC20555-0001, ANDTOTHEPAPERNORK REDUCTION PROJECT(3150-0104),
OFFICEOFMANAGEMENT ANDBUDGETllASHIHGTOH DC'20503.
FACILITYMANE1CookNuclearPlant-Unit1TEXT(ifserespaceisrequired.
useadditional NRCFons36Q's)(17)AnalslsoftheEventcont'dDO(XETNIGER250-315.YEAR97LERNIGER6SEQUENTIAL 006REVISION01PAGE37OF10ReactorVesselHeadVentValveTheCookNuclearPlanthastwoheadventvalves,onlyoneofwhichisrequiredbythetechnical specifications tobeoperable.
Onlyoneoftheheadventvalveswasimpactedbyacrackedflooduptube.Thereactorvesselheadventsystem(1-NSO-021) isaseries/parallel arrangement wherefourvalvesaresuppliedbytwoseparatepowertrains.Anidentical arrangement existsforthepressurizer headvent.NocreditistakenforthereactorheadventsintheFSARdesignbasisaccidentanalysis.
Theyarestrictlyacontingency tobeusedforsevereaccidents.
Thereactorheadventswereinstalled intheCookNuclearPlantinresponseto10CFR50.44 (c)(3)(iii) toventahydrogenbubbleinthereactorheadintheeventofadegradedcoreaccidentwithsignificant hydrogengeneration.
ThisheadventisalsousedintheEmergency Operating Procedures toaidinvesseldepressurization afterallothermechanisms havefailed,including boththeprimaryandsecondary poweroperatedreliefvalves.ColdLetoHotLeIn'ection ValvesValves1-IMO-315, 1-IMO-316 and1-IMO-325 arerequiredtofunctionwhenswitching fromcoldlegtohotleginjection following alossofcoolantaccident.
Valves1-IMO-315 and1-IMO-325 arerequiredtoopentoprovideahotlegflowpathtoloops1,2,3,and4.Valve1-IMO-316 isrequiredtoclosetoblockthecoldlegflowpathtoloops1and4.Usingthecurrentlicensedmethodology, theinability toswitchtohotlegrecirculation wouldresultinboronprecipitation inthecoreandpossibleheattransferdegradation, potentially leadingtoacladdingtemperature heatup.However,Westinghouse hasdeveloped anewmethodology which,iflicensedandimplemented, wouldeliminate theneedtoswitchtohotlegrecirculation.
Thismethodology modelstheflowthroughthegapbetweenthehotlegnozzleandthebarrelasamechanism fortransporting boratedvesselwatertothesump.TheWestinghouse WCAPpresentsthemethodology anddocuments agenericanalysisthatisapplicable tomostWestinghouse 3and4loopplant,including Cook.Amongtheconclusions drawnfromthegenericanalysisisthattheECCSdoesnotneedtobealignedtotheRCShotlegspost-LOCA inordertolimitthebuildupofboron.Assuch,thehotIegnozzlegapwouldhavelimitedthebuildupofboronaftertheLOCA,eveniftheECCScouldnothavealignedtothehotlegs.Thiswouldhaveprevented boronprecipitation inthecore,maintaining theheattransfercapability
.Thustheinability toaligntheECCStothehotlegswouldnothaveresultedinaviolation ofanyofthe10CFR50.46criteria.
Power0cratedReliefValveBlockValve1-NMO-151 isanormallyopenblockvalveforapressurizer poweroperatedreliefvalve(PORV),andistheonlyoneofthethreePORVblockvalvesthatwasimpactedbyacrackedflooduptube.TheCookNuclearPlantpressurizer hasthreePORVswhichlimitreactorcoolantsystempressure.
ThePORVs,whicharespringclosedandair-openuponactuation oftheirassociated solenoidvalve,operateautomatically orbyremotemanualcontrol.RemotelyoperatedblockvalvesareprovidedtoisolatethePORVs.  


