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{{#Wiki_filter:.-,ACCELERATEDDISf/'TIONDEMONSATIONSYSTEMREGULATORYINFORMATIONDISTRIBUTIONSYSTEM(RIDS)ACCESSIONNBR:9402250130DOC.DATE:94/02/15NOTARIZED:YESDOCKETFACIL:50-315DonaldC.CookNuclearPowerPlant,Unit1,IndianaM05000315AUTH.NAMEAUTHORAFFILIATIONFITZPATRICK,E.IndianaMichiganPowerCo.(formerlyIndiana6MichiganEleRECIP.NAMERECIPIENTAFFILIATIONDocumentControlBranch(DocumentControlDesk)R
{{#Wiki_filter:.-,ACCELERATED DISf/'TIONDEMONSATIONSYSTEMREGULATORY INFORMATION DISTRIBUTION SYSTEM(RIDS)ACCESSION NBR:9402250130 DOC.DATE:
94/02/15NOTARIZED:
YESDOCKETFACIL:50-315 DonaldC.CookNuclearPowerPlant,Unit1,IndianaM05000315AUTH.NAMEAUTHORAFFILIATION FITZPATRICK,E.
IndianaMichiganPowerCo.(formerly Indiana6MichiganEleRECIP.NAME RECIPIENT AFFILIATION DocumentControlBranch(Document ControlDesk)R


==SUBJECT:==
==SUBJECT:==
ApplicationforexigentamendtolicenseDPR-58,revisingTSI4.4.5,"SGs"toincorporateacceptancecriterionforSGtubedegradationintubesheetregionknownasF*.WestinghuseDreptsWCAP-139706WCAP-13971encl.WCAP-13970withheld.SDISTRIBUTIONCODE:AP01DCOPIESRECEIVED:LTRENCLSIZE:TITLE:ProprietaryReviewDistribution-PreOperatingLicense6OperatingR/NOTES:ghJCIPP~31'IlA>P4ICA'Pl3$40-RECIPIENTIDCODE/NAMEPD3-1LAHICKMAN,JINTERNAL:QD~OREGFILE01EXTERNALNRCPDRCOPIESLTTRENCL11331i1110IhrP)RECIPIENTIDCODE/NAMEPD3-,1PDOGC/HDS2COPIESLTTRENCL1110DDDNOTETOALL"RIDS"RECIPIENTS:PLEASEHELPUSlOREDUCEWASTE!CONTACTTHEDOCUMENTCONTROLDESK,ROOMPl-37(EXT.20079)TOELIMINATEYOURNAMEFROMDISTRIBUTIONLISTSFORDOCUMENTSYOUDON'TNEED!TOTALNUMBEROFCOPIESREQUIRED:LTTR9ENCL7DD  
Application forexigentamendtolicenseDPR-58,revising TSI4.4.5,"SGs"toincorporate acceptance criterion forSGtubedegradation intubesheet regionknownasF*.Westinghuse DreptsWCAP-13970 6WCAP-13971 encl.WCAP-13970 withheld.
/*0I'1e~FjfIIcI IndianainlchlganPo'warCompanyP.O.Box16631Coiumbus,OH43216AEP:NRC:1166KDonaldC.CookNuclearPlantUnit1DocketNo.50-315LicenseNo.DPR-58TECHNICALSPECIFICATIONCHANGESTOINCORPORATEMSTEAMGENERATORTUBEPLUGGINGCRITERIONU.S.NuclearRegulatoryCommissionDocumentControlDeskWashington,D.C.20555Attn:T.E.MurleyFebruary15,1994
SDISTRIBUTION CODE:AP01DCOPIESRECEIVED:LTR ENCLSIZE:TITLE:Proprietary ReviewDistribution
-PreOperating License6Operating R/NOTES:ghJCIPP~31'IlA>P4ICA'Pl3$40-RECIPIENT IDCODE/NAME PD3-1LAHICKMAN,J INTERNAL:
QD~OREGFILE01EXTERNALNRCPDRCOPIESLTTRENCL11331i1110IhrP)RECIPIENT IDCODE/NAME PD3-,1PDOGC/HDS2COPIESLTTRENCL1110DDDNOTETOALL"RIDS"RECIPIENTS:
PLEASEHELPUSlOREDUCEWASTE!CONTACTTHEDOCUMENTCONTROLDESK,ROOMPl-37(EXT.20079)TOELIMINATE YOURNAMEFROMDISTRIBUTION LISTSFORDOCUMENTS YOUDON'TNEED!TOTALNUMBEROFCOPIESREQUIRED:
LTTR9ENCL7DD  
/*0I'1e~FjfIIcI Indianainlchlgan Po'warCompanyP.O.Box16631Coiumbus, OH43216AEP:NRC:1166KDonaldC.CookNuclearPlantUnit1DocketNo.50-315LicenseNo.DPR-58TECHNICAL SPECIFICATION CHANGESTOINCORPORATE MSTEAMGENERATOR TUBEPLUGGINGCRITERION U.S.NuclearRegulatory Commission DocumentControlDeskWashington, D.C.20555Attn:T.E.MurleyFebruary15,1994


