ML17165A409

Three Mile Island Nuclear Station, Unit 1 - T1R22 Refuel Outage MRP-227-A Reactor Internals Scope Deferral Review

ML17165A409
Person / Time
Site:	Three Mile Island
Issue date:	06/14/2017
From:	David Helker Exelon Generation Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
TMl-17-059
Download: ML17165A409 (19)

Text

Exelon Generation 10 CFR 54 TMl-17-059 June 14, 2017 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555 Three Mile Island Nuclear Station, Unit 1 (TMI) Renewed Facility Operating License No. DPR-50 NRC Docket No. 50-289

Subject:

T1 R22 Refuel Outage MRP-227-A Reactor Internals Scope Deferral Review

References:

(1) TMl-12-069, "Submittal of Inspection Plan for Reactor Internals," dated April 16, 2012 (2) Letter, Meena K. Khanna, Chief, Plant Licensing Branch 1-2 to Michael J. Pacilio, President and Chief Nuclear Officer, Exelon Nuclear, "Three Mile Island Nuclear Station, Unit 1 -Staff Assessment of the Reactor Vessel Internals Inspection Plan (TAC NO. MF1459)," dated December 19, 2014 In Reference 1 TMI provided the Inspection Plan for TMI Reactor Vessel Internals in accordance with License Renewal Activity No. 36 of Appendix A of NUREG-1928, "Safety Evaluation Report Related to the License Renewal of Three Mile Island Nuclear Station, Unit 1," dated October 2009, and MRP-227-A, "Materials Reliability Program: Pressurized Water Reactor Internals Inspection and Evaluation Guidelines (MRP-227-A)," dated December 2011. In Reference 2 the U.S. Nuclear Regulatory Commission (NRC) reviewed the TMI Inspection Plan for Reactor Vessel Internals (RVI) and concluded that the licensee's RVI Inspection Plan was acceptable because it was consistent with the inspection and evaluation guidelines of MRP-227-A, the licensee had addressed six of the eight licensee action items specified in MRP-227-A appropriately, and had made regulatory commitments to submit analyses fulfilling the other two action items on an acceptable schedule.

TMI has elected to delay implementation of the final scope of RVI MRP-227-A examinations from the T1 R22 (2017) refueling outage to the T1 R23 (2019) refueling outage. Per the requirements of MRP-227-A, these "needed" examinations are to be U.S. Nuclear Regulatory Commission T1 R22 Refueling Outage MRP-227-A Reactor Internals Scope Deferral June 14, 2017 Page 2 completed no later than two refueling outages from the beginning of the license renewal period or during the next 10-year ISi interval.

T1 R22 (2017) is the second refueling outage after entry into the period of extended operation (April 2014). The examinations are being rescheduled due to the economic uncertainty surrounding the continued operation of TMI. On May 30, 2017, Exelon announced that it will prematurely retire TMI on or around September 30, 2019, absent needed policy reforms. In light of this decision and based on the industry experience from performing the required examinations, Exelon has evaluated the remaining MRP-227-A examinations scheduled for the T1 R22 refueling outage and determined that it is technically justifiable to defer the examinations to the following T1 R23 refueling outage. Attachment 1 provides a revised commitment.

The remaining commitments in Reference 1 remain unchanged.

Attachment 2 provides the Exelon Materials Degradation Management Process (MDMP) Deviation Form. Attachment 3 provides the Technical Evaluation 04020993-02, TMI MRP-227-A Inspection Deviation-T1 R22. Should you have any questions concerning this submittal, please contact Frank Mascitelli at 610-765-5512.

Respectfully, David P. Helker Manager, Licensing

& Regulatory Affairs Exelon Generation Company, LLC Attachments:

1) 2) 3) Summary of Regulatory Commitments Exelon Materials Degradation Management Process (MDMP) Deviation Form Technical Evaluation 04020993-02, TMI MRP-227-A Inspection Deviation-T1 R22. cc: USNRC Regional Administrator, Region I USNRC Project Manager, TMl-1 USNRC Senior Resident Inspector TMl-1 Director, Bureau of Radiation Protection

-PA Department of Environmental Resources Chairman, Board of County Commissioners of Dauphin County, PA Chairman, Board of Supervisors of Londonderry Township, PA R. R. Janati, Commonwealth of Pennsylvania ATTACHMENT 1

SUMMARY

OF REGULATORY COMMITMENTS The following table identifies commitments made in this document. (Any other actions discussed in the submittal represent intended or planned actions. They are described to the NRC for the NRC's information and are not regulatory commitments.)

