ML18142A468
| ML18142A468 | |
| Person / Time | |
|---|---|
| Issue date: | 05/23/2018 |
| From: | NRC/RES/DE |
| To: | |
| Rezai A, NRR-DMLR 415-1328 | |
| References | |
| Download: ML18142A468 (14) | |
Text
Overview of Component Integrity Research Activities Industry/NRC Materials Programs Technical Information Exchange 1
1 May23,2018 ComponentIntegrityBranch DivisionofEngineering OfficeofNuclearRegulatoryResearch
Research Areas
- PointsofContact
- RajIyengar,BranchChief,ComponentIntegrityBranch
- RobertTregoning,SeniorLevelAdvisor
- ResearchAreas
- ReactorPressureVesselIntegrity-MarkKirk
- PipingIntegrity PatrickRaynaud/SaraLyons
- ProbabilisticFractureMechanics-PatrickRaynaud/MattHomiack
- NondestructiveExamination-CarolNove
- AdvancedNonlightWaterReactors(ANLWR)- RajIyengar/Matt Gordon/SaraLyons
- ASMESectionXICoordination&50.55aRegulatoryGuide Rulemaking-MichaelBenson/BruceLin 2
2
RPV Integrity
- Overview
- Objective:
- ConfirmthecontinuedoperatingintegrityoftheRPV(includingtheSLRperiod)
- Assesstheaccuracyofformulaethatpredictfutureembrittlementstatesforvessel materials
- Driver:UserneedfromNRR;AssistancerequestfromNRO;RARfromNRRfortraining; SupportofRGGIBinperiodicRGreviews(e.g.,RG1.99)
- Collaboration:JAEA,JNRA
- Ongoingactivities
- RPVEmbrittlement
- AssessmentofshallowflaweffectsonRPVintegrity
- Predictionoffluencebeyondthebeltline
- REAPmaintenanceandadditionofnewsurveillancedata
- Codes&Standards:ASME SectionXI;ASTM
- FinalizationofPTSregulatoryguide(RG1.230)and technicalbasisdocument(NUREG2163) 3 3
08/15/2017 RPVIntegritylRESFOBrief 4
Accomplishment Highlight:
Late Blooming Phases PossibleConcern:Possiblerapid embrittlementinlowcoppersteelswith highnickel&manganese.Mechanismnot accountedforbyUSNRCpredictions.
RESReview:Comprehensiveliterature review&surveillancedataassessment demonstrateLBPsarenot ofconcernfor USRPVs.
LevelofNi>1%postulatedforLBPoccurrence Steelalloys/conditionsofpossibleconcern largelyabsentfromUSAfleet Evidenceofdelayedacceleratedembrittlement islacking CurrentStatus:Ongoingresearch(DOE, intl.)tobetterunderstandLBPs.Newdata suggestsnosuddenlateembrittlement andmuchsmallerTvaluesforUSA steels.
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RPV Integrity Accomplishments and Path Forward
- Accomplishments
- TLRonRPVfluenceevaluationmethodologyforbeyondthe activecoreregion
- IndependentreviewofNuScalePowerPressureand TemperatureLimits(PTL)MethodologyreportforNRO
- PathForward
- SupportNROforNuScale applicationreview
- Continuecodesandstandardssupport(ASTME10;ASMECC N830revision) 5 5
Piping Integrity
- Overview
- Objective:Develop/Enhanceanalyticalmethodsandtoolstoassess structuralintegrityofreactorpipingsystems
- Driver:NRRUserNeedRequest
- Collaboration:EPRI,NEA/CSNI
- Ongoingactivities
- Developmentofmodelingguidelinesforassessmentofweldresidual stress(WRS)effectsinassessmentofcomponentintegrity
- Assessmentofresearchandindustryexperienceinpeeningofreactor components
- ParticipationinASMEBoilerandPressureVesselCode,SectionXI
- CoordinationofASMEBPVCodeCaseRegulatoryGuidesto incorporatebyreferenceinto10CFR50.55a
- EvaluationofExtendedFiniteElementMethod(xFEM)forapplicability incrackgrowth(PWSCC)analyses 6
7 OngoingActivity:
ApplyingxFEM TechniquestoPWSCCGrowth ApplicationofExtendedFiniteElementMethod(xFEM)topredictPWSCC crackgrowthin3Dcomponentgeometries.
ConventionalFEM:
- Usesidealizedcrackshapeandgrowthmodel(semielliptical)
- Assumesplanar(2D)crackgrowth
- Uses2DWRSprofileforcrackgrowthwhichispathdependentanduserdefined xFEM:
- Meshindependentanalysisofflaws
- SIFcalculationofmultiplecracksshapeswithoutmajorchangestomodel
- 3Dcrackgrowthwithoutremeshing ParticipationininternationaleffortonbenchmarkingofxFEM capabilities.
