Calculated distributions of Pu concentrations within spent fuel assemblies of Fugen reactor

Seya, Michio; Katano, Yoshiaki; Ebara, Noriyasu

For evaluation of the data measured data of Fugen spent fuel assemblies by the PNAR/SINRD detector, which was obtained in the JAEA and USDOE (LANL) collaboration, we need data on the Pu content distribution in the measured assemblies. For nuclear material accountancy, JAEA has data on the quantity of Pu in each spent fuel assembly that is based on burn-up calculations. However, this calculation is just for the total amount of Pu in an assembly. Therefore, we have done burn-up calculations for two MOX-B type assemblies with high burn-up and very low burn-up to obtain Pu content distributions along the vertical axis of an assembly and also distribution differences among inner, middle and outer fuel rods. The data of the Pu content distributions within an assembly will be useful for evaluating the measured data.