MRCFORH366A.SNUCLEARREGULATORYCOXRISSIOHLICENSEEEVEBFZCONTINUATIONBYORBMO.3150-0104EXPIRES5/31/95ESTIHATEDBURDENPERRESPOHSETOCOMPLYNITHTHISINFORHATIONCOLLECTIONRFCUEST:50.0'RS.FCRllARDCOHHENTSREGARDINGBURDENESTIHATETOTHEIHFORHATIOHAHDRECORDS'HANAGEHENTBRANCH'HHBB7714),U.S.NUCLEARREGULATORYCOHHISSIOH,NASNIHGTON,DC20555-0001,AHDTOTHEPAPERHORXREDUCTIONPROJECT(3150-0104),OFFICEOFHANAGEHENTANDBUDGETMASHIHGTOHDC20503.FACILITYMARECookNuclearPlant-Unit1TEXTOfcorespacefsrequired.useadditionalHRCFona366A's)(17)AnalsisoftheEventcont'dDOCKETNUMBER250-315YEAR97LERNUMBER6SEOUEHTIALREVISIGH01PAGE3SOP10Power0cratedReliefValveBlockcont'dToevaluatetheimpactofthecrackedflooduptubes,fourconditionswereconsidered:1)FSARaccidents;2)highenergylinebreaksinsidecontainmentwhereimmediateisolationofthePORVisrequired;3)conditionsoutsideofthenormalFSARanalysiswhereitmaybenecessarytoisolatethePORVaftertheelectricwirehousedinthecrackedPORVhasbeensubmergedforseveralhours,and4)conditionsoutsidetheFSARanalysiswhereitmaybenecessarytoopenanisolatedPORVaftertheelectricwirehousedlnthecrackedPORVhasbeensubmergedforseveralhours.Eachoftheseconditionsisdiscussedbelow.ThesingleChapter14accidentanalysiswhichrequiresPORVoperabilityisthesteamgeneratortuberupture(SGTR)withalossofoffsitepower.Inthisevent,onePORVisrequiredtoreduceprimarysystempressureduringtherecoveryphaseoftheaccidenttoslightlyabovethesecondarysidepressure.AsecondPORVisrequiredtobeoperableforsinglefailureconsiderations.TheUFSARChapter14SGTRisnotconsideredtobeafloodingevent,andthereforethecrackedflooduptubeswouldnothaveimpactedthePORVblockvalveoperabilityforthisaccident.fCreditistakenintheplantemergencyoperatingproceduresforthePORVstorecoverfromavarietyofaccidents.Thiswouldincludethecategoryofeventsandaccidentsthatcc"dcausethePORVstoopenandfailtoclose,resultinginasmallbreakLOCA(e.g.normalplantcooldown,activationofthesafetyinjectionsystem,orseveretransientssuchasafeedwaterlinebr'eakorsteamlinebreakinsidecontainment).ThemainfunctionofthePORVblockvalvesistoisolateaPORVifthePORVfailsintheopenposition.Foreventsofthetypecitedabove,eithertheydonotcausecontainmentflooding,oriftheydocauseflooding,theneedtoclosethePORVsoccursearlyenoughinthetransientthattheblockvalveswouldstillbeconsideredoperableinspiteofthewaterintrusionthatmayhaveoccurredduetocracksintheflooduptubes.Athirdcategoryofeventsincludelongtermrecoveryactionssuchasresponsetoinadequatecorecoolingorresponsetodegradedcorecoolingwherethecontainmentcouldbeflooded.EachoftheseeventsrequirethatastuckopenPORVbeisolated.Theseeventsarebeyondthoseconsideredintheplantdesignbasis,anditisconsideredhighlyunlikelythatanadverseaccidentofthistypecouldoccuratthesametimethataPORVsticksopen,thecablesaresubmerged,andtheblockvalvefailstoclosewhenitisrequired.ThefinalcategoryiseventsthatrequireaPORVtobeopentofacilitateaccidentrecovery.Anexampleofthiswouldbethefeedwaterlinebreakrecovery.However,notallofthethreePORVswouldhavebeenaffectedbycracksintheflooduptubes,andatleastonewouldbeavailableforthispurpose.Thismeetstheminimumrequirement.
MRCFORH366A.SNUCLEARREGULATORY COXRISSIOH LICENSEEEVEBFZCONTINUATION BYORBMO.3150-0104 EXPIRES5/31/95ESTIHATED BURDENPERRESPOHSETOCOMPLYNITHTHISINFORHATION COLLECTIONRFCUEST:50.0'RS.FCRllARDCOHHENTSREGARDING BURDENESTIHATETOTHEIHFORHATIOH AHDRECORDS'HANAGEHENT BRANCH'HHBB 7714),U.S.NUCLEARREGULATORY COHHISSIOH, NASNIHGTON, DC20555-0001, AHDTOTHEPAPERHORX REDUCTION PROJECT(3150-0104),
NRCFORM366A.S.NUCLEARREGULATORYCOMMISSIONLICENSEEEVENTCONTINUATIONROVEDBYOMBHO.3150-0104EXPIRES5/31/95ESTIMATEDBURDENPERRESPONSETOCOMPLYNITHTHISIHFORMATIONCOLLECTIOHREQUEST:50.0HRS;.,FORIIARDCOMMENTSREGARDINGBURDENESTIMATETO'HEINFORMATIONANDRECORDSMANAGEMENTBRANCH(MHBB7714),U.S.NUCLEARREGULATORYCOMMISSION;'WASHINGTON,DC20555-0001,ANDTOTHEPAPERNORKREDUCTIONPROJECT(3150.0104),OFFICEOFMANAGEMENTANDBUDGET'NASHIHGTONDC20503.FACILITYNAME1CookNuclearPlant-Unit1TEXT(ifaorespaceisrequired.useaddit(onalNRCFora366A's)(17)AnalslsoftheEventcont'dDOCKETNU)IER250-315LERNUMBER6YEARSEQUENTIAL97-006REVISIOH01PAGE39OF10Unit2ContainmentAirRecirculation/HdroenSkimmerFanTheCookNuclearPlanthastwocontainmentairrecirculation/hydrogenskimmer(CEQfans),onlyoneofwhichisrequiredforaccidentmitigation.Onlyonefanwasadverselyimpactedbyacrackedflooduptube.TheCEQfansarerequiredtoprovideacontinuousmixingofthecontainmentatmosphereforthelongtermpostblowdownaccidentenvironment.Theyarealsorequiredtopreventtheformationofhydrogenpocketswithinthevariouscompartmentsandsubcompartmentsoftheicecondensercontainment.Twofullcapacityfans,eachcapableofblowingairfromtheuppervolumeintothelowervolumeareprovided.Foraccidentanalysisconditions,onlyonefanismodeledbaseduponthelimitingsinglefailureofatrainofcontainmentsafeguardsequipment.TheairrecirculationfanshavesufficientheadtoovercomethecompartmentpressuredifferentialsthatoccuraftertheinitialRCSblowdown.Thefanswillblowairfromtheuppercompartmenttothelowercompartmenttherebyretumlngairtothelowercompartmentwhichwasdisplacedbytheblowdown.AlthoughthefansaremodeledduringboththecontainmentresponsetransientfollowingaLOCAandMSLB,thegreatestimpactresultingfromtheiractivationisseenduringtheLOCAtransientresponseduetothelongtermtransientscenario.Theairreturnfansaremodeledtooperateuponreachingthehigh-highcontainmentpressuresetpointfollowingatenminutedelay.DuringtheLOCAresponsetransientthefansprovideaflowpathearlyinthetransient,thereforetheirfunctionplaysanimportantrole(beforethetimeofpeakpressure)inthecontainmentresponsecalculation.SimilarlyduringtheMSLBcontainmentresponsecalculationthefansfunctioninalikewisemanner.However,thetimethefansactivatefollowthetimewhenthecontainmentpeakpressureandtemperatureoccurs,thereforetheirimpactonthecontainmentresponsetransientisminimal.Theirprimaryeffectisontherateofcontainmentdepressurizationandcooldownafter10minutesintotheMSLBcontainmentresponsetransient.BaseduponsensitivitieswhichhavebeenperformedforanicecondenserplantsimilartotheCookNuclearPlantwhenconsideringinoperableairreturnfans,theeffectofthelossoftheairreturnfanoncontainmentpeakpressurewas5psi.SincetheCookdesignpressureis12psi,thismeansthatthemaximumpressureachievedbythecontainmentshouldbothfansbelostis17psi.Althoughabovetheplantdesignbasisof12psi,thisiswellwithinthecontainmentultimatecapabilityofapproximately36psi.ThepotentiallossofCEQfansalsomeansthelossofabilitytoremovehydrogenfromthecompartmentsoftheCookNuclearPlant.Thiswillnotoccuruntiltwohoursintotheaccident.AspartoftheCookNuclearPlant'sprobabilisticriskassessment,studieshavebeenperformedtoevaluatethelossofCEQfansfollowingasevereaccident.Thesestudieshaveconcludedthatnoadverseimpactoncontainmentperformanceisexpectedduetocontainmentrecirculationfanfailures.Onthebasisoftheabove,itisconcludedthatthelossofoneCEQfandidnotadverselyimpactthepublichealthandsafety.Itisfurtherpointedout,thatonlyoneofthetworedundantfanswasimpacted,andthereforefollowingahighenergylinebreakinsidecontainmenttheplantmayhavestayedwithitsdesignbasiscontainmentpressureof12psi.
OFFICEOFHANAGEHENT ANDBUDGETMASHIHGTOH DC20503.FACILITYMARECookNuclearPlant-Unit1TEXTOfcorespacefsrequired.
NRCFORH366A.S.NUCLEARREGULATORYCOXHISSICILICENSEEEVENTCONTINUATIONBY'ORBNO.3150-0104EXPIRES5/31/95ESTIHATEDBURDENPER-RESPONSETOCOHPLYWITHTHISINFORHATION.COLLECTION'REQUEST:50.0NRS'.FORIIARDCOHHENTSREGARDINGBURDENESTIHATETOTHEINFORHATIONANDRECORDSHANAGEHENTBRANCH(HNBB7714),U.S.NUCLEARREGULATORYCOHHISSION,MASNINGTON,DC20555-0001,ANDTOTHEPAPERNORKREDUCTIONPROJECT(3150-0104),OFFICEOF"HANAGEHENTANDBUDGETMASNINGTONDC20503.FACILITYNAHE1CookNuclearPlant-Unit1TEXT((fmorespaceisrequired.useadditionalNCForm36EA's)(17)CorrectiveActionDOIETNUNBER25015YEAR97LERNUNBER6SEQUENTIALREVISION01PAGE310OF10Criticalareasforallflooduptubesineachunithavebeeninspectedforcracks.ThedamagedUnit1EQfiooduptubesandUnit2flooduptubeshavebeenreplaced.PreventiveActionAdequateprecautionsforweldinginthevicinityofelectricalequipmenthavebeenidentifiedintheAEPWeldingManual,GeneralWeldingRequirements,step6.13whichincondensedversionstates:basematerialsandothermetallicregionsoutsideoftheweldzoneshallbeprotectedtopreventinadvertentarcstrikes.Inaddition,PMI-2270(FIREPROTECTION),containstheWelding,Burning,8GrindingPermitwhichisissuedforallweldingactivities.Thepermitcoversarearequirementswhichprovidedirectiontocoverelectricalequipmentaridcabletrayswithfireblanket.Tosupplementtheseplantrequirements,aninspectionasstatedbelowwillbeperformedtoverifythatthetubeshavenotbeendamagedpriortostart-upafteroutageworkhasbeenperformed.WorkStandardstotheNuclearPlantMaintenance(NPM)andEnvironmentalQualificationPreservationDocuments(EQPD)willbeenhancedtoidentifythatwhileworkingontheflooduptubesthereisaneedtoavoidaddingunduelocalizedstresstotheflooduptubesandthentoverifythatnocrackshavedeveloped.TheWorkStandardstotheNPMforflooduptubeinstallationhavealreadybeenrevisedtoincludetheseprecautions.Asalongtermaction,newEQPDwillbeissuedbyJune1,1998forflooduptubestoidentifythecriticalEQparameters.Inspectionswillbemadeatthebeginningofeachoutagetocheckforanycracks.Inspectionswillalsobemadeattheendoftheoutagetoensurethatnooutageactivitiesdamagedanytubes.Inaddition,althoughnotcontainedinaformalprogram,theknowledgethatthetubesaresubjecttothistypeofdamagewillheightenawarenessandimproveworkbeingdoneonandaroundtheflooduptubes.FailedComonentIdentificationNotApplicablePreviousSimilarEventsNone}}
