Publications Repository - Helmholtz-Zentrum Dresden-Rossendorf

The Mariko code, based on the method of characteristics, has been used to calculate several two-dimensional full core heterogeneous 23-group transport theory solutions for hot zero power states of the WWER-1000 reactor. The initial loading for the three-year fuel cycle is considered. Helios-1.5 has been used to prepare 23-group cross-section data. The benchmarks differ by the positions (up or down) of the control rods groups. The asymptotic assembly-averaged and cell-averaged two-group diffusion parameters for all assembly types, the group-to-group albedos on the radial reflector boundary, and the effective diffusion parameters, including reference discontinuity factors, for the radial reflector nodes are all calculated by Mariko. The accuracy of the SPPS-1.6 and DYN3D nodal diffusion codes and the HEX2DA/B pin-by-pin diffusion codes have been tested. The benchmark with all control rods down poses a great problem for the nodal diffusion codes, the maximum error in the relative assembly-wise power distribution reaching 18% for SPPS-1.6. The pin-by-pin codes perform well in all cases.