ML17165A409

T1R22 Refuel Outage MRP-227-A Reactor Internals Scope Deferral Review

ML17165A409
Person / Time
Site:	Crane
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. 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. of TMl-17-059 letter to NRC) during the T1 R23 (2019) refueling outage.

ATTACHMENT 2 EXELON MATERIALS DEGRADATION MANAGEMENT PROCESS (MDMP) DEVIATION FORM

ERAA4003 MDMPDeviationForm Page1of2 Utility:Exelon ApplicableSite(s)andUnitNo.:ThreeMileIslandUnit1 UtilityContact(s):RossShacklett/MarkTorborg,TMIEngineeringPrograms,HeatherMalikowski, CorporateAssetManagement IssueProgram(IP)activityordocument:MaterialsReliabilityProgram:PressurizedWaterReactor InternalsInspectionandEvaluationGuidelines(MRP227A)

Scope/DescriptionofDeviation:

TMIhaselectedtodelayimplementationofthefinalscopeofReactorVesselInternalsMRP227A examinationsforonerefuelingoutage(fromT1R222017toT1R232019).PertherequirementsofMRP 227A,theneededexaminationsshallbecompletednolaterthantworefuelingoutagesfromthe beginningofthelicenserenewalperiodorduringthenext10yearISIinterval.T1R22(2017)isthe secondrefuelingoutageafterentryintotheperiodofextendedoperation(April2014).Through correspondencewiththeNRC,approvedonDecember19,2014(ML14297A411),Exelonstatedthat examinationofRVIcomponentsthatareaccessibleonlywhiletheCoreSupportAssembly(CSA)is removedwillbeperformedduringthe2015refuelingoutage(RFO),andthatotherRVIcomponentswill beexaminedduringthe2017RFO.

DuringrefuelingoutageT1R21,(October2015)Exelonsuccessfullyexecutedapartialimplementationof theMRP227Aexaminations.

CompletedMRP227AInspections-T1R21 Component ExamType UpperCoreBarrelBoltsandLockingDevices UT LowerCoreBarrelBoltsandLockingDevices UT FlowDistributorBoltsandLockingDevices UT LowerGridAssemblyAlloyX750DoweltoguideBlockWelds VT3 LowerGridShockPadBoltingandLockingDevices(proactiveaugmentedexam)

UT&VT3 Theremainingexaminations,originallyscheduledforT1R22,beingdelayeduntilT1R23arelistedbelow.

RemainingMRP227AInspections Component ExamType PlenumWearPads(WeldmentRibPads)

VT3 PlenumCoverSupportFlange VT3 ControlRodGuideTube(CRGT)spacercastings VT3 CSSventvalvetop&bottomretainingrings VT3 Baffletoformerbolts UT LockingDevices,includingLockingWelds,ofBaffletoFormerBoltandInternal BaffletoBaffleBolts VT3 Baffleplates VT3 IMIguidetubespiders VT3 IMIguidetubespidertolowergridribsectionwelds VT3

ERAA4003 MDMPDeviationForm Page2of2 ReasonforDeviation:

Theexaminationsarebeingrescheduledduetotheeconomicuncertaintysurroundingthecontinued operationofThreeMileIslandUnit1.OnMay30,2017,Exelonannouncedthattheywillprematurely retireThreeMileIslandGeneratingStationonoraroundSeptember30,2019,absentneededpolicy reforms.Inlightofthisdecisionandbasedontheindustryexperiencefromperformingtherequired examinations,ExelonhasdetermineditisnotprudenttoperformtheremainingMRP227A examinationsduringT1R22andistechnicallyjustifiabletodefertheexaminationstothefollowing refuelingoutage,T1R23.ReferencetheEClistedbelowforadditionaltechnicalevaluation.

IRNumber:04020993 ECNumber:0402099302 TimeFrametheDeviationwillbeinEffect:ThisdeviationwillbeineffectuntilrefuelingoutageT1R23 (2019)orTMI1retirementin2019.

