Thirty-five nations currently count active civil nuclear programmes, with some 440 reactors online worldwide*.
Today, the United States, France and Japan have the highest number of nuclear reactors among countries with existing programmes.
Following the 1973 Three Mile Island accident in the United States, and especially Chernobyl in 1986, most Western countries recoiled from nuclear power. However, as the use of fossil fuels falls into disfavour, civil nuclear energy is back on many policy agendas.
*All figures from World Nuclear Association (1 May 2010)