Comparison of some calculations by codes MCU and WIMS/D4 for WWER-440 fuel assemblies

Some comparison of methodical calculations by the computer codes MCU-RFFI and WIMS/D4 for WWER-440 fuel assembly are presented. The comparisons of identical 2D calculations by these codes show good agreement on Kef (difference not more than 0.009) and pin-by-pin power distribution (difference not more than 5%) for fuel configurations with fresh and burnt-out fuel assemblies adjacent to water holes (with transverse dimensions equal to WWER-440 assembly) when varying water/uranium ratio, boron concentration in coolant, presence or absence of fresh or burnt-out absorber which separates the fuel assembly from the water hole. The results could be used for 3D power distribution calculations in the regions with significant non-uniformities in the core where diffusion approach is inapplicable. (author)