COMMITMENT TYPE COMMITMENT COMMITTED DATE One-Time Programmatic OR "OUTAGE" Action (Yes/No) {Yes/No) Yes No TMI will complete the deferred MRP-T1 R23 (2019) refueling 227-A inspections (described in outage. Attachment 2 of TMl-17-059 letter to NRC) during the T1 R23 (2019) refueling outage.

ATTACHMENT 2 EXELON MATERIALS DEGRADATION MANAGEMENT PROCESS (MDMP) DEVIATION FORM ER AA 4003Attachment2MDMPDeviationFormPage1of2Utility:ExelonApplicableSite(s)andUnitNo.:ThreeMileIslandUnit1UtilityContact(s):RossShacklett/MarkTorborg,TMIEngineeringPrograms,HeatherMalikowski,CorporateAssetManagementIssueProgram(IP)activityordocument:MaterialsReliabilityProgram:PressurizedWaterReactorInternalsInsp ectionandEvaluationGuidelines(MRP 227 A)Scope/DescriptionofDeviation:TMIhaselectedtodelayimplementationofthefinalscopeofReactorVesselInternalsMRP 227 Aexaminationsforonerefuelingoutage(fromT1R222017toT1R23 2019).PertherequirementsofMRP 227 A,the"needed"examinationsshallbecompletednolaterthantworefuelingoutagesfromthebeginningofthelicenserenewalperiodorduringthenext10 yearISIinterval.T1R22(2017)isthesecondrefuelingoutageafterentryintotheperiodofextendedoperation(April2014).ThroughcorrespondencewiththeNRC,approvedonDecember19,2014(ML14297A411),ExelonstatedthatexaminationofRVIcompo nentsthatareaccessibleonlywhiletheCoreSupportAssembly(CSA)isremovedwillbeperformedduringthe2015refuelingoutage(RFO),andthatotherRVIcomponentswillbeexaminedduringthe2017RFO.DuringrefuelingoutageT1R21,(October2015)ExelonsuccessfullyexecutedapartialimplementationoftheMRP 227 Aexaminations.CompletedMRP 227 AInspections-T1R21ComponentExamTypeUpperCoreBarrelBoltsandLockingDevicesUTLowerCoreBarrelBoltsandLockingDevicesUTFlowDistributorBoltsandLockingDevicesUTLowerGridAssemblyAlloyX 750Dowel toguideBlockWeldsVT 3LowerGridShockPadBoltingandLockingDevices(proactiveaugmentedexam)UT&VT 3Theremainingexaminations,originallyscheduledforT1R22,beingdelayeduntilT1R23arelistedbelow.RemainingMRP 227 AInspectionsComponentExamTypePlenumWearPads(WeldmentRibPads)VT 3PlenumCoverSupportFlangeVT 3ControlRodGuideTube(CRGT)spacercastingsVT 3CSSventvalvetop&bottomretainingringsVT 3Baffle to formerboltsUTLockingDevices,includingLockingWelds,ofBaffle to FormerBoltandInternalBaffle toBaffleBoltsVT 3BaffleplatesVT 3IMIguidetubespidersVT 3IMIguidetubespider to lowergridribsectionweldsVT 3 ER AA 4003Attachment2MDMPDeviationFormPage2of2ReasonforDeviation:TheexaminationsarebeingrescheduledduetotheeconomicuncertaintysurroundingthecontinuedoperationofThreeMileIslandUnit1.OnMay30,2017,ExelonannouncedthattheywillprematurelyretireThreeMileIslandGeneratingStationonoraroundSeptember30,2019,absentneededpolicyreforms.Inlightofthisdecisionandbasedontheindustryexperiencefromperformingtherequiredexaminations,ExelonhasdetermineditisnotprudenttoperformtheremainingMRP 227 AexaminationsduringT1R22andistechnicallyjustifiabletodefertheexaminationstoth efollowingrefuelingoutage,T1R23.ReferencetheEClistedbelowforadditionaltechnicalevaluation.IRNumber:04020993ECNumber:04020993 02TimeFrametheDeviationwillbeinEffect:ThisdeviationwillbeineffectuntilrefuelingoutageT1R23(2019)orTMI 1retirementin2019.DeviationfromthisIPdocumentisclassifiedas:NEEDEDTheonlyNEI03 08recommendationinMRP 227 Athatwouldnotbemetis"Needed"item7.3,ReactorInternalsGuidelinesImplementationRequirement."EachcommercialU.S.PWRunitshallimplementTables4 1through4 9andTables5 1through5 3fortheapplicabledesignwithintwenty fourmonthsfollowingissuanceofMRP 227 A."PreparedBy:RossShacklettDate:StationProgramManager:MarkTorborgDate:SiteEngineeringDirector:BlairWunderlyDate:CorporateMDMPOwner:HarryL.SmithDate:CorporateAssetManagementManager:JamesCirilliDate:CorporateProgramsDirector:ThomasBassoDate:SiteVicePresident:EdwardCallanDate:SeniorVPofEngineering&TechnicalServices:ScotGreenleeDate:

