Monte Carlo minicell approach for a detailed MOX fuel-pin power profile analysis

The U.S. Department of Energy (DOE) is pursuing two options to dispose of surplus weapons-grade plutonium (WGPu). One option is to burn the WGPu in a mixed-oxide (MOX) fuel form in light water reactors (LWRs). A significant challenge is to demonstrate that the differences between the WG and reactor-grade (RG) MOX fuel are minimal, and therefore, the commercial MOX experience base is applicable. MOX fuel will be irradiated in the Advanced Test Reactor (ATR) to investigate this assertion. Detailed power distributions throughout the MOX pins are required to determine temperature distributions. The purpose of this work is to develop a new Monte Carlo procedure for accurately determining power distributions in fuel pins located in the ATR reflector. Conventional LWR methods are not appropriate because of the unique ATR geometry