Lifetime Extension of the Phénix Plant

The French fast reactor prototype Phénix was put into commercial operation in 1974. The total time of power operation of the plant is [approximately]100000 h representing 3860 equivalent fuel power days (EFPD). With the initial objective of the demonstration of fast breeder reactors achieved, since the early 1990s, the role of the reactor as an irradiation facility has been emphasized, particularly in support of the Commissariat à l'Energie Atomique research and development program on long-lived radioactive waste transmutation. This new objective required an extension of the planned reactor lifetime. A major renovation program was carried out in the plant from 1994 to 2003, involving safety upgrading, component inspections and repairs, and the 10-yr statutory maintenance. The main work consisted of the addition of a backup control rod to the reactor; improvement of earthquake protection by reinforcement of buildings and components and replacement of the emergency water cooling circuit; improvement of protection against sodium fire by partitioning the secondary sodium circuit in the steam generator building, reinforcement of steam generator casing, and installation of an antiwhip system on the high-pressure steam pipes; replacement of hot parts of the 321 stainless steel secondary loops and steam generator modules, affected by delayed reheat cracking; special inspections of the reactor internal structures to demonstrate their good condition. An extensive plant requalification program was carried out following the renovation work, and the plant resumed power operation in June 2003. Six operating cycles are planned, representing a total irradiation time of 720 EFPD equivalent to [approximately]5.5 yr of operation.