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TMIMRP 227 AInspectionDeviation-T1R22TechnicalEvaluation04020993 02Page1of111.ReasonForEvaluation/Scope:TMIhaselectedtodelayimplementationofthefinalscopeofMRP 227 Aexaminationsforonerefuelingoutage,fromT1R22in2017toT1R23in2019.TheexaminationsarebeingrescheduledduetotheeconomicuncertaintysurroundingthecontinuedoperationofThreeMileIslandUnit1.OnMay30,2017,ExelonannouncedthattheywillprematurelyretireThreeMileIslandGeneratingStationonoraroundSeptember30,2019,absentneededpolicyreforms.PertherequirementsofMRP 227 A,the"needed"examinationsshal lbecompletednolaterthantworefuelingoutagesfromthebeginningofthelicenserenewalperiodorduringthenext10yearISIinterval.T1R22(2017)isthesecondrefuelingoutageafterentryintotheperiodofextendedoperation(April2014).ThroughcorrespondencewiththeNRC,approvedonDecember19,2014(ML14297A411),Exelonstatedthatexa m inationofRVIcomponentsthatareaccessibleonlywhiletheCoreSupportAssembly(CSA)isremovedwillbeperformedduringthe2015refuelingoutage(RFO),andthatotherRVIcomponentswillbeexaminedduringthe2017RFO.DuringrefuelingoutageT1R21(October2015),Exelonexecutedapartialim ple mentationoftheMRP 227 Aexaminations(componentsonlyaccessiblewhiletheCoreSupportAssembly(CSA)isremoved).Theremainingexaminations,originallyscheduledforT1R22andbeingdelayeduntilT1R23arelistedbelow.AllotherMRP 227 ArequiredexamswerecompletedinT1R21(2015):RemainingMRP 227 AInspectionsComponentExamTypePlenumWearPads(WeldmentRibPads)VT 3PlenumCoverSupportFlangeVT 3ControlRodGuideTube(CRGT)spacercastingsVT 3CSSventvalvetop&bottomretainingringsVT 3Baffle to formerboltsUTLockingDevices,includingLockingWelds,ofBaffle to FormerBoltandInternalBaffle toBaffleBoltsVT 3BaffleplatesVT 3IMIguidetubespidersVT 3IMIguidetubespider to lowergridribsectionweldsVT 3ThisevaluationwilldeterminetheacceptabilityofdelayingtheremainingMRP 227 A"needed"examinationsbyonerefuelingoutage(fromT1R22in2017toT1R23in2019).2.DetailedEvaluation:ThefollowingcomponentexaminationsareneededtofulfilltheMRP 227 Areactorinternalsprimaryexaminationrequirements.AllotherMRP 227 ArequiredexamswerecompletedinT1R21(2015).OperatingExperiencefromOconee1,2,3andArkansasNuclearOne1MRP227 Aexaminationswasreviewedforrelevantfindings.Oconee1,2,3andArkansasNucle a rOne1shareasimilarB&WReactor TMIMRP 227 AInspectionDeviation-T1R22TechnicalEvaluation04020993 02Page2of11VesselInternaldesignandaccountforfourofthesixoperatingB&Wsites.ThreeMileIslandandDavis BessehavenotcompletedtheMRP 227 AexaminationandaccountfortheremainingtwoB&Wsites.Foragecomparison,TMI 1willbeatapproximately32.2EFPYduringT1 R22and34.00EFPYduringT1R23.Oconee1wasat30.61EFPY,Oconee2wasat31.82EFPY,Oconee3wasat31.67EFPY,andANO 1wasat32.403EFPYwhenMRP 227 Ainspectionswereperformed.Whiletheesti matedEFPYforTMI 1performingMRP227 AexamsinT1R23isgreaterthantheotherB&Wunitsbyapproximately1.5 3.5EFPY,alloftheexaminationfindingsatthesesitesallowedfora10 yearre inspectioninterval.Thereforethereislowriskthatwaitinganotherfuelcycletocom pleteth eMR P 227 Aexaminationswouldallowsignificantagingdegradationtodevelopthatwouldbeconsideredunacceptableforcontinuedservice.NoTMI 1specifichistoricaloperatingpracticesordesigndifferenceswereidentifiedthatwouldcauseconcernforhavingworsefindingsthantheotherB&Wunits.2.1PlenumWearPa ds(Wel dmentRibPads)2.1.1NEI03 08InspectionRequirementsTheNEI03 08inspectionrequirementsforthePlenumWearPads(WeldmentRibPads)arecomprisedof1)aonetimephysicalmeasurementtodeterminethedifferentialheightofthetopofplenumribpadstoreactorvesselseatingsurface,withtheplen uminthereactorvesseland2)subsequentvisual(VT 3)examinationonthe10 yearISIinterval.Thisinspectionisintendedtoidentifylossofmaterialandassociatedlossofcoreclampingpre load(wear).2.1.2IndustryOPEXMRP 227 AinspectionreportsfromOconee1,2,3andArkansasNuclearOn e1werereviewedforsignificantdiscoveries.NoservicerelateddegradationorrelevantindicationswerenotedduringtheMRP 227 AinspectionsofthePlenumWearPads(WeldmentRibPads)atanyofthesimilarunits.2.1.3TMIInspectionResultsCoreclampingmeasurementswereobtainedatTMI 1byAREVAin2010tosatisfytheMRP 227 Aexaminationrequirementsforaone timephysicalmeasurementofthedifferentialheightoftopoftheplenumribpadstothereactorvesselseatingsurface.Thismeasurementwastakenwiththeplenumcoverweldmentribpads,plenumcoversupportflange,andCSStopflangeinsi detheRV,butwiththefuelassembliesremovedperSe ction4.3.1ofMRP227 A.Theconclusionsofthecoreclampingsummarydocumentarethattherewasnoevidenceofwearoccurringduringtheserviceperiodandthemeasurementswereacceptable.Therefore,thecoreclampingme asurementsatTM I 1meettheone timephysicalmeasurementrequirementinMRP 227 A.(Reference4.3&4.4)2.1.4Conclusion TMIMRP 227 AInspectionDeviation-T1R22TechnicalEvaluation04020993 02Page3of11Delayingthevisualinspection(VT 3)ofthePlenumWearPads(WeldmentRibPads)byonecycleisacceptable.InspectionsatsimilarB&Wunitshavenotrevealedanyconcernswithmaterialcondition.PreviousTMIinspectionsdidnotidentifyevidenceofwearoccurri ng.Therefore,therearenotechnicalconcernswithdelayingthevisualinspection.2.2PlenumCoverSupportFlange2.2.1NEI03 08InspectionRequirementsTheNEI03 08inspectionrequirementforthePlenumCoverSupportFlangeisavisual(VT 3)examinationonthe10 yearISIinterval.Thisinspectio nisintendedtoidentifylossofmaterialandassociatedlossofcoreclampingpre load(wear).2.2.2IndustryOPEXMRP 227 AinspectionreportsfromOconee1,2,3andArkansasNuclearOne1werereviewedforsignificantdiscoveries.Noservicerelateddegradationorrelevantindicationswerenote ddurin gtheMRP 227 AinspectionsofthePlenumCoverSupportFlangeatanyofthesimilarunits.2.2.3TMIInspectionResultsVisualinspectionsofthePlenumCoverSupportFlangethatmeetthescopeofMRP 227 Ahavenotbeenperformedpreviously.However,duringT1R22(2015),ASMESectionXIvisual(VT 3)inspectionsofthePlenumCo verSupportFlangewereperformed.Theexamcovered360°oftheaccessiblesurfacesofthePlenumCoverSupportFlangeforwear(SectionXI).Therewerelimitationsduetothecavitywallconfiguration.Thebottomandtheinboardflangesurfaceswereexaminedinco njunctionwithth eClampingSurfacesandthePlenumCoverandRibattachmentsexaminations.Noservicerelateddegradationorrelevantindicationswerenotedduringthisinspection.(Reference4.5)2.2.4ConclusionDelayingthevisualinspection(VT 3)ofthePlenumCoverSupportFlangebyonecycleisacceptable.InspectionsatsimilarB&Wunitshavenotrevealedanyconc ernswithmaterialcondi tion.PreviousTMIinspectionsdidnotidentifyanydegradation.2.3ControlRodGuideTube(CRGT)SpacerCastings2.3.1NEI03 08InspectionRequirementsTheNEI03 08inspectionrequirementfortheCRGTSpacerCastingsisavisual(VT 3)examinationofaccessiblesurfacesateachofthefourscrewlocations(atevery90°)of100%oftheCRGTSpacerCastingsonthe10 yearISIinterval.

