EvaluationofirradiationdamageeffectbyapplyingelectricpropertiesbasedtechniquesOriginalResearchArticle

Themostimportanteffectofthedegradationbyradiationisthedecreaseintheductilityofthepressurevesselofthereactor(RPV)ferriticsteels.ThemainwaytodeterminethemechanicalbehaviouroftheRPVsteelsistensileandimpacttests,fromwhichtheductiletobrittletransitiontemperature(DBTT)anditsincreaseduetoneutronirradiationcanbecalculated.ThesetestsaredestructiveandregularlyappliedtosurveillancespecimenstoassesstheintegrityofRPV.Thepossibilityofapplyingvalidatednon-destructiveageingmonitoringtechniqueswouldhoweverfacilitatethesurveillanceofthematerialsthatformthereactorvessel. TheJRC-IEhasdevelopedtwodevices,focusedonthemeasurementoftheelectricalpropertiestoassessnon-destructivelytheembrittlementstateofmaterials.Thefirsttechnique,calledSeebeckandThomsonEffectsonAgedMaterial(STEAM),isbasedonthemeasurementoftheSeebeckcoefficient,characteristicofthematerialandrelatedtothemicrostructuralchangesinducedbyirradiationembrittlement.Withthesameaimthesecondtechnique,namedResistivityEffectsonAgedMaterial(REAM),measuresinsteadtheresistivityofthematerial. Thepurposeofthisresearchistocorrelatetheresultsoftheimpacttests,STEAMandREAMmeasurementswiththechangeinthemechanicalpropertiesduetoneutronirradiation.Theseresultswillmakepossibletheimprovementofsuchtechniquesbasedonthemeasurementofmaterialelectricalpropertiesfortheirapplicationtotheirradiationembrittlementassessment.