Author/Authors :
ArmandoC.Marino، نويسنده , , PabloC.Florido، نويسنده ,
Abstract :
ArgentineanAtuchaandEmbalseNPP,bothPHWRwithonlinerefuellingwithapproximately68,000fuelelements,irradiatedatstandardburnup,duringtherefuellingthefuelchangesthepowerclosetoamathematicalidealstep.Recently,Atuchacorestartedtooperatefullywithslightlyenricheduranium(SEU,0.85%ofenrichment)increasingtheburnupmorethan50%,thusproducingthefirstirradiateddatabaseofonlinerefuellingatextendedburnupusingcommercialfuelelements.
TheBACOcodewasextensivelyusedinArgentinatomodelthephysicalbehaviourofbothfuelelements,naturalUO2andSEU.ThehoopstresspredictedbyBACOattheinnersurfaceofthecladdingcorrelateverywellwiththefuelfailureprobabilityoverawiderangeoftests.Usingthedatabaseofpresentcommercialextendedburnupfuel,asimplecriterionoffuelfailuretakingintoaccountprobabilisticandparametricanalysiscorrelateverywellwiththepresentirradiationexperience,inagreementwithpreviousBACOexperiencewhichconfirmtheexpectedbehaviourandtheSEUfuelelementdesign.
