Analyses with latest major nuclear data libraries of the fission rate ratios for several TRU nuclides in the FCA-IX experiments

In the 1980s, a series of integral experiments was conducted in FCA-IX assemblies with systematically changed neutron spectra covering from the intermediate to fast ones. The experiments provide systematic data of central fission rates for TRU nuclides containing minor actinides, Np-237, Pu-238, Pu-239, Pu-242, Am-241, Am-243, and Cm-244. Regarding the fission rate ratios relative to Pu-239, benchmark models had been recently developed for validation of nuclear data for the TRU's fission cross sections. In this paper, the latest major nuclear data libraries, JENDL-4.0, ENDF/B-VII.1, and JEFF-3.2, are compared on the benchmark models. For the libraries, the analyses by a Monte Carlo calculation code show obvious overestimations particularly for the fission rate ratios of Cm-244 to Pu-239. Additionally, a large discrepancy about by 20% between the libraries is revealed for the fission rate ratio of Pu-238 to Pu-239 measured in the intermediate neutron spectrum. The causes of discrepancies are furthermore clarified by sensitivity analyses.