DeviationfromthisIPdocumentisclassifiedas:NEEDED TheonlyNEI0308recommendationinMRP227Athatwouldnotbemetis"Needed"item7.3,Reactor InternalsGuidelinesImplementationRequirement.EachcommercialU.S.PWRunitshallimplement Tables41through49andTables51through53fortheapplicabledesignwithintwentyfourmonths followingissuanceofMRP227A.

PreparedBy:

RossShacklett

Date:

StationProgramManager:

MarkTorborg

Date:

SiteEngineeringDirector:

BlairWunderly

Date:

CorporateMDMPOwner:

HarryL.Smith

Date:

CorporateAssetManagement Manager:

JamesCirilli

Date:

CorporateProgramsDirector:

ThomasBasso

Date:

SiteVicePresident:

EdwardCallan

Date:

SeniorVPofEngineering&

TechnicalServices:

ScotGreenlee

Date:

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ATTACHMENT 3 TECHNICAL EVALUATION 04020993*02 TMI MRP-227-A INSPECTION DEVIATION-T1R22.

TMIMRP227AInspectionDeviation-T1R22 TechnicalEvaluation0402099302 Page1of11

1. ReasonForEvaluation/Scope:

TMIhaselectedtodelayimplementationofthefinalscopeofMRP227Aexaminationsforone refuelingoutage,fromT1R22in2017toT1R23in2019.Theexaminationsarebeingrescheduleddueto theeconomicuncertaintysurroundingthecontinuedoperationofThreeMileIslandUnit1.OnMay30, 2017,ExelonannouncedthattheywillprematurelyretireThreeMileIslandGeneratingStationonor aroundSeptember30,2019,absentneededpolicyreforms.

PertherequirementsofMRP227A,theneededexaminationsshallbecompletednolaterthantwo refuelingoutagesfromthebeginningofthelicenserenewalperiodorduringthenext10yearISI interval.T1R22(2017)isthesecondrefuelingoutageafterentryintotheperiodofextendedoperation (April2014).ThroughcorrespondencewiththeNRC,approvedonDecember19,2014(ML14297A411),

ExelonstatedthatexaminationofRVIcomponentsthatareaccessibleonlywhiletheCoreSupport Assembly(CSA)isremovedwillbeperformedduringthe2015refuelingoutage(RFO),andthatotherRVI componentswillbeexaminedduringthe2017RFO.

DuringrefuelingoutageT1R21(October2015),ExelonexecutedapartialimplementationoftheMRP 227Aexaminations(componentsonlyaccessiblewhiletheCoreSupportAssembly(CSA)isremoved).

Theremainingexaminations,originallyscheduledforT1R22andbeingdelayeduntilT1R23arelisted below.AllotherMRP227ArequiredexamswerecompletedinT1R21(2015):

RemainingMRP227AInspections Component ExamType PlenumWearPads(WeldmentRibPads)

VT3 PlenumCoverSupportFlange VT3 ControlRodGuideTube(CRGT)spacercastings VT3 CSSventvalvetop&bottomretainingrings VT3 Baffletoformerbolts UT LockingDevices,includingLockingWelds,ofBaffletoFormerBoltandInternal BaffletoBaffleBolts VT3 Baffleplates VT3 IMIguidetubespiders VT3 IMIguidetubespidertolowergridribsectionwelds VT3 ThisevaluationwilldeterminetheacceptabilityofdelayingtheremainingMRP227Aneeded examinationsbyonerefuelingoutage(fromT1R22in2017toT1R23in2019).

2. DetailedEvaluation:

ThefollowingcomponentexaminationsareneededtofulfilltheMRP227Areactorinternalsprimary examinationrequirements.AllotherMRP227ArequiredexamswerecompletedinT1R21(2015).

OperatingExperiencefromOconee1,2,3andArkansasNuclearOne1MRP227Aexaminationswas reviewedforrelevantfindings.Oconee1,2,3andArkansasNuclearOne1shareasimilarB&WReactor

TMIMRP227AInspectionDeviation-T1R22 TechnicalEvaluation0402099302 Page2of11 VesselInternaldesignandaccountforfourofthesixoperatingB&Wsites.ThreeMileIslandandDavis BessehavenotcompletedtheMRP227AexaminationandaccountfortheremainingtwoB&Wsites.

