Editing Uranium (section)

==History==

===Pre-discovery use===
The use of [[pitchblende]], uranium in its natural [[oxide]] form, dates back to at least the year 79 AD, when it was used in the [[Roman Empire]] to add a yellow color to [[ceramic]] glazes.<ref name="LANL" /> Yellow glass with 1% uranium oxide was found in a Roman villa on Cape [[Posillipo]] in the [[Gulf of Naples]], Italy, by R. T. Gunther of the [[University of Oxford]] in 1912.{{sfn|Emsley|2001|p=482}} Starting in the late [[Middle Ages]], pitchblende was extracted from the [[Habsburg]] silver mines in [[Jáchymov|Joachimsthal]], [[Bohemia]] (now Jáchymov in the Czech Republic) in the [[Ore Mountains]], and was used as a coloring agent in the local [[glass]]making industry.{{sfn|Emsley|2001|p=477}} In the early 19th century, the world's only known sources of uranium ore were these mines.

===Discovery===
[[File:Uranus_Voyager2_color_calibrated.png|thumb|left|upright|The planet [[Uranus]], which uranium is named after]]
The [[discovery of the chemical elements|discovery]] of the element is credited to the German chemist [[Martin Heinrich Klaproth]]. While he was working in his experimental laboratory in [[Berlin]] in 1789, Klaproth was able to precipitate a yellow compound (likely [[sodium diuranate]]) by dissolving [[pitchblende]] in [[nitric acid]] and neutralizing the solution with [[sodium hydroxide]].{{sfn|Emsley|2001|p=477}} Klaproth assumed the yellow substance was the oxide of a yet-undiscovered element and heated it with [[charcoal]] to obtain a black powder, which he thought was the newly discovered metal itself (in fact, that powder was an [[oxide of uranium]]).{{sfn|Emsley|2001|p=477}}<ref>{{cite journal
| title = Chemische Untersuchung des Uranits, einer neuentdeckten metallischen Substanz
| author = Klaproth, M. H.
| journal = Chemische Annalen
| volume = 2
| date = 1789
| pages = 387–403
| author-link = Martin Heinrich Klaproth}}</ref> He named the newly discovered element after the planet [[Uranus]] (named after the primordial [[Uranus (mythology)|Greek god of the sky]]), which had been discovered eight years earlier by [[William Herschel]].<ref>{{cite encyclopedia|edition=4th|title=Uranium|encyclopedia=The American Heritage Dictionary of the English Language |publisher=Houghton Mifflin Company|url=http://www.answers.com/uranium|access-date=15 January 2007|archive-date=27 July 2011 |archive-url=https://web.archive.org/web/20110727194715/http://www.answers.com/uranium|url-status=dead}}</ref>

In 1841, [[Eugène-Melchior Péligot]], Professor of Analytical Chemistry at the [[Conservatoire National des Arts et Métiers]] (Central School of Arts and Manufactures) in [[Paris]], isolated the first sample of uranium metal by heating [[uranium tetrachloride]] with [[potassium]].{{sfn|Emsley|2001|p=477}}<ref>{{cite journal| title=Recherches Sur L'Uranium
| author=Péligot, E.-M. |journal=[[Annales de chimie et de physique]]
| volume=5 |issue=5 |date=1842
| pages=5–47 |url=http://gallica.bnf.fr/ark:/12148/bpt6k34746s/f4.table}}</ref>

[[File:Becquerel plate.jpg|thumb|[[Henri Becquerel]] discovered [[radioactivity]] by exposing a [[photographic plate]] to uranium in 1896.|alt=Two fuzzy black features on a fuzzy white paper-like background. There is a handwriting at the top of the picture.]]
[[Henri Becquerel]] discovered radioactivity by using uranium in 1896.<ref name="ColumbiaEncy" /> Becquerel made the discovery in Paris by leaving a sample of a uranium salt, K{{sub|2}}UO{{sub|2}}(SO{{sub|4}}){{sub|2}} (potassium uranyl sulfate), on top of an unexposed [[photographic plate]] in a drawer and noting that the plate had become "fogged".{{sfn|Emsley|2001|p=478}} He determined that a form of invisible light or rays emitted by uranium had exposed the plate.

