Scientists split over fall of Superphenix

French scientists are divided over the closure of Superphenix, the world's largest fast breeder nuclear reactor, and the reopening of the smaller Phenix fast breeder reactor to study incineration of radioactive waste.

Last month a committee led by the prime minister confirmed the decision to close the trouble-plagued reactor. It also agreed to earmark Fr500 million (Pounds 50 million) to foster renewable energy sources. A decision on siting subterranean laboratories for research into radioactive waste stored underground was deferred until after regional elections this month.

Phenix was designated to supplant Superphenix's research role by a 1991 law that separated research on nuclear waste management into three strands: the storage of waste at surface level and the burial of waste, the study of transmutation/incineration to cut radioactive volumes and shelf life.

"Phenix is a 30-year-old reactor in poor shape," said Monique Sene, a physicist and member of the College de France. "Parts of it are irradiated. I am not sure that it is a viable tool, even taking into account the Atomic Energy Commission's (CEA) work on it." The CEA plans to spend Fr250 million to put Phenix back in action. Phenix started operation in 1973. In 1989-1990 it suffered unexplained power fluctuations. Soon after, cracks were found in the secondary sodium cooling circuit, and the reactor was shut. It reopened in 1994 for a few months before being shut again.

Roland Desbordes, president of the Independent Commission of Research and Information on Radioactivity, said Phenix was being re-opened to help the civil nuclear sector save face. "Closing Superphenix is an admission of defeat by the nuclear lobby. Phenix is perhaps better for research as it is smaller, but you are asking a fast-breeder reactor to do the opposite of what it was conceived to do."

Hubert Doubre, of the PACE research programme on nuclear waste at the National Centre for Scientific Research, said: "The closure of Superphenix has deprived research projects. Phenix is being maintained so as not to deprive them of a research instrument. One can understand the frustration of Superphenix's backers. It was so costly. The CEA had tried to establish the conditions under which the reactor could incinerate waste, but the factors that would have made Superphenix a force were reliability and safety."

The National Union of Scientific Researchers has not taken a public position. "There are too many different opinions," said an official who asked not to be named. He accused the CGT union of trying to gain public support for Superphenix by suggesting the entire civil nuclear industry was under threat.