ML13354B706
| ML13354B706 | |
| Person / Time | |
|---|---|
| Site: | Dresden  |
| Issue date: | 01/15/2014 |
| From: | European Commission |
| To: | Office of Nuclear Regulatory Research |
| Kirk M | |
| Shared Package | |
| ML13354B690 | List: |
| References | |
| Download: ML13354B706 (2) | |
Text
FinalInternationalWorkshop,Dresden,1516Jan2014 Sessionon:MaterialsAssessmentandSurveillanceGuidelines
CurrentPracticeandFuturePossibilitiesforSurveillance ProgramDesignandEmbrittlementTrending MarkKirk1(UnitedStatesNuclearRegulatoryCommission),mark.kirk@nrc.gov
Introduction Thispaperaddressestwotopics.Firsttherequirementsofsurveillanceprogramsthattrackthe irradiationembrittlementofnuclearreactorpressurevessel(RPV)steels,andhowthese requirementshaveevolvedovertime,isaddressed.Secondtheembrittlementtrendcurves (ETCs)thataredevelopedasmathematicalrepresentationsofdatacollectedfromthese programs(andothersources)arediscussed,includingadiscussionofrecentactivitieswithinthe AmericanSocietyforTestingandMaterials(ASTM)dedicatedtothistopic.
SurveillanceProgramDesign Theearliestguidelinesconcerningasurveillanceprogramtotracktheirradiationembrittlement ofnuclearRPVsteelswerepublishedin1961asASTMStandardPracticeE185.Thispractice, whichhasevolvedthroughmultiplerevisionstoitscurrentversion(E18510),includes recommendationsinfourareas:whattypesofspecimensshouldbetested,whatmaterialsfrom theRPVshouldbemonitored,howtheradiationandenvironmentalconditionstowhichthese materialsaresubjectedshouldbeestablished(especiallywithrespecttohowtheconditionsof thesurveillancespecimensrelatetotheconditionsintheRPVwall),andalsorecommendations onhowsamplingistobeperformed(including,forexample,thecapsulepullschedule,the locationintheweld,plate,orforgingfromwhichmechanicaltestsamplesshouldberemoved, etc.).Earlyrecommendationsreliedonjudgementduetothethennascentstateofcommercial generationofelectricitybynuclearmeans.Inthispresentationanearlyevaluationof surveillancepracticeandrequirementsintheUnitedStatesisreviewedtoprovideaperspective onthebasisofsomerequirementsthatremaintothisday.Additionally,theevolutionofthese requirementsistracked(seeFigure1).Commentaryisalsoprovidedoncurrentinternational practices,andonsomepossibilitiesforfurtherrefinementofsurveillancerequirementsinthe future.
EmbrittlementTrendCurves(ETCs)
Beginninginthe1970sETCsweredevelopedfromthesurveillancedatageneratedbyE185(and thelike)monitoringprograms.ETCsprovidemathematicalmodelsthatexpressthejointeffects ofexposureconditionsandsteelcompositiononthechangeinmechanicalproperties (predominantlyCharpytransitiontemperatureshift(T41J),butalsoCharpyuppershelfenergy drop(USE)and,morerecently,fracturetoughnesstransitiontemperatureshift(To))causedby neutronirradiation.Figure2illustratestheconsiderableactivityduringthelastdecadeinthe developmentand,insomecases,codificationofnewT41JETCs.Thispresentationincludesa discussionofongoingactivitieswithinASTMSubcommitteeE10.02ontheBehaviourandUseof NuclearStructuralMaterialstostatisticallyevaluatetheseETCswithrespecttoavailable 1Theopinionsexpressedherearethoseoftheauthoralone.Theydonotrepresentanofficialpositionofthe UnitedStatesNuclearRegulatoryCommission.
FinalInternationalWorkshop,Dresden,1516Jan2014 Sessionon:MaterialsAssessmentandSurveillanceGuidelines
surveillancedatafromcommercialpowerreactors.Theaimofthisevaluationistoprovidea recommendationonapotentialrevisiontotheETCappearinginASTMStandardGuideE900, PredictingRadiationInducedTransitionTemperatureShiftinReactorVesselMaterials.
Acknowledgements Theauthorispleasedtoacknowledgethefollowingindividualsfortheirhelpinproviding backgroundmaterial,andfortheirmanyusefuldiscussionsthathaveinformedthispaper:
HieronymusHein,ClaudeBenhamou,andJohannesMay(AREVA),PatrickTodeschini(EDF),
RachidChaouadi(SCKCEN),RobertGérard(Tractebel),NaokiSoneda(CRIEPI),BrianHall (Westinghouse),andTimHardinandBobCarter(EPRI).
Figure1: EvolutionofthevariousrequirementsofASTMStandardPracticeE185,DesignofSurveillancePrograms forLightWaterModeratedNuclearPowerReactorVessels,fromitsfirstpublicationin1961untilthe currentday.VerticaldashedlinesindicatedatesofE185revision.
Figure2: Timelinegivingtheadoptionand/orpublicationdatesofvariousT41JETCsthathavebeenadoptedby variouscountries,bycodesandstandardsorganizations,orappearinginthetechnicalliterature.(n.b.,
ThislistisanincompleterepresentationofthetotalityofETCs;itisprovidedtoillustratetheincreased ETCdevelopmentactivityinthelastdecade).
1960 1970 1980 1990 2000 2010 Specimens Charpy Tensile Toughness forlowUSE 8forTo 8
15(u)8(i) 15(u)12(i) 15(u)15(i) 18(u)12(i) 6(u)3(i) 4(u)3(i) 4(u)2(i)
Processing Materials samethermal&stressreliefhistoryasRPV Chemistry chemicalanalysisrequired CMMs Req Matls desirable optional limitingbase&weld,+HAZ limitingbase&weld B:MAX[RTNDT(u)]
W: representative HAZ WallLF desirable Irrad.Cond.
Location Sameasmatl.accepttests Sampling Temp
>1017 Accel Cap Therm Cap Temperaturemonitoredwitheutecticalloys Fluenceminforsurveillanceconsideration damagemay bereducedor accelerated duplicateRPVas closeaspossible 3
5 3
1.55
>Wall
>Wall
>Wall PullSched Reserve Integrated Integratedprogramsmaybepossible asmoredatabecomesavailable 6capsules uncut Archivestockfor2capsules 1/4tforbase,awayfromrootforweld 3
3, 1
@DL 23(reqd.)12(standby):dependsonT41J 24(R)1(S)
=f(T41J) 2capsules 1970 1980 1990 2000 2010 2020 (FIM/FIS)
(edf)
(FFI)
ETCCitation,Country,orOrganization Debarberis Chaouadi(RADAMO)
Erickson(Fit6)
Kirk(WRC(5))
ASTM(E90002)
France(asnoted)
Japan(JEAC4201)
USA(Reg.Guide1.99)