The blast at the Marcoule plant occurred around midday Monday, and authorities have preemptively set up a perimeter around the facility in case of a radiation leak. The explosion is thought to have been caused by a fire near the furnace of a radioactive waste storage unit.
One of the oldest plants in France, Marcoule generates power by recycling decommissioned nuclear weapons. There are no reactors at the facility, and the plant uses the uranium and plutonium from nuclear weapons to create a fuel called MOX, which can be used at other power stations.
The plant is in France's Languedoc-Roussillon region, near the Mediterranean coast. It is about 30 miles from the city of Nimes.
Contrary to most European countries, France has recently reinvested in nuclear energy. After the Fukushima disaster in Japan in March, which was the largest nuclear accident since the 1986 Chernobyl disaster, countries like Germany, Switzerland and Italy voted to discontinue its nuclear programs.
But in June, France's President Nicolas Sarkozy said he was committing one billion euros (about $1.36 billion) to nuclear power.
We are going to devote a billion euros to the nuclear program of the future, particularly fourth-generation technology, Sarkozy told a news conference in June.
We are also going to release substantial resources from the big loan to strengthen research in the sphere of nuclear safety.
There are more than 20 operating nuclear plants and 58 reactors in France, and the country gets 78.8 percent of its electric from nuclear power, the most of any country in the world.
The last nuclear accident in France occurred in August, 2009, when the nuclear rods jammed at a plant in Gravelines, causing a system failure and a reactor to shut down.
Yet, Sarkozy insits that France's nuclear plants are the safest in the world.
After the explosions at the Fukushima reactors in the spring, the European Union ordered all 143 nuclear plants among its member states to under go new safety tests. The results of the inspections are due later this month.
Marcoule is operated by SOCODEI, a waste solutions subsidiary of électricité de France. EDF is the largest utility company in the world. It produces 22 percent of the electricity for the European Union, about 75 percent of which comes from nuclear power.
Electricité de France also partners with a number of companies in the United States, including Unistar Nuclear Energy, EnXco and Constellation Energy, which owns three nuclear power stations on the East Coast.