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Fissioning of plutonium-239 provides more than one-third of the total energy produced in a typical commercial nuclear power plant. [6] Reactor fuel would accumulate much more than 0.8% plutonium-239 during its service life if some plutonium-239 were not constantly being "burned off" by fissioning. A small percentage of plutonium-239 can be ...
Radioactive isotope table "lists ALL radioactive nuclei with a half-life greater than 1000 years", incorporated in the list above. The NUBASE2020 evaluation of nuclear physics properties F.G. Kondev et al. 2021 Chinese Phys. C 45 030001.
242 Pu's half-life is about 15 times as long as 239 Pu's half-life; therefore, it is 1/15 as radioactive and not one of the larger contributors to nuclear waste radioactivity. 242 Pu's gamma ray emissions are also weaker than those of the other isotopes. [15] 243 Pu has a half-life of only 5 hours, beta decaying to americium-243.
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]
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.
At least 3,300 nuclides have been experimentally characterized [1] (see List of radioactive nuclides by half-life for the nuclides with decay half-lives less than one hour). A nuclide is defined conventionally as an experimentally examined bound collection of protons and neutrons that either is stable or has an observed decay mode .
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.
The plutonium-238 used in these RTGs has a half-life of 87.74 years, in contrast to the 24,110 year half-life of plutonium-239 used in nuclear weapons and reactors. A consequence of the shorter half-life is that plutonium-238 is about 275 times more radioactive than plutonium-239 (i.e. 17.3 curies (640 GBq)/g compared to 0.063 curies (2.3 GBq ...