Editing Radioactive waste (section)

==== Front end ====
Waste from the front end of the [[nuclear fuel cycle]] is usually alpha-emitting waste from the extraction of uranium. It often contains radium and its decay products.

[[Uranium dioxide]] (UO<sub>2</sub>) concentrate from mining is a thousand or so times as radioactive as the [[granite]] used in buildings. It is refined from [[yellowcake]] (U<sub>3</sub>O<sub>8</sub>), then converted to [[uranium hexafluoride]] gas (UF<sub>6</sub>). As a gas, it undergoes [[enriched uranium|enrichment]] to increase the [[U-235]] content from 0.7% to about 4.4% (LEU). It is then turned into a hard [[ceramic]] oxide (UO<sub>2</sub>) for assembly as reactor fuel elements.<ref>{{cite book |last=Cochran |first=Robert |url=http://www.new.ans.org/store/i_350015 |title=The Nuclear Fuel Cycle: Analysis and Management |publisher=American Nuclear Society |year=1999 |isbn=0-89448-451-6 |location=La Grange Park, Illinois |pages=52–57 |language=en-us |access-date=2011-09-04 |archive-url=https://web.archive.org/web/20111016144333/http://www.new.ans.org/store/i_350015 |archive-date=2011-10-16 |url-status=dead}}</ref>

The main by-product of enrichment is [[depleted uranium]] (DU), principally the [[Uranium-238|U-238]] isotope, with a U-235 content of ~0.3%. It is stored, either as UF<sub>6</sub> or as U<sub>3</sub>O<sub>8</sub>. Some is used in applications where its extremely high density makes it valuable such as [[anti-tank]] [[KE-penetrator|shells]], and on at least [[Pen Duick|one occasion]] even a sailboat [[keel]].<ref>{{cite web |url=http://www.janes.com/defence/news/jdw/jdw010108_1_n.shtml |title=Global Defence News and Defence Headlines – IHS Jane's 360 |url-status=live |archive-url=https://web.archive.org/web/20080725032900/http://www.janes.com/defence/news/jdw/jdw010108_1_n.shtml |archive-date=2008-07-25}}</ref> It is also used with plutonium for making [[mixed oxide fuel]] (MOX) and to dilute, or [[enriched uranium#Downblending|downblend]], highly enriched uranium from weapons stockpiles which is now being redirected to become reactor fuel.