useadditional HRCFona366A's)(17)AnalsisoftheEventcont'dDOCKETNUMBER250-315YEAR97LERNUMBER6SEOUEHTIAL REVISIGH01PAGE3SOP10Power0cratedReliefValveBlockcont'dToevaluatetheimpactofthecrackedflooduptubes,fourconditions wereconsidered:
1)FSARaccidents; 2)highenergylinebreaksinsidecontainment whereimmediate isolation ofthePORVisrequired; 3)conditions outsideofthenormalFSARanalysiswhereitmaybenecessary toisolatethePORVaftertheelectricwirehousedinthecrackedPORVhasbeensubmerged forseveralhours,and4)conditions outsidetheFSARanalysiswhereitmaybenecessary toopenanisolatedPORVaftertheelectricwirehousedlnthecrackedPORVhasbeensubmerged forseveralhours.Eachoftheseconditions isdiscussed below.ThesingleChapter14accidentanalysiswhichrequiresPORVoperability isthesteamgenerator tuberupture(SGTR)withalossofoffsitepower.Inthisevent,onePORVisrequiredtoreduceprimarysystempressureduringtherecoveryphaseoftheaccidenttoslightlyabovethesecondary sidepressure.
AsecondPORVisrequiredtobeoperableforsinglefailureconsiderations.
TheUFSARChapter14SGTRisnotconsidered tobeafloodingevent,andtherefore thecrackedflooduptubeswouldnothaveimpactedthePORVblockvalveoperability forthisaccident.
fCreditistakenintheplantemergency operating procedures forthePORVstorecoverfromavarietyofaccidents.
Thiswouldincludethecategoryofeventsandaccidents thatcc"dcausethePORVstoopenandfailtoclose,resulting inasmallbreakLOCA(e.g.normalplantcooldown, activation ofthesafetyinjection system,orseveretransients suchasafeedwater linebr'eakorsteamlinebreakinsidecontainment).
ThemainfunctionofthePORVblockvalvesistoisolateaPORVifthePORVfailsintheopenposition.
Foreventsofthetypecitedabove,eithertheydonotcausecontainment
: flooding, oriftheydocauseflooding, theneedtoclosethePORVsoccursearlyenoughinthetransient thattheblockvalveswouldstillbeconsidered operableinspiteofthewaterintrusion thatmayhaveoccurredduetocracksintheflooduptubes.Athirdcategoryofeventsincludelongtermrecoveryactionssuchasresponsetoinadequate corecoolingorresponsetodegradedcorecoolingwherethecontainment couldbeflooded.EachoftheseeventsrequirethatastuckopenPORVbeisolated.
Theseeventsarebeyondthoseconsidered intheplantdesignbasis,anditisconsidered highlyunlikelythatanadverseaccidentofthistypecouldoccuratthesametimethataPORVsticksopen,thecablesaresubmerged, andtheblockvalvefailstoclosewhenitisrequired.
ThefinalcategoryiseventsthatrequireaPORVtobeopentofacilitate accidentrecovery.
Anexampleofthiswouldbethefeedwater linebreakrecovery.
However,notallofthethreePORVswouldhavebeenaffectedbycracksintheflooduptubes,andatleastonewouldbeavailable forthispurpose.Thismeetstheminimumrequirement.
NRCFORM366A.S.NUCLEARREGULATORY COMMISSION LICENSEEEVENTCONTINUATION ROVEDBYOMBHO.3150-0104 EXPIRES5/31/95ESTIMATED BURDENPERRESPONSETOCOMPLYNITHTHISIHFORMATION COLLECTIOH REQUEST:50.0HRS;.,FORIIARDCOMMENTSREGARDING BURDENESTIMATETO'HEINFORMATION ANDRECORDSMANAGEMENT BRANCH(MHBB7714),U.S.NUCLEARREGULATORY COMMISSION;
'WASHINGTON, DC20555-0001, ANDTOTHEPAPERNORK REDUCTION PROJECT(3150.0104),
OFFICEOFMANAGEMENT ANDBUDGET'NASHIHGTON DC20503.FACILITYNAME1CookNuclearPlant-Unit1TEXT(ifaorespaceisrequired.
useaddit(onal NRCFora366A's)(17)AnalslsoftheEventcont'dDOCKETNU)IER250-315LERNUMBER6YEARSEQUENTIAL 97-006REVISIOH01PAGE39OF10Unit2Containment AirRecirculation/H droenSkimmerFanTheCookNuclearPlanthastwocontainment airrecirculation/hydrogen skimmer(CEQfans),onlyoneofwhichisrequiredforaccidentmitigation.
Onlyonefanwasadversely impactedbyacrackedflooduptube.TheCEQfansarerequiredtoprovideacontinuous mixingofthecontainment atmosphere forthelongtermpostblowdownaccidentenvironment.
Theyarealsorequiredtopreventtheformation ofhydrogenpocketswithinthevariouscompartments andsubcompartments oftheicecondenser containment.
Twofullcapacityfans,eachcapableofblowingairfromtheuppervolumeintothelowervolumeareprovided.
Foraccidentanalysisconditions, onlyonefanismodeledbaseduponthelimitingsinglefailureofatrainofcontainment safeguards equipment.
Theairrecirculation fanshavesufficient headtoovercomethecompartment pressuredifferentials thatoccuraftertheinitialRCSblowdown.
Thefanswillblowairfromtheuppercompartment tothelowercompartment therebyretumlngairtothelowercompartment whichwasdisplaced bytheblowdown.
Althoughthefansaremodeledduringboththecontainment responsetransient following aLOCAandMSLB,thegreatestimpactresulting fromtheiractivation isseenduringtheLOCAtransient responseduetothelongtermtransient scenario.
Theairreturnfansaremodeledtooperateuponreachingthehigh-high containment pressuresetpointfollowing atenminutedelay.DuringtheLOCAresponsetransient thefansprovideaflowpathearlyinthetransient, therefore theirfunctionplaysanimportant role(beforethetimeofpeakpressure) inthecontainment responsecalculation.
Similarly duringtheMSLBcontainment responsecalculation thefansfunctioninalikewisemanner.However,thetimethefansactivatefollowthetimewhenthecontainment peakpressureandtemperature occurs,therefore theirimpactonthecontainment responsetransient isminimal.Theirprimaryeffectisontherateofcontainment depressurization andcooldownafter10minutesintotheMSLBcontainment responsetransient.
Baseduponsensitivities whichhavebeenperformed foranicecondenser plantsimilartotheCookNuclearPlantwhenconsidering inoperable airreturnfans,theeffectofthelossoftheairreturnfanoncontainment peakpressurewas5psi.SincetheCookdesignpressureis12psi,thismeansthatthemaximumpressureachievedbythecontainment shouldbothfansbelostis17psi.Althoughabovetheplantdesignbasisof12psi,thisiswellwithinthecontainment ultimatecapability ofapproximately 36psi.Thepotential lossofCEQfansalsomeansthelossofabilitytoremovehydrogenfromthecompartments oftheCookNuclearPlant.Thiswillnotoccuruntiltwohoursintotheaccident.
AspartoftheCookNuclearPlant'sprobabilistic riskassessment, studieshavebeenperformed toevaluatethelossofCEQfansfollowing asevereaccident.
Thesestudieshaveconcluded thatnoadverseimpactoncontainment performance isexpectedduetocontainment recirculation fanfailures.
Onthebasisoftheabove,itisconcluded thatthelossofoneCEQfandidnotadversely impactthepublichealthandsafety.Itisfurtherpointedout,thatonlyoneofthetworedundant fanswasimpacted, andtherefore following ahighenergylinebreakinsidecontainment theplantmayhavestayedwithitsdesignbasiscontainment pressureof12psi.
NRCFORH366A.S.NUCLEARREGULATORY COXHISSICILICENSEEEVENTCONTINUATION BY'ORBNO.3150-0104 EXPIRES5/31/95ESTIHATED BURDENPER-RESPONSE TOCOHPLYWITHTHISINFORHATION.COLLECTION'REQUEST:
50.0NRS'.FORIIARDCOHHENTSREGARDING BURDENESTIHATETOTHEINFORHATION ANDRECORDSHANAGEHENT BRANCH(HNBB7714),U.S.NUCLEARREGULATORY COHHISSION, MASNINGTON, DC20555-0001, ANDTOTHEPAPERNORK REDUCTION PROJECT(3150-0104),
OFFICEOF"HANAGEHENT ANDBUDGETMASNINGTON DC20503.FACILITYNAHE1CookNuclearPlant-Unit1TEXT((fmorespaceisrequired.
useadditional NCForm36EA's)(17)Corrective ActionDOIETNUNBER25015YEAR97LERNUNBER6SEQUENTIAL REVISION01PAGE310OF10Criticalareasforallflooduptubesineachunithavebeeninspected forcracks.ThedamagedUnit1EQfiooduptubesandUnit2flooduptubeshavebeenreplaced.
Preventive ActionAdequateprecautions forweldinginthevicinityofelectrical equipment havebeenidentified intheAEPWeldingManual,GeneralWeldingRequirements, step6.13whichincondensed versionstates:basematerials andothermetallicregionsoutsideoftheweldzoneshallbeprotected topreventinadvertent arcstrikes.Inaddition, PMI-2270(FIREPROTECTION),
containstheWelding,Burning,8GrindingPermitwhichisissuedforallweldingactivities.
Thepermitcoversarearequirements whichprovidedirection tocoverelectrical equipment aridcabletrayswithfireblanket.Tosupplement theseplantrequirements, aninspection asstatedbelowwillbeperformed toverifythatthetubeshavenotbeendamagedpriortostart-upafteroutageworkhasbeenperformed.
WorkStandards totheNuclearPlantMaintenance (NPM)andEnvironmental Qualification Preservation Documents (EQPD)willbeenhancedtoidentifythatwhileworkingontheflooduptubesthereisaneedtoavoidaddingunduelocalized stresstotheflooduptubesandthentoverifythatnocrackshavedeveloped
.TheWorkStandards totheNPMforflooduptubeinstallation havealreadybeenrevisedtoincludetheseprecautions.
Asalongtermaction,newEQPDwillbeissuedbyJune1,1998forflooduptubestoidentifythecriticalEQparameters.
Inspections willbemadeatthebeginning ofeachoutagetocheckforanycracks.Inspections willalsobemadeattheendoftheoutagetoensurethatnooutageactivities damagedanytubes.Inaddition, althoughnotcontained inaformalprogram,theknowledge thatthetubesaresubjecttothistypeofdamagewillheightenawareness andimproveworkbeingdoneonandaroundtheflooduptubes.FailedComonentIdentification NotApplicable PreviousSimilarEventsNone}}

