ML17171A187

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NRC Staff Presentation - Baffle-Former Bolt Inspections at Indian Point
ML17171A187
Person / Time
Site: Indian Point  Entergy icon.png
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.NuclearRegulatoryCommissionJune14,2017 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.ofboltswithUTindicationsNo.ofboltsthatcouldnotbeUTexaminedTotalNo.ofPotentiallyDegradedBoltsNo.ofBoltsReplacedNo.BoltswithUTindicationsthatfaileduponremovalIndianPoint,Unit231.1Mar20163118214227278103IndianPoint,Unit328.6Mar201702563259270354Total number of baffle-former bolts at IP2/3 is 832/unit Conclusion*StructuralintegrityofbaffleformerassemblyismaintainedatIndianPointdueto-ReplacementofallboltswithUTindications-Replacementofadditionalnondegradedboltsfor"margin"and-Subsequentboltinspectionsateveryrefuelingoutage*NRCwillcontinuetoinspectboltexaminationresultsthroughthebaselineinspectionprogramatIndianPoint*Morebroadly,theNRCstaffwillcontinuetocloselymonitorthebaffleformerboltoperatingexperienceandupdatedinspectionguidancetoensurestructuralintegrity5