ML18012A096
| ML18012A096 | |
| Person / Time | |
|---|---|
| Issue date: | 01/17/2018 |
| From: | David Rudland, Steve Ruffin, Simon Sheng, On Yee NRC/NRR/DMLR/MPHB |
| To: | |
| Rezai A, NRR-DMLR 415-1328 | |
| Shared Package | |
| ML18002A510 | List: |
| References | |
| CAC AR0852 | |
| Download: ML18012A096 (8) | |
Text
OnYee MaterialsEngineer NRR/DMLR/MVIB SteveRuffin BranchChief NRR/DMLR/MVIB Industry/NRCNonDestructiveExamination TechnicalInformationExchangeMeeting January17,2018 Rockville,Maryland,USA SimonC.F.Sheng SeniorMaterialsEngineer NRR/DMLR/MVIB DavidRudland SeniorTechnicalAdvisor NRR/DMLR ASMECodeCaseN702 StaffThoughtsonUpdatingConditioninRG1.147 and RevisedReviewProceduresforReliefRequests
Overview
- ASMECodeCaseN702
- ApplicationStatus
- StaffThoughtsonUpdatingConditioninRegulatory Guide(RG)1.147
- RevisedReviewProcedures-CurrentandFuture Applications
- CommentsonProbabilisticFractureMechanics(PFM)
Analysis
- Conclusion 2
ASMECodeCaseN702 Purpose Providesalternativerequirementstoinspectonly25%oftheBWRreactor pressurevessel(RPV)nozzles(i.e.,nozzleinnerradiusandnozzletoshellwelds) eachinserviceinspection(ISI)intervalinsteadoftheASMECoderequired inspectionof100%ofthenozzles AllowstheuseofVT1visualexaminationinlieuofvolumetricexaminationfor thenozzleinsideradiussection SupportingTechnicalDocuments BWRVIP108,TechnicalBasisfortheReductionofInspectionRequirementsfor theBWRNozzletoVesselShellWeldsandNozzleBlendRadii BWRVIP241,PFMEvaluationfortheBWRNozzletoVesselShellWeldsand NozzleBlendRadii BWRVIP241,AppendixA,forperiodofextendedoperation(PEO)
CorrespondingNRCsafetyevaluations(SEs) 3
ApplicationStatus
- AlmostallBWRshaveanapprovedapplicationsforuse ofCodeCaseN702duringa10yearISIintervalwithin theinitial40yearsofplantoperation
- *Onlyonelicenseehasneversubmittedan applicationforuseofCodeCaseN702
- In2017,therewere~8applicationsfora10yearISI intervalwithinthePEOand~3applicationsfora10 yearISIintervalwithintheinitial40yearsofplant operation 4
StaffThoughtsonUpdating ConditioninRG1.147
- Applicabilityevaluationforinitial40yearsofplant operationwouldonlybesubmittedonce
- ApplicabilityevaluationforthePEOshallbein accordancewithBWRVIP241,AppendixA,andwouldonly besubmittedonce
- PlantspecificPFManalysisisalwaysanoption
- Applicabilityevaluationforinitial40yearsofplant operationandthePEOcanbecombined andwouldonlybe submittedonce
- IfVT1isused,CodeCaseN6481,Alternative RequirementsforInnerRadiusExaminationofClass1 ReactorVesselNozzles,withtheconditioninRG1.147, shallbefollowed 5
RevisedReviewProcedure CurrentandFutureApplications
- NRCevaluationoftherepeatapplicationswithininitial 40yearsofplantoperationwillbeexpedited
- Asingleapplicationcancovertheentireinitial40years ofplantoperation
- Applicationsthatcoverthelicenserenewalperiodcanbe fortheentirePEO
- Ifalicenseecannotdemonstratethatitsapplicationfor thePEOisinaccordancewithBWRVIP241,AppendixA, aplantspecificPFManalysiscanbeused
- Applicationsforinitial40yearsofplantoperationandthe PEOcanbecombined
- IfVT1isused,CodeCaseN6481,Alternative RequirementsforInnerRadiusExaminationofClass1 ReactorVesselNozzles,withtheconditioninRG1.147, shallbefollowed 6
CommentsonPFMAnalysis
- TheNRCSEapprovedBWRVIP108basedontheProbability offailure(PoF)valuesfromthegenericPFManalysisforthe mostappropriatesimulationcaseprovidedbyEPRI
- 80%ofthesimulatedcasesindicatethatnormal operationislimiting
- 1.19E7forLTOPand1.98E6forthenormaloperation-SeeSEonBWRVIP108
- PlantspecificPFManalysisshouldaddressbothLTOPand thenormaloperation,consistentwithBWRVIP108A
- RecentNRCPFManalysisonBranchTechnicalPosition53 study(ML16364A285)indicatedthat100°Fcooldown followingsaturationcurveforBWRsmaynotbe insignificant 7
Conclusion
- Revisedreviewproceduresfortherepeatapplications withininitial40yearsandapplicationsfortheentirePEO eliminatesunnecessaryNRCandindustryburden
- Revisedreviewprocedureswillmaintainanacceptable levelofqualityandsafetybecausethesubmitted informationwillbethesamefromoneISIintervaltothe nextaslongastheyarewithinthe40yearoperationor withinthePEO
- StaffthoughtsonupdatingconditioninRG1.147are consistentwiththerevisedreviewprocedures
- Appropriateresults(i.e.,LTOPandnormalcondition)in plantspecificPFManalysiswillassistthereviewofCode CaseN702applications 8