One person has been killed and four others injured in an explosion at the southern French nuclear plant of Marcoule. A French nuclear official said there were no radioactive leaks after the blast, caused by a fire near a furnace in a radioactive waste storage site. A security perimeter has been set up because of the risk of leakage. The plant produces MOX fuel, which recycles plutonium from nuclear weapons, but does not include reactors. It is a major site involved with the decommissioning of nuclear facilities.