(OECDCSNI)
Piping Integrity Accomplishments and Path Forward
- Accomplishments
- DraftNUREGonWRSvalidation
- SectionXIStandardsCommitteeandExecutiveCommittee participation
- IssueddraftRegulatoryGuidesforASMECodeCases,20092013and 2015editionstoincorporatebyreferenceinto10CFR50.55a
- PathForward
- IssuefinalreportsonWRSvalidation
- DevelopandimplementresearchplanforvalidationxFEMAanalysis forPWSCCpredictions
- ContinueASMESectionXIengagement
- PreparedraftRegulatoryGuidesforASMECodeCasesfor2017 EditionoftheBoilerandPressureVesselCode 8
8
Probabilistic Component Integrity
- Overview
- Objective:Developprobabilisticmethodstoensure structuralintegrityofpipingsystems
- Driver:NRRUserNeedRequest
- Collaboration:EPRI,JNRA,JAEA,SSM,CNSC
- Ongoingactivities
- SupportNRRintheacceptanceandapplicationofxLPRv2
- DevelopmentofProbabilisticFractureMechanics RegulatoryGuide
- ContinueeffortonV&VofFAVORcode,maintenance, applications,development,andmodernization 9
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Probabilistic Component Integrity Accomplishments and Path Forward
- Accomplishments
- xLPRverificationandvalidationtesting
- xLPRcodetheoryandhandsontrainingprovidedtoNRCstaff
- xLPRPWSCCinitiationmodelparameterdevelopment,confirmatory analyses,andvalidation
- CompleteddraftreportonIncreasingConfidenceinPFMAnalyses
- InitiatedworkonFAVORV&V,maintenance,andapplications
- PathForward
- SupportNRRregulatoryacceptabilityreviewforxLPR
- CompleteeffortstoensurepublicreleaseofxLPR
- InitiatestudiesonleakbeforebreakapplicationswithxLPR
- DevelopPFMDraftRegulatoryGuide,withNUREGtechnicalbasis documentandPFMpilotstudiestotestguidance
- BringFAVORuptomodernstandards,adaptFAVOR tosolveevolvingreactorpressurevesselissues 10 10
- Overview
- Objective:EvaluateeffectivenessandreliabilityofNDEtechniques
- Driver:NRRUserNeedRequest
- Collaboration:EPRI,DOE,International
- Ongoingactivities
- CompletionofcomprehensivesummaryofNDEresearchonCASSand assessmentofstateoftheartininspectingweldsinCASSmaterials
- AssessmentofindustrysCASSroundrobin(rigorous,statistically based)
- Providetechnicalbasisforconducting,interpreting,andapplyingthe resultsofultrasonictesting(UT)Modeling
- Assesstheeffectsofincompleteexaminationcoverage
- AssessmentofhumanfactorsissuesinNDE
- Supportcodes&standardsactivities(ASME-SectionXI)
- Assessmentofinspectionsystemsforstoragecasks 11 11
ANLWR Materials and Component Integrity Overview
- Objective:Assesstheperformanceneedsandissuesforstructuralmaterialstobe usedinadvancednonLWRs(ANLWRs);Supportthedevelopmentofaregulatory frameworkformaterialsrelatedissuesforANLWRs
- Driver:NRCVisionandStrategyonANLWRs
- Strategy2:Acquire/developsufficientcomputercodesandtoolstoperformnonLWR regulatoryreviews
- Strategy4:FacilitateindustrycodesandstandardsneededtosupportthenonLWRlife cycle Ongoingactivities
- Identificationofregulatorygapsforsodiumfastreactorsandmoltensaltreactors, buildingonthepasteffortsforhightemperaturegasreactors
- Assessmentofmaterials/componentintegrityissuesformoltensaltreactors(MSR)
- Operationalexperiencecompendiaformaterials/componentintegrityissuesfor sodiumfastreactors(SFR)andhightemperaturegasreactors(HTGR)
- ParticipationinASMECodesandStandardsSectionsIIIandXIactivities 12 12
ANLWR Materials Accomplishments Technical gap assessment for materials/component integrity for molten salt reactors - ORNL
Draft report summary:
Limited high-temperature creep data at the highest possible core outlet temperatures Limited data on salt purity effects on coolant compatibility and performance Limited data and mechanistic understanding on irradiation degradation effects Operational experience compendia for sodium fast reactors (SFRs) and high-temperature gas reactors (HTGR) - EWC-Commercial Over 100 OpE sources have been identified and reviewed for SFRs
[Phenix, SuperPhenix, FFTF, EBR-II] and HTGRs [Fort St Vrain, Peach Bottom, AVR and THTR-300]
Weld design and quality are critical for SFRs Thermal fatigue is much more significant in SFRs than LWRs Design flaws seem to dominate HTGRs, resulting in unexpectedly high temperatures, moisture and oxygen ingress, and trapped pebbles Separate bilateral engagements with Office of Nuclear Regulation, UK; IRSN-France; and JAEA and JNRZ - Japan 13 13
ANLWR Materials Accomplishments and Path Forward Supportknowledgeanddataenhancementofenvironmental effectsonreactorcomponents(internals,piping,welds,coatings) athightemperatures.(corrosion,radiationeffects)
Develop/Enhancecomputationalcodesforcomponentintegrity applicabletoANLWRs Exploreopportunitiestoobtaininformation,data,andassessment toolsthroughdomesticandinternationalcollaboration Conductresearchactivitiestodeveloptechnicalbasestoresolve majormaterialsrelatedissues 14 14