France launched its large-scale nuclear program in the 1970s, fueled by the Middle East oil crisis that saw a monumental jump in oil prices.

France has very few natural energy resources. It has no oil or gas, and its coal resources are very poor and virtually exhausted, making nuclear power an attractive alternative to energy dependence.

By the late 1980s, France built more than 50 nuclear reactors, satisfying its power needs and even exporting electricity to other European countries. It now has 59.

The nuclear plants account for more than 75 percent of France's total electricity production, making it the world's second largest nuclear power producer.

France is also the world's largest net exporter of electric power, exporting 18 percent of its total production to Italy, Britain, Germany, Belgium and the Netherlands.

Centraco, the site of Monday's explosion, is on the grounds of the Marcoule nuclear research center. It produces fuel from recycled waste.

The cause of the explosion is not yet known.