Thermal and Fast Reactor Benchmark Tests of JENDL-3TDepartment of Reactor Engineering Japan Atomic Energy Research Institute, Tokai, Ibaraki, Japan Benchmark tests of JENDL-3T data were performed by analysing a lot of critical experiments for thermal and fast reactors, and the results were compared with those obtained using JENDL-2 data. The calculated results are summarized as follows: (1) Thermal reactors: In U-235 fuel cores, the keff calculated with JENDL-3T cross sections increased about 0.3 % with respect to the JENDL-2 based values. The increase reflects the 0.24 % increase in ν(U-235) at the 2200m/sec. In Pu-239 fuel cores, the keff calculated with JENDL-3T data decrease about 0.6 % with respect to the JENDL-2 values, and the overprediction by JENDL-2 is improved. In U-233 fuel cores, the keff obtained with JENDL-3T data decrease about 1 % with respect to JENDL-2 values, and gives good agreement with the experiments. (2) Fast reactors: The keff calculated with JENDL-3T data is overestimated for U-fuel cores and underestimated for Pu-fuel cores. The reaction rate ratios of Pu239(n,f)/U235(n,f) are in a good agreement with the experimental values, though U238(n,c)/Pu239(n,f) and U238(n,f)/U235(n,f) are overestimated. Moreover, the sodium void reactivity is in a good agreement with the experiments, and this is compared with overprediction of that obtained with JENDL-2 data. KEYWORDS: benchmark test, JENDL-3T, thermal reactor, high-conversion light water reactor, fast reactor, effective multiplication factor, reaction rate ratio, sodium void reactivity, Doppler reactivity, reaction rate distribution |