Revision as of 07:16, 29 June 2018

LER 97-006-01:on 970327,equipment in Containment Rendered Inoperable Due to Cracked Floodup Tubes Identified.Caused by Work Practices That Resulted in Two Separate Types of Failures.Critical Areas inspected.W/970530 Ltr
ML17334B632
Person / Time
Site: Cook American Electric Power icon.png
Issue date: 05/30/1997
From: BLIND A A, FINISSI M
INDIANA MICHIGAN POWER CO. (FORMERLY INDIANA & MICHIG
To:
NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
LER-97-006, LER-97-6, NUDOCS 9706050294
Download: ML17334B632 (17)
v • d • e


Text

CATEGORYREGULATOINFORMATION DISTRIBUTION TEM(RIDS)ACCESSION NBR:9706050294 DOC.DATE:

97/05/30NOTARIZED:

NODOCKETFACZL:50;315 DonaldC.CookNuclearPowerPlant,Unit1,IndianaM05000315tAOTH.QAME

'UTHORAFFILIATION FINZSSZ,M.

IndianaMichiganPowerCo.(formerly Indiana&MichiganEleBLIND,A.A.

IndianaMichiganPowerCo.(formerly Indiana&MichiganEleRECIP.NAME RECIPIENT AFFILIATION

SUBJECT:

LER97-006-01:on 970327,equipment incontainment renderedinoperable duetocrackedflooduptubeswasidentified.

Causedbyworkpractices thatresultedintwoseparatetypesoffailures.

Criticalareasinspected.W/970530 ltr.DISTRIBUTION CODE:.IE22TCOPIESRECEIVED:LTR ENCLSIZE:TITLE:50.73/50.9 LicenseeEventReport(LER),IncidentRpt,etc.NOTES:EINTERNAL:

RECIPIENT IDCODE/NAME PD3-3PDFILECENTERNRR/DRCH/HHFB NRR/DRCH/HOLB NRR/DRPM/PECB NRR/DSSA/SRXB RGN3FILE01COPIESLTTRENCL112211111111111111RECIPIENT IDCODE/NAME HICKMAN,J AEOD/SPD/RRAB NRR/DE/ECGB NRR/DE/EMEB NRR/DRCH/HICB NRR/DRCH/HQMB NRR/DSSA/SPLB RES/DET/EIB COPIESLTTRENCL11111111111111l,lDEXTERNAL:

LSTLOBBYWARDNOACPOORE,W.NRCPDR1111~11LITCOBRYCE,JHNOACQUEENER,DS NUDOCSFULLTXT111111UNNOTETOALL"RIDS"RECIPIENTS:

PLEASEHELPUSTOREDUCEWASTETHCONTACTTHEDOCUMENTCONTROLDESKiROOMOWFN5D-5(EXT.

415-2083)

TOELIMINATE YOURNAMEFROMDISTRIBUTION LISTSFORDOCUMENTS YOUDON'TNEED!FULLTEXTCONVERSION REQUIREDTOTALNUMBEROFCOPIESRF"ZRED:LTTR24ENC'4 IndianaMichiganPowerCompanyCookNuclearPianiOneCookPlaceBridgman, MI49106IMay30,1997UnitedStatesNuclearRegulatory Commission DocumentControlDeskWashington, DC20555Operating LicensesDPR-58DocketNo.50-315DocumentControlManager:Inaccordance withthecriteriaestablished by10CFR50.73entitledLicenseeEvent~lhfI'gpibig1iltd.'7-006-01 Sincerely, A.A.BlindSiteVicePresident I(ImbdAttachment c:A.B.Beach,RegionIIIE.E.Fitzpatrick P.A.BarrettS.J.BrewerJ.R.PadgettD.HahnRecordsCenter,INPONRCResidentInspector 9706050294 970530PDRADQCK050003i58PDRllllllllllllllllllllllliilllill flillli

NRCFORM366(5-92)S.NUCLEARREGUULTORY COMMISSION LICENSEEEVIDENTREPORT(LER)ROVEDBYOHBNO.3150-0104 EXPIRES5/31/95ESTIMATED BURDENPERRESPONSETOCOMPLYlllTHTHIINFORMATION'COLLECTIOM REQUEST:50.0MRS.-FORNARCOMMENTSREGARDIHG BURDENESTIMATE ToTHINFORMATION ANDRECORDSMANAGEMENT BRANCH(MMB7714),U.STNUCLEARREGULATORY COMMISSION NASHIMGTON, DC20555-0001, ANDTOTHEPAPERMORREDUCTION PROJECT(3150.0104),

OFFICE0MANAGEMENT ANDBUDGETNASHINGTOH DC20503.'ACILITY NAME(1),OonaldC.CookNuclearPlant-Unit1DOCKETNUMBER(2)50.315Page1of10TITLE(4)EuimentinContainmentRenderedlno erableDuetoCrackedFloodu TubesMONTHDAYYEAREVENTDATE5YEARLERNUMBER6SEQUENTIAL MUHBERREVISIONNUMBERMOHTHDAYYEARREPORTDATE7FACILITYNAMECook-Unit2DOCKETNUHBER50-316OTHERFACILITIES INVOLVED8279700601053097FACILITYNAMEDOCKETNUMBEROPERATING MODE(9)P(XJERLEVEL(10)0THISREPORTISSUBMITTED PURSUANT20.2201(b) 20.2203a120.2203(a)(2)(i) 20.2203a2ii20.2203(a)(2)(iii) 20.2203(a)(2)(iv)

?0.2203(a)(2)(v) 20.2203(a){3)(i) 20.2203a3ii20.2203(a)(4) 50.36c150.36(c)(2) 50.73(a)(2)(i) 50.73(a)(2)(ii) 50.73(a)(2){iii) 5073a)(2iv'0.73(a)(2)(v) 50.73a2vii50.73(a)(2)(viii)(A) 50.73(a)(2)(viii)(B) 50.73(a)(2)(x) 73.71(b)73.7toOTHER(SpecifyinAbstractbetouandinText,NRCForm366A)TOTHEREQUIREMENTS OFt0CFR:CheckoneormorettNAMELICENSEECONTACTFORTHISLER12Mr.MikeFinissi,SystemEngineering

-Electrical Supervisor TELEPHONE NUMBER(IncludeAreaCode)616/465-5901, x2830COMPLETEONELINEFOREACHCOMPONENT FAILUREDESCRIBED INTHISREPORT13CAUSESYSTEMCOMPOHEHT MANUFACTURER REPORTABLE TONPRDSCAUSESYSTEHCOMPOHEHT MANUFACTURER REPORTABLE TONPRDSSUPPLEMENTAL REPORTEXPECTED14YES(Ifyes,completeEXPECTEDSUBMISSIOH DATE).XHOEXPECTEDSUBMISSION DATE(15)MONTHDAYYEARABSTRACT(Limitto1400spaces,i.e.,approximately 15single-spaced typevritten tines)(16)ThisLERrevisionisbeingsubmitted toprovideadditional information regarding thesafetysignificance andtherootcausedetermination forcrackedilooduptubes(FUTS)foundinCookUnits1and2.Duringaninspection offiooduptubesformoistureintrusion, 3FUTSwiththruwalldefectswereidentified.

Asaresult,pro-activemeasuresweretakentoinspecttheremaining Unit1FUTS.Thisresultedlntheidentification ofsixadditional thruwalldefectsinUnit1.Asaresult,Unit2FUTswereinspected, and2crackedtubeswerefound.Ofthe11totaldamagedtubes,Unit1contained 7FUTSandUnit2contained 1FUTwithanassociated circuitthatisneededforacddentmitigation orpostacddentmonitoring.

OnMarch23theUnit2condition wasreportedunder10CFR50.72(b)(1)(ii).

OnMarch27Unit1condition wasreportedunder10CFR50.72(b)(2)g.

ENSnotifications weremadeforboth.Thedamagehasbeenattributed toworkpractices thatresultedintwodifferent typesoffailures-material stresscracksandrandomarcstrikes,mostprobablyearlyinplantNe.AlldamagedUnit1EQFUTShavebeenreplacedandbothUnit2tubeshavebeenreplaced.

