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{{#Wiki_filter:CATEGORY1REGULATO~INFORMATIONDISTRIBUTIONSYSTEM(RIDS)ACCESSIONNBR:9606260254DOC.DATE:96f06fl9NOTARIZED:YESDOCKET:FACIL:50-315DonaldC.CookNuclearPowerPlant,Unit1,IndianaM05000315AUTH.NAMEAUTHORAFFILIATIONFITZPATR:.CK,E.AmericanElectricPowerCo.,Inc.RECIP.NAMERECIPIENTAFFILIATIONDocument'ontrolBranch(DocumentControlDesk)SUBJE!T:ApplicationforamendtoLicenseDPR-58,addressingapplicablerequirementsofNRCGL95-05,"Voltage-BasedC.RepairCriteriaforRepairofWestinghouseSGTubesAffectedby,OutsideDiameterStressCorrosionCracking."ADISTRIBUTIONCODE:ADOIDCOPIESRECEIVED:LTRIENCL/SIZE:TITLE:ORSubmittal:GeneralDistributionENOTES:RECIPIENTIDCODE/NAMEPD3-1LAHICKMAN,JINTERNAL,~IEl.HE~NTE1%RR/DRCH~HICBNRR/DSSA/SRXBOGC/HDS2EXTERNAL:NOACCOPIESLTTRENCL11111111111011RECIPIENTIDCODE/NAMEPD3-1PDNRR/DE/EMCBNRR/DSSA/SPLBNUDOCS-ABSTRACTNRCPDRCOPIESLTTRENCL11111111D0NOTETOALL"RIDS"RECIPIENTS:PLEASEHELPUSTOREDUCEWASTE!CONTACTTHEDOCUMENTCONTROLDESK,ROOMOWFN5D-5(EXT.415-2083)TOELIMINATEYOURNAMEFROMDISTRIBUTIONLISTSFORDOCUMENTSYOUDON'TNEED!ITOTALNUMBEROFCOPIESREQUIRED:LTTR,12ENCLll eRf4>~4.1~'l4,C AmericanElectricP~1RiversidePlazaColumbus,OH4321523736142231000June19,1996AEP:NRC:1166AADocketNos.:50-315U.S.NuclearRegulatoryCommissionATTN:DocumentControlDeskWashington,D.C.20555Gentlemen:DonaldC.CookNuclearPlantUnit1TECHNICALSPECIFICATIONCHANGESTOINCORPORATE2VOLTSTEAMGENERATORTUBESUPPORTPLATEREPAIRCRITERIONThisletteranditsattachmentsprovideapplicationforamendmenttothetechnicalspecifications(T/Ss)ofDonaldC.CookNuclearPlantUnit1.Specifically,thisinformationaddressestheapplicablerequirementsofNRCGenericLetter(GL)95-05"Voltage-BasedRepairCriteriafortheRepairofWestinghouseSteamGeneratorTubesAffectedbyOutsideDiameterStressCorrosionCracking."Attachment1providesatechnicalsummaryoft:hespecificinspectionpracticesandcalculationmethodologiesoutlinedinGL95-05andthe10CFR50.92nosignificanthazardsevaluation.Theevaluationandresultssupportcontinueduseofthe2voltpluggingcriteriaasallowedbyGL95-05forfutureoperatingcycles.Attachment2containsexistingT/Spagesmarkedtoreflecttherequestedchanges.Attachment3providestheproposedrevisedT/Spages.Webelievetheproposedchangeswillnotresultin(1)asignificantchangeinthetypesofanyeffluentthatmaybereleasedoffsite,or(2)asignificantincreaseinindividualorcumulativeoccupat.i.onalradiationexposure.9606260254';.960619'DR''ADOCK.050003i5P.PDR U.S.NuclearRegulatoryCommissionPage2AEP:NRC:1166AATheseproposedchangeshavebeenreviewedbythePlantNuclearSafetyReviewCommitteeandtheNuclearSafetyandDesignReviewCommittee.Incompliancewiththerequirementsof10CFR50.91(b)(1),copiesofthisletteranditsattachmentshavebeentransmittedtotheMichiganPublicServiceCommissionandtotheMichiganDepartmentofPublicHealth.Sincerely,VicePresidentSWORNTOANDSUBSCRIBEDBEFOREMETHIS~~~4DAYOF1996teryPublicllgAttachmentscc:A.A.BlindG.CharnoffH.J.MillerNFEMSectionChiefNRCResidentInspector-BridgmanJ.R.Padgett U.S.NuclearRegulatoryCommissionPage3AEP:NRC:1166AAbc:S.J.Brewer/M.S.Ackerman/K.J.TothJ.A.KobyraD.R.Hafer/J.R.JensenJ.B.ShinnockJ.S.WiebeJ.B.Hickman,NRC-Washington,D.C.-w/attachmentPRONET-w/attachmentDC-N-6015.1 J'
{{#Wiki_filter:CATEGORY1REGULATO~
AmericanElectric1RiversidePlazaColumbus,OH4321523736142231000ANERlCAMELECfRICPOWERJune19,1996AEP:NRC:1166AADocketNos~:50-315U.S.NuclearRegulatoryCommissionATTN:DocumentControlDeskWashington,D.C.20555Gentlemen:DonaldC.CookNuclearPlantUnit1TECHNICALSPECIFICATIONCHANGESTOINCORPORATE2VOLTSTEAMGENERATORTUBESUPPORTPLATEREPAIRCRITERIONThisletteranditsattachmentsprovideapplicationforamendmenttothetechnicalspecifications(T/Ss)ofDonaldC.CookNuclearPlantUnit1.Specifically,thisinformationaddressestheapplicablerequirementsofNRCGenericLetter(GL)95-05"Voltage-BasedRepairCriteriafortheRepairofWestinghouseSteamGeneratorTubesAffectedbyOutsideDiameterStressCorrosionCracking."Attachment1providesatechnicalsummaryofthespecificinspectionpracticesandcalculationmethodologiesoutlinedinGL95-05andthe10CFR50.92nosignificanthazardsevaluation.Theevaluationandresultssupportcontinueduseofthe2voltpluggingcriteriaasallowedbyGL95-05forfutureoperatingcycles.Attachment2containsexistingT/Spagesmarkedtoreflecttherequestedchanges.Attachment3providestheproposedrevisedT/Spages.Webelievetheproposedchangeswillnotresultin(1)asignificantchangeinthetypesofanyeffluentthatmaybereleasedoffsite,or(2)asignificantincreaseinindividualorcumulativeoccupationalradiationexposure.
INFORMATION DISTRIBUTION SYSTEM(RIDS)ACCESSION NBR:9606260254 DOC.DATE:
U.S.NuclearRegulatoryCommissionPage2AEP:NRC:1166AATheseproposedchangeshavebeenreviewedbythePlantNuclearSafetyReviewCommitteeandtheNuclearSafetyandDesignReviewCommittee.Incompliancewiththerequirementsof10CFR50.91(b)(l),copiesofthisletteranditsattachmentshavebeentransmittedtotheMichiganPublicServiceCommissionandtotheMichiganDepartmentofPublicHealth.Sincerely,PgM.~,xi)E.E.FitzpatrickVicePresidentSWOP'OANDSUBSCRIBEDBEFOREMETHIS~cP4'AYOF1996.CotaryPublicw"llgAttachmentscc:A.A.BlindG.CharnoffH.J~MillerNFEMSectionChiefNRCResidentInspector-BridgmanJ.R.Padgett U.S.NuclearRegulatoryCommissionPage3AEP:NRC:1166AAbc:S.J.Brewer/M.S.Ackerman/K.J.TothJ.A.KobyraD.R.HaEer/J.R.JensenJ.B.ShinnockJ.S.WiebeJ.B.Hickman,NRC-Washington,D.C.-w/attachmentPRONET-w/attachmentDC-N-6015.1 ATTACHMENT1TOAEP:NRC:1166AADESCRIPTIONOFCHANGESTOTHEDONALDC.COOKNUCLEARPLANTUNIT1TECHNICALSPECIFICATIONS10CFR50.92EVALUATION Attachment1toAEP:NRC:1166AAPage1INTRODUCTIONThisamendmentrequestproposesachangetoCookNuclearPlantUnit1steamgenerators(SG)T/Ss4.4.5.2,4.4.5.4,4.4'.5,3.4.6.2andBases3/4.4.5and3/4.4.6.2toallowuseofGL95-05voltage-basedSGtubesupportplate(TSP)pluggingcriteria.ThechangeallowsSGtubeswithbobbincoileddycurrentindicationslessthanorequalto2voltsatTSPintersectionstoremaininservice,regardlessoftheapparentdepthoftubewallpenetrationif,asaresult,theprojectedend-of-cycle(EOC)distributionofcrackindicationsisshowntoresultinprimary-to-secondaryleakagelessthan8.4gpminthefaultedloopduringapostulatedsteamlinebreak(SLB)event.Indicationsgreaterthan2voltsbutlessthanorequaltotheuppervoltagerepairlimit(VU<L)mayremaininserviceifamotorizedrotatingpancakecoil(MRPC)probeinspectiondoesnotdetectdegradation.TheVUgLwillbedeterminedeachoutageusingthemostrecent,NRC-approvedindustrytubeburstdatabasetodeterminethevoltagecorrespondingtothetubestructurallimit(VSL).ThisamendmentwouldreducethenumberofSGtubespluggedduetoindicationsatsupportplateintersections.ReducingthenumberofpluggedtubesprovidesALARAbenefitsandmaintainsreactorcoolantsystem(RCS)flowmargin.Assessmentreportsaddressingtheeffectivenessofthevoltage-basedpluggingcriteriamethodologyaredescribedinWCAP-13187,Revision0,whichwascompletedfollowingfuelcycles13and14.ThisinformationwasreportedinsubmittaldocumentsAEP:NRC:1166JandAEP:NRC:1166AC.ThereportsconcludedthatthevoltagedistributionfoundbyinspectionatEOC13andEOC14,in1994and1995,respectively,wereingoodagreementwiththeprojections'hevoltagegrowthratescontinuetobeverysmall.Noin-servicetubeswerefoundforwhichthebobbincoilvoltageexceededthe2voltpluggingcriteriarepairlimitatEOC13orEOC14.Consideringtheresultsoftheaforementionedreports,continueduseofthe2voltpluggingcriteriaisjustified.SimilarassessmentandprojectionreportsbasedonGL95-05reportingrequirementswillbepreparedateachEOC.  
96f06fl9NOTARIZED:
YESDOCKET:FACIL:50-315 DonaldC.CookNuclearPowerPlant,Unit1,IndianaM05000315AUTH.NAMEAUTHORAFFILIATION FITZPATR:.CK,E.
AmericanElectricPowerCo.,Inc.RECIP.NAME RECIPIENT AFFILIATION Document'ontrol Branch(Document ControlDesk)SUBJE!T:Application foramendtoLicenseDPR-58,addressing applicable requirements ofNRCGL95-05,"Voltage-Based C.RepairCriteriaforRepairofWestinghouse SGTubesAffectedby,OutsideDiameterStressCorrosion Cracking."
ADISTRIBUTION CODE:ADOIDCOPIESRECEIVED:LTR IENCL/SIZE:TITLE:ORSubmittal:
GeneralDistribution ENOTES:RECIPIENT IDCODE/NAME PD3-1LAHICKMAN,J INTERNAL,~IEl.
HE~NTE1%RR/DRCH~HICB NRR/DSSA/SRXB OGC/HDS2EXTERNAL:
NOACCOPIESLTTRENCL11111111111011RECIPIENT IDCODE/NAME PD3-1PDNRR/DE/EMCB NRR/DSSA/SPLB NUDOCS-ABSTRACT NRCPDRCOPIESLTTRENCL11111111D0NOTETOALL"RIDS"RECIPIENTS:
PLEASEHELPUSTOREDUCEWASTE!CONTACTTHEDOCUMENTCONTROLDESK,ROOMOWFN5D-5(EXT.
415-2083)
TOELIMINATE YOURNAMEFROMDISTRIBUTION LISTSFORDOCUMENTS YOUDON'TNEED!ITOTALNUMBEROFCOPIESREQUIRED:
LTTR,12ENCLll eRf4>~4.1~'l4,C AmericanElectricP~1Riverside PlazaColumbus, OH4321523736142231000June19,1996AEP:NRC:1166AA DocketNos.:50-315U.S.NuclearRegulatory Commission ATTN:DocumentControlDeskWashington, D.C.20555Gentlemen:
DonaldC.CookNuclearPlantUnit1TECHNICAL SPECIFICATION CHANGESTOINCORPORATE 2VOLTSTEAMGENERATOR TUBESUPPORTPLATEREPAIRCRITERION Thisletteranditsattachments provideapplication foramendment tothetechnical specifications (T/Ss)ofDonaldC.CookNuclearPlantUnit1.Specifically, thisinformation addresses theapplicable requirements ofNRCGenericLetter(GL)95-05"Voltage-BasedRepairCriteriafortheRepairofWestinghouse SteamGenerator TubesAffectedbyOutsideDiameterStressCorrosion Cracking."
Attachment 1providesatechnical summaryoft:hespecificinspection practices andcalculation methodologies outlinedinGL95-05andthe10CFR50.92nosignificant hazardsevaluation.
Theevaluation andresultssupportcontinued useofthe2voltpluggingcriteriaasallowedbyGL95-05forfutureoperating cycles.Attachment 2containsexistingT/Spagesmarkedtoreflecttherequested changes.Attachment 3providestheproposedrevisedT/Spages.Webelievetheproposedchangeswillnotresultin(1)asignificant changeinthetypesofanyeffluentthatmaybereleasedoffsite,or(2)asignificant increaseinindividual orcumulative occupat.i.onal radiation exposure.
9606260254';.9606 19'DR''ADOCK.050003i5 P.PDR U.S.NuclearRegulatory Commission Page2AEP:NRC:1166AA TheseproposedchangeshavebeenreviewedbythePlantNuclearSafetyReviewCommittee andtheNuclearSafetyandDesignReviewCommittee.
Incompliance withtherequirements of10CFR50.91(b)(1),
copiesofthisletteranditsattachments havebeentransmitted totheMichiganPublicServiceCommission andtotheMichiganDepartment ofPublicHealth.Sincerely, VicePresident SWORNTOANDSUBSCRIBED BEFOREMETHIS~~~4DAYOF1996teryPublicllgAttachments cc:A.A.BlindG.CharnoffH.J.MillerNFEMSectionChiefNRCResidentInspector
-BridgmanJ.R.Padgett U.S.NuclearRegulatory Commission Page3AEP:NRC:1166AA bc:S.J.Brewer/M.
S.Ackerman/K.
J.TothJ.A.KobyraD.R.Hafer/J.R.JensenJ.B.ShinnockJ.S.WiebeJ.B.Hickman,NRC-Washington, D.C.-w/attachment PRONET-w/attachment DC-N-6015.1 J'
AmericanElectric1Riverside PlazaColumbus, OH4321523736142231000ANERlCAMELECfRICPOWERJune19,1996AEP:NRC:1166AA DocketNos~:50-315U.S.NuclearRegulatory Commission ATTN:DocumentControlDeskWashington, D.C.20555Gentlemen:
DonaldC.CookNuclearPlantUnit1TECHNICAL SPECIFICATION CHANGESTOINCORPORATE 2VOLTSTEAMGENERATOR TUBESUPPORTPLATEREPAIRCRITERION Thisletteranditsattachments provideapplication foramendment tothetechnical specifications (T/Ss)ofDonaldC.CookNuclearPlantUnit1.Specifically, thisinformation addresses theapplicable requirements ofNRCGenericLetter(GL)95-05"Voltage-BasedRepairCriteriafortheRepairofWestinghouse SteamGenerator TubesAffectedbyOutsideDiameterStressCorrosion Cracking."
Attachment 1providesatechnical summaryofthespecificinspection practices andcalculation methodologies outlinedinGL95-05andthe10CFR50.92nosignificant hazardsevaluation.
Theevaluation andresultssupportcontinued useofthe2voltpluggingcriteriaasallowedbyGL95-05forfutureoperating cycles.Attachment 2containsexistingT/Spagesmarkedtoreflecttherequested changes.Attachment 3providestheproposedrevisedT/Spages.Webelievetheproposedchangeswillnotresultin(1)asignificant changeinthetypesofanyeffluentthatmaybereleasedoffsite,or(2)asignificant increaseinindividual orcumulative occupational radiation exposure.
U.S.NuclearRegulatory Commission Page2AEP:NRC:1166AA TheseproposedchangeshavebeenreviewedbythePlantNuclearSafetyReviewCommittee andtheNuclearSafetyandDesignReviewCommittee.
Incompliance withtherequirements of10CFR50.91(b)(l),
copiesofthisletteranditsattachments havebeentransmitted totheMichiganPublicServiceCommission andtotheMichiganDepartment ofPublicHealth.Sincerely, PgM.~,xi)
E.E.Fitzpatrick VicePresident SWOP'OANDSUBSCRIBED BEFOREMETHIS~cP4'AYOF1996.CotaryPublicw"llgAttachments cc:A.A.BlindG.CharnoffH.J~MillerNFEMSectionChiefNRCResidentInspector
-BridgmanJ.R.Padgett U.S.NuclearRegulatory Commission Page3AEP:NRC:1166AA bc:S.J.Brewer/M.
S.Ackerman/K.
J.TothJ.A.KobyraD.R.HaEer/J.R.JensenJ.B.ShinnockJ.S.WiebeJ.B.Hickman,NRC-Washington, D.C.-w/attachment PRONET-w/attachment DC-N-6015.1 ATTACHMENT 1TOAEP:NRC:1166AA DESCRIPTION OFCHANGESTOTHEDONALDC.COOKNUCLEARPLANTUNIT1TECHNICAL SPECIFICATIONS 10CFR50.92EVALUATION Attachment 1toAEP:NRC:1166AA Page1INTRODUCTION Thisamendment requestproposesachangetoCookNuclearPlantUnit1steamgenerators (SG)T/Ss4.4.5.2,4.4.5.4,4.4'.5,3.4.6.2andBases3/4.4.5and3/4.4.6.2 toallowuseofGL95-05voltage-based SGtubesupportplate(TSP)pluggingcriteria.
ThechangeallowsSGtubeswithbobbincoileddycurrentindications lessthanorequalto2voltsatTSPintersections toremaininservice,regardless oftheapparentdepthoftubewallpenetration if,asaresult,theprojected end-of-cycle (EOC)distribution ofcrackindications isshowntoresultinprimary-to-secondary leakagelessthan8.4gpminthefaultedloopduringapostulated steamlinebreak(SLB)event.Indications greaterthan2voltsbutlessthanorequaltotheuppervoltagerepairlimit(VU<L)mayremaininserviceifamotorized rotatingpancakecoil(MRPC)probeinspection doesnotdetectdegradation.
TheVUgLwillbedetermined eachoutageusingthemostrecent,NRC-approved industrytubeburstdatabasetodetermine thevoltagecorresponding tothetubestructural limit(VSL).Thisamendment wouldreducethenumberofSGtubespluggedduetoindications atsupportplateintersections.
ReducingthenumberofpluggedtubesprovidesALARAbenefitsandmaintains reactorcoolantsystem(RCS)flowmargin.Assessment reportsaddressing theeffectiveness ofthevoltage-based pluggingcriteriamethodology aredescribed inWCAP-13187, Revision0,whichwascompleted following fuelcycles13and14.Thisinformation wasreportedinsubmittal documents AEP:NRC:1166J andAEP:NRC:1166AC.
Thereportsconcluded thatthevoltagedistribution foundbyinspection atEOC13andEOC14,in1994and1995,respectively, wereingoodagreement withtheprojections'he voltagegrowthratescontinuetobeverysmall.Noin-service tubeswerefoundforwhichthebobbincoilvoltageexceededthe2voltpluggingcriteriarepairlimitatEOC13orEOC14.Considering theresultsoftheaforementioned reports,continued useofthe2voltpluggingcriteriaisjustified.
Similarassessment andprojection reportsbasedonGL95-05reporting requirements willbepreparedateachEOC.  