During World War I when the [[Central Powers]] suffered a shortage of molybdenum to make artillery gun barrels and high speed tool steels, they routinely used [[ferrouranium]] alloy as a substitute, as it presents many of the same physical characteristics as molybdenum. When this practice became known in 1916 the US government requested several prominent universities to research the use of uranium in manufacturing and metalwork. Tools made with these formulas remained in use for several decades,<ref>{{cite web|url=https://books.google.com/books?id=-5c7AQAAMAAJ&q=ferrouranium+artillery&pg=PA367|title=The Electric Journal|date=10 April 1920|publisher=Westinghouse Club |via=Google Books}}</ref><ref>{{cite book |url=https://books.google.com/books?id=kfvBmuFOAiEC&pg=PA8 |title=Preparation of ferro-uranium |first1=Horace Wadsworth |last1=Gillett |first2=Edward Lawrence |last2=Mack |date=10 April 1917 |series=Technical Paper 177 – U.S. Bureau of Mines |publisher=U.S. Govt. print. off. |via=Google Books}}</ref> until the [[Manhattan Project]] and the [[Cold War]] placed a large demand on uranium for fission research and weapon development.

===Fission research===
[[File:UraniumCubesLarge.jpg|thumb|Cuboids of uranium produced during the Manhattan Project]]
A team led by [[Enrico Fermi]] in 1934 found that bombarding uranium with neutrons produces [[beta decay|beta rays]] ([[electron]]s or [[positron]]s from the elements produced; see [[beta particle]]).{{sfn|Seaborg|1968|p=773}} The fission products were at first mistaken for new elements with atomic numbers 93 and 94, which the Dean of the [[Sapienza University of Rome]], [[Orso Mario Corbino]], named [[ausenium and hesperium]], respectively.<ref>{{cite web
 |url          = https://www.nobelprize.org/nobel_prizes/physics/laureates/1938/fermi-lecture.pdf
 |last         = Fermi
 |first        = Enrico
 |date         = 12 December 1938
 |title        = Artificial radioactivity produced by neutron bombardment: Nobel Lecture
 |publisher    = Royal Swedish Academy of Sciences
 |access-date  = 14 June 2017
 |archive-url  = https://web.archive.org/web/20180809111423/https://www.nobelprize.org/nobel_prizes/physics/laureates/1938/fermi-lecture.pdf
 |archive-date = 9 August 2018
 |url-status     = dead
}}</ref><ref>{{cite journal |author=De Gregorio, A. |title=A Historical Note About How the Property was Discovered that Hydrogenated Substances Increase the Radioactivity Induced by Neutrons |date=2003 |pages=41–47 |volume=19 |journal=Nuovo Saggiatore |arxiv=physics/0309046}}</ref><ref>{{cite web |author=Nigro, M. |title=Hahn, Meitner e la teoria della fissione |url=http://www.brera.unimi.it/SISFA/atti/2003/312-321NigroBari.pdf |date=2004 |access-date=5 May 2009 |archive-date=25 March 2009 |archive-url=https://web.archive.org/web/20090325120427/http://www.brera.unimi.it/SISFA/atti/2003/312-321NigroBari.pdf |url-status=dead}}</ref><ref>{{cite web| author=van der Krogt, Peter |url=http://elements.vanderkrogt.net/element.php?sym=Pu |title=Elementymology & Elements Multidict |access-date=5 May 2009}}</ref> The experiments leading to the discovery of uranium's ability to fission (break apart) into lighter elements and release [[binding energy]] were conducted by [[Otto Hahn]] and [[Fritz Strassmann]]{{sfn|Seaborg|1968|p=773}} in Hahn's laboratory in Berlin. [[Lise Meitner]] and her nephew, physicist [[Otto Robert Frisch]], published the physical explanation in February 1939 and named the process "[[nuclear fission]]".<ref>{{cite journal
| title = Disintegration of Uranium by Neutrons: a New Type of Nuclear Reaction
| author1 = [[Lise Meitner|Meitner, L.]]
| author2 = [[Otto Frisch|Frisch, O.]]
| journal = Nature
| volume = 143
| date = 1939
| pages = 239–240
| doi = 10.1038/224466a0
| url = http://www.atomicarchive.com/Docs/Begin/Nature_Meitner.shtml |bibcode = 1969Natur.224..466M
| issue=5218| s2cid = 4188874
}}</ref> Soon after, Fermi hypothesized that fission of uranium might release enough neutrons to sustain a fission reaction. Confirmation of this hypothesis came in 1939, and later work found that on average about 2.5 neutrons are released by each fission of uranium-235.{{sfn|Seaborg|1968|p=773}} Fermi urged [[Alfred O. C. Nier]] to separate uranium isotopes for determination of the fissile component, and on 29 February 1940, Nier used an instrument he built at the [[University of Minnesota]] to separate the world's first [[uranium-235]] sample in the Tate Laboratory. Using [[Pupin Hall|Columbia University]]'s [[cyclotron]], [[John R. Dunning|John Dunning]] confirmed the sample to be the isolated fissile material on 1 March.<ref>{{cite web |title=Alfred O. C. Nier |url=https://www.aps.org/programs/outreach/history/historicsites/nier.cfm |website=www.aps.org |access-date=2016-12-04 |archive-date=19 July 2018 |archive-url=https://web.archive.org/web/20180719113725/https://www.aps.org/programs/outreach/history/historicsites/nier.cfm |url-status=dead }}</ref> Further work found that the far more common uranium-238 isotope can be [[Nuclear transmutation|transmuted]] into plutonium, which, like uranium-235, is also fissile by thermal neutrons. These discoveries led numerous countries to begin working on the development of nuclear weapons and [[nuclear power]]. Despite fission having been discovered in Germany, the ''[[Uranverein]]'' ("uranium club") Germany's wartime project to research nuclear power and/or weapons was hampered by limited resources, infighting, the exile or non-involvement of several prominent scientists in the field and several crucial mistakes such as failing to account for impurities in available graphite samples which made it appear less suitable as a [[neutron moderator]] than it is in reality. Germany's attempts to build a [[natural uranium]] / [[heavy water]] reactor had not come close to reaching criticality by the time the Americans reached [[Haigerloch]], the site of the last German wartime reactor experiment.<ref>{{cite web|author=Manfred Popp |url=https://www.spektrum.de/news/hitlers-atombombe-warum-es-sie-nicht-gab/1423529 |title=Wissenschaftsgeschichte: Hitlers Atombombe – warum es sie nicht gab – Spektrum der Wissenschaft |publisher=Spektrum.de |date=2016-09-21 |access-date=2022-02-25}}</ref>

