Benchmarking of WIMS-AECL/RFSP Multicell Methodology with MCNP for ACR-1000 Full-Core Calculations

摘要

For an accurate calculation of the power distribution in a reactor core, it is important to generate lattice-cell cross sections for the fuel lattice, accounting for local conditions and the burnup history of the fuel, as well as the effect of the neighbouring lattices. The cross-section data employed in commercial core-analysis diffusion codes are usually based on the use of single-lattice-cell calculations without considering the effect of the environment. This fundamental assumption is not sufficiently accurate for certain heterogeneous core configurations which may occur in the ACR-1000® . The multicell methodology developed in the CANDU® core-analysis code RFSP allows an accurate treatment of neutronic heterogeneity, while maintaining the basic structure of the single-lattice-cell-based reactor-physics methodology used for CANDU reactors for many years. This paper presents benchmarking results between WIMS-AECL/RFSP multicell methodology and MCNP5 full-core calculation for the ACR-1000. The benchmarking results show that the multicell methodology implemented in WIMS-AECL/RFSP can capture the effects due to heterogeneity in the ACR-1000 core-reflector interface.