Establishment of benchmark problems for TRU fission rate ratios of FCA-IX assemblies

In the IX-th experimental series in 1980's at the fast critical assembly (FCA) facility, central fission rate ratios for TRU such as ²³⁷Np, ²³⁸Pu, ²⁴²Pu, ²⁴¹Am, ²⁴³Am, ²⁴⁴Cm and ²³⁹Pu were measured in the seven uranium-fueled assemblies with systematically changed neutron spectra. In the report, benchmark problems with respect to central fission rate ratios were established for the assessment of the TRU's fission cross sections. Heterogeneous benchmark models were established by simplifying geometric details, except for the plate-wise heterogeneity, to a practical level. However, detailed data of FCA's fuel plate should be treated as sensitive information, so that the heterogeneous benchmark models cannot be currently opened. Therefore, homogeneous benchmark models were established also by homogenizing the plate-wise heterogeneity. The paper provides specific configurations and composition data of the homogeneous benchmark models and correction factors for the heterogeneous effects. Therefore, users can obtain equivalent results to those of the heterogeneous benchmark models. We reported the sample calculation results on the benchmark problems by using JENDL-4.0. (author)