TMIMRP 227 AInspectionDeviation-T1R22TechnicalEvaluation04020993 02Page4of11Thisinspectionisintendedtoidentifycracking(thermalembrittlement),includingthedetectionoffracturedspacersormissingscrews.2.3.2IndustryOPEXMRP 227 AinspectionreportsfromOconee1,2,3andArkansasNuclearOne1werereviewedforsignificantdis c overies.Noservicerelateddegradation,missingscrews,orrelevantindicationswerenotedduringtheMRP 227 AinspectionsoftheCRGTSpacerCastingsatanyofthesimilarunits.2.3.3TMIInspectionResultsVisualinspectionsoftheCRGTSpacerCastingsthatmeetthescopeofMRP227 Ahavenotbeenperformedpreviously.However,duringT1R22(2015),ASMESectionXIvisual(VT 3)inspectionsoftheaccessibleareasof69ControlRodGuideTubeAssemblieswereperformed.Theinspectionexaminedtheaccessibleareasofthecontrolrodguidestubesfromthetoplookingdown,aroundtheperipheryandthroughtheholesinth ecyli nder.Th einspectionidentifiedasmallflakeofforeignmaterialthatwaslikelyintroducedduringrefuelingactivitiesandwaseasilyretrieved.(Reference4.16)Nootherindicationswerenoted.(Reference4.5)AREVAhasnotedthatissueswithControlRodinsertiontimesareapotentialindicatorofiss u eswiththeCRGTSpacerCastings.RecentControlRodinsertiontimingduringT1R21didnotindicateanyissues.Therefore,itislesslikelyanissuewiththeCRGTSpacerCastingsexists.2.3.4ConclusionDelayingthevisualinspection(VT 3)oftheCRGTSpacerCastingsbyonecycleisacceptable.InspectionsatsimilarB&Wunitshavenotrevealedanyconcernswithmaterialcondition.PreviousTMIinspectionsdidnotidentifyanydegradation.2.4CoreSupportShield(CSS)VentValveTop&BottomRetainingRings2.4.1NEI03 08InspectionRequirementsTheNEI03 08inspectionrequirementfortheCSSVentValveTop&BottomRetainingRingsisavisual(VT 3)examinationof100%ofaccessiblesurfacesduringthe10 yearISIinterval.Thisinspectionisintendedtoidentifycracking(thermalembrittlement),includingthedetectionofsurfaceirregularities,suchasdamaged,fracturedmaterials,ormissingitems.2.4.2IndustryOPEXMRP 227 AinspectionreportsfromOconee1,2,3andArkansasNuclearOne1werereviewedforsignificantdiscoveries.NosignificantmaterialdegradationormissingitemswerediscoveredduringtheMRP 227 AinspectionsoftheCSSVentValveTop&BottomRetainingRingsatanyofthesimilarunits.

