3-D MONTE CARLO AND DISCRETE ORDINATES VOID COEFFICIENT ANALYSIS FOR THE LOS ALAMOS NATIONAL LABORATORY OMEGA WEST REACTOR USING MCNP AND THREEDANT

摘要

Three-dimensdioanl Monte Carlo and discrete ordinates computational modeling techniques have been used to characterizxe void coefficient behavior for three experimental channesl and several fuel assemblies in the Los Alamos Omega West nuclear reactor using MCNP and THREEDANT. Good agreement is observed in void coefficient behavior predicted by MCNP and THREEDANT. The experimental-channel gross-voiding calculations predict the existence of positve void coefficients due to overmoderation conditions. The fuel assemblies exhibit, for the most part, negative void coefficients, althoughu the possibility of localized small positivke void coefficients for one of the five assemblies analyzed is indicated.