plutonium240

Plutonium-240, denoted as 240Pu or Pu-240, is a radioactive isotope of plutonium. It is a fissile material, meaning it can sustain a nuclear chain reaction. Plutonium-240 is produced primarily as a byproduct of nuclear reactors that use plutonium-239. When plutonium-239 undergoes neutron capture, it can transform into plutonium-240.

This isotope is a significant component of spent nuclear fuel and is also found in plutonium extracted from such fuel. The presence of plutonium-240 in weapons-grade plutonium is undesirable because it contributes to spontaneous fission, which can lead to a premature detonation of a nuclear weapon. This phenomenon is known as pre-detonation. Therefore, efforts are made to minimize its concentration in plutonium intended for use in nuclear weapons.

Plutonium-240 has a relatively long half-life of about 6,561 years. It decays primarily through alpha emission, producing uranium-236. While not as fissile as plutonium-239, plutonium-240 can still contribute to criticality under certain conditions. Its high spontaneous fission rate is a key characteristic that differentiates it from other plutonium isotopes and has implications for both nuclear energy production and nuclear weapons proliferation.