On 2 December 1942, as part of the [[Manhattan Project]], another team led by Enrico Fermi was able to initiate the first artificial self-sustained [[nuclear chain reaction]], [[Chicago Pile-1]]. An initial plan using enriched uranium-235 was abandoned as it was as yet unavailable in sufficient quantities.<ref>{{cite web |url=http://large.stanford.edu/courses/2013/ph241/masters1/ |title=Chicago Pile One|website=large.stanford.edu|access-date=2016-12-04}}</ref> Working in a lab below the stands of [[Stagg Field]] at the [[University of Chicago]], the team created the conditions needed for such a reaction by piling together 360 tonnes of [[graphite]], 53 tonnes of [[uranium oxide]], and 5.5 tonnes of uranium metal, most of which was supplied by [[Westinghouse Lamp Plant]] in a makeshift production process.{{sfn|Seaborg|1968|p=773}}<ref>{{cite journal |last=Walsh |first=John |title=A Manhattan Project Postscript |journal=Science |date=19 June 1981 |volume=212 |pages=1369–1371 |bibcode=1981Sci...212.1369W |pmid=17746246 |url=http://pbadupws.nrc.gov/docs/ML0533/ML053340429.pdf |access-date=23 March 2013 |publisher=AAAS |doi=10.1126/science.212.4501.1369 |issue=4501}}</ref>