==DearDr.Murley:==
==DearDr.Murley:==
ThisletteranditsattachmentsconstituteanapplicationforanexigentamendmenttotheTechnicalSpecifications(T/Ss)forDonaldC.CookNuclearPlantUnit1.Specifically,wearerequestingachangetoT/S4.4.5(SteamGenerators)toincorporateanacceptancecriterionforsteamgeneratortubedegradationinthetubesheetregionknownasM.Thiscriterionhasbeenlicensedandsuccessfullyimplementedatanumberofoperatingplants.AsdiscussedwithyourstaffonFebruary9,1994,thereasonforrequestingthisonanexigentbasisisthatthechangeisassociatedwithsteamgeneratorrepairsduringthecurrentUnit1refuelingoutage.TherepairsarecurrentlyscheduledtobeginMarch6,1994.Therefore,werequestapprovalofthisamendmentrequestbyMarch4,inordertoavoidoutagedelays.Attachment1containsadescriptionoftheproposedT/Schangesaswellasthe10CFR50.92nosignificanthazardsevaluation.Attachment2containstheexistingT/Spagesmarkedtoreflectthechanges.Attachment3containstheproposedrevisedT/Spages.Attachment4containsWestinghouseElectricCorporation'sreportWCAP-13970,entitled"WTubePluggingCriterionforTubeswithDegradationintheTubesheetRollExpansionRegionofCookNuclearPlantUnit1SteamGenerators."Thisreportsupportsthe10CFR50.92evaluationcontainedinAttachment1.ThereportisconsideredproprietarytoWestinghouseElectricCorporation.Assuch,anaffidavitforwithholdingfrompublicdisclosureisprovidedinAttachment4.Anon-proprietaryversionoftheWCAP(WCAP-13971)isprovidedinAttachment5.)81~.689402250130940215PDRADOCK05000315,PDR~pg.00pic,PDpi~~g5~c.(pealf-y.V  
Thisletteranditsattachments constitute anapplication foranexigentamendment totheTechnical Specifications (T/Ss)forDonaldC.CookNuclearPlantUnit1.Specifically, wearerequesting achangetoT/S4.4.5(SteamGenerators) toincorporate anacceptance criterion forsteamgenerator tubedegradation inthetubesheet regionknownasM.Thiscriterion hasbeenlicensedandsuccessfully implemented atanumberofoperating plants.Asdiscussed withyourstaffonFebruary9,1994,thereasonforrequesting thisonanexigentbasisisthatthechangeisassociated withsteamgenerator repairsduringthecurrentUnit1refueling outage.Therepairsarecurrently scheduled tobeginMarch6,1994.Therefore, werequestapprovalofthisamendment requestbyMarch4,inordertoavoidoutagedelays.Attachment 1containsadescription oftheproposedT/Schangesaswellasthe10CFR50.92nosignificant hazardsevaluation.
Attachment 2containstheexistingT/Spagesmarkedtoreflectthechanges.Attachment 3containstheproposedrevisedT/Spages.Attachment 4containsWestinghouse ElectricCorporation's reportWCAP-13970, entitled"WTubePluggingCriterion forTubeswithDegradation intheTubesheet RollExpansion RegionofCookNuclearPlantUnit1SteamGenerators."
Thisreportsupportsthe10CFR50.92evaluation contained inAttachment 1.Thereportisconsidered proprietary toWestinghouse ElectricCorporation.
Assuch,anaffidavit forwithholding frompublicdisclosure isprovidedinAttachment 4.Anon-proprietary versionoftheWCAP(WCAP-13971) isprovidedinAttachment 5.)81~.689402250130 940215PDRADOCK05000315,PDR~pg.00pic,PDpi~~g5~c.(pealf-y.V  
.~~V.
.~~V.
Dr.T~E.Hurley2AEP:NRC:1166KWebelievetheproposedchangeswillnotresultin(1)asignificantchangeinthetypesofanyeffluentthatmaybereleasedoffsite,or(2)asignificantincreaseinindividualorcumulativeoccupationalradiationexposure.TheseproposedchangeshavebeenreviewedbythePlantNuclearSafetyReviewCommitteeandbytheNuclearSafetyandDesignReviewCommittee.Incompliancewiththerequirementsof10CFR50.91(b)(l),copiesofthisletteranditsattachmentshavebeentransmittedtotheMichiganPublicServiceCommissionandtotheMichiganDepartmentofPublicHealth.Thisletterissubmittedpursuantto10CFR50.30(b),and,assuch,anoathstatementisattached.Sincerely,E.EDFitztrickVicePresidentdrAttachmentscc:A.A.BlindG.CharnoffJ.B.Martin-RegionIIINFEMSectionChiefNRCResidentInspector-BridgmanJ.R.Padgett STATEOFOHIO)COUNTYOFFRANKLIN)E.E.Fitzpatrick,beingdulysworn,deposesandsaysthatheistheVicePresidentoflicenseeIndianaMichiganPowerCompany,thathehasreadtheforgoingTECHNICALSPECIFICATIONCHANGESTOINCORPORATEWSTEAMGENERATORTUBEPLUGGINGCRITERIONandknowsthecontentsthereof;andthatsaidcontentsaretruetothebestofhisknowledgeandbelief.Subscribedandsworntobeforemethis~~dayof19~.NOTARYPUBLICRlrhD.HILLlfoTARYPUBS.'lt'TATEOFpH[pN  
Dr.T~E.Hurley2AEP:NRC:1166K Webelievetheproposedchangeswillnotresultin(1)asignificant changeinthetypesofanyeffluentthatmaybereleasedoffsite,or(2)asignificant increaseinindividual orcumulative occupational radiation exposure.
TheseproposedchangeshavebeenreviewedbythePlantNuclearSafetyReviewCommittee andbytheNuclearSafetyandDesignReviewCommittee.
Incompliance withtherequirements of10CFR50.91(b)(l),
copiesofthisletteranditsattachments havebeentransmitted totheMichiganPublicServiceCommission andtotheMichiganDepartment ofPublicHealth.Thisletterissubmitted pursuantto10CFR50.30(b),
and,assuch,anoathstatement isattached.
Sincerely, E.EDFitztrickVicePresident drAttachments cc:A.A.BlindG.CharnoffJ.B.Martin-RegionIIINFEMSectionChiefNRCResidentInspector
-BridgmanJ.R.Padgett STATEOFOHIO)COUNTYOFFRANKLIN)
E.E.Fitzpatrick, beingdulysworn,deposesandsaysthatheistheVicePresident oflicenseeIndianaMichiganPowerCompany,thathehasreadtheforgoingTECHNICAL SPECIFICATION CHANGESTOINCORPORATE WSTEAMGENERATOR TUBEPLUGGINGCRITERION andknowsthecontentsthereof;andthatsaidcontentsaretruetothebestofhisknowledge andbelief.Subscribed andsworntobeforemethis~~dayof19~.NOTARYPUBLICRlrhD.HILLlfoTARYPUBS.'lt'TATE OFpH[pN  


