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Plutonium-239 present in reactor fuel can absorb neutrons and fission just as uranium-235 can. Since plutonium-239 is constantly being created in the reactor core during operation, the use of plutonium-239 as nuclear fuel in power plants can occur without reprocessing of spent fuel; the plutonium-239 is fissioned in the same fuel rods in which ...
Plutonium-240 (240 Pu or Pu-240) is an isotope of plutonium formed when plutonium-239 captures a neutron.The detection of its spontaneous fission led to its discovery in 1944 at Los Alamos and had important consequences for the Manhattan Project.
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. There has also been large-scale production of neptunium-237, which has resurrected the hitherto extinct fourth chain. [ 7 ]
Small traces of plutonium-239, a few parts per trillion, and its decay products are naturally found in some concentrated ores of uranium, [54] such as the natural nuclear fission reactor in Oklo, Gabon. [55] The ratio of plutonium-239 to uranium at the Cigar Lake Mine uranium deposit ranges from 2.4 × 10 −12 to 44 × 10 −12. [56]
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.
Historically, most plutonium-238 has been produced by Savannah River in their weapons reactor, by irradiating neptunium-237 (half life 2.144 Ma) with neutrons. [7] 237 93 Np + n → 238 93 Np. Neptunium-237 is a by-product of the production of plutonium-239 weapons-grade material, and when the site was shut down in 1988, 238 Pu was mixed with ...
Watchdogs are raising new concerns about legacy contamination in Los Alamos, the birthplace of the atomic bomb and home to a renewed effort to manufacture key components for nuclear weapons. A ...
Neptunium-239 has 146 neutrons and a half-life of 2.356 days. It is produced via β − decay of the short-lived uranium-239, and undergoes another β − decay to plutonium-239. This is the primary route for making plutonium, as 239 U can be made by neutron capture in uranium-238. [23]