US bomb scientist says enough plutonium for 25 bombs is missing

"In the case of plutonium, how much plutonium did they produce? Well, they produced between 140 and 162 tons. If they can’t find a tenth of 1 percent, that means there is 310 to 360 pounds of plutonium lying around somewhere," Reed, co-author of the new book The Nuclear Express: a Political History of the Bomb and its Proliferation, told the paper.

The United States and Russia are "hard at work looking for" the material, said Reed, a former nuclear-weapon designer at the Lawrence Livermore National Laboratory in California.