Calculations of k-infinity of Benchmark Experiments for Compositions of U-235 with Various Structural Materials

Abstract

Calculations of k∞ of benchmark experiments for compositions of highly enriched uranium and such structural materials of nuclear reactors as iron, chromium, nickel, zirconium, and molybdenum were performed using the MCNP code with continuous energy cross sections processed from different evaluated nuclear data files: ENDF/B-V, ENDF/B-VI.2, ENDF/B-VI.3, ENDF/B-VI.7, JEF-2.2, JENDL-3.2, and FOND-2.2. The experiments considered were especially designed to test the cross sections of the structural materials in the resonance energy region and they are highly sensitive to these cross sections. These experiments provide a valuable test for checking the cross sections of the considered structural materials. There are revealed several large, up to tens percents, discrepancies both between the calculations performed using different sets of evaluated nuclear data and with the experimental results. The results of calculations are presented in the report with the discussion about the differences in the cross sections that cause so significant discrepancies in the calculational results.