Attachment1toAEP:NRC:1166AAPage2APPLICATIONOFGL95-05TOTHECOOKNUCLEARPLANTUNIT1SG'ICENSEAMENDMENTTheCookNuclearPlantUnit1,2voltpluggingcriteriawillbeimplementedpertheguidanceofGL95-05alongwiththelatestindustrydatafortubeburstandleakage.NRCGL95-05willbefactoredintotheCookNuclearPlantUnit1pluggingcriteriaasfollows:Analystswillbebriefedregardingthepossibilityofprimarywaterstresscorrosioncracking(PWSCC)atTSPintersections.IfPWSCCisfoundatthesupportplateintersectionsitwillbereportedtotheNRCstaffpriortostartup.2)Theuseofsupportingdatasetsforcalculationofburstprobabilityandestimationofprimary-to-secondaryleakageduringapostulatedmainSLBforeachoutagewillbebasedonthemostcurrent,NRC-approvedindustrydatabase.ThelatestindustrydatabasewastransmittedtotheNRCunderBeaverValleyPowerStation',Unit1,March27,1996,lettertransmittingsupplementalinformationinsupportofarequestedT/Schange,foravoltage-basedSGtuberepaircriteria,originallyproposedintheirletterdatedDecember7,1995.Thatdatabasewasusedinthepreparationofthissubmittal.3)MainsteamlineburstprobabilityandleakagecalculationswillbeperformedfollowingtheguidanceofGL95-05,Section2,"TubeIntegrityEvaluation."Calculationsperformedinsupportofthevoltage-basedrepaircriteriawillfollowthemethodologydescribedinWCAP-14277,"SteamLineBreakLeakRateandTubeBurstProbabilityAnalysisMethodsforOutsideDiameterStressCorrosionCrackingatTubeSupportPlateIntersections,'"datedJanuary1995.Thecalculations,usingtheas-foundvoltagedistribution,willbeperformedpriortoreturningtheSGstoservice.TheprojectedEOCvoltagedistributionresultswillbereportedinthe90dayreport.4)Inspectionscope,dataacquisition,anddataanalysiswillbeperformedfollowingtheguidanceofGL95-05,Section3,"InspectionCriteria"andreferencedAppendixA,'DEDataAcquisitionandAnalysisGuidelines."AnMRPCinspectionwillbedoneonallindicationsexceeding2volts.AnMRPCinspectionwillalsobedoneonallintersectionswherecoppersignals,largemixedresiduals,ordentslargerthan5voltsinterferewithdetectionofflaws.
Attachment 1toAEP:NRC:1166AA Page2APPLICATION OFGL95-05TOTHECOOKNUCLEARPLANTUNIT1SG'ICENSE AMENDMENT TheCookNuclearPlantUnit1,2voltpluggingcriteriawillbeimplemented pertheguidanceofGL95-05alongwiththelatestindustrydatafortubeburstandleakage.NRCGL95-05willbefactoredintotheCookNuclearPlantUnit1pluggingcriteriaasfollows:Analystswillbebriefedregarding thepossibility ofprimarywaterstresscorrosion cracking(PWSCC)atTSPintersections.
II Attachment1toAEP:NRC:1166AAPage3Probewearinspectionsandre-inspectionswillbeperformedusingthefolloOingguidelines:Ifanyofthelastprobewearstandardsignalamplitudes,priortoprobereplacement,exceedthe215Xlimitbyavalueof"XX,"thenanyindicationsmeasuredsincethelastacceptableprobewearmeasurementthatarewithin"XX"oftheplugginglimitwillbereinspectedwiththenewprobe.Forexample,ifanyofthelastprobewearsignalamplitudespriortoprobereplacementwere17Xaboveorbelowtheinitialamplitude,thentheindicationsthatarewithin2X(17X-15X)oftheplugginglimitmustbereinspectedwiththenewprobe.Alternatively,thevoltagecriterionmaybeloweredtocompensatefortheexcessvariation;forthecaseabove,amplitudes)0.98timesthevoltagecriterioncouldbesubjecttorepair.5)TuberemovalandexaminationwillbeperformedbasedontheguidancecontainedinGL95-05,Section4,"TubeRemovalandExamination/Testing."Plansaretopullatubespecimenwithatleasttwointersectionsduringthe1997refuelingoutage.6)ApplicationofGL95-05,Section5,"OperationalLeakageRequirements,"wi,llbecontinued.TheSGtubeleakagelimitof150gallonsperdaythrougheachSGwillbemaintainedaspreviouslyapprovedbytheNRCforourpresentfuelcycle.CookNuclearPlantleakagemonitoringmethodsprovidetimelyleakdetection,trending,andresponsetorapidlyincreasingleaks.7)GL95-05,Section6,"ReportingRequirements,"willbeimplemented.AsstatedpreviouslyforSection2,thecalculationofleakageandburstprobabilityrequiredpriortoreturningtheSGstoservicewillbeperformedusingoftheas-foundEOCvoltagedistribution.
IfPWSCCisfoundatthesupportplateintersections itwillbereportedtotheNRCstaffpriortostartup.2)Theuseofsupporting datasetsforcalculation ofburstprobability andestimation ofprimary-to-secondary leakageduringapostulated mainSLBforeachoutagewillbebasedonthemostcurrent,NRC-approved industrydatabase.Thelatestindustrydatabasewastransmitted totheNRCunderBeaverValleyPowerStation',
hh0 Attachment1toAEP:NRC:1166AAPage4III.AEPCOMMENTSTOGL95-05ANDASSOCIATEDIMPACTTOAEPLICENSEAMENDMENTREUESTFORSGPLUGGINGCRITERIA1)GL95-05,Sectionl.b:AnalysesperformedbyWestinghousehaveshownthatnotubesintheCookNuclearPlantUnit1SGswouldbesubjecttocollapseduringalossofcoolantaccident(LOCA)plussafeshutdownearthquake(SSE)eventsTherefore,notubesareexcludedbasedonthiscriteria.Series51SGs,designedbyWestinghouse,donothaveflowdistributionbaffleplates;therefore,Sectionl.b.5isnotapplicable.2)GL95-05,Section3.c.3:Therequirementtoreinspectalltubespriortothelastprobechangeoutifthewearmeasurementexceeds15/isunnecessary.Reinspectionofindicationsnecessitatedbyout-of-specificationprobewearwillbeconductedaccordingtoitem4ofpage2ofthisattachment.IV.10CFR5092EVALUATIONBACKGROUNDCookNuclearPlantUnit1T/SAmendment200permittedtheimplementationofa2voltSGtubepluggingcriteria.Thatlicenseamendment,applicableonlyforthecurrentoperatingcycle(cycle15),requirestherepairofflaw-likebobbinindicationsabove2volts.Weareproposinguseofasimilar2voltrepaircriterionwithoutthecycle-specificlimitation.TheproposedpluggingcriteriaprogramfortheCookNuclearPlantUnit1SGsfollowstheguidanceandgeneralintentofGL95-05tomaintaintubestructuralandleakageintegrity.DESCRIPTIONOFTHEPLUGGINGCRITERIAREQUESTAsrequiredby10CFR50.91(a)(1),ananalysisisprovidedtodemonstratethattheproposedlicenseamendmenttoimplementapluggingcriteriafortheTSPelevationOutsideDiameterStressCorrosionCracking(ODSCC)occurringintheCookNuclearPlantUnit1SGsinvolvesanosignificanthazardsconsideration.Thepluggingcriteriautilizescorrelationsbetweeneddycurrentbobbincoilprobesignalamplitude(voltage)andtubeburstandleakagecapability.ThepluggingcriterionisbasedontestingoflaboratoryinducedODSCCspecimensandonextensiveexaminationof Attachment1toAEP:NRC:1166AAPage5pulledtubesfromoperatingSGs(industrywide--includingthreetubespulledin1992'epresentingnineintersectionsfromCookNuclearPlantUnit1).ConsistentwithGL95-05,thepluggingcriteriaprogramforCookNuclearPlantUnit1willincludethefollowingelementsaslistedunder"1.OverviewoftheVoltageRepairLimitApproach,"page3ofGL95-05.Performanenhancedinspectionoftubes,particularlyattheTSPintersections.A100KbobbincoilinspectionofhotlegTSPintersectionsandcoldlegintersections,downtothelowestcoldlegsupportplatewithknownODSCCindications,willbeperformed.Allflawindicationswithbobbinvoltagesgreaterthan2voltswillbeinspectedbyMRPC.UtilizeNondestructiveExamination(NDE)dataacquisitionandanalysisproceduresthatareconsistentwiththemethodologyusedtodevelopthevoltage-basedrepairlimits.Theinspectionscope,dataaquisistion,anddata-analysiswillbeperformedusingtheguidanceofSection3oftheGL.Repairtubesthatexceedthevoltagelimits.Flaw-likesignalsadjacenttotheTSP,withbobbinvoltageslessthanorequalto2volts,willbeallowedtoremaininservice.Flaw-likeindicationsadjacenttotheTSP,withabobbinvoltageofgreaterthan2voltsbutlessthanorequaltouppervoltagerepairlimit,mayremaininserviceifMRPCinspectiondoesnotdetectaflaw.Flawindicationswithavoltageofgreaterthantheuppervoltagerepairlimitwillberepaired.DeterminetheBeginningofCycle(BOC)voltagedistribution.BeginningofCyclevoltagedistributionwillbeestablishedfromtheactualtubeinspectionstobeperformedandwillbeestablishedusingcurrentprogrammethodology.ProjecttheEOCdistribution.AnEOCvoltagedistributionwillbeestablishedbasedontheEOCeddycurrenttestdata.EOCvoltagedistributionwillbeprojectedusingMonteCarlotechniquesasdescribedinWCAP-hI1 Attachment1toAEP:NRC:1166AAPage614277andwillincludeallowanceforeddycurrentuncertaintyasdefinedinGL95-05andaconservativevoltagegrowthrateallowance.FortheprojectedEOCvoltagedistribution,calculateboththeprimary-to-secondaryleakageunderpostulatedaccidentconditionsandtheconditionaltubeburstprobability.Asanalternative,theactualmeasuredEOCvoltagedistributioncanbeusedwhenitisimpracticaltocompletethe,projectedEOCcalculationpriortoreturningtheSGstoserviceforthepurposeofdeterminingwhetherthereportingcriteriainGI95-05Sections6.a.land6.a.3apply.Steamlinebreakleakagewillbecalculated,asdescribedinWCAP-14277,basedontheEOCprojectedvoltagedistribution.Projectedleakagemustremainbelow8.4gpminthefaultedloopforpermissibleoffsitedoseestimatestoremainacceptablewithin10Xofthe10CFR100guidelines.The8.4gpmleakageforoffsitedoseestimatesissmallerthantheleakagenumbercalculatedforacceptablecontrolroomdoseperGeneralDesignCriteria(GDC)19.Therefore,theoffsitedoseismorelimiting.ConditionaltubeburstprobabilitywillbecalculatedaccordingtothemethodologydescribedinWCAP-14277.ConsistentwithGL95-05,ifburstprobabilityisfoundtobegreaterthan1x10~theNRCwillbeconsulted.AsprescribedinGL95-05,anevaluationofprimary-to-secondaryleakage(andsubsequentlyoffsitedose)isrequiredforallplantsimplementingthepluggingcriteria.AllbobbincoilindicationsareincludedintheSLBleakageanalyses,alongwithconsiderationoftheprobabilityofdetection.Iftheprojectedleakageexceeds8.4gpminthefaultedloopduringapostulatedSLBevent,thenumberofindicationstowhichthepluggingcriteriaareappliedisreduced,throughtuberepair,untiltheprimary-to-secondaryleakagelimitsaresatisfied.EVALUATIONTubeDegradationCharacterizationIngeneral,thedegradationmorphologyoccurringattheTSPintersectionsatplantsintheU.S.canbedescribedasaxiallyorientedODSCC.ThedegradationmorphologyatCookNuclearPlantUnit1isentirelycompatiblewiththeoverallindustrydatabase.
Unit1,March27,1996,lettertransmitting supplemental information insupportofarequested T/Schange,foravoltage-based SGtuberepaircriteria, originally proposedintheirletterdatedDecember7,1995.Thatdatabasewasusedinthepreparation ofthissubmittal.
Attachment1toAEP:NRC:1166AAPage7SteamGeneratorTubeIntegrityInthedevelopmentofapluggingcriteriaforCookNuclearPlantUnit1,RegulatoryGuide(RG)1.121,"BasesforPluggingDegradedPWRSteamGeneratorTubes"andRGl.'83,"In-serviceInspectionofPWRSteamGeneratorTubes"areusedasthebasesfordeterminingthatSGtubeintegrityismaintainedwithinacceptablelimits.RegulatoryGuide1.121describesamethodacceptabletotheNRCstaffformeetingGDC14,15,31,and32byreducingtheprobabilityandconsequencesofSGtuberupturebydeterminingthelimitingsafeconditionsoftubewalldegradationbeyondwhichtubeswithunacceptablecracking,asestablishedbyin-serviceinspection,shouldberemovedfromservicebyplugging.ThisregulatoryguideusessafetyfactorsonloadsfortubeburststhatareconsistentwiththerequirementsofSectionIIIoftheASMECode.FortheTSPelevationdegradationoccurringintheCookNuclearPlantUnit1SGs,tubeburstcriteriaareinherentlysatisfiedduringnormaloperatingconditionsbythepresenceoftheTSP.ThepresenceoftheTSPenhancestheintegrityofthedegradedtubesinthatregionbyprecludingtubedeformationbeyondthediameterofthedrilledhole,thusprecludingtubeburst.Conservatively,nocreditistakeninthedevelopmentofthepluggingcriteriaforthepresenceoftheTSPduringaccidentconditions.Basedontheexistingdatabasefor7/8inchtubing,bursttestingindicatesthatthesafetyrequirementsfortubeburstmarginsduringaccidentconditionloadingcanbesatisfiedwithEOCbobbincoilsignalamplitudeslessthan8.8volts,regardlessofthedepthoftubewallpenetrationofthecracking.Uponimplementationoftheproposedpluggingcriteriaprogram,tubeleakageconsiderationsmustalsobeaddressed.Itmustbedeterminedthatthecrackswillnotleakexcessivelyduri~gallplantconditions.Forthe2voltinterimtubepluggingcriteriadevelopedfortheCookNuclearPlantUnit1SGtubes,noleakageisanticipatedduringnormaloperatingconditionsevenwiththepresenceofpotentialthroughwallcracks.Noprimary-to-secondaryleakageattheTSPhasbeendetectedinU.S.plants.Relativetotheexpectedleakageduringaccidentconditionloading,thelimitingeventwithrespecttodifferentialpressureexperiencedacrosstheSGtubesisapostulatedSLBevent.For7/8inchtubing,pulledtubedatasupportsnoleakageupto2.81voltsandlowprobabilityofleakagebetween2.81and6.0volts,forbothpulledtubesandmodelboilerspecimens,attheboundingSLBpressuredifferentialof2560psi.Steamlinebreakprimary-to-secondaryleakagewillbecalculatedasprescribedinGL95-05andWCAP14277,usingprojectedEOCeddycurrentdata.Thiscalculatedleakagemustbeshowntobelessthan8.4gpminthefaultedloop.
3)Mainsteamlineburstprobability andleakagecalculations willbeperformed following theguidanceofGL95-05,Section2,"TubeIntegrity Evaluation."
I Attachment1toAEP:NRC:1166AAPage8AdditionalConsiderations~*Theproposedamendmentwouldprecludeoccupationalradiationexposurethatwouldotherwisebeincurredbypersonnelinvolvedintubepluggingorrepairoperations.Byreducingnon-essentialtubeplugging,theproposedamendmentwouldminimizethelossofmargininthereactorcoolantflow,throughtheSGs,usedinLOCAanalyses.Theproposedamendmentwouldavoidlossofmargininreactorcoolantsystemflowand,therefore,assistinmaintainingminimumflowratesinexcessofthatrequiredforoperationatfullpower.ReductionintheamountoftuberepairrequiredcanreducethelengthofplantoutagesandreducethetimethattheSGsareopentothecontainmentenvironmentduringanoutage.A100Xeddycurrentbobbincoilprobeinspectionassociatedwithimplemen'tationofthepluggingcriteriaprogramwillhelptoidentifynewareasofconcernwhichmayarise,byprovidingalevelofin-serviceinspectionwhichisfarinexcessoftheT/Srequirementsutilizingthe40Xdepth-basedplugginglimitforacceptabletubewalldegradation.SIGNIFICANTHAZARDSANALYSISInaccordancewiththethreefactortestof10CFR50.92(c),implementationoftheproposedlicenseamendmentisanalyzedusingthefollowingstandardsandfoundnotto:1)involveasignificantincreaseintheprobabilityorconsequencesofanaccidentpreviouslyevaluated;2)createthepossibilityofanewordifferentkindofaccidentfromanyaccidentpreviouslyevaluated;or3)involveasignificantreductioninmarginofsafety.Conformanceoftheproposedamendmenttothestandardsforadeterminationofnosignificanthazardsasdefinedin10CFR50.92(threefactortest)isshowninthefollowingparagraphs:1)OperationofCookNuclearPlaneUnit1,inaccordancewiththeproposedlicenseamendment,doesnotinvolveasignificantincreaseintheprobabilityorconsequencesofanaccidentpreviouslyevaluated.Testingofmodelboilerspecimensforfreespantubing(noTSPrestraint)atroomtemperatureconditionsshowburstpressuresinexcessof5000psiforindicationsofouterdiameterstresscorrosioncrackingwithvoltagemeasurementsashighas19volts.BursttestingperformedonpulledtubesfromCookNuclearPlantUnit1withuptoa2.02voltindicationshowsmeasuredburstpressureinexcessof10,000psiatroomtemperature.Bursttestingperformedonpulledtubesfromotherplantsshowburstpressuresinexcessof5,300psiatroomtemperatures.Correctingfortheeffectsoftemperatureonmaterialpropertiesandminimumstrengthlevels(astheburst  
Calculations performed insupportofthevoltage-based repaircriteriawillfollowthemethodology described inWCAP-14277, "SteamLineBreakLeakRateandTubeBurstProbability AnalysisMethodsforOutsideDiameterStressCorrosion CrackingatTubeSupportPlateIntersections,'"
datedJanuary1995.Thecalculations, usingtheas-foundvoltagedistribution, willbeperformed priortoreturning theSGstoservice.Theprojected EOCvoltagedistribution resultswillbereportedinthe90dayreport.4)Inspection scope,dataacquisition, anddataanalysiswillbeperformed following theguidanceofGL95-05,Section3,"Inspection Criteria" andreferenced AppendixA,'DEDataAcquisition andAnalysisGuidelines."
AnMRPCinspection willbedoneonallindications exceeding 2volts.AnMRPCinspection willalsobedoneonallintersections wherecoppersignals,largemixedresiduals, ordentslargerthan5voltsinterfere withdetection offlaws.
II Attachment 1toAEP:NRC:1166AA Page3Probewearinspections andre-inspections willbeperformed usingthefolloOing guidelines:
Ifanyofthelastprobewearstandardsignalamplitudes, priortoprobereplacement, exceedthe215Xlimitbyavalueof"XX,"thenanyindications measuredsincethelastacceptable probewearmeasurement thatarewithin"XX"oftheplugginglimitwillbereinspected withthenewprobe.Forexample,ifanyofthelastprobewearsignalamplitudes priortoprobereplacement were17Xaboveorbelowtheinitialamplitude, thentheindications thatarewithin2X(17X-15X) oftheplugginglimitmustbereinspected withthenewprobe.Alternatively, thevoltagecriterion maybeloweredtocompensate fortheexcessvariation; forthecaseabove,amplitudes
)0.98timesthevoltagecriterion couldbesubjecttorepair.5)Tuberemovalandexamination willbeperformed basedontheguidancecontained inGL95-05,Section4,"TubeRemovalandExamination/Testing."
Plansaretopullatubespecimenwithatleasttwointersections duringthe1997refueling outage.6)Application ofGL95-05,Section5,"Operational LeakageRequirements,"
wi,llbecontinued.
TheSGtubeleakagelimitof150gallonsperdaythrougheachSGwillbemaintained aspreviously approvedbytheNRCforourpresentfuelcycle.CookNuclearPlantleakagemonitoring methodsprovidetimelyleakdetection,
: trending, andresponsetorapidlyincreasing leaks.7)GL95-05,Section6,"Reporting Requirements,"
willbeimplemented.
Asstatedpreviously forSection2,thecalculation ofleakageandburstprobability requiredpriortoreturning theSGstoservicewillbeperformed usingoftheas-foundEOCvoltagedistribution.
hh0 Attachment 1toAEP:NRC:1166AA Page4III.AEPCOMMENTSTOGL95-05ANDASSOCIATED IMPACTTOAEPLICENSEAMENDMENT REUESTFORSGPLUGGINGCRITERIA1)GL95-05,Sectionl.b:Analysesperformed byWestinghouse haveshownthatnotubesintheCookNuclearPlantUnit1SGswouldbesubjecttocollapseduringalossofcoolantaccident(LOCA)plussafeshutdownearthquake (SSE)eventsTherefore, notubesareexcludedbasedonthiscriteria.
Series51SGs,designedbyWestinghouse, donothaveflowdistribution baffleplates;therefore, Sectionl.b.5isnotapplicable.
2)GL95-05,Section3.c.3:Therequirement toreinspect alltubespriortothelastprobechangeout ifthewearmeasurement exceeds15/isunnecessary.
Reinspection ofindications necessitated byout-of-specification probewearwillbeconducted according toitem4ofpage2ofthisattachment.
IV.10CFR5092EVALUATION BACKGROUND CookNuclearPlantUnit1T/SAmendment 200permitted theimplementation ofa2voltSGtubepluggingcriteria.
Thatlicenseamendment, applicable onlyforthecurrentoperating cycle(cycle15),requirestherepairofflaw-like bobbinindications above2volts.Weareproposing useofasimilar2voltrepaircriterion withoutthecycle-specific limitation.
TheproposedpluggingcriteriaprogramfortheCookNuclearPlantUnit1SGsfollowstheguidanceandgeneralintentofGL95-05tomaintaintubestructural andleakageintegrity.
DESCRIPTION OFTHEPLUGGINGCRITERIAREQUESTAsrequiredby10CFR50.91(a)(1),ananalysisisprovidedtodemonstrate thattheproposedlicenseamendment toimplement apluggingcriteriafortheTSPelevation OutsideDiameterStressCorrosion Cracking(ODSCC)occurring intheCookNuclearPlantUnit1SGsinvolvesanosignificant hazardsconsideration.
Thepluggingcriteriautilizescorrelations betweeneddycurrentbobbincoilprobesignalamplitude (voltage) andtubeburstandleakagecapability.
Thepluggingcriterion isbasedontestingoflaboratory inducedODSCCspecimens andonextensive examination of Attachment 1toAEP:NRC:1166AA Page5pulledtubesfromoperating SGs(industry wide--including threetubespulledin1992'epresenting nineintersections fromCookNuclearPlantUnit1).Consistent withGL95-05,thepluggingcriteriaprogramforCookNuclearPlantUnit1willincludethefollowing elementsaslistedunder"1.OverviewoftheVoltageRepairLimitApproach,"
page3ofGL95-05.Performanenhancedinspection oftubes,particularly attheTSPintersections.
A100Kbobbincoilinspection ofhotlegTSPintersections andcoldlegintersections, downtothelowestcoldlegsupportplatewithknownODSCCindications, willbeperformed.
Allflawindications withbobbinvoltagesgreaterthan2voltswillbeinspected byMRPC.UtilizeNondestructive Examination (NDE)dataacquisition andanalysisprocedures thatareconsistent withthemethodology usedtodevelopthevoltage-based repairlimits.Theinspection scope,dataaquisistion, anddata-analysiswillbeperformed usingtheguidanceofSection3oftheGL.Repairtubesthatexceedthevoltagelimits.Flaw-like signalsadjacenttotheTSP,withbobbinvoltageslessthanorequalto2volts,willbeallowedtoremaininservice.Flaw-like indications adjacenttotheTSP,withabobbinvoltageofgreaterthan2voltsbutlessthanorequaltouppervoltagerepairlimit,mayremaininserviceifMRPCinspection doesnotdetectaflaw.Flawindications withavoltageofgreaterthantheuppervoltagerepairlimitwillberepaired.
Determine theBeginning ofCycle(BOC)voltagedistribution.
Beginning ofCyclevoltagedistribution willbeestablished fromtheactualtubeinspections tobeperformed andwillbeestablished usingcurrentprogrammethodology.
ProjecttheEOCdistribution.
AnEOCvoltagedistribution willbeestablished basedontheEOCeddycurrenttestdata.EOCvoltagedistribution willbeprojected usingMonteCarlotechniques asdescribed inWCAP-hI1 Attachment 1toAEP:NRC:1166AA Page614277andwillincludeallowance foreddycurrentuncertainty asdefinedinGL95-05andaconservative voltagegrowthrateallowance.
Fortheprojected EOCvoltagedistribution, calculate boththeprimary-to-secondary leakageunderpostulated accidentconditions andtheconditional tubeburstprobabili ty.Asanalternative, theactualmeasuredEOCvoltagedistribution canbeusedwhenitisimpractical tocompletethe,projected EOCcalculation priortoreturning theSGstoserviceforthepurposeofdetermining whetherthereporting criteriainGI95-05Sections6.a.land6.a.3apply.Steamlinebreakleakagewillbecalculated, asdescribed inWCAP-14277,basedontheEOCprojected voltagedistribution.
Projected leakagemustremainbelow8.4gpminthefaultedloopforpermissible offsitedoseestimates toremainacceptable within10Xofthe10CFR100guidelines.
The8.4gpmleakageforoffsitedoseestimates issmallerthantheleakagenumbercalculated foracceptable controlroomdoseperGeneralDesignCriteria(GDC)19.Therefore, theoffsitedoseismorelimiting.
Conditional tubeburstprobability willbecalculated according tothemethodology described inWCAP-14277.
Consistent withGL95-05,ifburstprobability isfoundtobegreaterthan1x10~theNRCwillbeconsulted.
Asprescribed inGL95-05,anevaluation ofprimary-to-secondary leakage(andsubsequently offsitedose)isrequiredforallplantsimplementing thepluggingcriteria.
Allbobbincoilindications areincludedintheSLBleakageanalyses, alongwithconsideration oftheprobability ofdetection.
Iftheprojected leakageexceeds8.4gpminthefaultedloopduringapostulated SLBevent,thenumberofindications towhichthepluggingcriteriaareappliedisreduced,throughtuberepair,untiltheprimary-to-secondary leakagelimitsaresatisfied.
EVALUATION TubeDegradation Characterization Ingeneral,thedegradation morphology occurring attheTSPintersections atplantsintheU.S.canbedescribed asaxiallyorientedODSCC.Thedegradation morphology atCookNuclearPlantUnit1isentirelycompatible withtheoverallindustrydatabase.
Attachment 1toAEP:NRC:1166AA Page7SteamGenerator TubeIntegrity Inthedevelopment ofapluggingcriteriaforCookNuclearPlantUnit1,Regulatory Guide(RG)1.121,"BasesforPluggingDegradedPWRSteamGenerator Tubes"andRGl.'83,"In-service Inspection ofPWRSteamGenerator Tubes"areusedasthebasesfordetermining thatSGtubeintegrity ismaintained withinacceptable limits.Regulatory Guide1.121describes amethodacceptable totheNRCstaffformeetingGDC14,15,31,and32byreducingtheprobability andconsequences ofSGtuberupturebydetermining thelimitingsafeconditions oftubewalldegradation beyondwhichtubeswithunacceptable
: cracking, asestablished byin-service inspection, shouldberemovedfromservicebyplugging.
Thisregulatory guideusessafetyfactorsonloadsfortubeburststhatareconsistent withtherequirements ofSectionIIIoftheASMECode.FortheTSPelevation degradation occurring intheCookNuclearPlantUnit1SGs,tubeburstcriteriaareinherently satisfied duringnormaloperating conditions bythepresenceoftheTSP.ThepresenceoftheTSPenhancestheintegrity ofthedegradedtubesinthatregionbyprecluding tubedeformation beyondthediameterofthedrilledhole,thusprecluding tubeburst.Conservatively, nocreditistakeninthedevelopment ofthepluggingcriteriaforthepresenceoftheTSPduringaccidentconditions.
Basedontheexistingdatabasefor7/8inchtubing,bursttestingindicates thatthesafetyrequirements fortubeburstmarginsduringaccidentcondition loadingcanbesatisfied withEOCbobbincoilsignalamplitudes lessthan8.8volts,regardless ofthedepthoftubewallpenetration ofthecracking.
Uponimplementation oftheproposedpluggingcriteriaprogram,tubeleakageconsiderations mustalsobeaddressed.
Itmustbedetermined thatthecrackswillnotleakexcessively duri~gallplantconditions.
Forthe2voltinterimtubepluggingcriteriadeveloped fortheCookNuclearPlantUnit1SGtubes,noleakageisanticipated duringnormaloperating conditions evenwiththepresenceofpotential throughwall cracks.Noprimary-to-secondary leakageattheTSPhasbeendetectedinU.S.plants.Relativetotheexpectedleakageduringaccidentcondition loading,thelimitingeventwithrespecttodifferential pressureexperienced acrosstheSGtubesisapostulated SLBevent.For7/8inchtubing,pulledtubedatasupportsnoleakageupto2.81voltsandlowprobability ofleakagebetween2.81and6.0volts,forbothpulledtubesandmodelboilerspecimens, attheboundingSLBpressuredifferential of2560psi.Steamlinebreakprimary-to-secondary leakagewillbecalculated asprescribed inGL95-05andWCAP14277,usingprojected EOCeddycurrentdata.Thiscalculated leakagemustbeshowntobelessthan8.4gpminthefaultedloop.
I Attachment 1toAEP:NRC:1166AA Page8Additional Considerations
~*Theproposedamendment wouldprecludeoccupational radiation exposurethatwouldotherwise beincurredbypersonnel involvedintubepluggingorrepairoperations.
Byreducingnon-essential tubeplugging, theproposedamendment wouldminimizethelossofmargininthereactorcoolantflow,throughtheSGs,usedinLOCAanalyses.
Theproposedamendment wouldavoidlossofmargininreactorcoolantsystemflowand,therefore, assistinmaintaining minimumflowratesinexcessofthatrequiredforoperation atfullpower.Reduction intheamountoftuberepairrequiredcanreducethelengthofplantoutagesandreducethetimethattheSGsareopentothecontainment environment duringanoutage.A100Xeddycurrentbobbincoilprobeinspection associated withimplemen'tation ofthepluggingcriteriaprogramwillhelptoidentifynewareasofconcernwhichmayarise,byproviding alevelofin-service inspection whichisfarinexcessoftheT/Srequirements utilizing the40Xdepth-based plugginglimitforacceptable tubewalldegradation.
SIGNIFICANT HAZARDSANALYSISInaccordance withthethreefactortestof10CFR50.92(c),
implementation oftheproposedlicenseamendment isanalyzedusingthefollowing standards andfoundnotto:1)involveasignificant increaseintheprobability orconsequences ofanaccidentpreviously evaluated; 2)createthepossibility ofanewordifferent kindofaccidentfromanyaccidentpreviously evaluated; or3)involveasignificant reduction inmarginofsafety.Conformance oftheproposedamendment tothestandards foradetermination ofnosignificant hazardsasdefinedin10CFR50.92(threefactortest)isshowninthefollowing paragraphs:
1)Operation ofCookNuclearPlaneUnit1,inaccordance withtheproposedlicenseamendment, doesnotinvolveasignificant increaseintheprobability orconsequences ofanaccidentpreviously evaluated.
Testingofmodelboilerspecimens forfreespantubing(noTSPrestraint) atroomtemperature conditions showburstpressures inexcessof5000psiforindications ofouterdiameterstresscorrosion crackingwithvoltagemeasurements ashighas19volts.Bursttestingperformed onpulledtubesfromCookNuclearPlantUnit1withuptoa2.02voltindication showsmeasuredburstpressureinexcessof10,000psiatroomtemperature.
Bursttestingperformed onpulledtubesfromotherplantsshowburstpressures inexcessof5,300psiatroomtemperatures.
Correcting fortheeffectsoftemperature onmaterialproperties andminimumstrengthlevels(astheburst  


