There is a risk of a radioactive leak after a blast at the southern French nuclear plant of Marcoule, media reports say.
One person was killed and three were injured in the explosion, following a fire in a storage site for radioactive waste, Le Figaro newspaper said.
It is a major site involved with the decommissioning of nuclear facilities.
It produces MOX fuel, which recycles plutonium from nuclear weapons, but does not include any reactors.
A spokesman for France's atomic energy commission said there had so far been no leak but a security perimeter had been set up because of the risk.
The plant is located in the Gard department in Languedoc-Roussillon region, near France's Mediterranean coast.
