ThesevereaccidentmitigationconceptandthedesignmeasuresforcoremeltretentionoftheEuropeanPressurizedReactor(EPR)OriginalResearchArticle

Forthemitigationofsevereaccidents,theEuropeanPressurizedWaterReactor(EPR)hasadoptedandimprovedthedefense-in-depthapproachesofitspredecessors,theFrench“N4”andtheGerman“Konvoi”plants.Beyondthecorrespondingevolutionarychanges,theEPRincludesanew,4thlevelofdefense-in-depththatisaimedatlimitingtheconsequencesofapostulatedsevereaccidentwithcoremelting.Itinvolvesastrengtheningoftheconfinementfunctionandtheavoidanceoflargeearlyreleases.Thelatterrequiresthepreventionofscenariosandeventsthatcanresultinhighloadsonthecontainment,e.g.,afailureoftheReactorPressureVessel(RPV)athighinternalpressure.Thisisachievedbydedicateddesignmeasures.