Attachment1toAEP:NRC:1166AAPage9testingwasdoneatroomtemperature),tubeburstresistancesignificantlyexceedsthesafetyfactorrequirementsofRG1.121.Asstatedearlier,tubeburstcriteriaareinherentlysatisfiedduringnormaloperatingconditionsduetotheproximityoftheTSP.TestdataindicatesthattubeburstcannotoccurwithintheTSP,evenfortubeswhichhave100Xthroughwallelectric-dischargemachinednotches0.75inchlong,providedtheTSPisadjacenttothenotchedarea,Sincetube-to-tubesupportplateproximityprecludestubeburstduringnormaloperatingconditions,itfollowsthatuseoftheproposedpluggingcriteriamust,therefore,retaintubeintegritycharacteristicswhichmaintaintheRG1.121marginofsafetyof1.43timestheboundingfaultedcondition(steamlinebreak)pressuredifferential.DuringapostulatedmainSLB,theTSPhasthepotentialtodeflectduringblowdown,therebyuncoveringtheintersection.Basedontheexistingdatabase,theRG1.121criterionrequiringmaintenanceofasafetyfactorof1.43timestheSLBpressuredifferentialontubeburstissatisfiedby7/8inchdiametertubingwithbobbincoilindicationswithsignalamplitudeslessthanV><,regardlessoftheindicateddepthmeasurement.A2voltpluggingcriteriacomparesfavorablywiththecurrentV><(8.8volt)structurallimit,consideringthepreviouslycalculatedgrowthratesforODSCCwithinCookNuclearPlantUnit1SGs.Consideringavoltagegrowthcomponentof0.8volts(40Xvoltagegrowthbasedon2voltsBOC)andanondestructiveexaminationuncertaintyof0.40volts(20Xvoltageuncertaintybasedon2voltsBOC),whenaddedtotheBOCpluggingcriteriaof2volts,resultsinaboundingEOCvoltageofapproximately3.2voltsforacycleoperation.A5.6voltsafetymarginexists(8.8-3.2voltEOC-5.6voltmargin).Forthevoltage/burstcorrelation,theEOCstructurallimitissupportedbyavoltageof8.8volts.UsingthisVz<of8.8volts,aBOCmaximumallowablerepairlimitcanbeestablishedusingtheguidanceofRG1.121.TheBOCmaximumallowablerepairlimitshouldnotpermitasignificantnumberofEOCindicationstoexceedtheVz<andshouldassurethatacceptabletubeburstprobabilitiesareattained.ByaddingNDEuncertaintyallowancesandanallowanceforcrackgrowthtotherepairlimit,thestructurallimitcanbevalidated.ThepreviouspluggingcriteriasubmittalestablishedtheconservativeNDEuncertaintylimit(V<><)of20XoftheBOCrepair-limit.Forconsistency,a40Xvoltagegrowthallowance(V<<)totheBOCrepairlimitisalsoincluded.ThisallowanceisextremelyconservativeforCookNuclear
Attachment 1toAEP:NRC:1166AA Page9testingwasdoneatroomtemperature),
tubeburstresistance significantly exceedsthesafetyfactorrequirements ofRG1.121.Asstatedearlier,tubeburstcriteriaareinherently satisfied duringnormaloperating conditions duetotheproximity oftheTSP.Testdataindicates thattubeburstcannotoccurwithintheTSP,evenfortubeswhichhave100Xthroughwall electric-discharge machinednotches0.75inchlong,providedtheTSPisadjacenttothenotchedarea,Sincetube-to-tube supportplateproximity precludes tubeburstduringnormaloperating conditions, itfollowsthatuseoftheproposedpluggingcriteriamust,therefore, retaintubeintegrity characteristics whichmaintaintheRG1.121marginofsafetyof1.43timestheboundingfaultedcondition (steamlinebreak)pressuredifferential.
Duringapostulated mainSLB,theTSPhasthepotential todeflectduringblowdown, therebyuncovering theintersection.
Basedontheexistingdatabase,theRG1.121criterion requiring maintenance ofasafetyfactorof1.43timestheSLBpressuredifferential ontubeburstissatisfied by7/8inchdiametertubingwithbobbincoilindications withsignalamplitudes lessthanV><,regardless oftheindicated depthmeasurement.
A2voltpluggingcriteriacomparesfavorably withthecurrentV><(8.8volt)structural limit,considering thepreviously calculated growthratesforODSCCwithinCookNuclearPlantUnit1SGs.Considering avoltagegrowthcomponent of0.8volts(40Xvoltagegrowthbasedon2voltsBOC)andanondestructive examination uncertainty of0.40volts(20Xvoltageuncertainty basedon2voltsBOC),whenaddedtotheBOCpluggingcriteriaof2volts,resultsinaboundingEOCvoltageofapproximately 3.2voltsforacycleoperation.
A5.6voltsafetymarginexists(8.8-3.2voltEOC-5.6voltmargin).Forthevoltage/burst correlation, theEOCstructural limitissupported byavoltageof8.8volts.UsingthisVz<of8.8volts,aBOCmaximumallowable repairlimitcanbeestablished usingtheguidanceofRG1.121.TheBOCmaximumallowable repairlimitshouldnotpermitasignificant numberofEOCindications toexceedtheVz<andshouldassurethatacceptable tubeburstprobabilities areattained.
ByaddingNDEuncertainty allowances andanallowance forcrackgrowthtotherepairlimit,thestructural limitcanbevalidated.
Thepreviouspluggingcriteriasubmittal established theconservative NDEuncertainty limit(V<><)of20XoftheBOCrepair-limit.Forconsistency, a40Xvoltagegrowthallowance (V<<)totheBOCrepairlimitisalsoincluded.
Thisallowance isextremely conservative forCookNuclear


