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In a fission nuclear reactor, uranium-238 can be used to generate plutonium-239, which itself can be used in a nuclear weapon or as a nuclear-reactor fuel supply. In a typical nuclear reactor, up to one-third of the generated power comes from the fission of 239 Pu, which is not supplied as a fuel to the reactor, but rather, produced from 238 U. [5] A certain amount of production of 239
The Gilbert U-238 Atomic Energy Laboratory was packaged in a customized metal case. The Gilbert U-238 Atomic Energy Lab is a toy lab set designed to allow children to create and watch nuclear and chemical reactions using radioactive material. The Atomic Energy Lab was released by the A. C. Gilbert Company in 1950.
Pu-239 is produced artificially in nuclear reactors when a neutron is absorbed by U-238, forming U-239, which then decays in a rapid two-step process into Pu-239. [22] It can then be separated from the uranium in a nuclear reprocessing plant. [23] Weapons-grade plutonium is defined as being predominantly Pu-239, typically about 93% Pu-239. [24]
Enriched uranium is a type of uranium in which the percent composition of uranium-235 (written 235 U) has been increased through the process of isotope separation.Naturally occurring uranium is composed of three major isotopes: uranium-238 (238 U with 99.2732–99.2752% natural abundance), uranium-235 (235 U, 0.7198–0.7210%), and uranium-234 (234 U, 0.0049–0.0059%).
Since 238 U has a much longer half-life than the lighter isotopes, DU is about 40% less radioactive than natural uranium. [2] [13] [14] Most of the alpha radiation comes from 238 U and 234 U [notes 1] whereas beta radiation comes from decay products 234 Th and 234 Pa that are formed within a few weeks. [clarification needed] [citation needed]
Natural uranium (99.3% U-238, 0.7% U-235) in fast breeder reactor: 86,000,000: Reactor-grade uranium (3.5% U-235) in light-water reactor: 3,456,000: 35%: Pu-238 α-decay:
234 U occurs in natural uranium as an indirect decay product of uranium-238, but makes up only 55 parts per million of the uranium because its half-life of 245,500 years is only about 1/18,000 that of 238 U. The path of production of 234 U is this: 238 U alpha decays to thorium-234. Next, with a short half-life, 234 Th beta decays to ...
The more 238 U nuclei in the mixture, the less likely absorption by a single nucleus of the moderating neutrons will take place. The effect of absorption in some 238 U nuclei on absorption in others is called resonance level shielding. It increases with increasing concentration of resonance absorbers. As an example, we can calculate the ...