Neutronics Studies of a Lead-Bismuth-Eutectic-Cooled Waste Transmuter

摘要

A transmuter utilizing a lead-bismuth-eutectic target/coolant is one option beingconsidered for the Accelerator Transmutation of Waste project. The system has a fast-neutron energy spectrum and several design options, such as the size of the system, the cycle length, the frequency and amount of fuel shuffled between cycles, and how often separations must be performed. The three main design options included a case with separations of fission products and uranium and shuffling of fuel elements each cycle, a case with shuffling of fuel elements without separations, and a system requiring separations but not shuffling of material each cycle. These systems were compared in the areas of estimated waste discharge produced (both during intermediate separations and end-of-life), burnup efficiency, and necessary processing (separations and shuffling) between cycles. Advantages of a fast vs a thermal system are addressed, as well as the use of burnable poison for controlling reactivity.