A LEAK in a cooling circuit last week forced reactor operators to shut down Superph茅nix, the world鈥檚 first commercial scale fast breeder reactor. Similar faults have plagued the reactor since it was switched on in 1986, and it has operated at full power for less than six months.
The reactor, at Creys-Malville near Lyons, faces political difficulties as well as technical ones. Last month, the French government appointed a 10-member commission to study whether Superph茅nix is worth retaining. Its member include some fervent opponents of the reactor, who are likely to ask serious questions about its future.
Superph茅nix is no stranger to reviews. Following the last one, published in 1994, the government decided that instead of operating as designed 鈥� to create, or 鈥渂reed鈥�, its own plutonium fuel 鈥� the reactor should be tried out as a waste-disposal plant. The aim would be to see if plutonium and other actinides loaded into the reactor core could be split into shorter- lived isotopes.
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The new commission will evaluate the reactor鈥檚 suitability for this research. Raymond Castaing, a physicist and president of the commission, says the group will not flinch from recommending closure if it feels this is necessary.
Opponents of Superph茅nix on the commission include Raymond Sen茅, a physicist at the Coll猫ge de France in Paris, who is a member of Europeans Against Superph茅nix. Jean-Paul Shapira of the National Institute for Nuclear and Particle Physics (INNPPP), in Orsay near Paris, has also recommended its shutdown. The commission also includes Nobel prizewinner Georges Charpak.
Shapira says the commission must establish how much plutonium the reactor could dispose of. In a report written in 1992, he estimated that the reactor could burn only 100 kilograms of plutonium a year. 鈥淥ne cannot justify starting up Superph茅nix to burn plutonium and minor actinides either as an industrial or research tool 鈥� 鈥� he wrote.
France鈥檚 nuclear research agency, the CEA, disagrees. It believes Superph茅nix could dispose of 200 kilograms of plutonium a year. But this amount is tiny compared with the 10 tonnes produced every year by France鈥檚 54 pressurised water reactors.
The commission must also decide whether the 1200-megawatt Superph茅nix has any advantages over its smaller cousin, the 250-megawatt Ph茅nix. Each load of fuel in Superph茅nix lasts for about four years, and Claude Detraz, director of the INNPPP, says this is too long to make it a good experimental tool. Results should first be obtained from Ph茅nix and then validated on a bigger scale with Superph茅nix, he suggests.
Philippe Hammer, CEA鈥檚 deputy director of nuclear reactors, admits that the reactor is not as flexible as Ph茅nix. But in some ways its size is a benefit. Too much extrapolation from small-scale experiments 鈥渋s always a dangerous thing鈥�, he says.
At present, the CEA is trying to prolong the life of Ph茅nix to about 2005. Saving Superph茅nix is a priority if fast breeder research is to continue beyond then. 鈥淔or the future of this type of reactor, results from Superph茅nix are important,鈥� says Hammer.
Some antinuclear campaigners see the commission as a golden opportunity to close Superph茅nix. They are optimistic not only because of the line-up on the panel, but also because of the leanings of the French environment minister, Corinne Lepage. Before taking office, she was a leading lawyer in the fight against Superph茅nix.
But last month Lepage refused to say whether she would scrap the reactor if the commission advised it. Apart from the loss of 700 jobs, closing the plant could leave France open to claims for compensation from foreign investors in Superph茅nix. And final closure would leave France with a bill for about 10 billion francs (拢1.28 billion) to decommission the reactor.