One nuclear reactor meltdown every three years on average.

NYT: “The three partial Japanese nuclear meltdowns bring the worldwide total to a dozen accidents with reactor core damage since the first one in 1957, and nuclear reactors worldwide are suffering such accidents about eight times more frequently than the United States’ safety goal, an American physicist said.”“Thomas B. Cochran, a Natural Resources Defense Council scientist, looked at 12 accidents — four in the United States, two in France, one each in Scotland, East Germany and Ukraine, and the three in Japan.”