uranium
Uranium is a chemical element with the symbol U and atomic number 92. It is a silvery-grey metal in the actinide series of the periodic table. A uranium atom has 92 protons and 92 electrons, of which 6 are valence electrons. Uranium is weak ...
ore from the ground. Over 50 thousand tons of uranium were produced in 2019.
Kazakhstan
Kazakhstan, officially the Republic of Kazakhstan, is a transcontinental country located mainly in Central Asia and partly in Eastern Europe. It borders Russia to the north and west, China to the east, Kyrgyzstan to the southeast, Uzbeki ...
,
Canada
Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by tot ...
, and Australia were the top three uranium producers, respectively, and together account for 68% of world production. Other countries producing more than 1,000 tons per year included
Namibia
Namibia (, ), officially the Republic of Namibia, is a country in Southern Africa. Its western border is the Atlantic Ocean. It shares land borders with Zambia and Angola to the north, Botswana to the east and South Africa to the south and ea ...
,
Niger
)
, official_languages =
, languages_type = National languagesRussia
Russia (, , ), or the Russian Federation, is a transcontinental country spanning Eastern Europe and Northern Asia. It is the largest country in the world, with its internationally recognised territory covering , and encompassing one-eig ...
,
Uzbekistan
Uzbekistan (, ; uz, Ozbekiston, italic=yes / , ; russian: Узбекистан), officially the Republic of Uzbekistan ( uz, Ozbekiston Respublikasi, italic=yes / ; russian: Республика Узбекистан), is a doubly landlocked co ...
, the
United States
The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territori ...
, and China. Nearly all of the world's mined uranium is used to power nuclear power plants. Historically uranium was also used in applications such as
uranium glass
Uranium glass is glass which has had uranium, usually in oxide diuranate form, added to a glass mix before melting for colouration. The proportion usually varies from trace levels to about 2% uranium by weight, although some 20th-century piec ...
or
ferrouranium
Ferrouranium, also called ferro-uranium, is a ferroalloy, an alloy of iron and uranium, after World War II usually depleted uranium.
Composition and properties
The alloy contains about 35–50% uranium and 1.5–4.0% carbon. At least two intermeta ...
but those applications have declined due to the radioactivity of uranium and are nowadays mostly supplied with a plentiful cheap supply of depleted uranium which is also used in uranium ammunition. In addition to being cheaper, depleted uranium is also less radioactive due to a lower content of short-lived and than natural uranium.
Uranium is mined by
in-situ leaching
In-situ leaching (ISL), also called in-situ recovery (ISR) or solution mining, is a mining process used to recover minerals such as copper and uranium through boreholes drilled into a deposit, ''in situ''. In situ leach works by artificially diss ...
(57% of world production) or by conventional
underground
Underground most commonly refers to:
* Subterranea (geography), the regions beneath the surface of the Earth
Underground may also refer to:
Places
* The Underground (Boston), a music club in the Allston neighborhood of Boston
* The Underground ...
or
open-pit mining
Open-pit mining, also known as open-cast or open-cut mining and in larger contexts mega-mining, is a surface mining technique of extracting rock or minerals from the earth from an open-air pit, sometimes known as a borrow.
This form of mini ...
of ores (43% of production). During in-situ mining, a leaching solution is pumped down drill holes into the uranium ore deposit where it dissolves the ore minerals. The uranium-rich fluid is then pumped back to the surface and processed to extract the uranium compounds from solution. In conventional mining, ores are processed by grinding the ore materials to a uniform particle size and then treating the ore to extract the uranium by chemical leaching. The milling process commonly yields dry powder-form material consisting of natural uranium, "
yellowcake
Yellowcake (also called urania) is a type of uranium concentrate powder obtained from leach solutions, in an intermediate step in the processing of uranium ores. It is a step in the processing of uranium after it has been mined but before f ...
," which is nowadays commonly sold on the uranium market as U3O8. While some nuclear power plants - most notably
heavy water reactor
A pressurized heavy-water reactor (PHWR) is a nuclear reactor that uses heavy water ( deuterium oxide D2O) as its coolant and neutron moderator. PHWRs frequently use natural uranium as fuel, but sometimes also use very low enriched uranium. The ...
uranium dioxide
Uranium dioxide or uranium(IV) oxide (), also known as urania or uranous oxide, is an oxide of uranium, and is a black, radioactive, crystalline powder that naturally occurs in the mineral uraninite. It is used in nuclear fuel rods in nuclear re ...