Attachment1toAEP:NRC:1166AAPage10PlantUnit1.Therefore,themaximumallowableuppervoltagerepairlimitV<<<forBOC,basedontheV><of8.8volts,canberepresentedbytheexpression:VURL+(VADExVURL)+(VMxVuRL)=8.8volts,or,themaximumallowableBOCrepairlimitcanbeexpressedas,Vz<<=8.8voltstructurallimit/1.6=5.5volts.Thisstructuralrepairlimitsupportsthisapplicationforpluggingcriteriaimplementationtorepairbobbinindicationsgreaterthan2voltsbasedonRPCconfirmationoftheindication.Conservatively,anupperlimitof5.5voltswillbeusedtorepairbobbincoilindicationswhichareabove2voltsbutdonothaveconfirmingRPCcalls.Relativetotheexpectedleakageduringaccidentconditionloadings,ithasbeenpreviouslyestablishedthatapostulatedmainSLBoutsideofcontainment,butupstreamofthemainsteamisolationvalve,representsthemostlimitingradiologicalconditionrelativetothepluggingcriteria.Insupportofimplementationofthepluggingcriteria,itwillbedeterminedwhetherthedistributionofcrackindicationsattheTSPintersectionsattheEOCareprojectedtobesuchthatprimary-to-secondaryleakagewouldresultinsiteboundarydoseswithinasmallfractionofthe10CFR100guidelines.AseparatecalculationhasdeterminedthisallowableSLBleakagelimittobe8.4gpm.AlthoughnotrequiredbytheCookNuclearPlantdesignbasis,thiscalculationusestherecommendedIodine-131transientspikingvaluesconsistentwithNUREG-0800,andtheT/Sreactorcoolantsystemactivitylimi,tof1microcuriepergramdoseequivalentIodine-131.Controlroomdosecalculationswerealsoperformedandfoundtobelesslimitingthantheoffsitedosecalculationleakrate.Therefore,themoreconservativeoffsitedoseleakrateisused.TheprojectedSLBleakageratecalculationmethodologyprescribedinGL95-05andWCAP14277willbeusedtocalculateEOCleakage,basedonactualEOCdistributionsandEOCprojecteddistributions.DuetotherelativelylowvoltagegrowthratesatCookNuclearPlantUnit1andtherelativelysmallnumberofindicationsaffectedbythepluggingcriteria,SLBleakagepredictionperGL95-05isexpectedtobesignificantlylessthanthepermissiblelevel.of8.4gpminthefaultedloop.Theinclusionofallintersectionsintheleakagemodel,alongwithapplicationofaprobabilityofdetectionof0.6,  
Attachment 1toAEP:NRC:1166AA Page10PlantUnit1.Therefore, themaximumallowable uppervoltagerepairlimitV<<<forBOC,basedontheV><of8.8volts,canberepresented bytheexpression:
VURL+(VADExVURL)+(VMxVuRL)=8.8volts,or,themaximumallowable BOCrepairlimitcanbeexpressed as,Vz<<=8.8voltstructural limit/1.6
=5.5volts.Thisstructural repairlimitsupportsthisapplication forpluggingcriteriaimplementation torepairbobbinindications greaterthan2voltsbasedonRPCconfirmation oftheindication.
Conservatively, anupperlimitof5.5voltswillbeusedtorepairbobbincoilindications whichareabove2voltsbutdonothaveconfirming RPCcalls.Relativetotheexpectedleakageduringaccidentcondition
: loadings, ithasbeenpreviously established thatapostulated mainSLBoutsideofcontainment, butupstreamofthemainsteamisolation valve,represents themostlimitingradiological condition relativetothepluggingcriteria.
Insupportofimplementation ofthepluggingcriteria, itwillbedetermined whetherthedistribution ofcrackindications attheTSPintersections attheEOCareprojected tobesuchthatprimary-to-secondary leakagewouldresultinsiteboundarydoseswithinasmallfractionofthe10CFR100guidelines.
Aseparatecalculation hasdetermined thisallowable SLBleakagelimittobe8.4gpm.AlthoughnotrequiredbytheCookNuclearPlantdesignbasis,thiscalculation usestherecommended Iodine-131 transient spikingvaluesconsistent withNUREG-0800, andtheT/Sreactorcoolantsystemactivitylimi,tof1microcuriepergramdoseequivalent Iodine-131.
Controlroomdosecalculations werealsoperformed andfoundtobelesslimitingthantheoffsitedosecalculation leakrate.
Therefore, themoreconservative offsitedoseleakrateisused.Theprojected SLBleakageratecalculation methodology prescribed inGL95-05andWCAP14277willbeusedtocalculate EOCleakage,basedonactualEOCdistributions andEOCprojected distributions.
Duetotherelatively lowvoltagegrowthratesatCookNuclearPlantUnit1andtherelatively smallnumberofindications affectedbythepluggingcriteria, SLBleakageprediction perGL95-05isexpectedtobesignificantly lessthanthepermissible level.of8.4gpminthefaultedloop.Theinclusion ofallintersections intheleakagemodel,alongwithapplication ofaprobability ofdetection of0.6,  