Foragecomparison,TMI1willbeatapproximately32.2EFPYduringT1R22and34.00EFPYduring T1R23.Oconee1wasat30.61EFPY,Oconee2wasat31.82EFPY,Oconee3wasat31.67EFPY,and ANO1wasat32.403EFPYwhenMRP227Ainspectionswereperformed.WhiletheestimatedEFPYfor TMI1performingMRP227AexamsinT1R23isgreaterthantheotherB&Wunitsbyapproximately1.5 3.5EFPY,alloftheexaminationfindingsatthesesitesallowedfora10yearreinspectioninterval.

ThereforethereislowriskthatwaitinganotherfuelcycletocompletetheMRP227Aexaminations wouldallowsignificantagingdegradationtodevelopthatwouldbeconsideredunacceptablefor continuedservice.NoTMI1specifichistoricaloperatingpracticesordesigndifferenceswereidentified thatwouldcauseconcernforhavingworsefindingsthantheotherB&Wunits.

2.1 PlenumWearPads(WeldmentRibPads) 2.1.1 NEI0308InspectionRequirements TheNEI0308inspectionrequirementsforthePlenumWearPads(WeldmentRibPads)arecomprised of1)aonetimephysicalmeasurementtodeterminethedifferentialheightofthetopofplenumrib padstoreactorvesselseatingsurface,withtheplenuminthereactorvesseland2)subsequentvisual (VT3)examinationonthe10yearISIinterval.

Thisinspectionisintendedtoidentifylossofmaterialandassociatedlossofcoreclampingpreload (wear).

2.1.2 IndustryOPEX MRP227AinspectionreportsfromOconee1,2,3andArkansasNuclearOne1werereviewedfor significantdiscoveries.Noservicerelateddegradationorrelevantindicationswerenotedduringthe MRP227AinspectionsofthePlenumWearPads(WeldmentRibPads)atanyofthesimilarunits.

2.1.3 TMIInspectionResults CoreclampingmeasurementswereobtainedatTMI1byAREVAin2010tosatisfytheMRP227A examinationrequirementsforaonetimephysicalmeasurementofthedifferentialheightoftopofthe plenumribpadstothereactorvesselseatingsurface.Thismeasurementwastakenwiththeplenum coverweldmentribpads,plenumcoversupportflange,andCSStopflangeinsidetheRV,butwiththe fuelassembliesremovedperSection4.3.1ofMRP227A.Theconclusionsofthecoreclamping summarydocumentarethattherewasnoevidenceofwearoccurringduringtheserviceperiodandthe measurementswereacceptable.Therefore,thecoreclampingmeasurementsatTMI1meettheone timephysicalmeasurementrequirementinMRP227A.(Reference4.3&4.4) 2.1.4 Conclusion

TMIMRP227AInspectionDeviation-T1R22 TechnicalEvaluation0402099302 Page3of11 Delayingthevisualinspection(VT3)ofthePlenumWearPads(WeldmentRibPads)byonecycleis acceptable.InspectionsatsimilarB&Wunitshavenotrevealedanyconcernswithmaterialcondition.

PreviousTMIinspectionsdidnotidentifyevidenceofwearoccurring.Therefore,therearenotechnical concernswithdelayingthevisualinspection.

2.2 PlenumCoverSupportFlange 2.2.1 NEI0308InspectionRequirements TheNEI0308inspectionrequirementforthePlenumCoverSupportFlangeisavisual(VT3) examinationonthe10yearISIinterval.

Thisinspectionisintendedtoidentifylossofmaterialandassociatedlossofcoreclampingpreload (wear).

2.2.2 IndustryOPEX MRP227AinspectionreportsfromOconee1,2,3andArkansasNuclearOne1werereviewedfor significantdiscoveries.Noservicerelateddegradationorrelevantindicationswerenotedduringthe MRP227AinspectionsofthePlenumCoverSupportFlangeatanyofthesimilarunits.

