Validation of the DYN3D-Serpent code system for SFR cores using selected BFS experiments. Part I: Serpent calculations.

A comparative study has been performed to evaluate the prediction capability of the DYN3D-Serpent code system for sodium fast reactor (SFR) cores. In this study, the calculation system was tested against the BFS-73-1 and BFS-62-3A experiments conducted at the Russian Institute of Physics and Power Engineering (IPPE). These experiments were designed for full-scale modeling of SFR cores, and for validation of codes and nuclear data. The study was performed in two parts. The first part is aimed at developing and validating a 3D full-core heterogeneous model of each of the experiments using the Serpent Monte-Carlo code (MC) code. This part meant as a first step towards the use of the Serpent MC code as a tool for preparation of homogenized group constants, and as a reference solution for code-to-code comparison with the DYN3D code. The second part is devoted to the homogenized group constants generation procedure and the DYN3D steady-state calculations. This paper covers the first part of the study. The experiments were simulated using the Serpent MC code, and the basic neutronic characteristics were evaluated and compared against experimental values. The calculated results agreed well with the measured values on most of the neutronic characteristics. It suggests that the Serpent MC code can reliably be used for the preparation of homogenized group constants and as a reference solution for code-to-code verification with the DYN3D code.