ATTACHMENT1TOAEP:NRC:1166KDESCRIPTIONANDJUSTIFICATIONOFCHANGES10CFR50.92ANALYSISFORCHANGESTOTHEDONALDC.COOKNUCLEARPLANTUNIT1TECHNICALSPECIFICATIONS ATTACHMENT1TOAEP:NRC:1166KPage1I.INTRODUCTIONThisamendmentrequestproposesachangetoTechnicalSpecification(TS)4.4.5(SteamGenerators)toincorporatearevisedacceptancecriterionforsteamgeneratortubeswithdegradationinthetubesheetrollexpansionregion.ThiscriterionforsteamgeneratortubeacceptancewasdevelopedbyWestinghouseElectricCorporationandisknownasW("F-Star").Thiscriterionwasdevelopedtoavoidunnecessarypluggingofsteamgeneratortubes.TheexistingT/Stuberepairingandpluggingcriteriaapplythroughoutthetubelength,butdonottakeintoaccountthereinforcingeffectofthetubesheetontheexternalsurfaceofthetubeintherollexpansionregion.Thepresenceofthetubesheetwillconstrainthetubeandwillcomplementitsintegrityinthatregionbyessentiallyprecludingtubedeformationbeyonditsexpandedoutsidediameter.Theresistancetobothtuberuptureandtubecollapseissignificantlystrengthenedbythetubesheet.Inaddition,theproximityofthetubesheetsignificantlyaffectstheleakbehaviorofthroughwalltubecracksinthisregion,i.e.,nosignificantleakagerelativetoplantT/Slimitsistobeexpected.TheWmethodologyanddeterminationoftheWdistanceareincludedinWCAP13970,entitled"WTubePluggingCriterionforTubesWithDegradationintheTubesheetRollExpansionRegionoftheDonaldC.CookUnit1SteamGenerators."Thisreport,preparedbyWestinghouseElectricCorporation,iscontainedinAttachment4.Anon-proprietaryversionofthereportisincludedinAttachment5.II.ESCRIPTIONOFTHECHANGESTheproposedchangesarethosenecessarytoincorporatetheWtubesheetregionpluggingcriterionintotheT/Ss.Thespecificchangesareasfollows:Arequirementisaddedtoinspect(intherollexpandedregion)alltubeswhichhavehadtheWcriteriaapplied.TherollexpandedregionofthesetubesmaybeexcludedfromtherequirementsofT/S4.4.5.2.b.l.DefinitionsforWdistanceandanWtubeareadded.Wdistanceisthedistancefromthebottomofthehardrolltransitiontowardthebottomofthetubesheetthathasbeenconservativelydeterminedtobe1.11inches(notincludingeddycurrentuncertainty).An,&tubeisatubewithdegradation,belowtheWdistance,equaltoorgreaterthan40$,andnotdegraded(i.e.,noindicationsofcracking)withintheWdistance.Thedefinitionof"Repair/PluggingLimit"(T/S4.4.5.4.a.6)ismodifiedtonotethatthe408repair/plugginglimitdoesnotapplytotheportionofthetubeinthetubesheetbelowtheWdistanceforWtubes.
ATTACHMENT 1TOAEP:NRC:1166KDESCRIPTION ANDJUSTIFICATION OFCHANGES10CFR50.92ANALYSISFORCHANGESTOTHEDONALDC.COOKNUCLEARPLANTUNIT1TECHNICAL SPECIFICATIONS ATTACHMENT 1TOAEP:NRC:1166K Page1I.INTRODUCTION Thisamendment requestproposesachangetoTechnical Specification (TS)4.4.5(SteamGenerators) toincorporate arevisedacceptance criterion forsteamgenerator tubeswithdegradation inthetubesheet rollexpansion region.Thiscriterion forsteamgenerator tubeacceptance wasdeveloped byWestinghouse ElectricCorporation andisknownasW("F-Star"
ATTACHMENT1TOAEP:NRC:1166KPage2ArequirementisaddedtoreporttotheNRCtheresultsofinspectionsperformedunderT/S4.4.5.2foralltubesthathavedefectsbelowtheWdistanceandwerenotplugged.III.10CFR5092EVALUATIONTheamendmenthasbeenproposedtoaddresseddycurrentindicationsoftubedegradationwhichcanoccurintherollexpandedportionofthetubeswithinthetubesheetinthesteamgeneratorsattheCookNuclearPlantUnit1.Thesesteamgeneratorswerefabricatedwitha2.75inchpartialdepthrollexpansioninthetubesheet.InterpretationofeddycurrentdatafromtheCookNuclearPlantUnit1andsimilarplantshasshownapotentialforprimarywaterstresscorrosioncracking(PWSCC)withintherollexpandedportionofthetubeinthetubesheet.Itcanbeshownthattubepluggingorsleevingisnotrequiredinmanysuchcasestomaintainsteamgeneratortubeintegrity.UsingexistingT/Stubepluggingcriteriaforthelengthoftubewithinthetubesheet,manyofthetubeswithpotentialindicationswouldhavetoberepairedorremovedfromservice.Theproposedamendmentwouldprecludeoccupationalradiationexposurethatwouldotherwisebeincurredbyplantworkersinvolvedintubepluggingorsleevingoperations.Theproposedamendmentwouldalsoavoidlossofmargininreactorcoolantsystemflowandthereforeassistinassuringthatminimumflowratesaremaintainedinexcessofthatrequiredforoperationatfullpower.Reductionintheamountoftubepluggingorsleevingrequiredcanreducethelengthofplantoutagesandreducethetimethatthesteamgeneratorisopentothecontainmentenvironmentduringanoutage.Thepossibilityoftuberepairbysleevingshouldnotbeconsideredareasontoexcludeuseofthisproposedtubesheetpluggingcriterion,butshouldbeconsideredoneoftheoptionsusedtoaddressdegradationintheexpandedregionofthetube.Thedisadvantagesoftubeplugsnotedabovealsoapplytosomeextenttosleeves.Theproposedamendmentaddressestheactionrequiredwhendegradationhasbeendetectedinthemechanicallyexpandedportionofsteamgeneratortubeswithinthesteamgeneratortubesheet.Existingtuberepairorpluggingcriteriadonottakeintoaccounttheeffectofthetubesheetontheexternalsurfaceofthetube.Thepresenceofthetubesheetwillenhancetheintegrityofpotentiallydegradedtubesinthatregionbyprecludingtubedeformationbeyondtheexpandedoutsidediameter.Structural(burst)integrityoftubeswithsignificantthroughwallaxialpenetrationlengthisprovidedintherollexpandedarea.AnaxiallengthofrollexpansionequaltotheWlengthatthetopoftherollexpansionofthetubeintothetubesheetprovidessufficientstructuralintegritytoprecludepulloutofthetubeduetopressureeffects,evenafter  
).Thiscriterion wasdeveloped toavoidunnecessary pluggingofsteamgenerator tubes.TheexistingT/Stuberepairing andpluggingcriteriaapplythroughout thetubelength,butdonottakeintoaccountthereinforcing effectofthetubesheet ontheexternalsurfaceofthetubeintherollexpansion region.Thepresenceofthetubesheet willconstrain thetubeandwillcomplement itsintegrity inthatregionbyessentially precluding tubedeformation beyonditsexpandedoutsidediameter.
Theresistance tobothtuberuptureandtubecollapseissignificantly strengthened bythetubesheet.
Inaddition, theproximity ofthetubesheet significantly affectstheleakbehaviorofthroughwalltubecracksinthisregion,i.e.,nosignificant leakagerelativetoplantT/Slimitsistobeexpected.
TheWmethodology anddetermination oftheWdistanceareincludedinWCAP13970,entitled"WTubePluggingCriterion forTubesWithDegradation intheTubesheet RollExpansion RegionoftheDonaldC.CookUnit1SteamGenerators."
Thisreport,preparedbyWestinghouse ElectricCorporation, iscontained inAttachment 4.Anon-proprietary versionofthereportisincludedinAttachment 5.II.ESCRIPTION OFTHECHANGESTheproposedchangesarethosenecessary toincorporate theWtubesheet regionpluggingcriterion intotheT/Ss.Thespecificchangesareasfollows:Arequirement isaddedtoinspect(intherollexpandedregion)alltubeswhichhavehadtheWcriteriaapplied.Therollexpandedregionofthesetubesmaybeexcludedfromtherequirements ofT/S4.4.5.2.b.l.
Definitions forWdistanceandanWtubeareadded.Wdistanceisthedistancefromthebottomofthehardrolltransition towardthebottomofthetubesheet thathasbeenconservatively determined tobe1.11inches(notincluding eddycurrentuncertainty).
An,&tubeisatubewithdegradation, belowtheWdistance, equaltoorgreaterthan40$,andnotdegraded(i.e.,noindications ofcracking) withintheWdistance.
Thedefinition of"Repair/Plugging Limit"(T/S4.4.5.4.a.6) ismodifiedtonotethatthe408repair/plugging limitdoesnotapplytotheportionofthetubeinthetubesheet belowtheWdistanceforWtubes.
ATTACHMENT 1TOAEP:NRC:1166K Page2Arequirement isaddedtoreporttotheNRCtheresultsofinspections performed underT/S4.4.5.2foralltubesthathavedefectsbelowtheWdistanceandwerenotplugged.III.10CFR5092EVALUATION Theamendment hasbeenproposedtoaddresseddycurrentindications oftubedegradation whichcanoccurintherollexpandedportionofthetubeswithinthetubesheet inthesteamgenerators attheCookNuclearPlantUnit1.Thesesteamgenerators werefabricated witha2.75inchpartialdepthrollexpansion inthetubesheet.
Interpretation ofeddycurrentdatafromtheCookNuclearPlantUnit1andsimilarplantshasshownapotential forprimarywaterstresscorrosion cracking(PWSCC)withintherollexpandedportionofthetubeinthetubesheet.
Itcanbeshownthattubepluggingorsleevingisnotrequiredinmanysuchcasestomaintainsteamgenerator tubeintegrity.
UsingexistingT/Stubepluggingcriteriaforthelengthoftubewithinthetubesheet, manyofthetubeswithpotential indications wouldhavetoberepairedorremovedfromservice.Theproposedamendment wouldprecludeoccupational radiation exposurethatwouldotherwise beincurredbyplantworkersinvolvedintubepluggingorsleevingoperations.
Theproposedamendment wouldalsoavoidlossofmargininreactorcoolantsystemflowandtherefore assistinassuringthatminimumflowratesaremaintained inexcessofthatrequiredforoperation atfullpower.Reduction intheamountoftubepluggingorsleevingrequiredcanreducethelengthofplantoutagesandreducethetimethatthesteamgenerator isopentothecontainment environment duringanoutage.Thepossibility oftuberepairbysleevingshouldnotbeconsidered areasontoexcludeuseofthisproposedtubesheet pluggingcriterion, butshouldbeconsidered oneoftheoptionsusedtoaddressdegradation intheexpandedregionofthetube.Thedisadvantages oftubeplugsnotedabovealsoapplytosomeextenttosleeves.Theproposedamendment addresses theactionrequiredwhendegradation hasbeendetectedinthemechanically expandedportionofsteamgenerator tubeswithinthesteamgenerator tubesheet.
Existingtuberepairorpluggingcriteriadonottakeintoaccounttheeffectofthetubesheet ontheexternalsurfaceofthetube.Thepresenceofthetubesheet willenhancetheintegrity ofpotentially degradedtubesinthatregionbyprecluding tubedeformation beyondtheexpandedoutsidediameter.
Structural (burst)integrity oftubeswithsignificant throughwall axialpenetration lengthisprovidedintherollexpandedarea.Anaxiallengthofrollexpansion equaltotheWlengthatthetopoftherollexpansion ofthetubeintothetubesheet providessufficient structural integrity toprecludepulloutofthetubeduetopressureeffects,evenafter  