Attachment1toAEP:NRC:1166AAPage11willresultinextremelyconservativeleakageestimations.Closeexaminat'ionoftheavailabledatashowsthatindicationsoflessthan2.8voltswillnotbeexpectedtoleakduringSLBconditions.TheproposedamendmentdoesnotresultinanyincreaseintheprobabilityorconsequencesofanaccidentpreviouslyevaluatedwithintheCookNuclearPlantUnit1FinalSafetyAnalysisReport(FSAR).2)Theproposedlicenseamendmentdoesnotcreatethepossibilityofanewordifferentkindofaccidentfromanyaccidentpreviouslyevaluated.ImplementationoftheproposedSGtubepluggingcriteriadoesnotintroduceanysignificantchangestotheplantdesignbasis.UseofthecriteriadoesnotprovideamechanismwhichcouldresultinanaccidentoutsideoftheregionoftheTSPelevations.Neitherasinglenoramultipletuberuptureeventwould,underanyplantconditions,beexpectedinaSGinwhichthepluggingcriteriahasbeenapplied.Specifically,wewillcontinuetoimplementamaximumleakageratelimitof150gpd(0.1gpm)perSGtohelpprecludethepotentialforexcessiveleakageduringallplantconditions.TheT/Slimitsimposedonprimary-to-secondaryleakageatoperatingconditionsareamaximumof0.4gpm(600gpd)forallSGswithamaximumof150gpdallowedforanyoneSG~TheRG1.121criteriaforestablishingoperationalleakageratelimitsthatrequireplantshutdownarebaseduponleak-before-break(LBB)considerationstodetectafreespancrackbeforepotentialtuberuptureduringfaultedplantconditions.The150gpdlimitshouldprovideforleakagedetectionandplantshutdownintheeventoftheoccurrenceofanunexpectedsinglecrackresultinginleakagethatisassociatedwiththelongestpermissiblecracklength.RegulatoryGuide1.121acceptancecriteriaforestablishingoperatingleakagelimitsarebasedonLBBconsiderationssuchthatplantshutdownisinitiatediftheleakageassociatedwiththelongestpermissiblecrack,isexceeded.Thelongestpermissiblecrackisthelengththatprovidesafactorofsafetyof1.43againstburstingatfaultedconditionsmaximumpressuredifferential.Avoltageamplitudeof8.8voltsfortypicalODSCCcorrespondstomeetingthistubeburstrequirementatalower95/predictionlimitontheburstcorrelationcoupledwith95/95lowertolerancelimitmaterialproperties.Alternatecrackmorphologiescancorrespondto
Attachment 1toAEP:NRC:1166AA Page11willresultinextremely conservative leakageestimations.
Closeexaminat'ion oftheavailable datashowsthatindications oflessthan2.8voltswillnotbeexpectedtoleakduringSLBconditions.
Theproposedamendment doesnotresultinanyincreaseintheprobability orconsequences ofanaccidentpreviously evaluated withintheCookNuclearPlantUnit1FinalSafetyAnalysisReport(FSAR).2)Theproposedlicenseamendment doesnotcreatethepossibility ofanewordifferent kindofaccidentfromanyaccidentpreviously evaluated.
Implementation oftheproposedSGtubepluggingcriteriadoesnotintroduce anysignificant changestotheplantdesignbasis.Useofthecriteriadoesnotprovideamechanism whichcouldresultinanaccidentoutsideoftheregionoftheTSPelevations.
Neitherasinglenoramultipletuberuptureeventwould,underanyplantconditions, beexpectedinaSGinwhichthepluggingcriteriahasbeenapplied.Specifically, wewillcontinuetoimplement amaximumleakageratelimitof150gpd(0.1gpm)perSGtohelpprecludethepotential forexcessive leakageduringallplantconditions.
TheT/Slimitsimposedonprimary-to-secondary leakageatoperating conditions areamaximumof0.4gpm(600gpd)forallSGswithamaximumof150gpdallowedforanyoneSG~TheRG1.121criteriaforestablishing operational leakageratelimitsthatrequireplantshutdownarebaseduponleak-before-break (LBB)considerations todetectafreespancrackbeforepotential tuberuptureduringfaultedplantconditions.
The150gpdlimitshouldprovideforleakagedetection andplantshutdownintheeventoftheoccurrence ofanunexpected singlecrackresulting inleakagethatisassociated withthelongestpermissible cracklength.Regulatory Guide1.121acceptance criteriaforestablishing operating leakagelimitsarebasedonLBBconsiderations suchthatplantshutdownisinitiated iftheleakageassociated withthelongestpermissible crack,isexceeded.
Thelongestpermissible crackisthelengththatprovidesafactorofsafetyof1.43againstburstingatfaultedconditions maximumpressuredifferential.
Avoltageamplitude of8.8voltsfortypicalODSCCcorresponds tomeetingthistubeburstrequirement atalower95/prediction limitontheburstcorrelation coupledwith95/95lowertolerance limitmaterialproperties.
Alternate crackmorphologies cancorrespond to


Attachment1toAEP:NRC:1166AAPage128.8voltssothatauniquecracklengthisnotdefinedbytheburstpressure"versusvoltagecorrelation.Consequently,typicalburstpressureversusthrough-wallcracklengthcorrelationswereusedtodefinethe"longestpermissiblecrack"forevaluatingoperatingleakagelimits.Consistentwiththecycle13,14and15licenseamendmentrequestsforpluggingcriteria,andSection5ofEnclosure1oftheGL,operationalleakagelimitswillremainat150gpd.perSG.AxialcracksleakingatthislevelareexpectedtoprovideLBBprotectionatboththeSLBpressuredifferentialof2560psiand,whilenotpartofanyestablishedLBBmethodology,LBBprotectionwillalsobeprovidedatavalueof1.43timestheSLBpressuredifferential.Thus,the150gpdlimitprovidesforplantshutdownpriortoreachingcriticalcracklengthsforSLBconditions.Additionally,thisLBBevaluationassumesthattheentirecreviceareaisuncoveredduringblowdown.Partialuncoverywillprovidebenefittotheburstcapacityoftheintersection.3)Theproposedlicenseamendmentdoesnotinvolveasignificantreductioninmarginofsafety.Theuseofthevoltage-basedbobbinprobeinterimTSPelevationpluggingcriteriaatCookNuclearPlantUnit1isdemonstratedtomaintainSGtubeintegritycommensuratewiththecriteriaofRG1.121.RegulatoryGuide1~121describesamethodacceptabletotheNRCstaffformeetingGDC14,15,31,and32byreducingtheprobabilityortheconsequencesofSGtuberupture.ThisisaccomplishedbydeterminingthelimitingconditionsofdegradationofSGtubing,asestablishedbyin-serviceinspection,forwhichtubeswithunacceptablecrackingshouldberemovedfromservice.Uponimplementationofthecriteria,evenundertheworstcaseconditions,theoccurrenceofODSCCattheTSPelevationsisnotexpectedtoleadtoaSGtuberuptureeventduringnormal,orfaultedplantconditions.ItwillbeconfirmedbyanalysisandcalculationthatEOCdistributionofcrackindicationsattheTSPelevationswillresultinacceptableprimary-to-secondaryleakageduringallplantconditionsandthatradiologicalconsequencesarenotadverselyimpacted.InaddressingthecombinedeffectsofaLOCAandSSEontheSGcomponent(asrequiredbyGDC2),ithasbeendeterminedthattubecollapsemayoccurintheSGsatsomeplants.ThepostulatedtubecollapseresultsfromadeformationofTSPsasaresultoflateralloadsatthewedgesupportsattheperipheryoftheplate.Thelateralloadsresultfromthe l
Attachment 1toAEP:NRC:1166AA Page128.8voltssothatauniquecracklengthisnotdefinedbytheburstpressure"versusvoltagecorrelation.
Attachment1toAEP:NRC:1166AAPage13combinedeffectsoftheLOCArarefactionwaveandSSEloadings.Theresultingpressuredifferentialonthedeformedtubesmaythencausesomeofthetubestocollapse.TherearetwoissuesassociatedwithapostulatedSGtubecollapse.First,thecollapseofSGtubingreducestheRCSflowareathroughthetubes.ThereductioninflowareaincreasestheresistancetoflowofsteamfromthecoreduringaLOCAwhich,inturn,maypotentiallyincreasepeakcladtemperature.Second,thereisapotentialthatpartialthrough-wallcracksintubescouldprogresstothrough-wallcracksduringtubedeformationorcollapse.Consequently,sincetheLBBmethodologyisapplicabletotheCookNuclearPlantUnit1reactorcoolantlooppiping,theprobabilityofbreaksintheprimarylooppipingissufficientlylowthattheyneednotbeconsideredinthestructuraldesignoftheplant.ThelimitingLOCAeventbecomeseithertheaccumulatorlinebreakorthepressurizersurgelinebreak.LossofcoolantaccidentloadsfortheprimarypipebreakswereusedtoboundtheCookNuclearPlantUnit1smallerbreaks.TheresultsoftheanalysisusingthelargerbreakinputsshowthattheLOCAloadswerefoundtobeofinsufficientmagnitudetoresultinSGtubecollapseorsignificantdeformation.AddressingRG1.83considerations,implementationof,thebobbincoilprobe,voltage-basedinterimtubepluggingcriteriaof2voltsissupplementedbyenhancededdycurrent,inspectionguidelinestoprovideconsistencyinvoltagenormalization,a100XeddycurrentinspectionsamplesizeattheTSPelevationsperT/S,andMRPCinspectionrequirementsforthelargerindicationsleftin-servicetocharacterizetheprincipaldegradationasODSCC.Asnotedpreviously,implementationoftheTSPelevationpluggingcriteriawilldecreasethenumberoftubeswhichmustberepaired.TheinstallationofSGtubeplugsreducestheRCSflowmargin.Thus,implementationofthepluggingcriteriawillmaintainthemarginofflowthatwouldotherwisebereducedintheeventofincreasedtubeplugging.Basedontheabove,itisconcludedthattheproposedlicenseamendmentrequestdoesnotresultinasignificantreductioninmarginwithrespecttoplantsafetyasdefinedintheFSARoranyBasesoftheplantT/Ss.
Consequently, typicalburstpressureversusthrough-wall cracklengthcorrelations wereusedtodefinethe"longestpermissible crack"forevaluating operating leakagelimits.Consistent withthecycle13,14and15licenseamendment requestsforpluggingcriteria, andSection5ofEnclosure 1oftheGL,operational leakagelimitswillremainat150gpd.perSG.AxialcracksleakingatthislevelareexpectedtoprovideLBBprotection atboththeSLBpressuredifferential of2560psiand,whilenotpartofanyestablished LBBmethodology, LBBprotection willalsobeprovidedatavalueof1.43timestheSLBpressuredifferential.
Thus,the150gpdlimitprovidesforplantshutdownpriortoreachingcriticalcracklengthsforSLBconditions.
Additionally, thisLBBevaluation assumesthattheentirecreviceareaisuncovered duringblowdown.
Partialuncoverywillprovidebenefittotheburstcapacityoftheintersection.
3)Theproposedlicenseamendment doesnotinvolveasignificant reduction inmarginofsafety.Theuseofthevoltage-based bobbinprobeinterimTSPelevation pluggingcriteriaatCookNuclearPlantUnit1isdemonstrated tomaintainSGtubeintegrity commensurate withthecriteriaofRG1.121.Regulatory Guide1~121describes amethodacceptable totheNRCstaffformeetingGDC14,15,31,and32byreducingtheprobability ortheconsequences ofSGtuberupture.Thisisaccomplished bydetermining thelimitingconditions ofdegradation ofSGtubing,asestablished byin-service inspection, forwhichtubeswithunacceptable crackingshouldberemovedfromservice.Uponimplementation ofthecriteria, evenundertheworstcaseconditions, theoccurrence ofODSCCattheTSPelevations isnotexpectedtoleadtoaSGtuberuptureeventduringnormal,orfaultedplantconditions.
Itwillbeconfirmed byanalysisandcalculation thatEOCdistribution ofcrackindications attheTSPelevations willresultinacceptable primary-to-secondary leakageduringallplantconditions andthatradiological consequences arenotadversely impacted.
Inaddressing thecombinedeffectsofaLOCAandSSEontheSGcomponent (asrequiredbyGDC2),ithasbeendetermined thattubecollapsemayoccurintheSGsatsomeplants.Thepostulated tubecollapseresultsfromadeformation ofTSPsasaresultoflateralloadsatthewedgesupportsattheperiphery oftheplate.Thelateralloadsresultfromthe l
Attachment 1toAEP:NRC:1166AA Page13combinedeffectsoftheLOCArarefaction waveandSSEloadings.
Theresulting pressuredifferential onthedeformedtubesmaythencausesomeofthetubestocollapse.
Therearetwoissuesassociated withapostulated SGtubecollapse.
First,thecollapseofSGtubingreducestheRCSflowareathroughthetubes.Thereduction inflowareaincreases theresistance toflowofsteamfromthecoreduringaLOCAwhich,inturn,maypotentially increasepeakcladtemperature.
Second,thereisapotential thatpartialthrough-wall cracksintubescouldprogresstothrough-wall cracksduringtubedeformation orcollapse.
Consequently, sincetheLBBmethodology isapplicable totheCookNuclearPlantUnit1reactorcoolantlooppiping,theprobability ofbreaksintheprimarylooppipingissufficiently lowthattheyneednotbeconsidered inthestructural designoftheplant.ThelimitingLOCAeventbecomeseithertheaccumulator linebreakorthepressurizer surgelinebreak.LossofcoolantaccidentloadsfortheprimarypipebreakswereusedtoboundtheCookNuclearPlantUnit1smallerbreaks.TheresultsoftheanalysisusingthelargerbreakinputsshowthattheLOCAloadswerefoundtobeofinsufficient magnitude toresultinSGtubecollapseorsignificant deformation.
Addressing RG1.83considerations, implementation of,thebobbincoilprobe,voltage-based interimtubepluggingcriteriaof2voltsissupplemented byenhancededdycurrent,inspection guidelines toprovideconsistency involtagenormalization, a100Xeddycurrentinspection samplesizeattheTSPelevations perT/S,andMRPCinspection requirements forthelargerindications leftin-service tocharacterize theprincipal degradation asODSCC.Asnotedpreviously, implementation oftheTSPelevation pluggingcriteriawilldecreasethenumberoftubeswhichmustberepaired.
Theinstallation ofSGtubeplugsreducestheRCSflowmargin.Thus,implementation ofthepluggingcriteriawillmaintainthemarginofflowthatwouldotherwise bereducedintheeventofincreased tubeplugging.
Basedontheabove,itisconcluded thattheproposedlicenseamendment requestdoesnotresultinasignificant reduction inmarginwithrespecttoplantsafetyasdefinedintheFSARoranyBasesoftheplantT/Ss.
I,}}
I,}}