Topreventthecracksduetoinstallation practices fromreoccurring, theCookPlantFUTInstallation WorkInstructions willbemodifiedtocontainadditional guidance.

Weldingpractices havebeensuflidently enhancedsincetheearlyportionoftheplantlife topredudearestrikesonFUTS.Inspections oftheFUTSfordamagewillalsobeperformed atthebeginning andtheendoftherefueling outagesuntilassurance isreachedthatnofurtherproblemswerefound.Postulated failuresthatcouldresultfromthecrackedflooduptubeswereevaluated andfoundnottopresentasignifican riskwithregardtotheprotection ofthepublichealthandsafety.

NRCFORH366A~SNUCLEARREGULATORY C(mHISSIONLICENSEE&/ENTCONTINUATION tPPROVEDBYOHB'O.3150.0104 EXPIRES5/31/95ESTIHATED BURDENPERRESPONSETOCOHPLY'WITHTHISIHFORHATION COLLECTION REQUEST:50.0NRS.'ORNARDCOHHEHTSREGARDING BURDENESTIHATETOTHEINFORHATION ANDRECORDSHANAGEHENT'RANCH'HNBB 7714),U.S.NUCLEARREGULATORY COHHISSION, NASHINGTON, DC20555-0001, ANDTOTHEPAPERIJORi(

REDUCTION PROJECT(3150-0104)

~OFFICEOFHANAGEHENT ANDBUDGETMASNINGTON DC20503.FACILITYNAÃE1CookNuclearPlant-Unit1TEXT(ifserespaceisrequired.

useadditicnal iaCFora366A's)(17)50-315LERNUHBER6'EARSEQUENTIAL 97-006REVISION01'PAGE32OF10Conditions PriortoOccurrence Unit1wasinMode6,Refueling Unit2wasinMode1,PowerOperation, at100percentRatedThermalPowerDescritlonofEventElectrical penetrations attheD.C.CookNuclearplantarelocatedbelowthepredicted floodinglevelinsidecontainment following alossofcoolantaccident.

Asaresult,safetyrelatedcablesareroutedthroughstainless steeltubes,knownasflooduptubes,whichpreventthewaterinthecontainment fromcontacting thecables.Thisprecaution isnecessary becausetheelectrical cableshavenotbeenenvironmentally qua1ified forsubmergence inwater.AllKatponwiresbelowflooduplevelsneededforEQarecontained inaflooduptube.ThereisnootherEQequipment belowflooduplevelwhichneedsflooduptubestomaintainitsqualification.

AsaresultofLER316/96-006-00, whichwaswrittentodocumentthediscovery ofmoistureintrusion intoFUTsduringUnit2's1996refueling outage,onethirdofUnit1'sFUTswereinspected formoistureintrusion duringits1997refueling outage.Duringtheflooduptubeinspection, ninetubesinUnit1werefoundtohavecrackswhichwouldallowwaterintrusion following alossofcoolantaccident.

AsaresultoftheUnit1findings, theflooduptubesinUnit2wereinspected, andtwocrackedtubeswerediscovered.

Thecablesthatarecontained insidetheflooduptubesareKaptoninsulated, andareviewofpartialtestdataforKaptoninsulated wiresinhighpHsolutions hasledtotheconclusion thatcablefailuresmayoccuraftertw'ohoursofsubmergence inthehighpHsolution(9to10)thatwouldfloodthelowercontainment following alossofcoolantaccident.

TheUnit1tubeswereinspected duringtheperiodMarch16,1997throughMarch23,1997.Following theinspection, thefollowing equipment whichisrequiredforaccidentmitigation orpostaccidentmonitoring wasidentified asadversely impactedbytheexistence ofacrackedfiooduptube:1-8LP-1321-BLP-142 1-NTR-140 1-NTR-240 1-HR-11-VMO-102SteamGenerator threenarrowrange(EIIS/IP-LT) leveltransmitter SteamGenerator fournarrowrange(EIIS/IP-LT) leveltransmitter Reactorcoolantloop4hotlegwide(EIIS/TR) rangetemperature recorderthermalsensorReactorcoolantloop4coldlegwide(EIIS/TR) rangetemperature recorderthermalsensorHydrogenRecombiner (EIIS/BB-RCB)

Containment HydrogenSkimmer(EIIS/BB-IV) ventilation fanHV-CEQ-2suctionshutoffvalve

HRCFORH366A.S.NUCLEARREGULATORY COXHISSIOHLICENSEEZWHNTCONTINUATION

&PROVEDBYQS'NO.3150-0104 EXPIRES5/31/95ESTIHATED BURDENPERRESPONSE'TO COHPLYMITHTHISINFORHATION COLLECTION REQUEST:50.0HRS.FORMARDCOHHEHTSREGARDIHG BURDENESTIMATETOTHEIHFORHATIOH AHDRECORDSHANAGEHEHT.

BRANCH(HHBB7714),U.S.NUCLEARREGULATORY COHHISSIOHg MASHINGTON, DC20555-0001, AND-TOTHEPAPERMORK REDUCTION PROJECt(3150-0104),

OFFICEOFHANAGEHENT ANDBUDGETMASHIHGTOH DC20503;,FACILITYMAKE1CookNuclearPlant-Unit150-315LERHUHBER6YEARSEQUEHTIAL 97-006REVISION01~I~t4rraua3OF10TEXT((fcerespaceisrequ(red.

useaddit(onal NRCForm366A's)(17)DescritionofEventcont'd1-NSO-021 ReactorCoolantSystempost-accident (EIIS/AB-VTV) venttrainAsolenoidvalve1-IMO-315 EastRHRandNorthSafetyInjection to(EIIS/BO-INV) reactorcoolantloops1and4hotlegsshutoffvalve1-IMO-316 EastRHRandNorthSafetyInjection to(EIIS/BO-INV) reactorcoolantloops1and4coldlegsshutoffvalve1-IMO-325 WestRHRandsouthsafetyinjection to(EIIS/BO-INV) reactorcoolantloops2and3hotlegsshutoffvalve1-NMO-151Pressurizer reliefvalveNRV-151(EIIS/AB-ISV) upstreamshutoffvalve1-33-NRV-153 Pressurizer trainApressurereliefvalveNRV-153closelimitswitchTheUnit2flooduptubeswereinspected onMarch23,1997.Atthattime,acrackwasfoundintheflooduptube2-IP3-3.Thisflooduptubecontainsacablewhichsuppliespowertooneoftwocontainment recirculation (CEQ)fans(EIIS/BB-FAN).

TheCEQfansoperatelongtermfollowing alossofcoolantaccident, andabsentqualification dataforwatersubmergence, continued operation oftheimpactedCEQfancouldnotbeguaranteed.

CauseoftheEventThetubedamagehasbeenattributed toworkpractices thatresultedintwoseparatetypesoffailures-material stresscracksandrandomarcstrikes,mostprobablyearlyintheplantlife.Inthreeisolatedinstances, unrelated tothematerialstresscracks,thetubeexhibited holesinthetubeapproximately 1/8"-1/4" wide.Theseholeshadaburnedappearance suchthattheymayhavebeencausedbyweldingactivities inthevicinityoftheflooduptubes.Theothercauseisduetolocalized stressestothematerialatthepointwherethetubetransitions fromflexibletoarigidconfiguration.

Thecausalanalysisevaluated thebasictubeconstruction, inspected damagedtubes,andperformed aninspection ontheinstallation intheannulus.Theflooduptubeconstruction isastandardsingle-ply helicalcorrugated bellowsthatisconstructed fromaType321stainless steel.BothendsoftheflooduptubeareweldedtoaType304stainless steelfittingwithmalethreads.Thefittingsconstitute arigidpointwhilethebellowsthemselves areaflexiblemember.Thistypeofconstruction allowsthetubetoflexuniformly throughout itsentirelengthexceptatthepointwhereitconnectstothefittings.

HRCFORN366A.S.NUCLEARREGUULTORY COXNISSIOM LICENSEELWENTCONTINUATION ROVEDBYONBNO.3150-01,04 EXPIRES5/31/95ESTINATED BURDENPERRESPOHSETO'COHPLY MITHTHISIHFORHATIOH COLLECTIOH REQUEST:50.0NRS;FORNARDCONHEHTSREGARDING BURDENESTINATETOTHEINFORNATION ANDRECORDSNANAGEHEHT BRANCH"(NHBB7714),U.S.NUCLEARREGULATORY COHHISSION, IIASHIHGTON, DC20555-0001, AHDTOTHEPAPERHORK REDUCTION PROJECT(3150-0104),

OFFICEOFHANAGEHEHT ANDBUDGETMASHINGTOH DC20503.FACILITYMANE1CookNuclearPlant-Unit1TEXT(ifsorespaceisrequired.

useadditional HRCFore366A's)(17)CauseoftheEventcont'dDOCKETNU)IBER250-315YEAR97LERNIGER6SEQUENTIAL REVISICH01PAGE34OF10Anexamination oftwocrackedtubeswhichhadthissecondtypeoffailurewasperformed byDCCNPmetallurgical engineers

.Aportionoftheirinvestigation follows:"Anexamination oftwotypically crackedtubesrevealeda3/4"longlinearindication orientedparalleltothecorrugation attherootofaconvolution.

