A heavy, fissionable, radioactive, metallic element (atomic number 94). Plutonium occurs in nature in trace amounts. It can also be produced as a byproduct of the fission reaction in a uranium-fueled nuclear reactor and can be recovered for future use.
A radioactive element with the atomic number 94 and an average atomic weight of 244.
A silvery-white radioactive metal that exists as a solid under normal conditions. It is produced when uranium absorbs a neutron. Small amounts of plutonium occur in nature, but large amounts have been artificially produced in nuclear reactors. Hanford produced plutonium for use in nuclear weapons. Most forms of plutonium have very long half-lives. For example, plutonium 239 (which Hanford produced) has a half-life of 24,100 years. Plutonium can cause cancer.