The site of the explosion is the massive Marcoule Nuclear complex, located about 130 kilometers (81 miles) northwest of Marseilles, the country’s second-biggest city.
The International Atomic Energy Agency (IAEA) has contacted French authorities to learn more about how the explosion may have happened.
“We are working on this issue,” IAEA director general Yukiya Amano told a news conference in Vienna during a week-long meeting of the IAEA’s 35-nation governing board.
The accident came just a week after the French president, Nicolas Sarkozy, bucked the anti-nuclear trend following Japan’s Fukushima disaster and pledged $1.37 billion of new investment in atomic power. By contrast, neighboring Germany took eight of its older reactors off the grid in the wake of the Japanese disaster and lawmakers have voted to shut the country’s nine remaining nuclear plants by 2022.
France is the world’s most nuclear-dependent country in the world, with more than three-quarters of its energy needs supplied by 58 nuclear reactors which are dotted across the countryside. France is also a major exporter of nuclear power, and treats nuclear waste from around the world.
Immediately after the explosion, shares in EDF fell by 5.59% on the Paris stock exchange.