plutonium-239

Plutonium-239 is a radioactive isotope used primarily as fuel in nuclear reactors and in nuclear weapons. It is produced in reactors from uranium-238, a common uranium isotope. Pu-239 is fissile, meaning it can sustain a chain reaction when split, releasing significant energy. Due to its radioactivity and potential for weaponization, handling and disposal require strict safety measures. It has a half-life of about 24,100 years, making it persist in the environment for a very long time. Its unique properties make it both a valuable resource for nuclear energy and a material of concern for nuclear proliferation and safety.