Critical mass calculation of a fuel randomization system using Solomon

Watanabe, Tomoaki  ; Ueki, Taro  ; Suyama, Kenya

Solomon, a Monte Carlo solver being developed by JAEA, is capable of calculating criticality in multi-material randomized systems for criticality evaluation of fuel debris. This study conducted a criticality mass analysis of a system with several kinds of burnup fuels distributed randomly using Solomon. The result showed that the disorder of the fuel composition distribution causes significant variations in the critical mass. The obtained critical sizes were distributed close to a normal distribution, which makes it reasonable to estimate the critical mass and uncertainty of a multi-material randomized system as a mean and standard deviation, respectively.