Japan on Tuesday admitted that 206kg of its plutonium – enough to make about 25 nuclear bombs – is unaccounted for. Government scientists said that 6,890kg of plutonium had been extracted since 1977 from spent nuclear fuel at a processing plant about 120km north east of Tokyo. But that is 3 per cent short of the amount the plant was estimated to have produced. About 5kg to 8kg of plutonium are needed to make a 20-kiloton atomic bomb similar to the one that destroyed Nagasaki in 1945. Experts said the missing amount was surprisingly large. There is normally a margin of error of 1 per cent or less when measuring liquid plutonium, which can dissolve into other elements. Full Story