The nuclear emergency unfolding in Japan is causing concern worldwide about the potential risks of power plants, radiation and contamination.
Twenty-nine countries generate nuclear power. Half of them—15 to be exact—rely on nuclear energy for 25 percent or more of their electricity.
The places most dependent on nuclear power were part of the USSR, including Armenia and the Ukraine, or part of the Warsaw Pact, including Slovakia, formerly part of Czechoslovakia.
That's because the Soviets saw heavy industry as a sign of economic virility. Nothing is more "major" than nuclear power, according to Mark Fitzpatrick, a Senior Fellow for Non-Proliferation at London’s International Institute for Strategic Studies.
During the Cold War, he says, there was terrible pollution and no civil society to push back or object to what might be regarded as an over-concentration of nuclear facilities.
The world's biggest nuclear power is France, where 58 plants generate 75 percent of the nation's electricity.
In the 1960s and 1970s, French President Charles de Gaulle developed atomic power as an act of independence from America and Britain, virtually withdrawing from NATO in the process.
Areva , 95 percent controlled by the French government, is the biggest builder of nuclear reactors around the world.
In the United States, we get about 20 percent of our electricity from nuclear power.
There are 104 nuclear reactors in the country, operating in 31 states.
Not a single one has been built since 1978, so they're all at least 33 years old.
Vermont gets more of its power from nuclear energy than any other state: 72 percent.
Other top nuclear-generating states include New Jersey (four plants), Connecticut and South Carolina (seven plants), which all get more than half of their power from nuclear facilities.
Illinois is right behind them at 48 percent (11 plants).
California has four major nuclear facilities that generate about 15 percent of the state's electricity. Officials say those plants are protected from any potential tsunami threat in the Pacific Ocean.