Search results
Results From The WOW.Com Content Network
Plutonium-239 (239 Pu or Pu-239) is an isotope of plutonium. ... Plutonium-239 has a half-life of 24,110 years. [1] Nuclear properties
Plutonium-239 has half-life 24,100 years. 239 Pu and 241 Pu are fissile; meaning their nuclei can split by being bombarded by slow thermal neutrons, releasing energy, gamma radiation and more neutrons. It can therefore sustain a nuclear chain reaction, leading to applications in nuclear weapons and nuclear reactors.
plutonium-239: 24,110 761 10 12 seconds (teraseconds) isotope half-life millennia ... half-life 10 15 years 10 24 seconds hafnium-174: 70 2.2 vanadium-50: 140 4.4
With a relatively short half-life, 239 U decays to 239 Np, which decays into 239 Pu. [ 57 ] [ 58 ] Finally, exceedingly small amounts of plutonium-238, attributed to the extremely rare double beta decay of uranium-238, have been found in natural uranium samples.
Weapons-grade plutonium is defined as being predominantly Pu-239, typically about 93% Pu-239. [24] Pu-240 is produced when Pu-239 absorbs an additional neutron and fails to fission. Pu-240 and Pu-239 are not separated by reprocessing. Pu-240 has a high rate of spontaneous fission, which can cause a nuclear weapon to pre-detonate.
Today some of these formerly extinct isotopes are again in existence as they have been manufactured. Thus they again take their places in the chain: plutonium-239, used in nuclear weapons, is the major example, decaying to uranium-235 via alpha emission with a half-life 24,500 years.
The Hiroshima bomb, made from highly enriched uranium-235, was about 16 kilotons (equivalent to 16,000 tonnes of TNT), while the Nagasaki bomb, made from plutonium-239, was about 21 kilotons ...
Disposal of plutonium and other high-level wastes is a more difficult problem that continues to be a subject of intense debate. As an example, plutonium‑239 has a half-life of 24,100 years, and a decay of ten half-lives is required before a sample is considered to cease its radioactivity.