===Nuclear weaponry===
[[File:Atomic cloud over Hiroshima - NARA 542192 - Edit.jpg|thumb|upright|[[Mushroom cloud]] over Hiroshima after the dropping of the uranium-fired '[[Little Boy]]'|alt=White fragmentred mushroom-like smoke cloud evolving from the ground.]]
Two types of atomic bomb were developed by the United States during [[World War II]]: a uranium-based device (codenamed "Little Boy") whose fissile material was highly [[enriched uranium]], and a plutonium-based device (see [[Trinity test]] and "Fat Man") whose plutonium was derived from uranium-238. Little Boy became the first nuclear weapon used in war when it was detonated over [[Hiroshima]], [[Japan]], on 6 August 1945. Exploding with a yield equivalent to 12,500 tonnes of [[TNT]], the blast and thermal wave of the bomb destroyed nearly 50,000 buildings and killed about 75,000 people (see [[Atomic bombings of Hiroshima and Nagasaki]]).{{sfn|Emsley|2001|p=478}} Initially it was believed that uranium was relatively rare, and that [[nuclear proliferation]] could be avoided by simply buying up all known uranium stocks, but within a decade large deposits of it were discovered in many places around the world.<ref>Helmreich, J.E. ''Gathering Rare Ores: The Diplomacy of Uranium Acquisition, 1943–1954'', Princeton UP, 1986: ch. 10 {{ISBN|0-7837-9349-9}}</ref>

===Reactors===
[[File:First four nuclear lit bulbs.jpeg|thumb|Four light bulbs lit with electricity generated from the first artificial electricity-producing nuclear reactor, [[Experimental Breeder Reactor I|EBR-I]] (1951)|alt=An industrial room with four large illuminated light bulbs hanging down from a bar.]]
The [[X-10 Graphite Reactor]] at [[Oak Ridge National Laboratory]] (ORNL) in Oak Ridge, Tennessee, formerly known as the Clinton Pile and X-10 Pile, was the world's second artificial nuclear reactor (after Enrico Fermi's Chicago Pile) and was the first reactor designed and built for continuous operation. [[Argonne National Laboratory]]'s [[Experimental Breeder Reactor I]], located at the Atomic Energy Commission's National Reactor Testing Station near [[Arco, Idaho]], became the first nuclear reactor to create electricity on 20 December 1951.<ref>{{cite web |url=http://www.ne.anl.gov/About/reactors/frt.shtml |title=Reactors Designed by Argonne National Laboratory: Fast Reactor Technology |publisher=U.S. Department of Energy, Argonne National Laboratory |date=2012 |access-date=25 July 2012}}</ref> Initially, four 150-watt light bulbs were lit by the reactor, but improvements eventually enabled it to power the whole facility (later, the town of Arco became the first in the world to have all its [[electricity]] come from nuclear power generated by [[BORAX-III]], another reactor designed and operated by [[Argonne National Laboratory]]).<ref>{{cite web |url=http://web.em.doe.gov/tie/history.html |title=History and Success of Argonne National Laboratory: Part 1 |publisher=U.S. Department of Energy, Argonne National Laboratory |date=1998 |access-date=28 January 2007 |archive-url=https://web.archive.org/web/20060926155637/http://web.em.doe.gov/tie/history.html |archive-date=26 September 2006 |url-status=dead}}</ref><ref>{{cite web |title=Reactors Designed by Argonne National Laboratory: Light Water Reactor Technology Development |publisher=U.S. Department of Energy, Argonne National Laboratory |date=2012 |url=http://www.ne.anl.gov/About/reactors/lwr3.shtml#fragment-5 |access-date=25 July 2012}}</ref> The world's first commercial scale nuclear power station, [[Obninsk Nuclear Power Plant|Obninsk]] in the [[Soviet Union]], began generation with its reactor AM-1 on 27 June 1954. Other early nuclear power plants were [[Calder Hall nuclear power station|Calder Hall]] in England, which began generation on 17 October 1956,<ref>{{cite news |title=1956: Queen switches on nuclear power |date=17 October 1956 |work=[[BBC News]] |url=http://news.bbc.co.uk/onthisday/hi/dates/stories/october/17/newsid_3147000/3147145.stm |access-date=28 June 2006}}</ref> and the [[Shippingport Atomic Power Station]] in [[Pennsylvania]], which began on 26 May 1958. Nuclear power was used for the first time for propulsion by a [[submarine]], the [[USS Nautilus (SSN-571)|USS ''Nautilus'']], in 1954.{{sfn|Seaborg|1968|p=773}}<ref>{{cite web |title=STR (Submarine Thermal Reactor) in "Reactors Designed by Argonne National Laboratory: Light Water Reactor Technology Development" |publisher=U.S. Department of Energy, Argonne National Laboratory |url=http://www.ne.anl.gov/About/reactors/lwr3.shtml#fragment-2 |date=2012 |access-date=25 July 2012}}</ref>

