Multi-cell correction method for treatment of heterogeneities in full-core calculation of CANDU-type reactors

This paper presents a multi-cell correction method that has been developed and implemented in the code suit WIMS-AECL / RFSP to capture the effects of the lattice-cell neighbourhood, while maintaining the basic structure of the single-cell-based reactor-physics methodology traditionally used for CANDU reactor calculations. To validate the efficiency in treating the core-reflector interface heterogeneity as well as the checkerboard-core-voiding scenario, the results of WIMS-AECL / RFSP calculations (with and without multi-cell correction) are compared with the results of MCNP5 full-core calculations for CANDU-type reactors. The presented results show that the multi-cell method is effective, generic, and capable of capturing the heterogeneity effects of the neighbourhood in CANDU-type reactors. (author)