ATTACHMENT1TOAEP:NRC:1166KPage3assumingthatthetubehasexperiencedacompletecircumferentialseparationatorbelowthebottomoftheF+distance.ThissameaxiallengthofrollexpansionofthetubeintothetubesheetprovidesabarriertoleakageduringallplantconditionsforthroughwallcrackingofthetubeintheexpandedregionbelowW.TheproposedchangedesignatesaportionofthetubeforwhichtubedegradationofadefinedtypedoesnotnecessitateremedialactionexceptasdictatedforcompliancewithtubeleakagelimitsassetforthintheT/Ss.Asnotedabove,theareasubjecttothischangeisintheexpandedportionofthetubewithinthetubesheetofthesteamgenerators.TheWlengthhasbeendeterminedtobe1.11inches.Soundrollexpansionof1.11incheswillsatisfyallapplicablerecommendationsofRegulatoryGuide1.121,withregardtotubeburstcapability.Conformanceoftheproposedamendmentstothestandardsforadeterminationofnosignificanthazardasdefinedin10CFR50.92(threefactortest)isshowninthefollowing:1)OperationofDonaldC.CookNuclearPlantUnit1inaccordancewiththeproposedlicenseamendmentdoesnotinvolveasignificantincreaseintheprobabilityorconsequencesofanaccidentpreviouslyevaluated.Thesupportingtechnicalandsafetyevaluationsofthesubjectcriteriondemonstratethatthepresenceofthetubesheetwillenhancethetubeintegrityintheregionofthehardrollbyprecludingtubedeformationbeyonditsinitialexpandedoutsidediameter.Theresistancetobothtuberuptureandtubecollapseisstrengthenedbythepresenceofthetubesheetinthatregion.Theresultofhardrollingofthetubeintothetubesheetisaninterferencefitbetweenthetubeandthetubesheet.Tuberupturecannotoccurbecausethecontactbetweenthetubeandtubesheetdoesnotpermitsufficientmovementoftubematerial.Theradialpreloaddevelopedbytherollingprocesswillsecureapostulatedseparatedtubeendwithinthetubesheetduringallplantconditions.Inasimilarmanner,thetubesheetdoesnotpermitsufficientmovementoftubematerialtopermitbucklingcollapseofthetubeduringpostulatedLOCAloadings.Thetypeofdegradationforwhich,theWcriterionhasbeendeveloped(crackingwithacircumferentialorientation)cantheoreticallyleadtoapostulatedtuberuptureeventprovidedthatthepostulatedthrough-wallcircumferentialcrackexistsnearthetopofthetubesheet.Anevaluationincludinganalysisandtestinghasbeendonetodeterminetheresistivestrengthofrollexpandedtubeswithinthetubesheet.ThisevaluationprovidesthebasisfortheacceptancecriteriafortubedegradationsubjecttotheWcriterion.  
ATTACHMENT 1TOAEP:NRC:1166K Page3assumingthatthetubehasexperienced acompletecircumferential separation atorbelowthebottomoftheF+distance.
Thissameaxiallengthofrollexpansion ofthetubeintothetubesheet providesabarriertoleakageduringallplantconditions forthroughwallcrackingofthetubeintheexpandedregionbelowW.Theproposedchangedesignates aportionofthetubeforwhichtubedegradation ofadefinedtypedoesnotnecessitate remedialactionexceptasdictatedforcompliance withtubeleakagelimitsassetforthintheT/Ss.Asnotedabove,theareasubjecttothischangeisintheexpandedportionofthetubewithinthetubesheet ofthesteamgenerators.
TheWlengthhasbeendetermined tobe1.11inches.Soundrollexpansion of1.11incheswillsatisfyallapplicable recommendations ofRegulatory Guide1.121,withregardtotubeburstcapability.
Conformance oftheproposedamendments tothestandards foradetermination ofnosignificant hazardasdefinedin10CFR50.92(threefactortest)isshowninthefollowing:
1)Operation ofDonaldC.CookNuclearPlantUnit1inaccordance withtheproposedlicenseamendment doesnotinvolveasignificant increaseintheprobability orconsequences ofanaccidentpreviously evaluated.
Thesupporting technical andsafetyevaluations ofthesubjectcriterion demonstrate thatthepresenceofthetubesheet willenhancethetubeintegrity intheregionofthehardrollbyprecluding tubedeformation beyonditsinitialexpandedoutsidediameter.
Theresistance tobothtuberuptureandtubecollapseisstrengthened bythepresenceofthetubesheet inthatregion.Theresultofhardrolling ofthetubeintothetubesheet isaninterference fitbetweenthetubeandthetubesheet.
Tuberupturecannotoccurbecausethecontactbetweenthetubeandtubesheet doesnotpermitsufficient movementoftubematerial.
Theradialpreloaddeveloped bytherollingprocesswillsecureapostulated separated tubeendwithinthetubesheet duringallplantconditions.
Inasimilarmanner,thetubesheet doesnotpermitsufficient movementoftubematerialtopermitbucklingcollapseofthetubeduringpostulated LOCAloadings.
Thetypeofdegradation forwhich,theWcriterion hasbeendeveloped (cracking withacircumferential orientation) cantheoretically leadtoapostulated tuberuptureeventprovidedthatthepostulated through-wall circumferential crackexistsnearthetopofthetubesheet.
Anevaluation including analysisandtestinghasbeendonetodetermine theresistive strengthofrollexpandedtubeswithinthetubesheet.
Thisevaluation providesthebasisfortheacceptance criteriafortubedegradation subjecttotheWcriterion.  


