By late 1987, 21 nuclear generating units with an aggregate 19,946 MWe were in operation in the Federal Republic of Germany. They generated 130,582 GWh in 1987, which is 9. 1% more than the 119,666 GWh produced in 1986. The ten units with design powers of up to 1000 MW, which have an aggregate generating capacity of 5510 MWe, converted a gross 38,860. 1 GWh of nuclear energy into electrical energy. Excluding the AVR Juelich and KNK II Karlsruhe experimental nuclear power plants and the THTR-300 prototype nuclear power station at Hamm-Uentrop, the seven plants in commercial operation throughout 1987 attained an average availability in terms of time of 87. 1% (1986:83. 1%) and an average capacity availability of 85. 0% (80. 3%). The unplanned share in the nonavailability of capacity in 1987 averaged 2. 4%.