WWER-1000basemetalreferencesteelanditscharacterisationOriginalResearchArticle

Thesurveillanceprogrammesofwesternpowerreactorsinclude,inmanycases,standardreferencematerialsinadditiontoactualpressurevesselsteels.Thesearespecimenscutfromstandardsteelplates(HeavySectionSteelTechnology,JRQ,etc.)thataresimilarincompositionandheattreatmenttothebasematerialintherespectivereactorpressurevessels,andaresupposedtoserveasamonitorbycomparingtheradiationembrittlementoftheplant-specificmaterialtothereferencematerial,andtodetectanomaliesintheradiationenvironmentofthesurveillancecapsules. AcorrelationmonitormaterialfortheeasternWWER-1000(similarastheJRQforwesternreactors)isneededinordertodeterminethereliabilityofaccelerateddataforthevalidationofreactorpressurevesselsurveillancedata.Referencematerialsshouldbewellcharacterisedintermsofirradiationbehaviour(transitiontemperatureshift,non-destructivesignal,etc.).Themagnitudeofthesensitivitytoirradiationforthismaterialshouldbemeasurablefortheselectedexposures.InthissubjecttheIAEAislaunchinganewco-ordinatedresearchprogramme.Materialisalreadymanufactured,andtheJRC-IEhasbecomeitscustodian.Adetailedplanforcharacterisationofthereferencesteelissetup,includingirradiationconditions,post-irradiationtestingtechniquesandimplementationplan.Itisexpectedtheparticipationofseveralresearchinstitutesworldwideinaroundrobin,whichwillallowabettercomprehensionofWWER-1000steelʹsbehaviourandwillbeconsideredasabenchmarkingbetweendifferentlaboratories. TheJRC-InstituteforEnergyincollaborationwiththeRussianResearchCentre–KurchatovInstituteisperformingthe“asreceived”materialcharacterisationbybothdestructivemethodsandnon-destructivetechniques. Thenon-destructivetechniquesusedattheJRC-IEpremisesarenovelmethodsspeciallydevelopedfornon-destructiveassessmentoftheembrittlementstateofmaterials,astheSTEAMmethodandthemeasurementofmagneticproperties.TheSTEAMtechnique(SeebeckandThomsoneffectsonagedmaterial),isbasedonthemeasurementoftheSeebeckcoefficient.ThemagneticpropertiesevaluationisdonethroughBarkhausennoiseandpermeabilitymeasurements. Thispaperpresentsapreliminaryanalysisoftheresultsobtainedbyallinvolvinglaboratories.