Author/Authors :
AliciaDenis، نويسنده , , AlejandroSoba، نويسنده ,
Abstract :
Thispapersummarizesthepresentstatusofacomputercodethatdescribessomeofthemainphenomenaoccurringinanuclearfuelrodthroughoutitslife.Temperaturedistribution,thermalexpansion,elasticandplasticstrains,creep,mechanicalinteractionbetweenpelletandcladding,fissiongasrelease,gasmixing,swelling,anddensificationaremodeled.Themodularstructureofthecodeallowsfortheincorporationofmodelstosimulatedifferentphenomenaandmaterialproperties.Collapsiblerodscanbealsosimulated.
Thecodeisbidimensional,assumescylindricalsymmetryfortherodandusesthefiniteelementmethodtointegratethedifferentialequations.Thestress–strainandheatconductionproblemsarenonlinearduetoplasticityandtothetemperaturedependenceofthethermalconductivity.Thefissiongasinventoryiscalculatedwithadiffusionmodel,assumingsphericalgrainsandusingaone-dimensionalfiniteelementscheme.Pressureincrease,swellinganddensificationarecoupledwiththestressfield.
GoodresultsareobtainedforthesimulationoftheirradiationtestsofthefirstargentineprototypesofMOXfuels,wherethebambooeffectisclearlyobserved,andoftheFUMEXseriesforthefuelcenterlinetemperature,theinsiderodpressureandthefractionalgasrelease.
