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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 ...
The material must be 85% or more of 235 U and is known as weapons grade uranium, though for a crude and inefficient weapon 20% enrichment is sufficient (called weapon(s)-usable). Even lower enrichment can be used, but this results in the required critical mass rapidly increasing.
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.
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 ...
Orano, the France-based parent company of Orano USA, is a world leader in the nuclear fuel supply chain, from its uranium mines in Canada, Kazakhstan and Niger, to its methods of recycling used ...
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.