TMIMRP 227 AInspectionDeviation-T1R22TechnicalEvaluation04020993 02Page5of11ANO 1identifiedsomerelevantindicationsontheoriginalandmodifiedlockingdevices.However,theseindicationsweredeterminedtobeacceptableforcontinuedserviceandnotinterferewiththeventvalvefunction.2.4.3TMIInspectionResultsVentvalvetestingandin spectionsarerequiredtobeperformedeachrefuelingoutage,perTechSpec4.16.ThisrequirementisfulfilledbytheTMl 1ReactorInternalsVentValveInspectionandExerciseprocedure.Theaccessibleareasoftheventvalvearetypicallyinspected,includingthelockingdevices.Additionally,ventvalveoperationistestedthroughm a nualactuation.Rece ntinspectionsin2015didnotidentifyanyissueswithventvalveretainingrings.However,ventvalveRC V144Awasreplacedduetoexternalimpactdamagetothepressureplateandlockingdevice.VentvalvelockingdeviceswereexaminedforallventvalvesTechSpecrequirementsandTM IspecificcommitmenttoMRP 227 AandPWROGinterimguidance.RC V 144A(adjacenttothehotleg)wasfoundwithafailedlockingdeviceinwhichthespringretainerhadwornthroughthelockingcup.Thelockingcupandspringretainerwerefunctionalas found,bu tanassessmentofoperabilityov e rthenextcyclecouldnotbemade.Thedamagemechanismwasflowinducedwearandwasbelievedtooriginatein1R18afterexternalimpactfromthePlenum.Thisventvalvewasoftheoriginaldesign.(Reference4.6)Remainingventvalvesexhibitedimpactdamageonthelockingde vicesfromth einstallationofthePlenum.Th isimpactdamagedidnotaffecttheabilityofthelockingdevicestoperformtheirdesignfunctions2.4.4ConclusionDelayingthevisualinspection(VT 3)oftheCSSVentValveTop&BottomRetainingRingsbyonecycleisacceptable.InspectionsatsimilarB&Wunitshavenotrevealedanyconcernswithmaterialconditionoftheventvalveretainingrings.PreviousTMIinspectionsdidnotidentifyevidenceofservicerelatedcrackingormissingitems.FunctionaltestingwillcontinuetobeperformedinT1R22.Therefore,therearenotechnicalconcernswithdelayingthevisualinspection.2.5Baffle toFormerBolts2.5.1NEI03 08InspectionRequirementsTheNEI03 08inspectionrequirementfortheBaffle to FormerBoltsisabaselinevolumetricexamination(UT)of100%ofaccessibleboltsnolaterthantworefuelingoutagesfromthebeginningofthelicenserenewalperiod.Thisinspectionisintendedtoidentifycracking(IrradiationAssistedStr e ssCorrosionCracking,IrradiationEmbrittlement,andOverload).

