An oven reportedly exploded at the Marcoule nuclear site near Nimes in the south of France. The site produces MOX fuel, which recycles plutonium from nuclear weapons, and is partly used by the French nuclear power company Areva.

Part of the process involves firing superheated pellets of plutonium and uranium in an oven to reduce them in size to make them easier to store…

The papers said the body of one male worker at the plant had been “found carbonised”, but it added that there was no evidence that the explosion had “caused any radioactive leak”.

A spokesman for the French atomic energy authority told journalists: “For the moment, there is nothing coming out.”