Revision as of 07:17, 29 June 2018

Application for Amend to License DPR-58,addressing Applicable Requirements of NRC GL 95-05, Voltage-Based Repair Criteria for Repair of Westinghouse SG Tubes Affected by Outside Diameter Stress Corrosion Cracking.
ML17334B590
Person / Time
Site: Cook American Electric Power icon.png
Issue date: 06/19/1996
From: FITZPATRICK E
AMERICAN ELECTRIC POWER CO., INC.
To:
NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML17333A478 List:
References
AEP:NRC:1166AA, GL-95-05, GL-95-5, NUDOCS 9606260254
Download: ML17334B590 (34)
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Text

CATEGORY1REGULATO~

INFORMATION DISTRIBUTION SYSTEM(RIDS)ACCESSION NBR:9606260254 DOC.DATE:

96f06fl9NOTARIZED:

YESDOCKET:FACIL:50-315 DonaldC.CookNuclearPowerPlant,Unit1,IndianaM05000315AUTH.NAMEAUTHORAFFILIATION FITZPATR:.CK,E.

AmericanElectricPowerCo.,Inc.RECIP.NAME RECIPIENT AFFILIATION Document'ontrol Branch(Document ControlDesk)SUBJE!T:Application foramendtoLicenseDPR-58,addressing applicable requirements ofNRCGL95-05,"Voltage-Based C.RepairCriteriaforRepairofWestinghouse SGTubesAffectedby,OutsideDiameterStressCorrosion Cracking."

ADISTRIBUTION CODE:ADOIDCOPIESRECEIVED:LTR IENCL/SIZE:TITLE:ORSubmittal:

GeneralDistribution ENOTES:RECIPIENT IDCODE/NAME PD3-1LAHICKMAN,J INTERNAL,~IEl.

HE~NTE1%RR/DRCH~HICB NRR/DSSA/SRXB OGC/HDS2EXTERNAL:

NOACCOPIESLTTRENCL11111111111011RECIPIENT IDCODE/NAME PD3-1PDNRR/DE/EMCB NRR/DSSA/SPLB NUDOCS-ABSTRACT NRCPDRCOPIESLTTRENCL11111111D0NOTETOALL"RIDS"RECIPIENTS:

PLEASEHELPUSTOREDUCEWASTE!CONTACTTHEDOCUMENTCONTROLDESK,ROOMOWFN5D-5(EXT.

415-2083)

TOELIMINATE YOURNAMEFROMDISTRIBUTION LISTSFORDOCUMENTS YOUDON'TNEED!ITOTALNUMBEROFCOPIESREQUIRED:

LTTR,12ENCLll eRf4>~4.1~'l4,C AmericanElectricP~1Riverside PlazaColumbus, OH4321523736142231000June19,1996AEP:NRC:1166AA DocketNos.:50-315U.S.NuclearRegulatory Commission ATTN:DocumentControlDeskWashington, D.C.20555Gentlemen:

DonaldC.CookNuclearPlantUnit1TECHNICAL SPECIFICATION CHANGESTOINCORPORATE 2VOLTSTEAMGENERATOR TUBESUPPORTPLATEREPAIRCRITERION Thisletteranditsattachments provideapplication foramendment tothetechnical specifications (T/Ss)ofDonaldC.CookNuclearPlantUnit1.Specifically, thisinformation addresses theapplicable requirements ofNRCGenericLetter(GL)95-05"Voltage-BasedRepairCriteriafortheRepairofWestinghouse SteamGenerator TubesAffectedbyOutsideDiameterStressCorrosion Cracking."

Attachment 1providesatechnical summaryoft:hespecificinspection practices andcalculation methodologies outlinedinGL95-05andthe10CFR50.92nosignificant hazardsevaluation.

Theevaluation andresultssupportcontinued useofthe2voltpluggingcriteriaasallowedbyGL95-05forfutureoperating cycles.Attachment 2containsexistingT/Spagesmarkedtoreflecttherequested changes.Attachment 3providestheproposedrevisedT/Spages.Webelievetheproposedchangeswillnotresultin(1)asignificant changeinthetypesofanyeffluentthatmaybereleasedoffsite,or(2)asignificant increaseinindividual orcumulative occupat.i.onal radiation exposure.

9606260254';.9606 19'DRADOCK.050003i5 P.PDR U.S.NuclearRegulatory Commission Page2AEP:NRC:1166AA TheseproposedchangeshavebeenreviewedbythePlantNuclearSafetyReviewCommittee andtheNuclearSafetyandDesignReviewCommittee.

Incompliance withtherequirements of10CFR50.91(b)(1),

copiesofthisletteranditsattachments havebeentransmitted totheMichiganPublicServiceCommission andtotheMichiganDepartment ofPublicHealth.Sincerely, VicePresident SWORNTOANDSUBSCRIBED BEFOREMETHIS~~~4DAYOF1996teryPublicllgAttachments cc:A.A.BlindG.CharnoffH.J.MillerNFEMSectionChiefNRCResidentInspector

-BridgmanJ.R.Padgett U.S.NuclearRegulatory Commission Page3AEP:NRC:1166AA bc:S.J.Brewer/M.

S.Ackerman/K.

J.TothJ.A.KobyraD.R.Hafer/J.R.JensenJ.B.ShinnockJ.S.WiebeJ.B.Hickman,NRC-Washington, D.C.-w/attachment PRONET-w/attachment DC-N-6015.1 J'

AmericanElectric1Riverside PlazaColumbus, OH4321523736142231000ANERlCAMELECfRICPOWERJune19,1996AEP:NRC:1166AA DocketNos~:50-315U.S.NuclearRegulatory Commission ATTN:DocumentControlDeskWashington, D.C.20555Gentlemen:

DonaldC.CookNuclearPlantUnit1TECHNICAL SPECIFICATION CHANGESTOINCORPORATE 2VOLTSTEAMGENERATOR TUBESUPPORTPLATEREPAIRCRITERION Thisletteranditsattachments provideapplication foramendment tothetechnical specifications (T/Ss)ofDonaldC.CookNuclearPlantUnit1.Specifically, thisinformation addresses theapplicable requirements ofNRCGenericLetter(GL)95-05"Voltage-BasedRepairCriteriafortheRepairofWestinghouse SteamGenerator TubesAffectedbyOutsideDiameterStressCorrosion Cracking."

Attachment 1providesatechnical summaryofthespecificinspection practices andcalculation methodologies outlinedinGL95-05andthe10CFR50.92nosignificant hazardsevaluation.

Theevaluation andresultssupportcontinued useofthe2voltpluggingcriteriaasallowedbyGL95-05forfutureoperating cycles.Attachment 2containsexistingT/Spagesmarkedtoreflecttherequested changes.Attachment 3providestheproposedrevisedT/Spages.Webelievetheproposedchangeswillnotresultin(1)asignificant changeinthetypesofanyeffluentthatmaybereleasedoffsite,or(2)asignificant increaseinindividual orcumulative occupational radiation exposure.

U.S.NuclearRegulatory Commission Page2AEP:NRC:1166AA TheseproposedchangeshavebeenreviewedbythePlantNuclearSafetyReviewCommittee andtheNuclearSafetyandDesignReviewCommittee.

Incompliance withtherequirements of10CFR50.91(b)(l),

copiesofthisletteranditsattachments havebeentransmitted totheMichiganPublicServiceCommission andtotheMichiganDepartment ofPublicHealth.Sincerely, PgM.~,xi)

E.E.Fitzpatrick VicePresident SWOP'OANDSUBSCRIBED BEFOREMETHIS~cP4'AYOF1996.CotaryPublicw"llgAttachments cc:A.A.BlindG.CharnoffH.J~MillerNFEMSectionChiefNRCResidentInspector

-BridgmanJ.R.Padgett U.S.NuclearRegulatory Commission Page3AEP:NRC:1166AA bc:S.J.Brewer/M.

S.Ackerman/K.

J.TothJ.A.KobyraD.R.HaEer/J.R.JensenJ.B.ShinnockJ.S.WiebeJ.B.Hickman,NRC-Washington, D.C.-w/attachment PRONET-w/attachment DC-N-6015.1 ATTACHMENT 1TOAEP:NRC:1166AA DESCRIPTION OFCHANGESTOTHEDONALDC.COOKNUCLEARPLANTUNIT1TECHNICAL SPECIFICATIONS 10CFR50.92EVALUATION Attachment 1toAEP:NRC:1166AA Page1INTRODUCTION Thisamendment requestproposesachangetoCookNuclearPlantUnit1steamgenerators (SG)T/Ss4.4.5.2,4.4.5.4,4.4'.5,3.4.6.2andBases3/4.4.5and3/4.4.6.2 toallowuseofGL95-05voltage-based SGtubesupportplate(TSP)pluggingcriteria.

ThechangeallowsSGtubeswithbobbincoileddycurrentindications lessthanorequalto2voltsatTSPintersections toremaininservice,regardless oftheapparentdepthoftubewallpenetration if,asaresult,theprojected end-of-cycle (EOC)distribution ofcrackindications isshowntoresultinprimary-to-secondary leakagelessthan8.4gpminthefaultedloopduringapostulated steamlinebreak(SLB)event.Indications greaterthan2voltsbutlessthanorequaltotheuppervoltagerepairlimit(VU<L)mayremaininserviceifamotorized rotatingpancakecoil(MRPC)probeinspection doesnotdetectdegradation.

TheVUgLwillbedetermined eachoutageusingthemostrecent,NRC-approved industrytubeburstdatabasetodetermine thevoltagecorresponding tothetubestructural limit(VSL).Thisamendment wouldreducethenumberofSGtubespluggedduetoindications atsupportplateintersections.

