What are fissile materials?
Fissile materials are composed of atoms that can be split by neutrons in a self-sustaining chain-reaction to release enormous amounts of energy. In nuclear reactors, the fission process is controlled and the energy is harnessed to produce electricity. In nuclear weapons, the fission energy is released all at once to produce a violent explosion. The most important fissile materials for nuclear energy and nuclear weapons are an isotope of plutonium, plutonium-239, and an isotope of uranium, uranium-235. Uranium-235 occurs in nature. For all practical purposes, plutonium-239 does not. What is plutonium-239? Plutonium-239 (hereafter referred to as “plutonium”) is a heavy element consisting of 94 protons and 145 neutrons. It can have a number of chemical forms. Nuclear weapons use plutonium metal. Plutonium dioxide is used as a component of some nuclear fuels. Plutonium has a half-life of over 24,000 years (a half-life is the time it takes for half of a given amount of radioactive material