), the vast majority of commercial nuclear power plants and many
research reactor
Research reactors are nuclear fission-based nuclear reactors that serve primarily as a neutron source. They are also called non-power reactors, in contrast to power reactors that are used for electricity production, heat generation, or marit ...
s require
uranium enrichment
Enriched uranium is a type of uranium in which the percent composition of uranium-235 (written 235U) has been increased through the process of isotope separation. Naturally occurring uranium is composed of three major isotopes: uranium-238 (238 ...
, which raises the content of from the natural 0.72% to 3-5% (for use in
light water reactor
The light-water reactor (LWR) is a type of thermal-neutron reactor that uses normal water, as opposed to heavy water, as both its coolant and neutron moderator; furthermore a solid form of fissile elements is used as fuel. Thermal-neutron react ...
s) or
even higher
''Even Higher'' is a book describing the future of TV broadcasting, as predicted by various industry figures.
Published in 2012 by Broadgate Publications in Richmond, London, United Kingdom, ''Even Higher '' is the follow-up volume to ''High ...
, depending on the application. Enrichment requires conversion of the yellowcake into
uranium hexafluoride
Uranium hexafluoride (), (sometimes called "hex") is an inorganic compound with the formula UF6. Uranium hexafluoride is a volatile white solid that reacts with water, releasing corrosive hydrofluoric acid. The compound reacts mildly with alumin ...
and production of the fuel (again usually uranium dioxide, but sometimes
uranium carbide
Uranium carbide, a carbide of uranium, is a hard refractory ceramic material. It comes in several stoichiometries (''x'' differs in ), such as uranium methanide (UC, CAS number 12070-09-6), uranium sesquicarbide (U2C3, CAS number 12076-62-9),
a ...
,
uranium hydride
Uranium hydride, also called uranium trihydride (UH3), is an inorganic compound and a hydride of uranium.
Properties
Uranium hydride is a highly toxic, brownish grey to brownish black pyrophoric powder or brittle solid. Its density at 20 ° ...
or
uranium nitride
Uranium nitrides is any of a family of several ceramic materials: uranium mononitride (UN), uranium sesquinitride (U2N3) and uranium dinitride (UN2). The word nitride refers to the −3 oxidation state of the nitrogen bound to the uranium.
Uranium ...
) from that feedstock.
History
Early uranium mining
Uranium minerals were noticed by miners for a long time prior to the discovery of uranium in 1789. The uranium mineral pitchblende, also known as
uraninite
Uraninite, formerly pitchblende, is a radioactive, uranium-rich mineral and ore with a chemical composition that is largely UO2 but because of oxidation typically contains variable proportions of U3O8. Radioactive decay of the uranium causes ...
Saxony
Saxony (german: Sachsen ; Upper Saxon: ''Saggsn''; hsb, Sakska), officially the Free State of Saxony (german: Freistaat Sachsen, links=no ; Upper Saxon: ''Freischdaad Saggsn''; hsb, Swobodny stat Sakska, links=no), is a landlocked state of ...
, as early as 1565. Other early reports of pitchblende date from 1727 in
Jáchymov
Jáchymov (); german: Sankt Joachimsthal or ''Joachimsthal'') is a spa town in Karlovy Vary District in the Karlovy Vary Region of the Czech Republic. It has about 2,300 inhabitants.
The historical core of the town from the 16th century is we ...
and 1763 in Schwarzwald. The suffix "-blende" applied by Ore Mountain miners to the mineral long before the discovery of the element uranium indicates a mineral that ''looks'' like it contains some usable metal but (according to then available knowledge) doesn't. Terms for minerals later identified to contain
cobalt
Cobalt is a chemical element with the symbol Co and atomic number 27. As with nickel, cobalt is found in the Earth's crust only in a chemically combined form, save for small deposits found in alloys of natural meteoric iron. The free element, p ...
(c.f. "
Kobold
A kobold (occasionally cobold) is a mythical sprite. Having spread into Europe with various spellings including "goblin" and "hobgoblin", and later taking root and stemming from Germanic mythology, the concept survived into modern times in Ge ...