TMIMRP 227 AInspectionDeviation-T1R22TechnicalEvaluation04020993 02Page6of112.5.2IndustryOPEXBaffle to FormerBoltUTexaminationshavebeenofconcernwiththerecentinspectionresultsfromseveralWestinghouse4loopdownflowunits.AREVAissuedaCustomerServiceBulletin(CSB)16 02inresponsetoWestinghouseNSAL16 1.CSB16 02concludedthattheOEislimited,atthistime,toasubsetofdesignandoperatingconditionsfortheWestinghouse4 loopdown flowoperatingunitsandnotanimmediaterisktothesafetyandoperabilityoftheB&Wdesigned177 FAuni ts.Oconee1sharesasimilarboltdesi gnwithTMI 1.MRP 227 Ainspectionreportswerereviewedforsignificantdiscoveries.Noservicerelateddegradation,relevantindications,ormissing,non functional,orremovedlockingdevicesorweldswerediscoveredduringtheOconee1MRP 227 Ainspections.OtherB&Wunits(ANO 1,Oconee2&3)haveadiffe rentboltdesignbu tsimilaroperatingconditions.TheseexamresultsprovidefurthersupportinginspectiondatathattheissueisnotaconcernforB&Wunits.BasedupontheoperatingexperienceandconclusionsfromtheAREVACSB ,thereislowriskfordelayin gtheexamatTM I.2.5.3TMIInspectionResultsVisualinspectionsoftheBaffle toFormerBoltswereperformedinT1R21(2015).Theseinspectionsdidnotidentifyanyservicerelatedmaterialdegradationissues.AlthoughthescopeoftheseinspectionsdidnotcovertheMRP 227 AscopeofUTinspections,novisualmaterialdegradatio nissueswerenoted.(Reference4.5)2.5.4ConclusionDelayingthebaselinevolumetricexamination(UT)oftheBaffle to FormerBoltsbyonecycleisacceptable.UTinspectionsatsimilarB&Wunitshavenotrevealedanyconcernswithmaterialcondition.PreviousvisualinspectionsatTMIdidnotidentifyanyservicerelateddegradati o nissues.Therefore,therearenotechnicalconcernswithdelayingtheUTinspectiononecycle.2.6LockingDevices,IncludingLockingWelds,ofBaffle toFormerBoltandInternalBaffle toBaffleBolts2.6.1NEI03 08InspectionRequirementsTheNEI03 08inspectionrequirementforlockingdevicesofbaffle to formerboltandinternalbaffle to baffleboltsisavisual(VT 3)examinationof100%ofaccessiblebaffle to formerandinternalbaffle to baffleboltlockingdevicesduringthe10 yearISIinterval.Thisinspectionisintendedtoidentifycracking(IrradiationAssistedStressCorrosionCracking,IrradiationEmbri ttle me nt,andOverload),includingthedetectionofmissing,nonfunctional,orremovedlockingdevicesorwelds.

