The authority and local police officials said there had been no radiation leak. The site, about 20 miles from Avignon, has no nuclear reactors, the authority said.
Olivier Isnard, an emergency manager at France's Institute for Radioprotection and Nuclear Safety, said the explosion took place in the foundry of the waste processing plant, which was melting down about 4 tons of used, mildly radioactive metal objects. The cause of the explosion was not yet known, he said, but he emphasised that the level of radiation - about 67,000 becquerels - contained in the molten metal was minor. The French Interior Ministry said the workers were not contaminated. The Nuclear Safety Authority said one of the four injured people was in serious condition.
Isnard said that initial tests at the Centraco site showed no change to environmental radiation levels, and that the foundry building's conditioning and ventilation systems continued to function normally. The safety authority dispatched a crisis team and a group of specialised firefighters to take air and soil samples for further analysis, he said.
France gets 77 percent of its electricity from nuclear power, a much higher ratio than in other large economies.
(San Francisco Chronicle)