Validation of the MCNP6 code for SFR shielding design analysis.

In this paper, the uncertainty of the Monte Carlo code MCNP6 for the Sodium-cooled Fast Reactor (SFR) shielding design is studied. Shielding analysis, which ensures the radiation safety of the core design, is challenging for the Monte Carlo modeling because it is associated with large uncertainties. In order to evaluate the performance of the MCNP6 for the shielding design of the SFR, four SFR shielding benchmarks from the Shielding Integral Benchmark Archive Database (SINBAD) benchmark suit, i.e., JANUS Phase VIII, SDT12, EURAC_Na, and HARMO_Na were selected and analyzed. In this research, the Weight Window variance reduction technique and the latest neutron data library ENDF/B-VII.1 was used in the modeling of the benchmark problems. The results and the validation of the MCNP6 models with the available measurement data are presented in this paper. These results would contribute to the assessments of radiological protection and shielding design of the Korean Prototype Gen-IV Sodium-cooled Fast Reactor (PGSFR).