Decommissioning of the thorium high-temperature reactor, THTR 300

The pebble bed thorium high-temperature reactor THTR 300 was shut down on September 1, 1989, after > 16 000 h operation time. The THTR 300 is a project that is jointly sponsored by the Federal Republic of Germany, North Rhine-Westphalia, and Hochtemperatur-Kernkraftwerk GmbH. The public financers of this prototype reactor and the operators could not solve the financial problems for continued operation of this technically intact plant. The decommissioning decision had not been expected by the operator. This is why safe enclosure, the German term for SAFSTOR, turned out to be the only technical solution for quick decommissioning of the plant, apart from financial reasons and the nonavailability of a final storage facility. The plant is intended to be dismantled after ∼30 yr of safe enclosure, provided respective funds are available. The decommissioning was and will be performed in three steps, which are largely scheduled one after the other