2.2.3 TMIInspectionResults VisualinspectionsofthePlenumCoverSupportFlangethatmeetthescopeofMRP227Ahavenot beenperformedpreviously.However,duringT1R22(2015),ASMESectionXIvisual(VT3)inspectionsof thePlenumCoverSupportFlangewereperformed.Theexamcovered360°oftheaccessiblesurfacesof thePlenumCoverSupportFlangeforwear(SectionXI).Therewerelimitationsduetothecavitywall configuration.Thebottomandtheinboardflangesurfaceswereexaminedinconjunctionwiththe ClampingSurfacesandthePlenumCoverandRibattachmentsexaminations.Noservicerelated degradationorrelevantindicationswerenotedduringthisinspection.(Reference4.5) 2.2.4 Conclusion Delayingthevisualinspection(VT3)ofthePlenumCoverSupportFlangebyonecycleisacceptable.

InspectionsatsimilarB&Wunitshavenotrevealedanyconcernswithmaterialcondition.PreviousTMI inspectionsdidnotidentifyanydegradation.

2.3 ControlRodGuideTube(CRGT)SpacerCastings 2.3.1 NEI0308InspectionRequirements TheNEI0308inspectionrequirementfortheCRGTSpacerCastingsisavisual(VT3)examinationof accessiblesurfacesateachofthefourscrewlocations(atevery90°)of100%oftheCRGTSpacer Castingsonthe10yearISIinterval.

TMIMRP227AInspectionDeviation-T1R22 TechnicalEvaluation0402099302 Page4of11 Thisinspectionisintendedtoidentifycracking(thermalembrittlement),includingthedetectionof fracturedspacersormissingscrews.

2.3.2 IndustryOPEX MRP227AinspectionreportsfromOconee1,2,3andArkansasNuclearOne1werereviewedfor significantdiscoveries.Noservicerelateddegradation,missingscrews,orrelevantindicationswere notedduringtheMRP227AinspectionsoftheCRGTSpacerCastingsatanyofthesimilarunits.

2.3.3 TMIInspectionResults VisualinspectionsoftheCRGTSpacerCastingsthatmeetthescopeofMRP227Ahavenotbeen performedpreviously.However,duringT1R22(2015),ASMESectionXIvisual(VT3)inspectionsofthe accessibleareasof69ControlRodGuideTubeAssemblieswereperformed.Theinspectionexamined theaccessibleareasofthecontrolrodguidestubesfromthetoplookingdown,aroundtheperiphery andthroughtheholesinthecylinder.Theinspectionidentifiedasmallflakeofforeignmaterialthatwas likelyintroducedduringrefuelingactivitiesandwaseasilyretrieved.(Reference4.16)Noother indicationswerenoted.(Reference4.5)

AREVAhasnotedthatissueswithControlRodinsertiontimesareapotentialindicatorofissueswiththe CRGTSpacerCastings.RecentControlRodinsertiontimingduringT1R21didnotindicateanyissues.

Therefore,itislesslikelyanissuewiththeCRGTSpacerCastingsexists.

2.3.4 Conclusion Delayingthevisualinspection(VT3)oftheCRGTSpacerCastingsbyonecycleisacceptable.Inspections atsimilarB&Wunitshavenotrevealedanyconcernswithmaterialcondition.PreviousTMIinspections didnotidentifyanydegradation.

2.4 CoreSupportShield(CSS)VentValveTop&BottomRetainingRings 2.4.1 NEI0308InspectionRequirements TheNEI0308inspectionrequirementfortheCSSVentValveTop&BottomRetainingRingsisavisual (VT3)examinationof100%ofaccessiblesurfacesduringthe10yearISIinterval.

Thisinspectionisintendedtoidentifycracking(thermalembrittlement),includingthedetectionof surfaceirregularities,suchasdamaged,fracturedmaterials,ormissingitems.

2.4.2 IndustryOPEX MRP227AinspectionreportsfromOconee1,2,3andArkansasNuclearOne1werereviewedfor significantdiscoveries.Nosignificantmaterialdegradationormissingitemswerediscoveredduringthe MRP227AinspectionsoftheCSSVentValveTop&BottomRetainingRingsatanyofthesimilarunits.

