Effect of the new ENDF/B-VIII.1 Nuclear Data Library on Criticality Calculations of the DNRR with LEU Fuel

This paper reports the criticality calculations of the Dalat Nuclear Research Reactor (DNRR) with low enriched uranium fuel using the MCNP6.3 code and the newly released ENDF/B-VIII.1 data library. The work aims to evaluate the effect of the ENDF/B-VIII.1 data library on the criticality analysis of the DNRR and compared to previous libraries ENDF/B-VIII.0 and JENDL-5. The calculations were conducted based on ten criticality conditions of the core consisting of 92 LEU fuel bundles, and compared against measurement and with that obtained with previous versions of data libraries. A tendency was observed that ENDF/B-VIII.1 yields higher keff values compared to ENDF/B-VIII.0, with the largest discrepancy of 150 pcm, but closer to JENDL-5. The deviation compared to the experiments is from -111 to +145 pcm. This discrepancy indicates a generally good agreement between calculations and measurements, and among the three latest libraries.This paper reports the criticality calculations of the Dalat Nuclear Research Reactor (DNRR) with low enriched uranium fuel using the MCNP6.3 code and the newly released ENDF/B-VIII.1 data library. The work aims to evaluate the effect of the ENDF/B-VIII.1 data library on the criticality analysis of the DNRR and compared to previous libraries ENDF/B-VIII.0 and JENDL-5. The calculations were conducted based on ten criticality conditions of the core consisting of 92 LEU fuel bundles, and compared against measurement and with that obtained with previous versions of data libraries. A tendency was observed that ENDF/B-VIII.1 yields higher keff values compared to ENDF/B-VIII.0, with the largest discrepancy of 150 pcm, but closer to JENDL-5. The deviation compared to the experiments is from -111 to +145 pcm. This discrepancy indicates a generally good agreement between calculations and measurements, and among the three latest libraries.