Thecrackwaslocatedadistanceoftwoconvolutions fromtheweldattaching thebellowstothethreadedfitting.Oneendofthecrack,hadaY-pattern crackthatisindicative ofacrackinitiation pointduetoexcessive bendingstressinthethinmaterial.

Duetothecrack'slocation, thedefectisnotweldingrelated.Althoughnotusedinthisapplication, thecorrugated bellowsiscapableofwithstanding motion,lateraloffset,angularrotation, aswellasaxialextension andcompression overtheentirelengthoftheflooduptube.However,withinalocalized region,suchaswherethebellowsareattachedtothethreadedfitting,thebellowstransitions fromflexibletorigid.Atthislocation, thethinbellowsmaterialwillnotwithstand anybendingortorsional rotationloading."

Theflooduptubeinstallation intheannuluswasreviewedtodetermine whichconfiguration wasmorepronetofailure.Itwasfoundthatallthoseflooduptubesthathavethistypeofdefectwereinthoseinstallations wherethereisaminimumofseventubesperpenetration.

Thisisattributed tothefactthatthosepenetration" installations withmoreflooduptubesalsohavemorestringent bendingrestrictions duetospacerestrictions.

Thefactthatallthesecrackswerenearthefittingendoftheflooduptubeandinthoseinstallations whichrequiresmallerbendingradiiconfirmthatthecrackswereduetolocalized stress.Duetothetype,location, orientation ofthedefectandlackofloadingduringservice,thesedefectsweremostprobablyinitiated inthebellowsduringinstallation orsubsequent rework.AnalsisoftheEventTheseeventsarereportable undertheprovisions of10CFR50.73(a)(2)()l.

(8),operation prohibited bytheplant'stechnical specifications, 10CFR50.73(a)(2)(ii),

anyeventorcondition thatresultedinthecondition ofthenuclearpowerplant,including itsprincipal safetybarriers, beingseriously

degraded, and10CFR50.73(a)(2)(ii)(B),

acondition whichisoutsideofthedesignbasisoftheplant.Thecablesarerequiredtobeenvironmentally qualified per10CFR50.49.

However,theenvironmental qualification testingdidnotincludesubmerging thecableinwater.PartialtestdataforKaptoninsulated cableshowsthatonetestsamplefailedaftertwohours,andasecondtestsamplefailedafterfortyeighthours.Onthisbasis,itwasdetermined thatKaptoninsulated cablewasnotsuitableforlongtermusesubmerged inasumpsolutionhavingapHof9-10.

iiRCFORH366AU.S.NUCLEARREGULATORY COO)ISSIONLICENSEEEVENTCONTINUATION APPROVEDBYO)IBNO.3150-0104 EXPIRES5i31/95ESTINATEO BURDENPERRESPONSETOCOHPLYMITHTHISlNFORHATION COLLECTION REaUESTs50.0.HRS.FORMAROCOHHENTSREGARDIHG'BURDEN ESTIHATETO'HEINFORNATION ANDRECORDSHANAGEHENT BRANCH(HNBB7714),U.S.NUCLEARREGULATORY COHHISSIONg MASHINGTOH, DC20555.0001, ANDTOTHEPAPERMORK REDUCTION PROJECT(3150-0104)

~OFFICEOFHANAGEXENT ANDBUDGETMASHINGTON DC20503.FACILITYNAKE1CookNuclearPlant-Unit1TEXT(ifcerespaceisrequired, useadditional HRCFora366A's)(17)AnalsisoftheEventcont'dDOCKETaRJÃBER250-315YEAR97LERNURSER6SEOUENTIAL REVISION01PAGE35OF10Becausethecracksinfiooduptubesarelocatedbelowthecontainment flooduplevel,water,couldenterthetubeandthecablewouldbesubmerged inasodiumhydroxide solutionhavingapHof9to10.Submergence inthis.solutionwoulddegradetheKaptoninsulation, anditwouldeventually fail.Asthetimetofailure.cannotbeaccurately predicted, anyequipment requiredforIongtermaccidentmitigation wasconsidered tobeinoperable.

Equipment whichcouldcompleteitssafetyfunctionwithintwohoursfollowing theaccidentwasconsidered operableforthepurposeoftheanalysispresented inthisLER.iltisnotpossibletotellwhenthetubesbecamecracked.However,theapparentcauseofthecracks,weldingarcstrikesandstresscracking, indicates thattheyexistedpriortodiscovery.

Therefore, itisassumedthattheunitwasinT/S3.0.3,whichisreportable asacondition whichisoutsidethedesignbasisoftheplantandasoperation prohibited bytheplant'stechnical specifications.

Theresultoftheevaluation isthat,althoughthepotential forequipment failureplacedtheplantoutsideofitslicensing basisinmanyinstances, therewasnopostulated failurethatisconsidered tohaveamajorimpactwithregardtoprotecting thepublichealthandsafety.Also,inmanycasestheequipment wasbackedupbyunaffected redundant equipment and/orequipment whichco'uldperformasimilarsafetyfunction.

Unit1NarrowRaneSteamGenerator LevelTransmitters Thenarrowrangesteamgenerator leveltransmitters (1-BLP-132,

-142)provideasignaltothereactorprotection system,andtheyareusedforpostaccidentmonitoring ofthesteamgenerator level(Technical specification 3.3.3.8requiresoneoperablechannelpersteamgenerator).

Theprotection systemfunctionwouldbeaccomplished priortothecable'sbecomingsubmerged.

Therearethreenarrowrangesteamgenerator leveltransmitters persteamgenerator, andthepostaccidentmonitoring functioncouldbeaccomplished byeithertheremaining twonarrowrangetransmitters.

HotLeWideRaneTemeratureRecorderThehotlegwiderangetemperature recorder(1-NTR-140,

-240)signalisrequiredasinputtotheRCSIsubcooling monitor,andthesubcooling monitoring systemwouldbelesseffective sinceinputtemperatures fromanentireRCSloopwouldbelost.Theoperatoralsohasavailable subcooling indication usingthecoreexitthermocouples.

Thisisactuallythepreferred methodofdetermining subcooling sinceitprovidesconservative results.Thusthelossof1-NTR-140and1-NTR-240 wouldnothavesignificantly impactedplantoperations andisjudgedtohavehadnoadverseimpactonpublichealthandsafety.

MRCFORM366AS.N)CLEARREGULATORY COMMISSION LICENSEE'TTENTCONTlNUATION (NBMO-3150-0104 EXPIRES5/3'I/95ESTIMATED BURDENPERRESPONSETOCOMPLYWITHTHISINFORMATION COLLECTION REQUEST:50.0HRS.FORWARDCOMMENTSREGARDING BURDENESTIMATETOTHEINFORMATION ANORECORDSMANAGEMEHT BRANCH(MNBB7714),U.S.NUCLEARREGULATORY COMHISSIOH

~WASHINGTON, OC20555-0001, ANOTOTHEPAPERWORK REDUCTION PROJECT(31500104)gOFFICEOFMANAGEMENT ANDBUDGETWASHINGTON DC20503.FACILITYNAMECookNuclearPlant-Unit1TEXTitfNorespaceisrequired.

useadditional MICFons3664's)(I7),AnalslsoftheEventcont'd50-31597LERMINBER6SEQUENTIAL REVISION01PAGE36OF10HdroenRecombiner TheCookNuclearPlanthastwohydrogenrecombiners ofwhichonlyoneisrequiredforaccidentmitigation.

Onlyoneofthetworecombiners (1-HR-1)wasadversely impactedbyacrackedflooduptube.Thehydrogenrecombiner isusedtomaintainthelong-term hydrogenconcentration insidecontainment below4volumepercent.Althoughtheprincipal meansofhydrogencontrolthatisincludedfntheplantdesignbasisaretwoelectrichydrogenrecombiners combinedwithtwocontainment airrecirculation fans,additional meansofhydrogencontrol,hydrogenigniters, wereaddedtoaddressthepossibility ofexcessive hydrogenconcentrations thatmayexistfollowing asevereaccident.

Ananalysishasbeenperformed toshowthattheignitersarecapableofpreventing hydrogenignitionfromendangering thepublichealthandsafetywhenhydrogenconcentrations areexcessively high.Therefore, intheeventthatbothrecombiners weretofail,andthehydrogenconcentrations weretobuilduptoexcessive amounts,itisbelievedthatthehydrogenigniterswouldpreventtheensuingproblemswithhydrogenignitionfromadversely impacting publichealthandsafety.Althoughtheignitersdonothavethedatatosupportlongevity ofoperation, theyarecapableofsupporting operation foratleastoneweek.Itisbelievedthattheigniterswouldlastforperiodsconsiderable beyondthattime.Duringthetimethattherewastotalrelianceonthehydrogenigniters, itmaybepossibletorepairtheunaffected electrichydrogenrecombiner (iftherepaircouldbeperformed outsidethecontainment) orestablish someothermeansoflongtermhydrogencontrol,ifitwerenecessary.