===Prehistoric naturally occurring fission===
{{Main|Natural nuclear fission reactor}}
In 1972, French physicist [[Francis Perrin (physicist)|Francis Perrin]] discovered fifteen ancient and no longer active natural nuclear fission reactors in three separate ore deposits at the [[Oklo mine]] in [[Gabon]], Africa, collectively known as the [[Natural nuclear fission reactor|Oklo Fossil Reactors]]. The ore deposit is 1.7&nbsp;billion years old; then, uranium-235 constituted about 3% of uranium on Earth.<ref name="OCRWM">{{cite web |title=Oklo: Natural Nuclear Reactors |work=Office of Civilian Radioactive Waste Management |url=http://www.ocrwm.doe.gov/factsheets/doeymp0010.shtml |archive-url=https://web.archive.org/web/20040603085718/http://www.ocrwm.doe.gov/factsheets/doeymp0010.shtml |archive-date=3 June 2004 |access-date=28 June 2006}}</ref> This is high enough to permit a sustained chain reaction, if other supporting conditions exist. The capacity of the surrounding sediment to contain the health-threatening [[nuclear waste]] products has been cited by the U.S. federal government as supporting evidence for the feasibility to store spent nuclear fuel at the [[Yucca Mountain nuclear waste repository]].<ref name="OCRWM" />

===Contamination and the Cold War legacy===
[[File:US and USSR nuclear stockpiles.svg|thumb|U.S. and USSR/Russian nuclear weapons stockpiles, 1945–2005|alt=A graph showing evolution of number of nuclear weapons in the US and USSR and in the period 1945–2005. US dominates early and USSR later years with and crossover around 1978.]]
Above-ground [[nuclear testing|nuclear tests]] by the Soviet Union and the United States in the 1950s and early 1960s and by [[France]] <!-- SEE TALK and [[Israel]] -->into the 1970s and 1980s{{sfn|Emsley|2001|p=480}} spread a significant amount of [[nuclear fallout|fallout]] from uranium [[daughter isotope]]s around the world.<ref>{{cite journal |author=Warneke, T. |author2=Croudace, I. W. |author3=Warwick, P. E. |author4=Taylor, R. N. |name-list-style=amp |title=A new ground-level fallout record of uranium and plutonium isotopes for northern temperate latitudes |journal=Earth and Planetary Science Letters| date=2002 |volume=203 |issue=3–4 |pages=1047–1057 |doi=10.1016/S0012-821X(02)00930-5 |bibcode=2002E&PSL.203.1047W}}</ref> Additional fallout and pollution occurred from several [[nuclear and radiation accidents|nuclear accidents]].<ref>{{cite magazine |url=http://www.time.com/time/photogallery/0,29307,1887705,00.html |archive-url=https://web.archive.org/web/20090328130544/http://www.time.com/time/photogallery/0,29307,1887705,00.html |url-status=dead |archive-date=28 March 2009 |title=The Worst Nuclear Disasters |magazine=Time |date=25 March 2009 |access-date=24 May 2010}}</ref>

