Plutonium-239 is an isotope of plutonium. Plutonium-239 is one of the three fissile isotopes used for the production of nuclear weapons and in nuclear reactors as a source of energy. Other fissile isotopes used are uranium-235 and uranium-233. Plutonium-239 has a half life of 24,110 years. The nuclear properties of plutonium-239, as well as the ability to produce large amounts of nearly pure plutonium-239, led to its use in nuclear weapons and nuclear power. The fissioning of an atom of uraniu… (More on Plutonium-239)