Superphénix (; , SPX) was a nuclear power station prototype on the Rhône river at Creys-Malville in France, close to the border with Switzerland. Superphénix was a 1,242 MWe fast breeder reactor with the twin goals of reprocessing nuclear fuel from France's line of conventional nuclear reactors, while also being an economical generator of power on its own. , Superphénix remains the largest breeder reactor ever built.
Construction began in 1976, the reactor went critical in 1985 and was connected to the grid in 1986. Despite many technical issues related to being a first-of-a-kind project most of its downtime was caused by administrative procedure: the plant was technically capable of resuming operations but was forbidden to do so. Technical problems were solved over time and, by 1996, the plant had reached an availability of 95%. Phénix demonstrated a breeding ratio of 1.16, meaning it produced 16% more fuel than it consumed, while also producing 233 MWe in normal operation.
Phénix ran without problems through the 1970s and 1980s, but between 1989 and 1990 experienced 4 power transients which triggered automatic SCRAM. A 1991 report did not clearly identify the cause. In 1993 renovation and life extension works started. The reactor was restarted in 2003 with a reduced power of 130 MWe.
Superphénix
thumb|right|A cut-away model of the Superphenix containment. From the [[National Atomic Museum in Albuquerque, New Mexico, United States]]
In 1971 and 1972, France, Germany and Italy signed agreements for the joint construction of full-scale breeders, one in France and one in Germany. The 1973 oil crisis made the issue of fuel security of significant importance. As part of the Messmer Plan, France began to plan for a future in which the vast majority of their electrical power would come from nuclear sources. New priority was given to a follow-on breeder design with the goal of continual operation, high CF, and economic operation even as a stand-alone reactor. This became the Superphénix design. resulted in the protestors' use of molotov cocktails. This July 1977 protest was finally broken up by the CRS with the death of Vital Michalon and over a hundred serious injuries, with the police using truncheons and firing tear gas grenades to disperse the protestors.
Rocket attack
Against a background of ongoing protest and low-level sabotage, on the night of January 18, 1982 an RPG-7 rocket-propelled grenade attack was launched against the unfinished plant. Five rockets were fired across the Rhône at the incomplete containment building. Two rockets hit and caused minor damage to the reinforced concrete outer shell, missing the reactor's empty core. Initially there were no claims of responsibility.
On May 8, 2003, Chaïm Nissim, who in 1985 was elected to the Geneva cantonal legislature for the Swiss Green Party, admitted carrying out the attack. He claimed that the weapons were obtained from Carlos the Jackal via the Belgian terrorist organisation Cellules Communistes Combattantes (Communist Combatant Cells).
Operation
Designed electrical power output was 1.20 GW, though year to year its availability was from zero to 33%. As time passed, problems developed from another source: the liquid sodium cooling system suffered from corrosion and leaks. These problems were eventually fixed and in December 1996 the power reached 90% of the nominal power.
In December 1990 structural damage occurred to the turbine hall, following heavy snowfall. Power production did not resume until the Direction de la sûreté des installations nucléaires approved it in 1992.
The plant was connected to EDF grid on 14 January 1986 and produced 4,300 GWh of electricity, worth about a billion 1995 Franc, during 10 months of operation, up until 1994. In 1996 it produced 3,400 GWh, worth about 850 million Francs, during 8 months of operation.
A 1998 "Inquiry commission on Superphenix and fast neutrons reactor sector"