Use of Monte Carlo code MCS for multigroup cross section generation for fast reactor analysis

Multigroup cross section (MG XS) generation by the UNIST in-house Monte Carlo (MC) code MCS for fast reactor analysis using nodal diffusion codes is reported. The feasibility of approach quantified two sodium reactors (SFRs) specified in OECD/NEA SFR benchmark: a 1000 MWth metal-fueled (MET-1000) and 3600 oxide-fueled (MOX-3600). accuracy few-group XSs generated verified another MC code, Serpent 2. neutronic steady-state whole-core problem analyzed MCS/RAST-K with 24-group XS set. Various core parameters interest (core keff, power profiles, reactivity feedback coefficients) are obtained both MCS. A code-to-code comparison indicates excellent agreement between solution stochastic solution; error keff less than 110 pcm, root-mean-square profiles within 1.0%, coefficients three standard deviations. Furthermore, super-homogenization-corrected improves prediction control rod worth all rods in. Therefore, results demonstrate that employing MG feasible high-fidelity analyses reactors.