ExperimentalinterpretationandcodevalidationbasedonthePHEBUS-FPprogramme:LessonslearntfromtheanalysisofthecontainmentscenarioofFPT1andFPT2testsOriginalResearchArticle

Thephenomenologicalscenarioofasevereaccidentisextremelycomplex.Itssimulationrequiresspecificmodelsofphenomenaofdifferentnature(i.e.,materialsbehavior,thermal–hydraulics,aerosols,etc.)andtheiradequatecouplinginsafetycomputercodes.Therefore,anexhaustiveandextensivevalidationagainstrepresentativedatabasesismandatory.PHEBUS-FPprojectis,beyondanydoubt,oneofthemorevaluabledatasourcesforthispurpose. ThemainlessonslearntfromthecontainmentsimulationsofFPT1andFPT2testsweresummarized.Severalsafetycomputercodes:CONTAIN2.0,MELCOR1.8.5andASTEC1.1havebeenused.Thisdiversityhasalloweda“user-independent”crosscomparisonofcodesanddata.Overall,codesestimateshavereproducedproperlyexperimentaltrendsandnovariablehasshownmajordiscrepancies.Bymeansofparametricstudies,ithasbeendemonstratedthattheminordiscrepanciesfounddidnotcomefromthehypothesesandapproximationsadopted.Inaddition,theanalysesofcodesresultshaveassistedintheinterpretationofexperimentsbyshowingpotentialexperimentaluncertainties(i.e.,steaminjectioninFPT1)orevenbycreditingdatafromaspecificmeasurementtechniqueoverotherdatasources(i.e.,samplingsoverγ-specinFPT1).