[en] The Wien Automatic System Planning Package (WASP) has been used for the development of an optimal capacity expansion plan for the power sector in Russia. The object of the WASP study is the Central Power Pool, which is the largest power pool in Russian and has an essential share of nuclear power in electricity generation. The objective of the study is to assess the long term competitiveness of nuclear power in the region. Major features of the model of the power system have been developed with WASP; the following items have been considered: four types of electricity generators: condensing fossil fuel plants, cogeneration fossil fuel plants, nuclear power plants and hydropower plants; nine fuel categories: the gas/fuel oil fuel, several types of coal and several nuclear fuels; and a model of the escalation of capital, operation and maintenance and fuel costs as a result of the economic transition. A regional optimal capacity expansion plan has been developed. The following conclusions can be drawn: (1) Until the year 2004, there will be no need for new electricity generation capacities because of the drop in demand in the 1990s, a certain lifetime margin of existing capacities, predetermined inputs of cogenerators and planned refurbishment/repowering measures. (2) The structure of the optimal capacity mix confirms that nuclear power can retain its role as one of the major electricity generation sources in the region. The most important factor with a positive effect upon the competitiveness of nuclear power plants is the projected escalation of the price of fossil fuels. (3) The application of WASP has proved that the model can serve as a valuable planning tool for power pools in Russia. (author). 13 refs, 8 figs, 10 tabs