TMIMRP227AInspectionDeviation-T1R22 TechnicalEvaluation0402099302 Page5of11 ANO1identifiedsomerelevantindicationsontheoriginalandmodifiedlockingdevices.However,these indicationsweredeterminedtobeacceptableforcontinuedserviceandnotinterferewiththevent valvefunction.

2.4.3 TMIInspectionResults Ventvalvetestingandinspectionsarerequiredtobeperformedeachrefuelingoutage,perTechSpec 4.16.ThisrequirementisfulfilledbytheTMl1ReactorInternalsVentValveInspectionandExercise procedure.Theaccessibleareasoftheventvalvearetypicallyinspected,includingthelockingdevices.

Additionally,ventvalveoperationistestedthroughmanualactuation.

Recentinspectionsin2015didnotidentifyanyissueswithventvalveretainingrings.However,vent valveRCV144Awasreplacedduetoexternalimpactdamagetothepressureplateandlockingdevice.

VentvalvelockingdeviceswereexaminedforallventvalvesTechSpecrequirementsandTMIspecific commitmenttoMRP227AandPWROGinterimguidance.RCV144A(adjacenttothehotleg)was foundwithafailedlockingdeviceinwhichthespringretainerhadwornthroughthelockingcup.The lockingcupandspringretainerwerefunctionalasfound,butanassessmentofoperabilityoverthenext cyclecouldnotbemade.Thedamagemechanismwasflowinducedwearandwasbelievedtooriginate in1R18afterexternalimpactfromthePlenum.Thisventvalvewasoftheoriginaldesign.(Reference 4.6)

Remainingventvalvesexhibitedimpactdamageonthelockingdevicesfromtheinstallationofthe Plenum.Thisimpactdamagedidnotaffecttheabilityofthelockingdevicestoperformtheirdesign functions 2.4.4 Conclusion Delayingthevisualinspection(VT3)oftheCSSVentValveTop&BottomRetainingRingsbyonecycleis acceptable.InspectionsatsimilarB&Wunitshavenotrevealedanyconcernswithmaterialconditionof theventvalveretainingrings.PreviousTMIinspectionsdidnotidentifyevidenceofservicerelated crackingormissingitems.FunctionaltestingwillcontinuetobeperformedinT1R22.Therefore,there arenotechnicalconcernswithdelayingthevisualinspection.

2.5 BaffletoFormerBolts 2.5.1 NEI0308InspectionRequirements TheNEI0308inspectionrequirementfortheBaffletoFormerBoltsisabaselinevolumetric examination(UT)of100%ofaccessibleboltsnolaterthantworefuelingoutagesfromthebeginningof thelicenserenewalperiod.

Thisinspectionisintendedtoidentifycracking(IrradiationAssistedStressCorrosionCracking,Irradiation Embrittlement,andOverload).

TMIMRP227AInspectionDeviation-T1R22 TechnicalEvaluation0402099302 Page6of11 2.5.2 IndustryOPEX BaffletoFormerBoltUTexaminationshavebeenofconcernwiththerecentinspectionresultsfrom severalWestinghouse4loopdownflowunits.AREVAissuedaCustomerServiceBulletin(CSB)1602in responsetoWestinghouseNSAL161.CSB1602concludedthattheOEislimited,atthistime,toa subsetofdesignandoperatingconditionsfortheWestinghouse4loopdownflowoperatingunitsand notanimmediaterisktothesafetyandoperabilityoftheB&Wdesigned177FAunits.

Oconee1sharesasimilarboltdesignwithTMI1.MRP227Ainspectionreportswerereviewedfor significantdiscoveries.Noservicerelateddegradation,relevantindications,ormissing,nonfunctional, orremovedlockingdevicesorweldswerediscoveredduringtheOconee1MRP227Ainspections.

OtherB&Wunits(ANO1,Oconee2&3)haveadifferentboltdesignbutsimilaroperatingconditions.

TheseexamresultsprovidefurthersupportinginspectiondatathattheissueisnotaconcernforB&W units.

BasedupontheoperatingexperienceandconclusionsfromtheAREVACSB,thereislowriskfordelaying theexamatTMI.

2.5.3 TMIInspectionResults VisualinspectionsoftheBaffletoFormerBoltswereperformedinT1R21(2015).Theseinspectionsdid notidentifyanyservicerelatedmaterialdegradationissues.Althoughthescopeoftheseinspectionsdid notcovertheMRP227AscopeofUTinspections,novisualmaterialdegradationissueswerenoted.

(Reference4.5) 2.5.4 Conclusion Delayingthebaselinevolumetricexamination(UT)oftheBaffletoFormerBoltsbyonecycleis acceptable.UTinspectionsatsimilarB&Wunitshavenotrevealedanyconcernswithmaterialcondition.

PreviousvisualinspectionsatTMIdidnotidentifyanyservicerelateddegradationissues.Therefore, therearenotechnicalconcernswithdelayingtheUTinspectiononecycle.

2.6 LockingDevices,IncludingLockingWelds,ofBaffletoFormerBoltandInternalBaffletoBaffle Bolts 2.6.1 NEI0308InspectionRequirements TheNEI0308inspectionrequirementforlockingdevicesofbaffletoformerboltandinternalbaffleto baffleboltsisavisual(VT3)examinationof100%ofaccessiblebaffletoformerandinternalbaffleto baffleboltlockingdevicesduringthe10yearISIinterval.

Thisinspectionisintendedtoidentifycracking(IrradiationAssistedStressCorrosionCracking,Irradiation Embrittlement,andOverload),includingthedetectionofmissing,nonfunctional,orremovedlocking devicesorwelds.

TMIMRP227AInspectionDeviation-T1R22 TechnicalEvaluation0402099302 Page7of11 2.6.2 IndustryOPEX Oconee1sharesasimilarB&WReactorVesselInternaldesignwithTMI1.MRP227Ainspection reportswerereviewedforsignificantdiscoveries.Noservicerelateddegradation,relevantindications, ormissing,nonfunctional,orremovedlockingdevicesorweldswerediscoveredduringtheMRP227A inspectionsofthelockingdevicesatanyofthesimilarunits.

2.6.3 TMIInspectionResults VisualinspectionsofthebaffletoformerboltswereperformedinT1R21(2015).Althoughthescopeof theseinspectionsdidnotcoverthefullMRP227Ascope,noservicerelateddegradationissuesor missinglockingdeviceswerenoted.(Reference4.5) 2.6.4 Conclusion Delayingthevisualinspection(VT3)ofthelockingdevicesofbaffletoformerboltandinternalbaffle tobaffleboltsbyonecycleisacceptable.InspectionsatsimilarB&Wunitshavenotrevealedany concernswithmaterialcondition.PreviousTMIvisualinspectionsofthebaffletoformerboltsdidnot identifyevidenceofservicerelateddegradationissuesormissinglockingdevices.Therefore,thereare notechnicalconcernswithdelayingtheMRP227Avisualinspection.

2.7 Baffleplates 2.7.1 NEI0308InspectionRequirements TheNEI0308inspectionrequirementforthebaffleplatesisavisual(VT3)examinationof100%ofthe accessiblesurfaceswithinoneincharoundeachflowandboltholeduringthe10yearISIinterval.

Thisinspectionisintendedtoidentifycracking(irradiationembrittlement),includingthedetectionof readilydetectiblecrackinginthebaffleplate.

2.7.2 IndustryOPEX MRP227AinspectionreportsfromOconee1,2,3andArkansasNuclearOne1werereviewedfor significantdiscoveries.Noservicerelateddegradation,cracking,orrelevantindicationswerenoted duringtheMRP227Ainspectionsofthebaffleplatesatanyofthesimilarunits.

2.7.3 TMIInspectionResults Generalexaminationsofthebaffleplatesduringnormalrefuelingoutageshavenotidentifiedany materialdegradation.VisualinspectionsofthebaffleplatesthatmeetthescopeofMRP227Ahavenot beenperformedpreviously.DuringT1R21(2015),visual(VT3)inspectionoftheaccessibleareasofthe CoreBarrelAssemblyFormerPlateswasperformed.TherewaslimitedaccessduetoUpperCSAFlange andBafflePlates.Norelevantindicationsobserved.(Reference4.5)

TMIMRP227AInspectionDeviation-T1R22 TechnicalEvaluation0402099302 Page8of11 2.7.4 Conclusion Delayingthevisualinspection(VT3)ofthebaffleplatesbyonecycleisacceptable.Inspectionsatsimilar B&Wunitshavenotrevealedanyconcernswithmaterialcondition.PreviousTMIinspectionsdidnot identifyevidenceofservicerelateddegradation.Therefore,therearenotechnicalconcernswith delayingthevisualinspection.

2.8 IncoreMonitoringInstrumentation(IMI)GuideTubeSpiders 2.8.1 NEI0308InspectionRequirements TheNEI0308inspectionrequirementfortheIMIGuideTubeSpidersisavisual(VT3)examinationof 100%oftopsurfacesofthe52spidercastingsnolaterthantworefuelingoutagesfromthebeginningof thelicenserenewalperiod.

Thisinspectionisintendedtoidentifycracking(thermalembrittlement,irradiationembrittlement),

includingthedetectionoffracturedormissingspiderarms.

2.8.2 IndustryOPEX MRP227AinspectionreportsfromOconee1,2,3andArkansasNuclearOne1werereviewedfor significantdiscoveries.Noservicerelateddegradationorfracturedormissingspiderarmswerenoted duringtheMRP227AinspectionsoftheIMIGuideTubeSpidersatanyofthesimilarunits.

2.8.3 TMIInspectionResults VisualinspectionsoftheIMIGuideTubeSpidersthatmeetthescopeofMRP227Ahavenotbeen performedpreviously.

2.8.4 Conclusion Delayingthevisualinspection(VT3)oftheIMIGuideTubeSpidersbyonecycleisacceptable.

InspectionsatsimilarB&Wunitshavenotrevealedanyconcernswithmaterialcondition.Therefore, therearenotechnicalconcernswithdelayingthevisualinspection.

2.9 IncoreMonitoringInstrumentation(IMI)GuideTubeSpidertoLowerGridRibSectionWelds 2.9.1 NEI0308InspectionRequirements TheNEI0308inspectionrequirementfortheIMIGuideTubeSpidertoLowerGridRibSectionWeldsis avisual(VT3)examinationof100%ofspidercastingweldstotheadjacentlowergridribsectionno laterthantworefuelingoutagesfromthebeginningofthelicenserenewalperiod.

TMIMRP227AInspectionDeviation-T1R22 TechnicalEvaluation0402099302 Page9of11 Thisinspectionisintendedtoidentifycracking(irradiationembrittlement),includingseparationof spiderarmsfromthelowergridribsectionattheweld.

2.9.2 IndustryOPEX MRP227AinspectionreportsfromOconee1,2,3andArkansasNuclearOne1werereviewedfor significantdiscoveries.NosignificantmaterialdegradationwasnotedduringtheOconee1&2MRP 227Ainspections.

Oconee3identifiedtwolinearindications,onelocatedjustbelowtheverticalweldtoeinthebase materialofthelowergridandtheothercomingfromthetopofthecastingattheweldtoeandgoing downwardintothecastingmaterial.Thelinearindicationinthelowergridmaterialisinarelativelylow stressareaanddoesnotresembleIGSCC.

ANO1identifiedindicationsontheIMItubespidertolowergridribsectionweldswhichexceededthe criteriafortriggeringscopeExpansionperMRP227A.However,inreviewingtheresultswithANO,ANO consideredthedeterminationasconservative,andnorepairsorreplacementswereneededtoaddress anyoftheinspectionfindings.

TheexpansioncomponentsfortheIMItubespidertolowergridribsectionweldsarethelowergridfuel assemblysupportpaditems:pad,padtoribsectionwelds,AlloyX750dowel,capscrew,andtheir lockingwelds.ANO1examinedtheseitemsduringthelastrefuelingoutageaspartoftheASMESection XIBN3VT3visualexaminationsandnoindicationswerefound.

