TheEPRoverallapproachforsevereaccidentmitigationOriginalResearchArticle

TheEPRdesignincludesprovisionstocopewithsevereaccidentsincludingcoremeltsituations: - Situationsthatwouldleadtolargeearlyreleasessuchascontainmentbypass,highreactivityaccidents,high-pressurecoremeltorglobalhydrogendetonationhavetobeprevented. - Allothersituations,includinglowpressurecoremelthavetobemitigatedinsuchawaythatthecorrespondingradiologicalconsequenceswouldnecessitateonlyverylimitedprotectivecountermeasuresinarelativelysmallareaandforalimitedtimeforthepopulationlivingintheneighborhoodofthepowerplant.Thismeansthattherewouldbenoneedforpermanentrelocation,noneedforevacuationoutsidetheimmediatevicinityoftheplant,limitedshelteringandnolong-termrestrictionsinfoodconsumption. Toreachthisobjective,whichisoneoftheSafetyAuthorityʹsrequirements,theEPRreliesonaveryrobustcontainmentandonvariousdesignmeasuresintendedtowithstandextremeloadscausedbyalargerangeofinternaleventsandexternalhazards.ThedeterministicmethodisusedfortheEPRsafetydemonstration,supplementedbyprobabilisticmethodsandappropriateR&Dwork. Thispaperoutlinesthemajormitigatingdesignfeatures,summarizestheresultsoftheLevel2PSAandgivesthemainresultsoftheevaluationoftheradiologicalconsequencesofcoremeltontheenvironment.