ATTACHMENT1TOAEP:NRC:1166KPage4TheWlengthofrollexpansionissufficienttoprecludetubepulloutfromtubedegradationlocatedbelowtheWdistance,regardlessoftheextentofthetubedegradation.TheexistingT/Sleakageraterequirementsandaccidentanalysisassumptionsremainunchangedintheunlikelyeventthatsignificantleakagefromthisregiondoesoccur.Asnotedabove,tuberuptureandpulloutisnotexpectedfortubesusingtheWcriterion.AnyleakageoutofthetubefromwithinthetubesheetatanyelevationinthetubesheetisfullyboundedbytheexistingsteamgeneratortuberuptureanalysisincludedintheCookNuclearPlantFSAR.ForplantswithpartialdepthrollexpansionlikeCookNuclearPlantUnit1,apostulatedtubeseparationwithinthetubenearthetopoftherollexpansion(withsubsequentlimitedtubeaxialdisplacement)wouldnotbeexpectedtoresultincoolantreleaseratesequaltothoseassumedintheFSARforasteamgeneratortuberuptureeventduetothelimitedgapbetweenthetubeandtubesheet(approximately0.013inchdiametralgap).Theproposedpluggingcriteriondoesnotadverselyimpactanyotherpreviouslyevaluateddesignbasisaccident.LeakagetestingofrollexpandedtubesindicatesthatforrolllengthsapproximatelyequaltotheWdistance,anypostulatedfaultedconditionprimarytosecondaryleakagefromWtubeswouldbeinsignificant.2)Theproposedlicenseamendmentdoesnotcreatethepossibilityofanewordifferentkindofaccidentfromanyaccidentpreviouslyevaluated.ImplementationoftheproposedWcriteriondoesnotintroduceanysignificantchangestotheplantdesignbasis.Useofthecriteriondoesnotprovideamechanismtoinitiateanaccidentoutsideoftheregionoftheexpandedportionofthetube.Anyhypotheticalaccidentasaresultofanytubedegradationintheexpandedportionofthetubewouldbeboundedbytheexistingtuberuptureaccidentanalysis.Tubebundlestructuralintegritywillbemaintained.TubebundleleaktightnesswillbemaintainedsuchthatanypostulatedaccidentleakagefromWtubeswillbenegligiblewithregardtooffsitedoses.3)Theproposedlicenseamendmentdoesnotinvolveasignificantreductioninamarginofsafety.TheuseoftheWcriterionhasbeendemonstratedtomaintainthe,integrityofthetubebundlecommensuratewiththerequirementsofRegGuide1.121(intendedforindicationsinthefreespanoftubes)andtheprimarytosecondarypressureboundaryundernormalandpostulatedaccidentconditions.AcceptabletubedegradationfortheWcriterionisanydegradationindicationinthetubesheetregion,morethanthedistancebelowthebottomofthetransitionbetweentherollexpansionandtheunexpandedtube.ThesafetyfactorsusedintheverificationofthestrengthofthedegradedtubeareconsistentwiththesafetyfactorsintheASMEBoilerandPressureVesselCodeusedinsteamgeneratordesign.TheWdistancehasbeenverifiedbytestingtobegreaterthanthelengthofrollexpansionrequiredtoprecludebothtubepulloutand
ATTACHMENT 1TOAEP:NRC:1166K Page4TheWlengthofrollexpansion issufficient toprecludetubepulloutfromtubedegradation locatedbelowtheWdistance, regardless oftheextentofthetubedegradation.
TheexistingT/Sleakageraterequirements andaccidentanalysisassumptions remainunchanged intheunlikelyeventthatsignificant leakagefromthisregiondoesoccur.Asnotedabove,tuberuptureandpulloutisnotexpectedfortubesusingtheWcriterion.
Anyleakageoutofthetubefromwithinthetubesheet atanyelevation inthetubesheet isfullyboundedbytheexistingsteamgenerator tuberuptureanalysisincludedintheCookNuclearPlantFSAR.Forplantswithpartialdepthrollexpansion likeCookNuclearPlantUnit1,apostulated tubeseparation withinthetubenearthetopoftherollexpansion (withsubsequent limitedtubeaxialdisplacement) wouldnotbeexpectedtoresultincoolantreleaseratesequaltothoseassumedintheFSARforasteamgenerator tuberuptureeventduetothelimitedgapbetweenthetubeandtubesheet (approximately


ATTACHMENT1TOAEP:NRC:1166KPage5significantleakageduringnormalandpostulatedaccidentconditions.Resistancetotubepulloutisbasedupontheprimarytosecondarypressuredifferentialasitactsonthesurfaceareaofthetube,whichincludesthetubewallcross-section,inadditiontotheinnerdiameterbasedareaofthetube.TheleaktestingacceptancecriteriaarebasedontheprimarytosecondaryleakagelimitintheT/SsandtheleakageassumptionsusedintheFSARaccidentanalyses.Implementationofthetubesheetpluggingcriterionwilldecreasethenumberoftubeswhichmustbetakenoutofservicewithtubeplugsorrepairedwithsleeves.BothplugsandsleevesreducetheRCSflowmargin;thus,implementationoftheWcriterionwillmaintainthemarginofflowthatwouldotherwisebereducedintheeventofincreasedpluggingorsleeving.Basedontheabove,itisconcludedthattheproposedchangedoesnotresultinasignificantreductioninmarginwithrespecttoplantsafetyasdefinedintheFSARortheT/SBases.}}
==0.0 13inchdiametral==
gap).Theproposedpluggingcriterion doesnotadversely impactanyotherpreviously evaluated designbasisaccident.
Leakagetestingofrollexpandedtubesindicates thatforrolllengthsapproximately equaltotheWdistance, anypostulated faultedcondition primarytosecondary leakagefromWtubeswouldbeinsignificant.
2)Theproposedlicenseamendment doesnotcreatethepossibility ofanewordifferent kindofaccidentfromanyaccidentpreviously evaluated.
Implementation oftheproposedWcriterion doesnotintroduce anysignificant changestotheplantdesignbasis.Useofthecriterion doesnotprovideamechanism toinitiateanaccidentoutsideoftheregionoftheexpandedportionofthetube.Anyhypothetical accidentasaresultofanytubedegradation intheexpandedportionofthetubewouldbeboundedbytheexistingtuberuptureaccidentanalysis.
Tubebundlestructural integrity willbemaintained.
Tubebundleleaktightness willbemaintained suchthatanypostulated accidentleakagefromWtubeswillbenegligible withregardtooffsitedoses.3)Theproposedlicenseamendment doesnotinvolveasignificant reduction inamarginofsafety.TheuseoftheWcriterion hasbeendemonstrated tomaintainthe,integrity ofthetubebundlecommensurate withtherequirements ofRegGuide1.121(intended forindications inthefreespanoftubes)andtheprimarytosecondary pressureboundaryundernormalandpostulated accidentconditions.
Acceptable tubedegradation fortheWcriterion isanydegradation indication inthetubesheet region,morethanthedistancebelowthebottomofthetransition betweentherollexpansion andtheunexpanded tube.Thesafetyfactorsusedintheverification ofthestrengthofthedegradedtubeareconsistent withthesafetyfactorsintheASMEBoilerandPressureVesselCodeusedinsteamgenerator design.TheWdistancehasbeenverifiedbytestingtobegreaterthanthelengthofrollexpansion requiredtoprecludebothtubepulloutand
 
