Editing Enriched uranium (section)

{{Short description|Uranium in which isotope separation has been used to increase its proportion of uranium-235}}
{{Use dmy dates|date=December 2020}}

'''Enriched uranium''' is a type of [[uranium]] in which the percent composition of [[uranium-235]] (written <sup>235</sup>U) has been increased through the process of [[isotope separation]]. Naturally occurring uranium is composed of three major isotopes:  [[uranium-238]] (<sup>238</sup>U with 99.2732–99.2752% [[natural abundance]]), [[uranium-235]] (<sup>235</sup>U, 0.7198–0.7210%), and [[uranium-234]] (<sup>234</sup>U, 0.0049–0.0059%).{{NUBASE2020|ref}} <sup>235</sup>U is the only [[primordial nuclide|nuclide existing in nature]] (in any appreciable amount) that is [[fissile]] with [[thermal neutron]]s.<ref>{{cite book|last=OECD Nuclear Energy Agency|title=Nuclear Energy Today|publisher=OECD Publishing|year=2003|isbn=9789264103283|page=25|url=https://books.google.com/books?id=PvL7twdmK9sC&pg=PA25}}</ref>[[File:Uranium enrichment proportions.svg|thumb|Proportions of uranium-238 (blue) and uranium-235 (red) found naturally versus enriched grades]]

Enriched uranium is a critical component for both civil [[nuclear power]] generation and military [[nuclear weapon]]s.

There are about 2,000&nbsp;[[tonne]]s of highly enriched uranium in the world,<ref>{{cite web | url=http://docs.nrdc.org/nuclear/files/nuc_06129701a_185.pdf | title=Safeguarding Nuclear Weapon-Usable Materials in Russia | first=Thomas B. |last=Cochran ([[Natural Resources Defense Council]]) | publisher=Proceedings of international forum on illegal nuclear traffic | date=12 June 1997 | url-status=dead | archive-url=https://web.archive.org/web/20120722184311/http://docs.nrdc.org/nuclear/files/nuc_06129701a_185.pdf | archive-date=22 July 2012}}</ref> produced mostly for [[nuclear power]], nuclear weapons, [[Nuclear marine propulsion|naval propulsion]], and smaller quantities for [[research reactor]]s.

The <sup>238</sup>U remaining after enrichment is known as [[depleted uranium]] (DU), and is considerably less [[radioactive]] than even natural uranium, though still very dense. Depleted uranium is used as a [[radiation shielding]] material and for [[Armour-piercing ammunition|armor-penetrating weapons]].
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