TMIMRP 227 AInspectionDeviation-T1R22TechnicalEvaluation04020993 02Page7of112.6.2IndustryOPEXOconee1sharesasimilarB&WReactorVesselInternaldesignwithTMI 1.MRP 227 Ainspectionreportswerereviewedforsignificantdiscoveries.Noservicerelateddegradation,relevantindications,ormissing,nonfunctional,orremovedlockingdevi cesorweldswerediscoveredduringtheMRP 227 Ainspectionsofthelockingdevicesatanyofthesimilarunits.2.6.3TMIInspectionResultsVisualinspectionsofthebaffle to formerboltswereperformedinT1R21(2015).AlthoughthescopeoftheseinspectionsdidnotcoverthefullMRP 227 Ascope,noservicerelateddegradationissuesormissinglockingdeviceswerenoted.(Reference4.5)2.6.4ConclusionDelayingthevisualinspection(VT 3)ofthelockingdevicesofbaffle to formerboltandinternalbaffle to baffleboltsbyonecycleisacceptable.InspectionsatsimilarB&Wuni tshav enotrevealedanyconcernswithmaterialcondition.PreviousTMIvisualinspectionsofthebaffle to formerboltsdidnotidentifyevidenceofservicerelateddegradationissuesormissinglockingdevices.Therefore,therearenotechnicalconcernswithdelayingtheMRP 227 Avisualinspection.2.7Baffleplates2.7.1NEI03 08Ins p ectionRequirementsTheNEI03 08inspectionrequirementforthebaffleplatesisavisual(VT 3)examinationof100%oftheaccessiblesurfaceswithinoneincharoundeachflowandboltholeduringthe10 yearISIinterval.Thisinspectionisintendedtoidentifycracking(irradiationembrittlement),includingth edetectionofreadilydetectiblecrackinginthebaffleplate.2.7.2IndustryOPEXMRP 227 AinspectionreportsfromOconee1,2,3andArkansasNuclearOne1werereviewedforsignificantdiscoveries.Noservicerelateddegradation,cracking,orrelevantindicationswerenotedduringtheMRP 227 Ainspectionsofthebaffleplatesatanyofthesimilaruni ts.2.7.3TMIInspectionResultsGeneralexaminationsofthebaffleplatesduringnormalrefuelingoutageshavenotidentifiedanymaterialdegradation.VisualinspectionsofthebaffleplatesthatmeetthescopeofMRP 227 Ahavenotbeenperformedpreviously.DuringT1R21(2015),visual(VT 3)inspectionoftheaccessibleareasoftheCoreBarrelAssemblyFormerPlateswasperformed.TherewaslimitedaccessduetoUpperCSAFlangeandBafflePlates.Norelevantindicationsobserved.(Reference4.5)

TMIMRP 227 AInspectionDeviation-T1R22TechnicalEvaluation04020993 02Page8of112.7.4ConclusionDelayingthevisualinspection(VT 3)ofthebaffleplatesbyonecycleisacceptable.InspectionsatsimilarB&Wunitshavenotrevealedanyconcernswithmaterialcondition.PreviousTMIinspectionsdidnotidentifyevidenceofservicerelateddegr adation.Therefore,therearenotechnicalconcernswithdelayingthevisualinspection.2.8IncoreMonitoringInstrumentation(IMI)GuideTubeSpiders2.8.1NEI03 08InspectionRequirementsTheNEI03 08inspectionrequirementfortheIMIGuideTubeSpidersisavisual(VT 3)examinationof100%oftopsur facesofthe52spidercastingsnolaterthantworefuelingoutagesfromthebeginningofthelicenserenewalperiod.Thisinspectionisintendedtoidentifycracking(thermalembrittlement,irradiationembrittlement),includingthedetectionoffracturedormissingspiderarms.2.8.2IndustryOPEXMRP 227 AinspectionreportsfromOconee1,2,3an dArka nsasNuclearOn e1werereviewedforsignificantdiscoveries.NoservicerelateddegradationorfracturedormissingspiderarmswerenotedduringtheMRP 227 AinspectionsoftheIMIGuideTubeSpidersatanyofthesimilarunits.2.8.3TMIInspectionResultsVisualinspectionsoftheIMIGui d eTubeSpidersthatmeetthescopeofMRP227 Ahavenotbeenperformedpreviously.2.8.4ConclusionDelayingthevisualinspection(VT 3)oftheIMIGuideTubeSpidersbyonecycleisacceptable.InspectionsatsimilarB&Wunitshavenotrevealedanyconcernswithmaterialcondition.Therefore,therearenotech nicalconcernswithdelayingthevisualinspection.