ATTACHMENT 1TOAEP:NRC:1166K Page5significant leakageduringnormalandpostulated accidentconditions.
Resistance totubepulloutisbasedupontheprimarytosecondary pressuredifferential asitactsonthesurfaceareaofthetube,whichincludesthetubewallcross-section, inadditiontotheinnerdiameterbasedareaofthetube.Theleaktestingacceptance criteriaarebasedontheprimarytosecondary leakagelimitintheT/Ssandtheleakageassumptions usedintheFSARaccidentanalyses.
Implementation ofthetubesheet pluggingcriterion willdecreasethenumberoftubeswhichmustbetakenoutofservicewithtubeplugsorrepairedwithsleeves.BothplugsandsleevesreducetheRCSflowmargin;thus,implementation oftheWcriterion willmaintainthemarginofflowthatwouldotherwise bereducedintheeventofincreased pluggingorsleeving.
Basedontheabove,itisconcluded thattheproposedchangedoesnotresultinasignificant reduction inmarginwithrespecttoplantsafetyasdefinedintheFSARortheT/SBases.}}

Revision as of 07:13, 29 June 2018

Application for Exigent Amend to License DPR-58,revising TS 4.4.5, SGs to Incorporate Acceptance Criterion for SG Tube Degradation in Tubesheet Region Known as F*.Westinghouse Repts WCAP-13970 & WCAP-13971 encl.WCAP-13970 Withheld
ML17331B238
Person / Time
Site: Cook American Electric Power icon.png
Issue date: 02/15/1994
From: FITZPATRICK E
INDIANA MICHIGAN POWER CO. (FORMERLY INDIANA & MICHIG
To:
NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML17331B239 List:
References
AEP:NRC:1166K, NUDOCS 9402250130
Download: ML17331B238 (16)
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Text

.-,ACCELERATED DISf/'TIONDEMONSATIONSYSTEMREGULATORY INFORMATION DISTRIBUTION SYSTEM(RIDS)ACCESSION NBR:9402250130 DOC.DATE:

94/02/15NOTARIZED:

YESDOCKETFACIL:50-315 DonaldC.CookNuclearPowerPlant,Unit1,IndianaM05000315AUTH.NAMEAUTHORAFFILIATION FITZPATRICK,E.

IndianaMichiganPowerCo.(formerly Indiana6MichiganEleRECIP.NAME RECIPIENT AFFILIATION DocumentControlBranch(Document ControlDesk)R

SUBJECT:

Application forexigentamendtolicenseDPR-58,revising TSI4.4.5,"SGs"toincorporate acceptance criterion forSGtubedegradation intubesheet regionknownasF*.Westinghuse DreptsWCAP-13970 6WCAP-13971 encl.WCAP-13970 withheld.

SDISTRIBUTION CODE:AP01DCOPIESRECEIVED:LTR ENCLSIZE:TITLE:Proprietary ReviewDistribution

-PreOperating License6Operating R/NOTES:ghJCIPP~31'IlA>P4ICA'Pl3$40-RECIPIENT IDCODE/NAME PD3-1LAHICKMAN,J INTERNAL:

QD~OREGFILE01EXTERNALNRCPDRCOPIESLTTRENCL11331i1110IhrP)RECIPIENT IDCODE/NAME PD3-,1PDOGC/HDS2COPIESLTTRENCL1110DDDNOTETOALL"RIDS"RECIPIENTS:

PLEASEHELPUSlOREDUCEWASTE!CONTACTTHEDOCUMENTCONTROLDESK,ROOMPl-37(EXT.20079)TOELIMINATE YOURNAMEFROMDISTRIBUTION LISTSFORDOCUMENTS YOUDON'TNEED!TOTALNUMBEROFCOPIESREQUIRED:

LTTR9ENCL7DD

/*0I'1e~FjfIIcI Indianainlchlgan Po'warCompanyP.O.Box16631Coiumbus, OH43216AEP:NRC:1166KDonaldC.CookNuclearPlantUnit1DocketNo.50-315LicenseNo.DPR-58TECHNICAL SPECIFICATION CHANGESTOINCORPORATE MSTEAMGENERATOR TUBEPLUGGINGCRITERION U.S.NuclearRegulatory Commission DocumentControlDeskWashington, D.C.20555Attn:T.E.MurleyFebruary15,1994

DearDr.Murley:

Thisletteranditsattachments constitute anapplication foranexigentamendment totheTechnical Specifications (T/Ss)forDonaldC.CookNuclearPlantUnit1.Specifically, wearerequesting achangetoT/S4.4.5(SteamGenerators) toincorporate anacceptance criterion forsteamgenerator tubedegradation inthetubesheet regionknownasM.Thiscriterion hasbeenlicensedandsuccessfully implemented atanumberofoperating plants.Asdiscussed withyourstaffonFebruary9,1994,thereasonforrequesting thisonanexigentbasisisthatthechangeisassociated withsteamgenerator repairsduringthecurrentUnit1refueling outage.Therepairsarecurrently scheduled tobeginMarch6,1994.Therefore, werequestapprovalofthisamendment requestbyMarch4,inordertoavoidoutagedelays.Attachment 1containsadescription oftheproposedT/Schangesaswellasthe10CFR50.92nosignificant hazardsevaluation.

Attachment 2containstheexistingT/Spagesmarkedtoreflectthechanges.Attachment 3containstheproposedrevisedT/Spages.Attachment 4containsWestinghouse ElectricCorporation's reportWCAP-13970, entitled"WTubePluggingCriterion forTubeswithDegradation intheTubesheet RollExpansion RegionofCookNuclearPlantUnit1SteamGenerators."

Thisreportsupportsthe10CFR50.92evaluation contained inAttachment 1.Thereportisconsidered proprietary toWestinghouse ElectricCorporation.

Assuch,anaffidavit forwithholding frompublicdisclosure isprovidedinAttachment 4.Anon-proprietary versionoftheWCAP(WCAP-13971) isprovidedinAttachment 5.)81~.689402250130 940215PDRADOCK05000315,PDR~pg.00pic,PDpi~~g5~c.(pealf-y.V

.~~V.

