Evaluation of the effect of source geometry models on dose rates of waste packages

An evaluation of surface dose rates calculated by MCNP with three different source geometric representations for a waste package containing 21 pressurized water reactor (PWR) spent fuel assemblies is provided. The three geometric representations for the source region consist of a radial homogenization inside the waste package cavity, a homogenization of the assembly contents within the transverse dimensions of the assembly, and a detailed geometric model. Conservative dose rates are predicted by the source homogenized inside the cavity, while the detailed and the homogenized assembly models give comparative results. (author)