2.9IncoreMonitoringInstrumentation(IMI)GuideTubeSpider toLowerGridRibSectionWelds2.9.1NEI03 08InspectionRequirementsTheNEI03 08inspectionrequirementfortheIMIGuideTubeSpider to LowerGridRibSectionWeldsisavisual(VT 3)e x aminationof100%ofspidercastingweldstotheadjacentlowergridribsectionnolaterthantworefuelingoutagesfromthebeginningofthelicenserenewalperiod.

TMIMRP 227 AInspectionDeviation-T1R22TechnicalEvaluation04020993 02Page9of11Thisinspectionisintendedtoidentifycracking(irradiationembrittlement),includingseparationofspiderarmsfromthelowergridribsectionattheweld.2.9.2IndustryOPEXMRP 227 AinspectionreportsfromOconee1,2,3andArka nsasNuclearOn e1werereviewedforsignificantdiscoveries.NosignificantmaterialdegradationwasnotedduringtheOconee1&2MRP 227 Ainspections.Oconee3identifiedtwolinearindications,onelocatedjustbelowtheverticalweldtoeinthebasematerialofthelowergridandtheothercomingfromthetopofthecastingattheweldtoean dgoingdownwardintothecastingmaterial.ThelinearindicationinthelowergridmaterialisinarelativelylowstressareaanddoesnotresembleIGSCC.ANO 1identifiedindicationsontheIMItubespider to lowergridribsectionweldswhiche x ceededth ecriteriafortriggeringscopeExpansionperMRP 227 A.However,inreviewingtheresultswithANO,ANOconsideredthedeterminationasconservative,andnorepairsorreplacementswereneededtoaddressanyoftheinspectionfindings.TheexpansioncomponentsfortheIMItubespider to lowergridribsectionweldsarethelo wergridfuelassemblysupportpadite m s:pad,pad to ribsectionwelds,AlloyX 750dowel,capscrew,andtheirlockingwelds.ANO 1examinedtheseitemsduringthelastrefuelingoutageaspartoftheASMESectionXIB N 3VT 3visualexaminationsandnoindicationswerefound.2.9.3TMIInspectionResultsVisualinspectionsoftheIMItubespider to lowergridribsectionweldsthatmeetthescopeofMRP 227 Ahavenotbeenperformedpreviously.TMIcompletedtheASMESectionXIB N 3examinationsinT1R21(2015)andnoreleva ntindica tionswerefoundinthisarea.Therefore,thereisnoconcernfortheexpansionitemifthePrimarycomponentisnotexaminedinT1R22.(Reference4.5)2.9.4ConclusionDelayingthevisualinspection(VT 3)oftheIMItubespider tolowergridribsectionweldsbyonecycleisacceptable

.InspectionsatsimilarB&Wunitshavenotrevealedanysignificantconcernswithmaterialcondition.PreviousTMIinspectionsforASMESectionXIB N 3examinationsdidnotidentifyanymaterialconditionissueswiththeexpansionitemsfortheprimarycomponent(i.e.thelowergridfuelassemblysupportpadite m s).Therefore,therearenotechnicalconcernswithdelayingthevisualinspection.3.Conclusion/Findings:DelayingtheremainingMRP 227 A"needed"examinationsbyonerefuelingoutageisacceptable.TherehavebeennosignificantdiscoveriesfromsimilarB&WplantsthathaveperformedtheMRP 227 A TMIMRP 227 AInspectionDeviation-T1R22TechnicalEvaluation04020993 02Page10of11inspections.BasedonindustryOperatingExperience,previousTMIinspections,andthedurationofthedelay(onecycle),therearenotechnicalconcernswithdelayingtheMRP 227 Aexaminations.4.

References:

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5.Approval:PreparedBy:RossShacklett(SeePassportforApproval)Date:CorporatePWRInternalsProgramOwnerReview:HeatherMalikowski(SeePassportforApproval)Date:IndependentReview:RobertMarcello(SeePassportforApproval)Date:StationProgramManagerApproval:MarkTorborg(SeePassportforApproval)Date: