ML17171A187

NRC Staff Presentation - Baffle-Former Bolt Inspections at Indian Point

ML17171A187
Person / Time
Site:	Indian Point
Issue date:	06/14/2017
From:	Rudland D L Office of Nuclear Reactor Regulation
To:
Setzer T C
References
Download: ML17171A187 (5)

Text

BaffleFormerBoltInspectionsatIndianPointRemarksbyDavidL.RudlandChief,VesselandInternalsIntegrityBranchOfficeofNuclearReactorRegulationsU.S.NuclearRegulatoryCommission June14,2017 BaffleformerAssemblyStainless steel bolts are 5/8" dia. x ~2" long Direct coolant flow through the core and provides lateral support to the core during a seismic event or loss-of-coolant

accident (LOCA).

2 BaffleBoltInspection

• MRP227Acoversinspectionofreactorinternals-MRPLetter2017011dictatedinterimguidance*Ultrasonicinspectiontechnique

-Oneprobeperbolt,severalsensorsandchannelsofdata-Qualifiedfordetectiononly-go/nogo*Techniqueappearsconservative

->50%ofboltsremovedretainedsomeloadcarryingcapacity3 RecentInspectionsatIndianPointPlantEFPY@DateofUTExamDateofUTExamNo.ofvisuallyfailedboltsNo.ofboltswithUTindications No.ofboltsthatcouldnotbeUTexaminedTotalNo.ofPotentiallyDegradedBoltsNo.ofBoltsReplacedNo.BoltswithUTindicationsthatfaileduponremovalIndianPoint,Unit231.1Mar20163118214227278103 IndianPoint,Unit328.6Mar20170256325927035 4Total number of baffle-former bolts at IP2/3 is 832/unit Conclusion

• StructuralintegrityofbaffleformerassemblyismaintainedatIndianPointdueto-ReplacementofallboltswithUTindications

-Replacementofadditionalnondegradedboltsfor"margin"and-Subsequentboltinspectionsateveryrefuelingoutage*NRCwillcontinuetoinspectboltexaminationresultsthroughthebaselineinspectionprogramatIndianPoint*Morebroadly,theNRCstaffwillcontinuetocloselymonitorthebaffleformerboltoperatingexperienceandupdatedinspectionguidancetoensurestructuralintegrity 5