Benchmark calculations by SCALE-4 for Pu-U systems with low Pu content

Sudo, Toshiyuki ; Shirai, Nobutoshi 

This report presents the results of criticality benchmark calculations performed to validate the SCALE-4 code system for Pu-U mixtures with low Pu content (less than 10wt.%) on the assumption that the SCALE is applied to the criticality safety analysis for nuclear fuel facilities handling LWR-MOX fuels. The SCALE-PC 4.1 on a personal computer and the SCALE 4.2 on a SUN EWS were used. The number of the calculated cases are 11 for homogeneous MOX systems, 13 for Pu-U nitrate solutions, and 57 for heterogeneous MOX fuel pin systems, sums up to 81. The calculation results show that there are no significant differences between the results from SCALE-PC 4.1 and SCALE 4.2 calculations. Maximum, minimum, and average k-effectives calculated by SCALE 4.2 are 0.993, 1.026, and 1.005 respectively. The average k-effectives for the critical systems mentioned above are 1.0150.006, 1.0110.003, and 1.0010.004 respectively, which indicates that SCALE-4 can accurately predict the k-effective for Pu-U mixtures with low Pu content.