Dr.T~E.Hurley2AEP:NRC:1166K Webelievetheproposedchangeswillnotresultin(1)asignificant changeinthetypesofanyeffluentthatmaybereleasedoffsite,or(2)asignificant increaseinindividual orcumulative occupational radiation exposure.

TheseproposedchangeshavebeenreviewedbythePlantNuclearSafetyReviewCommittee andbytheNuclearSafetyandDesignReviewCommittee.

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

copiesofthisletteranditsattachments havebeentransmitted totheMichiganPublicServiceCommission andtotheMichiganDepartment ofPublicHealth.Thisletterissubmitted pursuantto10CFR50.30(b),

and,assuch,anoathstatement isattached.

Sincerely, E.EDFitztrickVicePresident drAttachments cc:A.A.BlindG.CharnoffJ.B.Martin-RegionIIINFEMSectionChiefNRCResidentInspector

-BridgmanJ.R.Padgett STATEOFOHIO)COUNTYOFFRANKLIN)

E.E.Fitzpatrick, beingdulysworn,deposesandsaysthatheistheVicePresident oflicenseeIndianaMichiganPowerCompany,thathehasreadtheforgoingTECHNICAL SPECIFICATION CHANGESTOINCORPORATE WSTEAMGENERATOR TUBEPLUGGINGCRITERION andknowsthecontentsthereof;andthatsaidcontentsaretruetothebestofhisknowledge andbelief.Subscribed andsworntobeforemethis~~dayof19~.NOTARYPUBLICRlrhD.HILLlfoTARYPUBS.'lt'TATE OFpH[pN

ATTACHMENT 1TOAEP:NRC:1166KDESCRIPTION ANDJUSTIFICATION OFCHANGES10CFR50.92ANALYSISFORCHANGESTOTHEDONALDC.COOKNUCLEARPLANTUNIT1TECHNICAL SPECIFICATIONS ATTACHMENT 1TOAEP:NRC:1166K Page1I.INTRODUCTION Thisamendment requestproposesachangetoTechnical Specification (TS)4.4.5(SteamGenerators) toincorporate arevisedacceptance criterion forsteamgenerator tubeswithdegradation inthetubesheet rollexpansion region.Thiscriterion forsteamgenerator tubeacceptance wasdeveloped byWestinghouse ElectricCorporation andisknownasW("F-Star"

).Thiscriterion wasdeveloped toavoidunnecessary pluggingofsteamgenerator tubes.TheexistingT/Stuberepairing andpluggingcriteriaapplythroughout thetubelength,butdonottakeintoaccountthereinforcing effectofthetubesheet ontheexternalsurfaceofthetubeintherollexpansion region.Thepresenceofthetubesheet willconstrain thetubeandwillcomplement itsintegrity inthatregionbyessentially precluding tubedeformation beyonditsexpandedoutsidediameter.

Theresistance tobothtuberuptureandtubecollapseissignificantly strengthened bythetubesheet.

Inaddition, theproximity ofthetubesheet significantly affectstheleakbehaviorofthroughwalltubecracksinthisregion,i.e.,nosignificant leakagerelativetoplantT/Slimitsistobeexpected.

TheWmethodology anddetermination oftheWdistanceareincludedinWCAP13970,entitled"WTubePluggingCriterion forTubesWithDegradation intheTubesheet RollExpansion RegionoftheDonaldC.CookUnit1SteamGenerators."

Thisreport,preparedbyWestinghouse ElectricCorporation, iscontained inAttachment 4.Anon-proprietary versionofthereportisincludedinAttachment 5.II.ESCRIPTION OFTHECHANGESTheproposedchangesarethosenecessary toincorporate theWtubesheet regionpluggingcriterion intotheT/Ss.Thespecificchangesareasfollows:Arequirement isaddedtoinspect(intherollexpandedregion)alltubeswhichhavehadtheWcriteriaapplied.Therollexpandedregionofthesetubesmaybeexcludedfromtherequirements ofT/S4.4.5.2.b.l.

Definitions forWdistanceandanWtubeareadded.Wdistanceisthedistancefromthebottomofthehardrolltransition towardthebottomofthetubesheet thathasbeenconservatively determined tobe1.11inches(notincluding eddycurrentuncertainty).

An,&tubeisatubewithdegradation, belowtheWdistance, equaltoorgreaterthan40$,andnotdegraded(i.e.,noindications ofcracking) withintheWdistance.

Thedefinition of"Repair/Plugging Limit"(T/S4.4.5.4.a.6) ismodifiedtonotethatthe408repair/plugging limitdoesnotapplytotheportionofthetubeinthetubesheet belowtheWdistanceforWtubes.

ATTACHMENT 1TOAEP:NRC:1166K Page2Arequirement isaddedtoreporttotheNRCtheresultsofinspections performed underT/S4.4.5.2foralltubesthathavedefectsbelowtheWdistanceandwerenotplugged.III.10CFR5092EVALUATION Theamendment hasbeenproposedtoaddresseddycurrentindications oftubedegradation whichcanoccurintherollexpandedportionofthetubeswithinthetubesheet inthesteamgenerators attheCookNuclearPlantUnit1.Thesesteamgenerators werefabricated witha2.75inchpartialdepthrollexpansion inthetubesheet.

Interpretation ofeddycurrentdatafromtheCookNuclearPlantUnit1andsimilarplantshasshownapotential forprimarywaterstresscorrosion cracking(PWSCC)withintherollexpandedportionofthetubeinthetubesheet.

Itcanbeshownthattubepluggingorsleevingisnotrequiredinmanysuchcasestomaintainsteamgenerator tubeintegrity.

UsingexistingT/Stubepluggingcriteriaforthelengthoftubewithinthetubesheet, manyofthetubeswithpotential indications wouldhavetoberepairedorremovedfromservice.Theproposedamendment wouldprecludeoccupational radiation exposurethatwouldotherwise beincurredbyplantworkersinvolvedintubepluggingorsleevingoperations.

Theproposedamendment wouldalsoavoidlossofmargininreactorcoolantsystemflowandtherefore assistinassuringthatminimumflowratesaremaintained inexcessofthatrequiredforoperation atfullpower.Reduction intheamountoftubepluggingorsleevingrequiredcanreducethelengthofplantoutagesandreducethetimethatthesteamgenerator isopentothecontainment environment duringanoutage.Thepossibility oftuberepairbysleevingshouldnotbeconsidered areasontoexcludeuseofthisproposedtubesheet pluggingcriterion, butshouldbeconsidered oneoftheoptionsusedtoaddressdegradation intheexpandedregionofthetube.Thedisadvantages oftubeplugsnotedabovealsoapplytosomeextenttosleeves.Theproposedamendment addresses theactionrequiredwhendegradation hasbeendetectedinthemechanically expandedportionofsteamgenerator tubeswithinthesteamgenerator tubesheet.

Existingtuberepairorpluggingcriteriadonottakeintoaccounttheeffectofthetubesheet ontheexternalsurfaceofthetube.Thepresenceofthetubesheet willenhancetheintegrity ofpotentially degradedtubesinthatregionbyprecluding tubedeformation beyondtheexpandedoutsidediameter.

