Fetter, SteveFrank, von HippelNuclear weapons are carefully designed to have an extremely low probability of exploding accidentally with an appreciable yield—even if they are involved in a high-speed crash, struck by a bullet or consumed in a fire. The principal concern when nuclear warheads are involved in such accidents is the possible dispersal of plutonium into the environment. In particular, an explosion could disperse a significant fraction of the plutonium in a warhead as particles of respirable size.en-USnuclear weaponsplutoniuminsensitive high explosiveplutonium aerosolsArticle