ReducingthenumberofpluggedtubesprovidesALARAbenefitsandmaintains reactorcoolantsystem(RCS)flowmargin.Assessment reportsaddressing theeffectiveness ofthevoltage-based pluggingcriteriamethodology aredescribed inWCAP-13187, Revision0,whichwascompleted following fuelcycles13and14.Thisinformation wasreportedinsubmittal documents AEP:NRC:1166J andAEP:NRC:1166AC.

Thereportsconcluded thatthevoltagedistribution foundbyinspection atEOC13andEOC14,in1994and1995,respectively, wereingoodagreement withtheprojections'he voltagegrowthratescontinuetobeverysmall.Noin-service tubeswerefoundforwhichthebobbincoilvoltageexceededthe2voltpluggingcriteriarepairlimitatEOC13orEOC14.Considering theresultsoftheaforementioned reports,continued useofthe2voltpluggingcriteriaisjustified.

Similarassessment andprojection reportsbasedonGL95-05reporting requirements willbepreparedateachEOC.

Attachment 1toAEP:NRC:1166AA Page2APPLICATION OFGL95-05TOTHECOOKNUCLEARPLANTUNIT1SG'ICENSE AMENDMENT TheCookNuclearPlantUnit1,2voltpluggingcriteriawillbeimplemented pertheguidanceofGL95-05alongwiththelatestindustrydatafortubeburstandleakage.NRCGL95-05willbefactoredintotheCookNuclearPlantUnit1pluggingcriteriaasfollows:Analystswillbebriefedregarding thepossibility ofprimarywaterstresscorrosion cracking(PWSCC)atTSPintersections.

IfPWSCCisfoundatthesupportplateintersections itwillbereportedtotheNRCstaffpriortostartup.2)Theuseofsupporting datasetsforcalculation ofburstprobability andestimation ofprimary-to-secondary leakageduringapostulated mainSLBforeachoutagewillbebasedonthemostcurrent,NRC-approved industrydatabase.Thelatestindustrydatabasewastransmitted totheNRCunderBeaverValleyPowerStation',

Unit1,March27,1996,lettertransmitting supplemental information insupportofarequested T/Schange,foravoltage-based SGtuberepaircriteria, originally proposedintheirletterdatedDecember7,1995.Thatdatabasewasusedinthepreparation ofthissubmittal.

3)Mainsteamlineburstprobability andleakagecalculations willbeperformed following theguidanceofGL95-05,Section2,"TubeIntegrity Evaluation."

Calculations performed insupportofthevoltage-based repaircriteriawillfollowthemethodology described inWCAP-14277, "SteamLineBreakLeakRateandTubeBurstProbability AnalysisMethodsforOutsideDiameterStressCorrosion CrackingatTubeSupportPlateIntersections,'"

datedJanuary1995.Thecalculations, usingtheas-foundvoltagedistribution, willbeperformed priortoreturning theSGstoservice.Theprojected EOCvoltagedistribution resultswillbereportedinthe90dayreport.4)Inspection scope,dataacquisition, anddataanalysiswillbeperformed following theguidanceofGL95-05,Section3,"Inspection Criteria" andreferenced AppendixA,'DEDataAcquisition andAnalysisGuidelines."

AnMRPCinspection willbedoneonallindications exceeding 2volts.AnMRPCinspection willalsobedoneonallintersections wherecoppersignals,largemixedresiduals, ordentslargerthan5voltsinterfere withdetection offlaws.

II Attachment 1toAEP:NRC:1166AA Page3Probewearinspections andre-inspections willbeperformed usingthefolloOing guidelines:

Ifanyofthelastprobewearstandardsignalamplitudes, priortoprobereplacement, exceedthe215Xlimitbyavalueof"XX,"thenanyindications measuredsincethelastacceptable probewearmeasurement thatarewithin"XX"oftheplugginglimitwillbereinspected withthenewprobe.Forexample,ifanyofthelastprobewearsignalamplitudes priortoprobereplacement were17Xaboveorbelowtheinitialamplitude, thentheindications thatarewithin2X(17X-15X) oftheplugginglimitmustbereinspected withthenewprobe.Alternatively, thevoltagecriterion maybeloweredtocompensate fortheexcessvariation; forthecaseabove,amplitudes

)0.98timesthevoltagecriterion couldbesubjecttorepair.5)Tuberemovalandexamination willbeperformed basedontheguidancecontained inGL95-05,Section4,"TubeRemovalandExamination/Testing."

Plansaretopullatubespecimenwithatleasttwointersections duringthe1997refueling outage.6)Application ofGL95-05,Section5,"Operational LeakageRequirements,"

wi,llbecontinued.

TheSGtubeleakagelimitof150gallonsperdaythrougheachSGwillbemaintained aspreviously approvedbytheNRCforourpresentfuelcycle.CookNuclearPlantleakagemonitoring methodsprovidetimelyleakdetection,

trending, andresponsetorapidlyincreasing leaks.7)GL95-05,Section6,"Reporting Requirements,"

willbeimplemented.

Asstatedpreviously forSection2,thecalculation ofleakageandburstprobability requiredpriortoreturning theSGstoservicewillbeperformed usingoftheas-foundEOCvoltagedistribution.

hh0 Attachment 1toAEP:NRC:1166AA Page4III.AEPCOMMENTSTOGL95-05ANDASSOCIATED IMPACTTOAEPLICENSEAMENDMENT REUESTFORSGPLUGGINGCRITERIA1)GL95-05,Sectionl.b:Analysesperformed byWestinghouse haveshownthatnotubesintheCookNuclearPlantUnit1SGswouldbesubjecttocollapseduringalossofcoolantaccident(LOCA)plussafeshutdownearthquake (SSE)eventsTherefore, notubesareexcludedbasedonthiscriteria.

Series51SGs,designedbyWestinghouse, donothaveflowdistribution baffleplates;therefore, Sectionl.b.5isnotapplicable.

2)GL95-05,Section3.c.3:Therequirement toreinspect alltubespriortothelastprobechangeout ifthewearmeasurement exceeds15/isunnecessary.

Reinspection ofindications necessitated byout-of-specification probewearwillbeconducted according toitem4ofpage2ofthisattachment.

IV.10CFR5092EVALUATION BACKGROUND CookNuclearPlantUnit1T/SAmendment 200permitted theimplementation ofa2voltSGtubepluggingcriteria.

Thatlicenseamendment, applicable onlyforthecurrentoperating cycle(cycle15),requirestherepairofflaw-like bobbinindications above2volts.Weareproposing useofasimilar2voltrepaircriterion withoutthecycle-specific limitation.

TheproposedpluggingcriteriaprogramfortheCookNuclearPlantUnit1SGsfollowstheguidanceandgeneralintentofGL95-05tomaintaintubestructural andleakageintegrity.

DESCRIPTION OFTHEPLUGGINGCRITERIAREQUESTAsrequiredby10CFR50.91(a)(1),ananalysisisprovidedtodemonstrate thattheproposedlicenseamendment toimplement apluggingcriteriafortheTSPelevation OutsideDiameterStressCorrosion Cracking(ODSCC)occurring intheCookNuclearPlantUnit1SGsinvolvesanosignificant hazardsconsideration.

Thepluggingcriteriautilizescorrelations betweeneddycurrentbobbincoilprobesignalamplitude (voltage) andtubeburstandleakagecapability.

Thepluggingcriterion isbasedontestingoflaboratory inducedODSCCspecimens andonextensive examination of Attachment 1toAEP:NRC:1166AA Page5pulledtubesfromoperating SGs(industry wide--including threetubespulledin1992'epresenting nineintersections fromCookNuclearPlantUnit1).Consistent withGL95-05,thepluggingcriteriaprogramforCookNuclearPlantUnit1willincludethefollowing elementsaslistedunder"1.OverviewoftheVoltageRepairLimitApproach,"

page3ofGL95-05.Performanenhancedinspection oftubes,particularly attheTSPintersections.

A100Kbobbincoilinspection ofhotlegTSPintersections andcoldlegintersections, downtothelowestcoldlegsupportplatewithknownODSCCindications, willbeperformed.

Allflawindications withbobbinvoltagesgreaterthan2voltswillbeinspected byMRPC.UtilizeNondestructive Examination (NDE)dataacquisition andanalysisprocedures thatareconsistent withthemethodology usedtodevelopthevoltage-based repairlimits.Theinspection scope,dataaquisistion, anddata-analysiswillbeperformed usingtheguidanceofSection3oftheGL.Repairtubesthatexceedthevoltagelimits.Flaw-like signalsadjacenttotheTSP,withbobbinvoltageslessthanorequalto2volts,willbeallowedtoremaininservice.Flaw-like indications adjacenttotheTSP,withabobbinvoltageofgreaterthan2voltsbutlessthanorequaltouppervoltagerepairlimit,mayremaininserviceifMRPCinspection doesnotdetectaflaw.Flawindications withavoltageofgreaterthantheuppervoltagerepairlimitwillberepaired.

Determine theBeginning ofCycle(BOC)voltagedistribution.

Beginning ofCyclevoltagedistribution willbeestablished fromtheactualtubeinspections tobeperformed andwillbeestablished usingcurrentprogrammethodology.

ProjecttheEOCdistribution.

AnEOCvoltagedistribution willbeestablished basedontheEOCeddycurrenttestdata.EOCvoltagedistribution willbeprojected usingMonteCarlotechniques asdescribed inWCAP-hI1 Attachment 1toAEP:NRC:1166AA Page614277andwillincludeallowance foreddycurrentuncertainty asdefinedinGL95-05andaconservative voltagegrowthrateallowance.

Fortheprojected EOCvoltagedistribution, calculate boththeprimary-to-secondary leakageunderpostulated accidentconditions andtheconditional tubeburstprobabili ty.Asanalternative, theactualmeasuredEOCvoltagedistribution canbeusedwhenitisimpractical tocompletethe,projected EOCcalculation priortoreturning theSGstoserviceforthepurposeofdetermining whetherthereporting criteriainGI95-05Sections6.a.land6.a.3apply.Steamlinebreakleakagewillbecalculated, asdescribed inWCAP-14277,basedontheEOCprojected voltagedistribution.

Projected leakagemustremainbelow8.4gpminthefaultedloopforpermissible offsitedoseestimates toremainacceptable within10Xofthe10CFR100guidelines.

The8.4gpmleakageforoffsitedoseestimates issmallerthantheleakagenumbercalculated foracceptable controlroomdoseperGeneralDesignCriteria(GDC)19.Therefore, theoffsitedoseismorelimiting.

Conditional tubeburstprobability willbecalculated according tothemethodology described inWCAP-14277.

Consistent withGL95-05,ifburstprobability isfoundtobegreaterthan1x10~theNRCwillbeconsulted.

Asprescribed inGL95-05,anevaluation ofprimary-to-secondary leakage(andsubsequently offsitedose)isrequiredforallplantsimplementing thepluggingcriteria.

Allbobbincoilindications areincludedintheSLBleakageanalyses, alongwithconsideration oftheprobability ofdetection.

Iftheprojected leakageexceeds8.4gpminthefaultedloopduringapostulated SLBevent,thenumberofindications towhichthepluggingcriteriaareappliedisreduced,throughtuberepair,untiltheprimary-to-secondary leakagelimitsaresatisfied.

EVALUATION TubeDegradation Characterization Ingeneral,thedegradation morphology occurring attheTSPintersections atplantsintheU.S.canbedescribed asaxiallyorientedODSCC.Thedegradation morphology atCookNuclearPlantUnit1isentirelycompatible withtheoverallindustrydatabase.

Attachment 1toAEP:NRC:1166AA Page7SteamGenerator TubeIntegrity Inthedevelopment ofapluggingcriteriaforCookNuclearPlantUnit1,Regulatory Guide(RG)1.121,"BasesforPluggingDegradedPWRSteamGenerator Tubes"andRGl.'83,"In-service Inspection ofPWRSteamGenerator Tubes"areusedasthebasesfordetermining thatSGtubeintegrity ismaintained withinacceptable limits.Regulatory Guide1.121describes amethodacceptable totheNRCstaffformeetingGDC14,15,31,and32byreducingtheprobability andconsequences ofSGtuberupturebydetermining thelimitingsafeconditions oftubewalldegradation beyondwhichtubeswithunacceptable

cracking, asestablished byin-service inspection, shouldberemovedfromservicebyplugging.

Thisregulatory guideusessafetyfactorsonloadsfortubeburststhatareconsistent withtherequirements ofSectionIIIoftheASMECode.FortheTSPelevation degradation occurring intheCookNuclearPlantUnit1SGs,tubeburstcriteriaareinherently satisfied duringnormaloperating conditions bythepresenceoftheTSP.ThepresenceoftheTSPenhancestheintegrity ofthedegradedtubesinthatregionbyprecluding tubedeformation beyondthediameterofthedrilledhole,thusprecluding tubeburst.Conservatively, nocreditistakeninthedevelopment ofthepluggingcriteriaforthepresenceoftheTSPduringaccidentconditions.

Basedontheexistingdatabasefor7/8inchtubing,bursttestingindicates thatthesafetyrequirements fortubeburstmarginsduringaccidentcondition loadingcanbesatisfied withEOCbobbincoilsignalamplitudes lessthan8.8volts,regardless ofthedepthoftubewallpenetration ofthecracking.

Uponimplementation oftheproposedpluggingcriteriaprogram,tubeleakageconsiderations mustalsobeaddressed.

Itmustbedetermined thatthecrackswillnotleakexcessively duri~gallplantconditions.

Forthe2voltinterimtubepluggingcriteriadeveloped fortheCookNuclearPlantUnit1SGtubes,noleakageisanticipated duringnormaloperating conditions evenwiththepresenceofpotential throughwall cracks.Noprimary-to-secondary leakageattheTSPhasbeendetectedinU.S.plants.Relativetotheexpectedleakageduringaccidentcondition loading,thelimitingeventwithrespecttodifferential pressureexperienced acrosstheSGtubesisapostulated SLBevent.For7/8inchtubing,pulledtubedatasupportsnoleakageupto2.81voltsandlowprobability ofleakagebetween2.81and6.0volts,forbothpulledtubesandmodelboilerspecimens, attheboundingSLBpressuredifferential of2560psi.Steamlinebreakprimary-to-secondary leakagewillbecalculated asprescribed inGL95-05andWCAP14277,usingprojected EOCeddycurrentdata.Thiscalculated leakagemustbeshowntobelessthan8.4gpminthefaultedloop.

I Attachment 1toAEP:NRC:1166AA Page8Additional Considerations

~*Theproposedamendment wouldprecludeoccupational radiation exposurethatwouldotherwise beincurredbypersonnel involvedintubepluggingorrepairoperations.

Byreducingnon-essential tubeplugging, theproposedamendment wouldminimizethelossofmargininthereactorcoolantflow,throughtheSGs,usedinLOCAanalyses.