Basedonthecombination oftheunlikelihood offailureoftheredundant hydrogenrecombiner, combinedwiththeavailability ofthehydrogenigniters, itisconcluded thattherewouldbeanalmostnegligible chancethatthecracksinthefiooduptubesservicing electrical cablesto1-HR-1wouldhaveresultedinsignificant problemsassociated withhydrogenignitionshouldadesignbasisLOCAhaveoccurredattheplant.Itistherefore concluded thatthecrackintheflooduptubeassociated with1-HR-1didnotrepresent asignificant hazardwithregardtotheprotection ofthepublichealthandsafety.Containment Recirculation FanValveTheCookNuclearPlanthastworecirculation fans,onlyoneofwhichisrequiredforaccidentmitigation.

Onlyoneoftherecirculation fanswasimpactedbythecrackedflooduptubecontaining thecableassociated withvalve1-VMO-102.

Thecontainment airrecirculation systemvalveisactivated 10minutesaftertheaccidentoccurs.Basedonpartialtestdatawhichdemonstrate thataminimumoftwohoursisrequiredbeforeKaptoninsulation isdegradedtothepointwhereitisnolongereffective, itisconcluded thatthisvalvewouldhaveperformed itsfunctionpriortotheinsulation's beingsignificantly degraded.

MRCFORM366ASN)CI.EARREGULATORY COOIISSIONLICENSEEEVENTCONTINUATION BY(NBMO.3150-0104 EXPIRES5/31/95ESTIMATED BURDENPERRESPONSETOCOMPLYMITHTHISINFORMATION COLLECTION REQUEST:50.0HRS.FORNARDCOMMENTSREGARDING BURDENESTIMATETOTHEINFORMATION AHDRECORDSMANAGEMEHT BRANCH(MHBB7714),U.S.NUCLEARREGULATORY COMMISSION/

MASHIHGTOH, DC20555-0001, ANDTOTHEPAPERNORK REDUCTION PROJECT(3150-0104),

OFFICEOFMANAGEMENT ANDBUDGETllASHIHGTOH DC'20503.

FACILITYMANE1CookNuclearPlant-Unit1TEXT(ifserespaceisrequired.

useadditional NRCFons36Q's)(17)AnalslsoftheEventcont'dDO(XETNIGER250-315.YEAR97LERNIGER6SEQUENTIAL 006REVISION01PAGE37OF10ReactorVesselHeadVentValveTheCookNuclearPlanthastwoheadventvalves,onlyoneofwhichisrequiredbythetechnical specifications tobeoperable.

Onlyoneoftheheadventvalveswasimpactedbyacrackedflooduptube.Thereactorvesselheadventsystem(1-NSO-021) isaseries/parallel arrangement wherefourvalvesaresuppliedbytwoseparatepowertrains.Anidentical arrangement existsforthepressurizer headvent.NocreditistakenforthereactorheadventsintheFSARdesignbasisaccidentanalysis.

Theyarestrictlyacontingency tobeusedforsevereaccidents.

Thereactorheadventswereinstalled intheCookNuclearPlantinresponseto10CFR50.44 (c)(3)(iii) toventahydrogenbubbleinthereactorheadintheeventofadegradedcoreaccidentwithsignificant hydrogengeneration.

ThisheadventisalsousedintheEmergency Operating Procedures toaidinvesseldepressurization afterallothermechanisms havefailed,including boththeprimaryandsecondary poweroperatedreliefvalves.ColdLetoHotLeIn'ection ValvesValves1-IMO-315, 1-IMO-316 and1-IMO-325 arerequiredtofunctionwhenswitching fromcoldlegtohotleginjection following alossofcoolantaccident.

Valves1-IMO-315 and1-IMO-325 arerequiredtoopentoprovideahotlegflowpathtoloops1,2,3,and4.Valve1-IMO-316 isrequiredtoclosetoblockthecoldlegflowpathtoloops1and4.Usingthecurrentlicensedmethodology, theinability toswitchtohotlegrecirculation wouldresultinboronprecipitation inthecoreandpossibleheattransferdegradation, potentially leadingtoacladdingtemperature heatup.However,Westinghouse hasdeveloped anewmethodology which,iflicensedandimplemented, wouldeliminate theneedtoswitchtohotlegrecirculation.

Thismethodology modelstheflowthroughthegapbetweenthehotlegnozzleandthebarrelasamechanism fortransporting boratedvesselwatertothesump.TheWestinghouse WCAPpresentsthemethodology anddocuments agenericanalysisthatisapplicable tomostWestinghouse 3and4loopplant,including Cook.Amongtheconclusions drawnfromthegenericanalysisisthattheECCSdoesnotneedtobealignedtotheRCShotlegspost-LOCA inordertolimitthebuildupofboron.Assuch,thehotIegnozzlegapwouldhavelimitedthebuildupofboronaftertheLOCA,eveniftheECCScouldnothavealignedtothehotlegs.Thiswouldhaveprevented boronprecipitation inthecore,maintaining theheattransfercapability

.Thustheinability toaligntheECCStothehotlegswouldnothaveresultedinaviolation ofanyofthe10CFR50.46criteria.

Power0cratedReliefValveBlockValve1-NMO-151 isanormallyopenblockvalveforapressurizer poweroperatedreliefvalve(PORV),andistheonlyoneofthethreePORVblockvalvesthatwasimpactedbyacrackedflooduptube.TheCookNuclearPlantpressurizer hasthreePORVswhichlimitreactorcoolantsystempressure.

ThePORVs,whicharespringclosedandair-openuponactuation oftheirassociated solenoidvalve,operateautomatically orbyremotemanualcontrol.RemotelyoperatedblockvalvesareprovidedtoisolatethePORVs.

MRCFORH366A.SNUCLEARREGULATORY COXRISSIOH LICENSEEEVEBFZCONTINUATION BYORBMO.3150-0104 EXPIRES5/31/95ESTIHATED BURDENPERRESPOHSETOCOMPLYNITHTHISINFORHATION COLLECTIONRFCUEST:50.0'RS.FCRllARDCOHHENTSREGARDING BURDENESTIHATETOTHEIHFORHATIOH AHDRECORDS'HANAGEHENT BRANCH'HHBB 7714),U.S.NUCLEARREGULATORY COHHISSIOH, NASNIHGTON, DC20555-0001, AHDTOTHEPAPERHORX REDUCTION PROJECT(3150-0104),

OFFICEOFHANAGEHENT ANDBUDGETMASHIHGTOH DC20503.FACILITYMARECookNuclearPlant-Unit1TEXTOfcorespacefsrequired.

useadditional HRCFona366A's)(17)AnalsisoftheEventcont'dDOCKETNUMBER250-315YEAR97LERNUMBER6SEOUEHTIAL REVISIGH01PAGE3SOP10Power0cratedReliefValveBlockcont'dToevaluatetheimpactofthecrackedflooduptubes,fourconditions wereconsidered:

1)FSARaccidents; 2)highenergylinebreaksinsidecontainment whereimmediate isolation ofthePORVisrequired; 3)conditions outsideofthenormalFSARanalysiswhereitmaybenecessary toisolatethePORVaftertheelectricwirehousedinthecrackedPORVhasbeensubmerged forseveralhours,and4)conditions outsidetheFSARanalysiswhereitmaybenecessary toopenanisolatedPORVaftertheelectricwirehousedlnthecrackedPORVhasbeensubmerged forseveralhours.Eachoftheseconditions isdiscussed below.ThesingleChapter14accidentanalysiswhichrequiresPORVoperability isthesteamgenerator tuberupture(SGTR)withalossofoffsitepower.Inthisevent,onePORVisrequiredtoreduceprimarysystempressureduringtherecoveryphaseoftheaccidenttoslightlyabovethesecondary sidepressure.

AsecondPORVisrequiredtobeoperableforsinglefailureconsiderations.

TheUFSARChapter14SGTRisnotconsidered tobeafloodingevent,andtherefore thecrackedflooduptubeswouldnothaveimpactedthePORVblockvalveoperability forthisaccident.

fCreditistakenintheplantemergency operating procedures forthePORVstorecoverfromavarietyofaccidents.

Thiswouldincludethecategoryofeventsandaccidents thatcc"dcausethePORVstoopenandfailtoclose,resulting inasmallbreakLOCA(e.g.normalplantcooldown, activation ofthesafetyinjection system,orseveretransients suchasafeedwater linebr'eakorsteamlinebreakinsidecontainment).

