MethodsforassessingNPPcontainmentpressureboundaryintegrityOriginalResearchArticle

Researchisbeingconductedtoaddressagingofthecontainmentpressureboundaryinlight-waterreactorplants.Objectivesofthisresearchareto(1)understandthesignificantfactorsrelatingtocorrosionoccurrence,efficacyofinspection,andstructuralcapacityreductionofsteelcontainmentsandoflinersofconcretecontainments;(2)providetheU.S.NuclearRegulatoryCommission(USNRC)reviewersameansofestablishingcurrentstructuralcapacitymarginsorestimatingfutureresidualstructuralcapacitymarginsforsteelcontainmentsandconcretecontainmentsaslimitedbylinerintegrity;and(3)providerecommendations,asappropriate,oninformationtoberequestedoflicenseesforguidancethatcouldbeutilizedbyUSNRCreviewersinassessingtheseriousnessofreportedincidencesofcontainmentdegradation.Activitiesincludedevelopmentofadegradationassessmentmethodology;reviewsoftechniquesandmethodsforinspectionandrepairofcontainmentmetallicpressureboundaries;evaluationofcandidatetechniquesforinspectionofinaccessibleregionsofcontainmentmetallicpressureboundaries;establishmentofamethodologyforreliability-basedconditionassessmentsofsteelcontainmentsandliners;andfragilityassessmentsofsteelcontainmentswithlocalizedcorrosion.