Author/Authors :
C.K.Chao، نويسنده , , K.C.Yang، نويسنده , , C.C.Tseng، نويسنده ,
Abstract :
DelayedhydridecrackingintheZircaloyalloyhasbeenconsideredasapossibledegradationmechanismofspentnuclearfuelcladdingininterimdrystorage.Somerecentin-corefuelfailuresindicatedthatalongaxialcrackdevelopedinthecladdingwasasecondaryfailurebydelayedhydridecracking.TheaimofthisstudyistodefinetheeffectsofhydridereorientationonthefailureofZircaloycladding.Differenthydrideorientations,theamountofzirconiumhydrideandvariouscrackingtypes,allhavebeenconsideredfortheireffectsonthecrackgrowthandstabilityofthecladding,andhavebeenthoroughlydiscussedinthispaper.Afiniteelementcomputercode,ANSYS,hasbeenusedinconjunctionwiththestrainenergydensitytheory.Insummary,thecrackpropagationwillbeaggravatedifthehydrideorientationisshiftedfromthecircumferentialtotheradialdirection.Foralargercracklength,thezirconiumhydrideplaysanimportantroleinaffectingthecrackgrowthbecausethestrainenergydensityfactorincreasesasthehydrideapproachesthecracktip.Furthermore,whenthermaleffectsareconsidered,acompressivestressexistsattheinnersideofthecladding,whileatensilestressisfoundattheoutersideofcladding,thusresultingincrackpropagationfromtheoutersidetotheinnersideofthecladding.Thesefindingsareinaccordancewithotherexperimentalresultsinrelatedliterature.