Structural (burst)integrity oftubeswithsignificant throughwall axialpenetration lengthisprovidedintherollexpandedarea.Anaxiallengthofrollexpansion equaltotheWlengthatthetopoftherollexpansion ofthetubeintothetubesheet providessufficient structural integrity toprecludepulloutofthetubeduetopressureeffects,evenafter

ATTACHMENT 1TOAEP:NRC:1166K Page3assumingthatthetubehasexperienced acompletecircumferential separation atorbelowthebottomoftheF+distance.

Thissameaxiallengthofrollexpansion ofthetubeintothetubesheet providesabarriertoleakageduringallplantconditions forthroughwallcrackingofthetubeintheexpandedregionbelowW.Theproposedchangedesignates aportionofthetubeforwhichtubedegradation ofadefinedtypedoesnotnecessitate remedialactionexceptasdictatedforcompliance withtubeleakagelimitsassetforthintheT/Ss.Asnotedabove,theareasubjecttothischangeisintheexpandedportionofthetubewithinthetubesheet ofthesteamgenerators.

TheWlengthhasbeendetermined tobe1.11inches.Soundrollexpansion of1.11incheswillsatisfyallapplicable recommendations ofRegulatory Guide1.121,withregardtotubeburstcapability.

Conformance oftheproposedamendments tothestandards foradetermination ofnosignificant hazardasdefinedin10CFR50.92(threefactortest)isshowninthefollowing:

1)Operation ofDonaldC.CookNuclearPlantUnit1inaccordance withtheproposedlicenseamendment doesnotinvolveasignificant increaseintheprobability orconsequences ofanaccidentpreviously evaluated.

Thesupporting technical andsafetyevaluations ofthesubjectcriterion demonstrate thatthepresenceofthetubesheet willenhancethetubeintegrity intheregionofthehardrollbyprecluding tubedeformation beyonditsinitialexpandedoutsidediameter.

Theresistance tobothtuberuptureandtubecollapseisstrengthened bythepresenceofthetubesheet inthatregion.Theresultofhardrolling ofthetubeintothetubesheet isaninterference fitbetweenthetubeandthetubesheet.

Tuberupturecannotoccurbecausethecontactbetweenthetubeandtubesheet doesnotpermitsufficient movementoftubematerial.

Theradialpreloaddeveloped bytherollingprocesswillsecureapostulated separated tubeendwithinthetubesheet duringallplantconditions.

Inasimilarmanner,thetubesheet doesnotpermitsufficient movementoftubematerialtopermitbucklingcollapseofthetubeduringpostulated LOCAloadings.

Thetypeofdegradation forwhich,theWcriterion hasbeendeveloped (cracking withacircumferential orientation) cantheoretically leadtoapostulated tuberuptureeventprovidedthatthepostulated through-wall circumferential crackexistsnearthetopofthetubesheet.

Anevaluation including analysisandtestinghasbeendonetodetermine theresistive strengthofrollexpandedtubeswithinthetubesheet.

Thisevaluation providesthebasisfortheacceptance criteriafortubedegradation subjecttotheWcriterion.

ATTACHMENT 1TOAEP:NRC:1166K Page4TheWlengthofrollexpansion issufficient toprecludetubepulloutfromtubedegradation locatedbelowtheWdistance, regardless oftheextentofthetubedegradation.

TheexistingT/Sleakageraterequirements andaccidentanalysisassumptions remainunchanged intheunlikelyeventthatsignificant leakagefromthisregiondoesoccur.Asnotedabove,tuberuptureandpulloutisnotexpectedfortubesusingtheWcriterion.

Anyleakageoutofthetubefromwithinthetubesheet atanyelevation inthetubesheet isfullyboundedbytheexistingsteamgenerator tuberuptureanalysisincludedintheCookNuclearPlantFSAR.Forplantswithpartialdepthrollexpansion likeCookNuclearPlantUnit1,apostulated tubeseparation withinthetubenearthetopoftherollexpansion (withsubsequent limitedtubeaxialdisplacement) wouldnotbeexpectedtoresultincoolantreleaseratesequaltothoseassumedintheFSARforasteamgenerator tuberuptureeventduetothelimitedgapbetweenthetubeandtubesheet (approximately

0.0 13inchdiametral

gap).Theproposedpluggingcriterion doesnotadversely impactanyotherpreviously evaluated designbasisaccident.

Leakagetestingofrollexpandedtubesindicates thatforrolllengthsapproximately equaltotheWdistance, anypostulated faultedcondition primarytosecondary leakagefromWtubeswouldbeinsignificant.

2)Theproposedlicenseamendment doesnotcreatethepossibility ofanewordifferent kindofaccidentfromanyaccidentpreviously evaluated.

Implementation oftheproposedWcriterion doesnotintroduce anysignificant changestotheplantdesignbasis.Useofthecriterion doesnotprovideamechanism toinitiateanaccidentoutsideoftheregionoftheexpandedportionofthetube.Anyhypothetical accidentasaresultofanytubedegradation intheexpandedportionofthetubewouldbeboundedbytheexistingtuberuptureaccidentanalysis.

Tubebundlestructural integrity willbemaintained.

Tubebundleleaktightness willbemaintained suchthatanypostulated accidentleakagefromWtubeswillbenegligible withregardtooffsitedoses.3)Theproposedlicenseamendment doesnotinvolveasignificant reduction inamarginofsafety.TheuseoftheWcriterion hasbeendemonstrated tomaintainthe,integrity ofthetubebundlecommensurate withtherequirements ofRegGuide1.121(intended forindications inthefreespanoftubes)andtheprimarytosecondary pressureboundaryundernormalandpostulated accidentconditions.

Acceptable tubedegradation fortheWcriterion isanydegradation indication inthetubesheet region,morethanthedistancebelowthebottomofthetransition betweentherollexpansion andtheunexpanded tube.Thesafetyfactorsusedintheverification ofthestrengthofthedegradedtubeareconsistent withthesafetyfactorsintheASMEBoilerandPressureVesselCodeusedinsteamgenerator design.TheWdistancehasbeenverifiedbytestingtobegreaterthanthelengthofrollexpansion requiredtoprecludebothtubepulloutand

ATTACHMENT 1TOAEP:NRC:1166K Page5significant leakageduringnormalandpostulated accidentconditions.

Resistance totubepulloutisbasedupontheprimarytosecondary pressuredifferential asitactsonthesurfaceareaofthetube,whichincludesthetubewallcross-section, inadditiontotheinnerdiameterbasedareaofthetube.Theleaktestingacceptance criteriaarebasedontheprimarytosecondary leakagelimitintheT/Ssandtheleakageassumptions usedintheFSARaccidentanalyses.

Implementation ofthetubesheet pluggingcriterion willdecreasethenumberoftubeswhichmustbetakenoutofservicewithtubeplugsorrepairedwithsleeves.BothplugsandsleevesreducetheRCSflowmargin;thus,implementation oftheWcriterion willmaintainthemarginofflowthatwouldotherwise bereducedintheeventofincreased pluggingorsleeving.

Basedontheabove,itisconcluded thattheproposedchangedoesnotresultinasignificant reduction inmarginwithrespecttoplantsafetyasdefinedintheFSARortheT/SBases.

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