Theproposedamendment wouldavoidlossofmargininreactorcoolantsystemflowand,therefore, assistinmaintaining minimumflowratesinexcessofthatrequiredforoperation atfullpower.Reduction intheamountoftuberepairrequiredcanreducethelengthofplantoutagesandreducethetimethattheSGsareopentothecontainment environment duringanoutage.A100Xeddycurrentbobbincoilprobeinspection associated withimplemen'tation ofthepluggingcriteriaprogramwillhelptoidentifynewareasofconcernwhichmayarise,byproviding alevelofin-service inspection whichisfarinexcessoftheT/Srequirements utilizing the40Xdepth-based plugginglimitforacceptable tubewalldegradation.

SIGNIFICANT HAZARDSANALYSISInaccordance withthethreefactortestof10CFR50.92(c),

implementation oftheproposedlicenseamendment isanalyzedusingthefollowing standards andfoundnotto:1)involveasignificant increaseintheprobability orconsequences ofanaccidentpreviously evaluated; 2)createthepossibility ofanewordifferent kindofaccidentfromanyaccidentpreviously evaluated; or3)involveasignificant reduction inmarginofsafety.Conformance oftheproposedamendment tothestandards foradetermination ofnosignificant hazardsasdefinedin10CFR50.92(threefactortest)isshowninthefollowing paragraphs:

1)Operation ofCookNuclearPlaneUnit1,inaccordance withtheproposedlicenseamendment, doesnotinvolveasignificant increaseintheprobability orconsequences ofanaccidentpreviously evaluated.

Testingofmodelboilerspecimens forfreespantubing(noTSPrestraint) atroomtemperature conditions showburstpressures inexcessof5000psiforindications ofouterdiameterstresscorrosion crackingwithvoltagemeasurements ashighas19volts.Bursttestingperformed onpulledtubesfromCookNuclearPlantUnit1withuptoa2.02voltindication showsmeasuredburstpressureinexcessof10,000psiatroomtemperature.

Bursttestingperformed onpulledtubesfromotherplantsshowburstpressures inexcessof5,300psiatroomtemperatures.

Correcting fortheeffectsoftemperature onmaterialproperties andminimumstrengthlevels(astheburst

Attachment 1toAEP:NRC:1166AA Page9testingwasdoneatroomtemperature),

tubeburstresistance significantly exceedsthesafetyfactorrequirements ofRG1.121.Asstatedearlier,tubeburstcriteriaareinherently satisfied duringnormaloperating conditions duetotheproximity oftheTSP.Testdataindicates thattubeburstcannotoccurwithintheTSP,evenfortubeswhichhave100Xthroughwall electric-discharge machinednotches0.75inchlong,providedtheTSPisadjacenttothenotchedarea,Sincetube-to-tube supportplateproximity precludes tubeburstduringnormaloperating conditions, itfollowsthatuseoftheproposedpluggingcriteriamust,therefore, retaintubeintegrity characteristics whichmaintaintheRG1.121marginofsafetyof1.43timestheboundingfaultedcondition (steamlinebreak)pressuredifferential.

Duringapostulated mainSLB,theTSPhasthepotential todeflectduringblowdown, therebyuncovering theintersection.

Basedontheexistingdatabase,theRG1.121criterion requiring maintenance ofasafetyfactorof1.43timestheSLBpressuredifferential ontubeburstissatisfied by7/8inchdiametertubingwithbobbincoilindications withsignalamplitudes lessthanV><,regardless oftheindicated depthmeasurement.

A2voltpluggingcriteriacomparesfavorably withthecurrentV><(8.8volt)structural limit,considering thepreviously calculated growthratesforODSCCwithinCookNuclearPlantUnit1SGs.Considering avoltagegrowthcomponent of0.8volts(40Xvoltagegrowthbasedon2voltsBOC)andanondestructive examination uncertainty of0.40volts(20Xvoltageuncertainty basedon2voltsBOC),whenaddedtotheBOCpluggingcriteriaof2volts,resultsinaboundingEOCvoltageofapproximately 3.2voltsforacycleoperation.

A5.6voltsafetymarginexists(8.8-3.2voltEOC-5.6voltmargin).Forthevoltage/burst correlation, theEOCstructural limitissupported byavoltageof8.8volts.UsingthisVz<of8.8volts,aBOCmaximumallowable repairlimitcanbeestablished usingtheguidanceofRG1.121.TheBOCmaximumallowable repairlimitshouldnotpermitasignificant numberofEOCindications toexceedtheVz<andshouldassurethatacceptable tubeburstprobabilities areattained.

ByaddingNDEuncertainty allowances andanallowance forcrackgrowthtotherepairlimit,thestructural limitcanbevalidated.

Thepreviouspluggingcriteriasubmittal established theconservative NDEuncertainty limit(V<><)of20XoftheBOCrepair-limit.Forconsistency, a40Xvoltagegrowthallowance (V<<)totheBOCrepairlimitisalsoincluded.

Thisallowance isextremely conservative forCookNuclear

Attachment 1toAEP:NRC:1166AA Page10PlantUnit1.Therefore, themaximumallowable uppervoltagerepairlimitV<<<forBOC,basedontheV><of8.8volts,canberepresented bytheexpression:

VURL+(VADExVURL)+(VMxVuRL)=8.8volts,or,themaximumallowable BOCrepairlimitcanbeexpressed as,Vz<<=8.8voltstructural limit/1.6

=5.5volts.Thisstructural repairlimitsupportsthisapplication forpluggingcriteriaimplementation torepairbobbinindications greaterthan2voltsbasedonRPCconfirmation oftheindication.

Conservatively, anupperlimitof5.5voltswillbeusedtorepairbobbincoilindications whichareabove2voltsbutdonothaveconfirming RPCcalls.Relativetotheexpectedleakageduringaccidentcondition

loadings, ithasbeenpreviously established thatapostulated mainSLBoutsideofcontainment, butupstreamofthemainsteamisolation valve,represents themostlimitingradiological condition relativetothepluggingcriteria.

Insupportofimplementation ofthepluggingcriteria, itwillbedetermined whetherthedistribution ofcrackindications attheTSPintersections attheEOCareprojected tobesuchthatprimary-to-secondary leakagewouldresultinsiteboundarydoseswithinasmallfractionofthe10CFR100guidelines.

Aseparatecalculation hasdetermined thisallowable SLBleakagelimittobe8.4gpm.AlthoughnotrequiredbytheCookNuclearPlantdesignbasis,thiscalculation usestherecommended Iodine-131 transient spikingvaluesconsistent withNUREG-0800, andtheT/Sreactorcoolantsystemactivitylimi,tof1microcuriepergramdoseequivalent Iodine-131.

Controlroomdosecalculations werealsoperformed andfoundtobelesslimitingthantheoffsitedosecalculation leakrate.

Therefore, themoreconservative offsitedoseleakrateisused.Theprojected SLBleakageratecalculation methodology prescribed inGL95-05andWCAP14277willbeusedtocalculate EOCleakage,basedonactualEOCdistributions andEOCprojected distributions.

Duetotherelatively lowvoltagegrowthratesatCookNuclearPlantUnit1andtherelatively smallnumberofindications affectedbythepluggingcriteria, SLBleakageprediction perGL95-05isexpectedtobesignificantly lessthanthepermissible level.of8.4gpminthefaultedloop.Theinclusion ofallintersections intheleakagemodel,alongwithapplication ofaprobability ofdetection of0.6,

Attachment 1toAEP:NRC:1166AA Page11willresultinextremely conservative leakageestimations.

Closeexaminat'ion oftheavailable datashowsthatindications oflessthan2.8voltswillnotbeexpectedtoleakduringSLBconditions.

Theproposedamendment doesnotresultinanyincreaseintheprobability orconsequences ofanaccidentpreviously evaluated withintheCookNuclearPlantUnit1FinalSafetyAnalysisReport(FSAR).2)Theproposedlicenseamendment doesnotcreatethepossibility ofanewordifferent kindofaccidentfromanyaccidentpreviously evaluated.

Implementation oftheproposedSGtubepluggingcriteriadoesnotintroduce anysignificant changestotheplantdesignbasis.Useofthecriteriadoesnotprovideamechanism whichcouldresultinanaccidentoutsideoftheregionoftheTSPelevations.

Neitherasinglenoramultipletuberuptureeventwould,underanyplantconditions, beexpectedinaSGinwhichthepluggingcriteriahasbeenapplied.Specifically, wewillcontinuetoimplement amaximumleakageratelimitof150gpd(0.1gpm)perSGtohelpprecludethepotential forexcessive leakageduringallplantconditions.

TheT/Slimitsimposedonprimary-to-secondary leakageatoperating conditions areamaximumof0.4gpm(600gpd)forallSGswithamaximumof150gpdallowedforanyoneSG~TheRG1.121criteriaforestablishing operational leakageratelimitsthatrequireplantshutdownarebaseduponleak-before-break (LBB)considerations todetectafreespancrackbeforepotential tuberuptureduringfaultedplantconditions.

The150gpdlimitshouldprovideforleakagedetection andplantshutdownintheeventoftheoccurrence ofanunexpected singlecrackresulting inleakagethatisassociated withthelongestpermissible cracklength.Regulatory Guide1.121acceptance criteriaforestablishing operating leakagelimitsarebasedonLBBconsiderations suchthatplantshutdownisinitiated iftheleakageassociated withthelongestpermissible crack,isexceeded.

Thelongestpermissible crackisthelengththatprovidesafactorofsafetyof1.43againstburstingatfaultedconditions maximumpressuredifferential.

Avoltageamplitude of8.8voltsfortypicalODSCCcorresponds tomeetingthistubeburstrequirement atalower95/prediction limitontheburstcorrelation coupledwith95/95lowertolerance limitmaterialproperties.

Alternate crackmorphologies cancorrespond to

Attachment 1toAEP:NRC:1166AA Page128.8voltssothatauniquecracklengthisnotdefinedbytheburstpressure"versusvoltagecorrelation.

Consequently, typicalburstpressureversusthrough-wall cracklengthcorrelations wereusedtodefinethe"longestpermissible crack"forevaluating operating leakagelimits.Consistent withthecycle13,14and15licenseamendment requestsforpluggingcriteria, andSection5ofEnclosure 1oftheGL,operational leakagelimitswillremainat150gpd.perSG.AxialcracksleakingatthislevelareexpectedtoprovideLBBprotection atboththeSLBpressuredifferential of2560psiand,whilenotpartofanyestablished LBBmethodology, LBBprotection willalsobeprovidedatavalueof1.43timestheSLBpressuredifferential.

Thus,the150gpdlimitprovidesforplantshutdownpriortoreachingcriticalcracklengthsforSLBconditions.

Additionally, thisLBBevaluation assumesthattheentirecreviceareaisuncovered duringblowdown.

Partialuncoverywillprovidebenefittotheburstcapacityoftheintersection.

3)Theproposedlicenseamendment doesnotinvolveasignificant reduction inmarginofsafety.Theuseofthevoltage-based bobbinprobeinterimTSPelevation pluggingcriteriaatCookNuclearPlantUnit1isdemonstrated tomaintainSGtubeintegrity commensurate withthecriteriaofRG1.121.Regulatory Guide1~121describes amethodacceptable totheNRCstaffformeetingGDC14,15,31,and32byreducingtheprobability ortheconsequences ofSGtuberupture.Thisisaccomplished bydetermining thelimitingconditions ofdegradation ofSGtubing,asestablished byin-service inspection, forwhichtubeswithunacceptable crackingshouldberemovedfromservice.Uponimplementation ofthecriteria, evenundertheworstcaseconditions, theoccurrence ofODSCCattheTSPelevations isnotexpectedtoleadtoaSGtuberuptureeventduringnormal,orfaultedplantconditions.

Itwillbeconfirmed byanalysisandcalculation thatEOCdistribution ofcrackindications attheTSPelevations willresultinacceptable primary-to-secondary leakageduringallplantconditions andthatradiological consequences arenotadversely impacted.

Inaddressing thecombinedeffectsofaLOCAandSSEontheSGcomponent (asrequiredbyGDC2),ithasbeendetermined thattubecollapsemayoccurintheSGsatsomeplants.Thepostulated tubecollapseresultsfromadeformation ofTSPsasaresultoflateralloadsatthewedgesupportsattheperiphery oftheplate.Thelateralloadsresultfromthe l

Attachment 1toAEP:NRC:1166AA Page13combinedeffectsoftheLOCArarefaction waveandSSEloadings.

Theresulting pressuredifferential onthedeformedtubesmaythencausesomeofthetubestocollapse.

Therearetwoissuesassociated withapostulated SGtubecollapse.

First,thecollapseofSGtubingreducestheRCSflowareathroughthetubes.Thereduction inflowareaincreases theresistance toflowofsteamfromthecoreduringaLOCAwhich,inturn,maypotentially increasepeakcladtemperature.

Second,thereisapotential thatpartialthrough-wall cracksintubescouldprogresstothrough-wall cracksduringtubedeformation orcollapse.

Consequently, sincetheLBBmethodology isapplicable totheCookNuclearPlantUnit1reactorcoolantlooppiping,theprobability ofbreaksintheprimarylooppipingissufficiently lowthattheyneednotbeconsidered inthestructural designoftheplant.ThelimitingLOCAeventbecomeseithertheaccumulator linebreakorthepressurizer surgelinebreak.LossofcoolantaccidentloadsfortheprimarypipebreakswereusedtoboundtheCookNuclearPlantUnit1smallerbreaks.TheresultsoftheanalysisusingthelargerbreakinputsshowthattheLOCAloadswerefoundtobeofinsufficient magnitude toresultinSGtubecollapseorsignificant deformation.

Addressing RG1.83considerations, implementation of,thebobbincoilprobe,voltage-based interimtubepluggingcriteriaof2voltsissupplemented byenhancededdycurrent,inspection guidelines toprovideconsistency involtagenormalization, a100Xeddycurrentinspection samplesizeattheTSPelevations perT/S,andMRPCinspection requirements forthelargerindications leftin-service tocharacterize theprincipal degradation asODSCC.Asnotedpreviously, implementation oftheTSPelevation pluggingcriteriawilldecreasethenumberoftubeswhichmustberepaired.

Theinstallation ofSGtubeplugsreducestheRCSflowmargin.Thus,implementation ofthepluggingcriteriawillmaintainthemarginofflowthatwouldotherwise bereducedintheeventofincreased tubeplugging.

Basedontheabove,itisconcluded thattheproposedlicenseamendment requestdoesnotresultinasignificant reduction inmarginwithrespecttoplantsafetyasdefinedintheFSARoranyBasesoftheplantT/Ss.

I,

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