Author/Authors :
X.Y.Wang، نويسنده , , Y.S.Ling، نويسنده , , Z.Q.Shi، نويسنده ,
Abstract :
Anewfinitecloudmethod(5/μmethod)forcalculatingexternalexposuredoseinanuclearemergencyispresentedinthispaper.Themethodcalculatesexternalexposuredoseoveraspeciallyconstructedthree-dimensionalcolumnedspace,whoseundersidecenteristhelocationofthereceptorandundersideradiusandheightarebothfivetimesmeanfreepathofagamma-photon.Then,thespaceisdividedintomanygridcellsforintegraltocalculateexternalexposuredose(ordoserate).Thecalculationvaluesofairexternalexposuredoserateconversionfactorsandair-absorbeddoserateconversionfactorsbythe5/μmethodareaccordantwiththevaluespresentedinrelatedreferences.Comparingwiththediscretepointapproximationmethod(DPA)[USNRC,TheMESORADDoseAssessmentModel.NUREG/CR-4000Vol.1,1986]andtheNomogrammethod[USNRC,NomogramforEvaluationofDosesfromFiniteNobleGasClouds,NUREG-0851,1983],whicharetwotraditionalfinitecloudmethodsforcalculatingexternalexposuredose,the5/μmethodhasadistinctadvantageofmorefastcalculationspeed,whichisveryimportantinanuclearemergency.Whatismore,the5/μmethodcanbeappliedtogetherwiththree-dimensionalatmosphericdispersionmodels.