Uranium miners have a higher incidence of [[cancer]]. An excess risk of lung cancer among [[Navajo people|Navajo]] uranium miners, for example, has been documented and linked to their occupation.<ref name="Gilliland et al 2000">{{cite journal |journal=Journal of Occupational and Environmental Medicine |author=Gilliland, Frank D. |author2=Hunt, William C. |author3=Pardilla, Marla |author4=Key, Charles R. |title=Uranium Mining and Lung Cancer Among Navajo Men in New Mexico and Arizona, 1969 to 1993 |date=March 2000 |volume=42 |issue=3 |pages=278–283 |pmid=10738707 |doi=10.1097/00043764-200003000-00008}}</ref> The [[Radiation Exposure Compensation Act]], a 1990 law in the US, required $100,000 in "compassion payments" to uranium miners diagnosed with cancer or other respiratory ailments.<ref name="ajph.org">{{cite journal |title=The History of Uranium Mining and the Navajo People |doi=10.2105/AJPH.92.9.1410 |publisher=Ajph.org |pmid=12197966 |date=2002 |last1=Brugge |first1=Doug |last2=Goble |first2=Rob |journal=American Journal of Public Health |volume=92 |issue=9 |pages=1410–1419 |pmc=3222290}}</ref>

During the [[Cold War]] between the Soviet Union and the United States, huge stockpiles of uranium were amassed and tens of thousands of nuclear weapons were created using enriched uranium and plutonium made from uranium. After the [[Collapse of the Soviet Union (1985–1991)#Dissolution of the USSR|break-up of the Soviet Union]] in 1991, an estimated 600&nbsp;short tons (540&nbsp;metric tons) of highly enriched weapons grade uranium (enough to make 40,000 nuclear warheads) had been stored in often inadequately guarded facilities in the [[Russia|Russian Federation]] and several other former Soviet states.<ref name="EncyIntel" /> Police in [[Asia]], [[Europe]], and [[South America]] on at least 16 occasions from 1993 to 2005 have [[nuclear espionage|intercepted shipments]] of smuggled bomb-grade uranium or plutonium, most of which was from ex-Soviet sources.<ref name="EncyIntel" /> From 1993 to 2005 the [[Material Protection, Control, and Accounting Program]], operated by the [[federal government of the United States]], spent about US$550 million to help safeguard uranium and plutonium stockpiles in Russia. This money was used for improvements and security enhancements at research and storage facilities.<ref name="EncyIntel" />

Safety of nuclear facilities in Russia has been significantly improved since the stabilization of political and economical turmoil of the early 1990s. For example, in 1993 there were 29 incidents ranking above level 1 on the [[International Nuclear Event Scale]], and this number dropped under four per year in 1995–2003. The number of employees receiving annual radiation doses above 20 [[Sievert|mSv]], which is equivalent to a single full-body [[CT scan]],<ref>{{cite journal |pmid=9166072 |year=1997 |last1=Van Unnik |first1=J. G. |last2=Broerse |first2=J. J. |last3=Geleijns |first3=J. |last4=Jansen |first4=J. T. |last5=Zoetelief |first5=J. |last6=Zweers |first6=D. |title=Survey of CT techniques and absorbed dose in various Dutch hospitals |volume=70 |issue=832 |pages=367–371 |journal=The British Journal of Radiology|doi=10.1259/bjr.70.832.9166072 }} (3000 examinations from 18 hospitals)</ref> saw a strong decline around 2000. In November 2015, the Russian government approved a federal program for nuclear and radiation safety for 2016 to 2030 with a budget of 562 billion rubles (ca. 8 billion [[USD]]). Its key issue is "the deferred liabilities accumulated during the 70 years of the nuclear industry, particularly during the time of the Soviet Union". About 73% of the budget will be spent on decommissioning aged and obsolete nuclear reactors and nuclear facilities, especially those involved in state defense programs; 20% will go in processing and disposal of nuclear fuel and radioactive waste, and 5% into monitoring and ensuring of nuclear and radiation safety.<ref>[https://world-nuclear.org/information-library/country-profiles/countries-o-s/russia-nuclear-fuel-cycle.aspx Russia's Nuclear Fuel Cycle]. World Nuclear Association. Updated December 2021.</ref>