Earlier work and Ph.C3.A9nix Superphénix

plans french fast reactor date far 1958 s rapsodie, , followed in 1964 larger design power output of 1 gwe. construction of rapsodie facility started in 1962 , went critical on 28 january 1967. did not have power producing systems, 22 mw of thermal output (mwth) translate perhaps 9 mw of electrical output (mwe). experiments on core configurations carried out in masurca facility starting in 1966, , design of larger power-producing facility underway.

during 1960s, interest in nuclear power reaching crescendo. france, little uranium supply of own, large scale generation subject supply constraints, given nuclear power experiencing boom in construction suggested available supply limited on worldwide basis. in france s plans, breeders serve twin purposes of producing fuel conventional light water reactor fleet, producing fuel waste fuel reactors, thereby reducing amount of nuclear waste have dispose of. small number of breeders, estimated around 20, required fuel fleet of 200 light water reactors.

france began construction of phénix demonstration plant in november 1968, year after rapsodie went critical. fueled 931 kg of highly enriched plutonium, around 77% pu-239. fuel load capable of running 90 days maximum, in practice ran 2 month periods. due design, refueling required reactor shut down. result, had low capacity factor (cf), on order of 65%. prototype plant, high cf not design goal, although practical design have improve this. phénix demonstrated breeding ratio of 1.16, meaning produced 16% more fuel consumed, while producing 233 mwe in normal operation.

phénix ran without problems through 1970s , 80s, in 1990s began demonstrate number of unexplained behaviours, including large power transients. had serious safety implications, , reactor repeatedly shut down, spending of period 1991 1994 being studied while offline. long offline period required recertified, plant underwent significant refurbishment between 1994 , 2002. rectified in june 2003, @ reduced power of 130 mwe.