2.9.3 TMIInspectionResults VisualinspectionsoftheIMItubespidertolowergridribsectionweldsthatmeetthescopeofMRP 227Ahavenotbeenperformedpreviously.TMIcompletedtheASMESectionXIBN3examinationsin T1R21(2015)andnorelevantindicationswerefoundinthisarea.Therefore,thereisnoconcernforthe expansionitemifthePrimarycomponentisnotexaminedinT1R22.(Reference4.5) 2.9.4 Conclusion Delayingthevisualinspection(VT3)oftheIMItubespidertolowergridribsectionweldsbyonecycle isacceptable.InspectionsatsimilarB&Wunitshavenotrevealedanysignificantconcernswithmaterial condition.PreviousTMIinspectionsforASMESectionXIBN3examinationsdidnotidentifyany materialconditionissueswiththeexpansionitemsfortheprimarycomponent(i.e.thelowergridfuel assemblysupportpaditems).Therefore,therearenotechnicalconcernswithdelayingthevisual inspection.

3. Conclusion/Findings:

DelayingtheremainingMRP227Aneededexaminationsbyonerefuelingoutageisacceptable.There havebeennosignificantdiscoveriesfromsimilarB&WplantsthathaveperformedtheMRP227A

TMIMRP227AInspectionDeviation-T1R22 TechnicalEvaluation0402099302 Page10of11 inspections.BasedonindustryOperatingExperience,previousTMIinspections,andthedurationofthe delay(onecycle),therearenotechnicalconcernswithdelayingtheMRP227Aexaminations.

4.

References:

4.1 ANP2952,Rev.1;InspectionPlanfortheThreeMileIslandUnit1ReactorVesselInternals 4.2 AREVACustomerServiceBulletin1602;RelevanceofRecentBaffletoFormerBoltDegradation atWestinghousedesigned4LoopUnitsandItsImpactonB&Wdesigned177FARVInternals Operability 4.3 AREVADoc519129887000,ThreeMileIslandRVInternalsClampingTask 4.4 AREVADoc519199311000;PWROGPAMSC0835TechnicalJustificationfortheCoreClamping AreaVisualExamination 4.5 AREVADoc1809249614000;IVVI10YearISIandMRP227FinalReport(T1R21) 4.6 C2034392;ContingentReplacementRVInternalVentValve(T1R21) 4.7 CCAA309101,Rev.15;EngineeringTechnicalEvaluations 4.8 ERAA4003,Rev.4;MaterialsDegradationManagementProcess(MDMP)DeviationGuidance 4.9 MRP219,Rev.11;MaterialsReliabilityProgram:InspectionReport,2015(Oconee1,2,3) 4.10 MRP227A;MaterialsReliabilityProgram:PressurizedWaterReactorInternalsInspectionand EvaluationGuidelines,2011 4.11 NEI0308,Rev.3;GuidelinefortheManagementofMaterialIssues,February2017 4.12 NSAL161;WestinghouseNuclearSafetyAdvisoryLetter,BaffleFormerBolts 4.13 TableforReportingMRP227AInspectionResultsforB&WPlants;ArkansasNuclearOne-Unit 1,10/2/2016to11/16/2016 4.14 TMI1TechnicalSpecifications,Section4.16 4.15 02585279;ReactorVesselIVVHasDamage 4.16 02589021;T1R21FME:FlakeFoundonPlenum 4.17 NRCCorrespondenceML14297A411,StaffAssessmentoftheReactorVesselInternalsInspection Plan,December19,2014

TMIMRP227AInspectionDeviation-T1R22 TechnicalEvaluation0402099302 Page11of11

5. Approval:

PreparedBy:

RossShacklett (SeePassportforApproval)

Date:

CorporatePWRInternalsProgram OwnerReview:

Heather Malikowski (SeePassportforApproval)

Date:

IndependentReview:

RobertMarcello (SeePassportforApproval)

Date:

StationProgramManagerApproval:

MarkTorborg (SeePassportforApproval)

Date: