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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 ...
Natural uranium consists of three isotopes; the majority (99.274%) is U-238, while approximately 0.72% is U-235, fissile by thermal neutrons, and the remaining 0.0055% is U-234. If natural uranium is enriched to 3% U-235, it can be used as fuel for light water nuclear reactors. If it is enriched to 90% uranium-235, it can be used for nuclear ...
In fact, 235 U is the only naturally occurring fissile nucleus. [4] Because natural uranium is only about 0.72% 235 U by mass, it must be enriched to a concentration of 2–5% to be able to support a continuous nuclear chain reaction [5] when normal water is used as the moderator. The product of this enrichment process is called enriched uranium.
Natural uranium is made weapons-grade through isotopic enrichment. Initially only about 0.7% of it is fissile U-235, with the rest being almost entirely uranium-238 (U-238). They are separated by their differing masses. Highly enriched uranium is considered weapons-grade when it has been enriched to about 90% U-235. [citation needed]
In this method, an infrared laser is directed at uranium hexafluoride gas (if enrichment of uranium is desired), exciting molecules that contain a U-235 atom. A second laser, either also in the IR (infrared multiphoton dissociation) or in the UV, frees a fluorine atom, leaving uranium pentafluoride which then precipitates out of the gas.
A cascade of gas centrifuges at a U.S. enrichment plant in Piketon, Ohio, in 1984. Iran is using similar technology to enrich uranium. U.S. Department of EnergyIran’s nuclear program was a major ...
Infrared absorption spectra of the two UF 6 isotopes at 300 and 80 K. Schematic of a stage of an isotope separation plant for uranium enrichment with laser. An infrared laser with a wavelength of approx. 16 μm radiates at a high repetition rate onto a UF6 carrier gas mixture, which flows supersonically out of a laval nozzle.
In broad outlines, the nuclear fuel supply chain works like this: First, someone like Cameco (NYSE: CCJ) mines natural uranium, which contains about 0.7% of the isotope U-235 that is necessary for ...