About 10 ha are required for cooling towers, if the unit uses indirect or dry cooling. The same 10 ha surface is required if storage buildings for spent fuel and waste are foreseen on the layout. Finally, an area of about 10 ha is required in the vicinity of the power plant for an outdoor substation. Thus, a nuclear installation of one or two units requires a minimal area of 50-80 ha, depending on cooling method and needs for interim waste storage.