Nuclear power plants are normally designed for operation with condensing turbines for pure electricity production. The rational use of primary energy demands the combined production of electricity and low-temperature heat, especially for regions with high population densities. The choice of the plant layout for combined generation of electricity and heat from nuclear power stations depends on the requirements of the electrical and district heating grids, on technological criteria of the process, as well as on economic criteria. A 3782 MJ/s pressurized water reactor (PWR) nuclear steam supply system is used as a basis for the combined production of electricity and heat produced by extracting steam from the low pressure turbines of the turbo-generator and by installing a separate heating turbine. There are no important technical changes necessary in a PWR plant, designed for electricity generation, when changing to the combined generation of electricity and heat. Since the additional equipment for district heating production is designed in detail, the additional plant costs can be estimated. The result shows that, for a heating capacity range of 349 to 1163 MJ/s, the additional plant costs are on the order of 1 to 5% of the total investment for a 1300-MW(electric) PWR power station for pure electricity production.