KARMA 1.1 Benchmark Calculations for the B and W Critical Experiments with ENDF/B-VI R8 and ENDF/B-VII R0

The transport lattice code KARMA 1.1 has been developed at KAERI for the reactor physics analysis of the pressurized water reactor. This program includes the 47-group and 190-group libraries which are provided by the KAERI library processing system. These multi-group libraries have been processed from ENDF/B-VI R8 (E6R8) and ENDF/B-VII R0 (E7R0), respectively. As a part of code verification and validation for KARMA, benchmark calculations have been performed for the various critical experiments, which provide a more direct method for code evaluation. These critical experiments represent realistic reactor configurations with the typical PWR fuels. In this study KARMA has been benchmarked against the B and W 1810 series which consisted of a total of 23 different critical core configurations. The 1810 series is one of the most widely used to verify the modeling accuracy of gadolinia fuel. All core configurations have been analyzed, with the exception of Core 11, which was designed to measure resonance parameters. The multiplication factors have been calculated by using both the E6R8 and E7R0 based 47-group libraries, and the calculated fission rate distributions in the central pseudo-assembly for 6 cores have been compared to the measured one. Characteristics of the E6R8 and E7R0 libraries have been identified by comparing to the measured data for the B and W critical experiments