ThemainfunctionofthePORVblockvalvesistoisolateaPORVifthePORVfailsintheopenposition.

Foreventsofthetypecitedabove,eithertheydonotcausecontainment

flooding, oriftheydocauseflooding, theneedtoclosethePORVsoccursearlyenoughinthetransient thattheblockvalveswouldstillbeconsidered operableinspiteofthewaterintrusion thatmayhaveoccurredduetocracksintheflooduptubes.Athirdcategoryofeventsincludelongtermrecoveryactionssuchasresponsetoinadequate corecoolingorresponsetodegradedcorecoolingwherethecontainment couldbeflooded.EachoftheseeventsrequirethatastuckopenPORVbeisolated.

Theseeventsarebeyondthoseconsidered intheplantdesignbasis,anditisconsidered highlyunlikelythatanadverseaccidentofthistypecouldoccuratthesametimethataPORVsticksopen,thecablesaresubmerged, andtheblockvalvefailstoclosewhenitisrequired.

ThefinalcategoryiseventsthatrequireaPORVtobeopentofacilitate accidentrecovery.

Anexampleofthiswouldbethefeedwater linebreakrecovery.

However,notallofthethreePORVswouldhavebeenaffectedbycracksintheflooduptubes,andatleastonewouldbeavailable forthispurpose.Thismeetstheminimumrequirement.

NRCFORM366A.S.NUCLEARREGULATORY COMMISSION LICENSEEEVENTCONTINUATION ROVEDBYOMBHO.3150-0104 EXPIRES5/31/95ESTIMATED BURDENPERRESPONSETOCOMPLYNITHTHISIHFORMATION COLLECTIOH REQUEST:50.0HRS;.,FORIIARDCOMMENTSREGARDING BURDENESTIMATETO'HEINFORMATION ANDRECORDSMANAGEMENT BRANCH(MHBB7714),U.S.NUCLEARREGULATORY COMMISSION;

'WASHINGTON, DC20555-0001, ANDTOTHEPAPERNORK REDUCTION PROJECT(3150.0104),

OFFICEOFMANAGEMENT ANDBUDGET'NASHIHGTON DC20503.FACILITYNAME1CookNuclearPlant-Unit1TEXT(ifaorespaceisrequired.

useaddit(onal NRCFora366A's)(17)AnalslsoftheEventcont'dDOCKETNU)IER250-315LERNUMBER6YEARSEQUENTIAL 97-006REVISIOH01PAGE39OF10Unit2Containment AirRecirculation/H droenSkimmerFanTheCookNuclearPlanthastwocontainment airrecirculation/hydrogen skimmer(CEQfans),onlyoneofwhichisrequiredforaccidentmitigation.

Onlyonefanwasadversely impactedbyacrackedflooduptube.TheCEQfansarerequiredtoprovideacontinuous mixingofthecontainment atmosphere forthelongtermpostblowdownaccidentenvironment.

Theyarealsorequiredtopreventtheformation ofhydrogenpocketswithinthevariouscompartments andsubcompartments oftheicecondenser containment.

Twofullcapacityfans,eachcapableofblowingairfromtheuppervolumeintothelowervolumeareprovided.

Foraccidentanalysisconditions, onlyonefanismodeledbaseduponthelimitingsinglefailureofatrainofcontainment safeguards equipment.

Theairrecirculation fanshavesufficient headtoovercomethecompartment pressuredifferentials thatoccuraftertheinitialRCSblowdown.

Thefanswillblowairfromtheuppercompartment tothelowercompartment therebyretumlngairtothelowercompartment whichwasdisplaced bytheblowdown.

Althoughthefansaremodeledduringboththecontainment responsetransient following aLOCAandMSLB,thegreatestimpactresulting fromtheiractivation isseenduringtheLOCAtransient responseduetothelongtermtransient scenario.

Theairreturnfansaremodeledtooperateuponreachingthehigh-high containment pressuresetpointfollowing atenminutedelay.DuringtheLOCAresponsetransient thefansprovideaflowpathearlyinthetransient, therefore theirfunctionplaysanimportant role(beforethetimeofpeakpressure) inthecontainment responsecalculation.

Similarly duringtheMSLBcontainment responsecalculation thefansfunctioninalikewisemanner.However,thetimethefansactivatefollowthetimewhenthecontainment peakpressureandtemperature occurs,therefore theirimpactonthecontainment responsetransient isminimal.Theirprimaryeffectisontherateofcontainment depressurization andcooldownafter10minutesintotheMSLBcontainment responsetransient.

Baseduponsensitivities whichhavebeenperformed foranicecondenser plantsimilartotheCookNuclearPlantwhenconsidering inoperable airreturnfans,theeffectofthelossoftheairreturnfanoncontainment peakpressurewas5psi.SincetheCookdesignpressureis12psi,thismeansthatthemaximumpressureachievedbythecontainment shouldbothfansbelostis17psi.Althoughabovetheplantdesignbasisof12psi,thisiswellwithinthecontainment ultimatecapability ofapproximately 36psi.Thepotential lossofCEQfansalsomeansthelossofabilitytoremovehydrogenfromthecompartments oftheCookNuclearPlant.Thiswillnotoccuruntiltwohoursintotheaccident.

AspartoftheCookNuclearPlant'sprobabilistic riskassessment, studieshavebeenperformed toevaluatethelossofCEQfansfollowing asevereaccident.

Thesestudieshaveconcluded thatnoadverseimpactoncontainment performance isexpectedduetocontainment recirculation fanfailures.

Onthebasisoftheabove,itisconcluded thatthelossofoneCEQfandidnotadversely impactthepublichealthandsafety.Itisfurtherpointedout,thatonlyoneofthetworedundant fanswasimpacted, andtherefore following ahighenergylinebreakinsidecontainment theplantmayhavestayedwithitsdesignbasiscontainment pressureof12psi.

NRCFORH366A.S.NUCLEARREGULATORY COXHISSICILICENSEEEVENTCONTINUATION BY'ORBNO.3150-0104 EXPIRES5/31/95ESTIHATED BURDENPER-RESPONSE TOCOHPLYWITHTHISINFORHATION.COLLECTION'REQUEST:

50.0NRS'.FORIIARDCOHHENTSREGARDING BURDENESTIHATETOTHEINFORHATION ANDRECORDSHANAGEHENT BRANCH(HNBB7714),U.S.NUCLEARREGULATORY COHHISSION, MASNINGTON, DC20555-0001, ANDTOTHEPAPERNORK REDUCTION PROJECT(3150-0104),

OFFICEOF"HANAGEHENT ANDBUDGETMASNINGTON DC20503.FACILITYNAHE1CookNuclearPlant-Unit1TEXT((fmorespaceisrequired.

useadditional NCForm36EA's)(17)Corrective ActionDOIETNUNBER25015YEAR97LERNUNBER6SEQUENTIAL REVISION01PAGE310OF10Criticalareasforallflooduptubesineachunithavebeeninspected forcracks.ThedamagedUnit1EQfiooduptubesandUnit2flooduptubeshavebeenreplaced.

Preventive ActionAdequateprecautions forweldinginthevicinityofelectrical equipment havebeenidentified intheAEPWeldingManual,GeneralWeldingRequirements, step6.13whichincondensed versionstates:basematerials andothermetallicregionsoutsideoftheweldzoneshallbeprotected topreventinadvertent arcstrikes.Inaddition, PMI-2270(FIREPROTECTION),

containstheWelding,Burning,8GrindingPermitwhichisissuedforallweldingactivities.

Thepermitcoversarearequirements whichprovidedirection tocoverelectrical equipment aridcabletrayswithfireblanket.Tosupplement theseplantrequirements, aninspection asstatedbelowwillbeperformed toverifythatthetubeshavenotbeendamagedpriortostart-upafteroutageworkhasbeenperformed.

WorkStandards totheNuclearPlantMaintenance (NPM)andEnvironmental Qualification Preservation Documents (EQPD)willbeenhancedtoidentifythatwhileworkingontheflooduptubesthereisaneedtoavoidaddingunduelocalized stresstotheflooduptubesandthentoverifythatnocrackshavedeveloped

.TheWorkStandards totheNPMforflooduptubeinstallation havealreadybeenrevisedtoincludetheseprecautions.

Asalongtermaction,newEQPDwillbeissuedbyJune1,1998forflooduptubestoidentifythecriticalEQparameters.

Inspections willbemadeatthebeginning ofeachoutagetocheckforanycracks.Inspections willalsobemadeattheendoftheoutagetoensurethatnooutageactivities damagedanytubes.Inaddition, althoughnotcontained inaformalprogram,theknowledge thatthetubesaresubjecttothistypeofdamagewillheightenawareness andimproveworkbeingdoneonandaroundtheflooduptubes.FailedComonentIdentification NotApplicable PreviousSimilarEventsNone

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