The dismantling of the 3 UNGG-type reactors of the Chinon plant

This article describes the dismantling of the 3 UNGG-type reactors of the Chinon plant. The steel ball-shaped containment of the A1 reactor can assure a safe confinement for a very long time period so the installation itself has become its own storage site and as a consequence most materials and equipment have not been moved. On the contrary A2 and A3 reactors have no containment so the confinement of the reactor core and of the heat exchangers has required a complete re-designing of the 2 installations. The dismantling of A2, A3 reactors has led to an original method of packaging low-activity radioactive wastes. Some parts of pipes from the primary cooling system have been cut up and turned into waste containers by welding bottom and head. The third level in the dismantling process can not be reached unless the storage sites of high-level wastes are in service. (A.C.)