From the demand viewpoint, the connection of an installed nuclear thermal capacity of 290 MJ/s for district heating purposes would be possible in the central Ruhr District by 1982–1983. The nuclear district heating system is made up of several subsystems, for instance, a smaller size high-temperature reactor [500 MW(thermal)] as a nuclear heat-and-power plant and an interconnected district heating system with a feed temperature of 453 K (180°C). The expenditure for additional investments, additional fuel costs, and costs for substitute power capacity are charged to the thermal energy generation costs of the nuclear heat-and-power plant. For the nuclear district heating system, the district heating costs to the consumer will vary over wide limits, depending on local conditions, between 7.8 and 12.2 $/GJ at the commissioning date in 1983, assuming that all subsystems have to be newly installed. These costs can be lower than district heating costs in a conventional district heating system with fossil-fired heating stations.