Reactor physics of WWER-1000 core for safety documentation

Changes are described in the WWER-1000 reactor core as against the WWER-440 reactor, and the demands are summed up placed on newly built computer systems. For the calculation of few-group diffusion data there exist three systems of computer programs but not one of them is able to provide few-group diffusion constants with adequate accuracy. In the field of macrocodes there is the MOBY-DICK modular system which is suitable for the conception of the WWER-1000 reactor core. It is stated that having obtained the neutron physics characteristics of the first two two-year reactor fuelings, it is advantageous to concentrate on completing the completing the computer systems, preparing nuclear data, specifying physical models and comparing calculated and measured values. (E.S.)