Title of article
Risk-informeddesignguidanceforfuturereactorsystemsOriginalResearchArticle
Author/Authors
MichaelJ.Delaney، نويسنده , , GeorgeE.Apostolakis، نويسنده , , MichaelJ.Driscoll، نويسنده ,
Issue Information
روزنامه با شماره پیاپی سال 2005
Pages
20
From page
1537
To page
1556
Abstract
Futurereactordesignsfaceanuncertainregulatoryenvironment.ItisanticipatedthattherewillbesomelevelofprobabilisticinsightsintheregulationsandsupportingregulatorydocumentsforGeneration-IVnuclearreactors.Centraltocurrentregulationsaredesignbasisaccidents(DBAs)andthegeneraldesigncriteria(GDC),whichwereestablishedbeforeprobabilisticriskassessments(PRAs)weredeveloped.Theseregulationsimplementastructuralistapproachtosafetythroughtraditionaldefenseindepthandlargesafetymargins.Inarationalistapproachtosafety,accidentfrequenciesarequantifiedandprotectivemeasuresareintroducedtomakethesefrequenciesacceptablylow.Bothapproacheshaveadvantagesanddisadvantagesandfuturereactordesignandlicensingprocesseswillhavetoimplementahybridapproach.Thispaperpresentsaniterativefour-steprisk-informedmethodologytoguidethedesignoffuture-reactorsystemsusingagas-cooledfastreactoremergencycorecoolingsystemasanexample.Thismethodologyhelpsdesignerstoanalyzealternativedesignsunderpotentialrisk-informedregulationsandtoanticipatedesignjustificationstheregulatormayrequireduringthelicensingprocess.Theanalysisdemonstratedtheimportanceofcommon-causefailuresandtheneedforguidanceonhowtochangethequantitativeimpactofthesepotentialfailuresonthefrequencyofaccidentsequencesasthedesignchanges.Deliberationisanimportantpartofthefour-stepmethodologybecauseitsupplementsthequantitativeresultsbyallowingtheinclusioninthedesignchoiceofelementssuchasbestdesignpracticesandeaseofonlinemaintenance,whichusuallycannotbequantified.Thecasestudyshowedthat,insomeinstances,thestructuralistandtherationalistapproacheswereinconsistent.Inparticular,GDC35treatsthedouble-endedbreakofthelargestpipeinthereactorcoolantsystemwithconcurrentlossofoffsitepowerandasinglefailureinthemostcriticalplaceastheDBAfortheemergencycorecoolingsystem.Seventeenoutofthe45variationsthatweconsideredviolatedthisDBA,butpassedtheprobabilisticscreeningcriteria.UsingPRAtechniques,wefoundthatthemeanfrequencyofthisaccidentwasverylow,thusindicatingthatdeterministiccriteriasuchasGDC35mustbereassessedinthelightofriskinsights.
Journal title
Nuclear Engineering and Design Eslah
Serial Year
2005
Journal title
Nuclear Engineering and Design Eslah
Record number
894941
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