" the modern standard German word for
goblin
A goblin is a small, grotesque, monstrous creature that appears in the folklore of multiple European cultures. First attested in stories from the Middle Ages, they are ascribed conflicting abilities, temperaments, and appearances depending on ...
)
nickel
Nickel is a chemical element with symbol Ni and atomic number 28. It is a silvery-white lustrous metal with a slight golden tinge. Nickel is a hard and ductile transition metal. Pure nickel is chemically reactive but large pieces are slow ...
or "Wolfram" (the standard German term for
tungsten
Tungsten, or wolfram, is a chemical element with the symbol W and atomic number 74. Tungsten is a rare metal found naturally on Earth almost exclusively as compounds with other elements. It was identified as a new element in 1781 and first isol ...
) were similarly derived from superstitious belief that some sort of "mountain gnome" had somehow "hexed" the minerals to trick (c.f. The German use of the term "blenden" cognate of "blind" for "tricking") the miners. Thus examining old documents about the presence of "worthless" -blende type minerals allowed easier exploration, once the true nature of these ores had been discovered.
In the early 19th century, uranium ore was recovered as a byproduct of mining in Saxony, Bohemia, and
Cornwall
Cornwall (; kw, Kernow ) is a historic county and ceremonial county in South West England. It is recognised as one of the Celtic nations, and is the homeland of the Cornish people. Cornwall is bordered to the north and west by the Atlantic ...
. The first deliberate mining of radioactive ores took place in Joachimsthal, a silver-mining city now in the
Czech Republic
The Czech Republic, or simply Czechia, is a landlocked country in Central Europe. Historically known as Bohemia, it is bordered by Austria to the south, Germany to the west, Poland to the northeast, and Slovakia to the southeast. The ...
and origin of the word T(h)aler and from there dollar. Marie Skłodowska-Curie used pitchblende ore from Joachimsthal to isolate the element
radium
Radium is a chemical element with the symbol Ra and atomic number 88. It is the sixth element in group 2 of the periodic table, also known as the alkaline earth metals. Pure radium is silvery-white, but it readily reacts with nitrogen (rathe ...
, a decay product of uranium. This discovery earned her her first Nobel Prize and represents an important step in the history of nuclear physics. Until World War II, uranium was mined primarily for its radium content; some
carnotite
Carnotite is a potassium uranium vanadate radioactive mineral with chemical formula K2( U O2)2( VO4)2·3 H2O. The water content can vary and small amounts of calcium, barium, magnesium, iron, and sodium are often present.
Occurrence
Carnotite ...
deposits were mined primarily for the vanadium content. Sources for radium, contained in the uranium ore, were sought for use as
luminous paint
Luminous paint or luminescent paint is paint that exhibits luminescence. In other words, it gives off visible light through fluorescence, phosphorescence, or radioluminescence. There are three types of luminous paints: fluorescent paint, phosp ...
for watch dials and other instruments, as well as for health-related applications, some of which in retrospect were certainly harmful and some of which must be regarded as
nuclear quackery
Radioactive quackery is quackery that improperly promotes radioactive decay, radioactivity as a therapy for illnesses. Unlike radiotherapy, which is the science, scientifically sound use of radiation for the destruction of cell (biology), cells ...
even from a contemporary standpoint. Given that the half life of is almost 2.8 million times longer than that of , tons of uranium had to be processed to derive a few grams of radium, leaving large amounts of uranium with little economic uses. The byproduct uranium was used mostly as a yellow
pigment
A pigment is a colored material that is completely or nearly insoluble in water. In contrast, dyes are typically soluble, at least at some stage in their use. Generally dyes are often organic compounds whereas pigments are often inorganic compou ...
.
Ferrouranium
Ferrouranium, also called ferro-uranium, is a ferroalloy, an alloy of iron and uranium, after World War II usually depleted uranium.
Composition and properties
The alloy contains about 35–50% uranium and 1.5–4.0% carbon. At least two intermeta ...
started to be used by the
Central Powers
The Central Powers, also known as the Central Empires,german: Mittelmächte; hu, Központi hatalmak; tr, İttifak Devletleri / ; bg, Централни сили, translit=Tsentralni sili was one of the two main coalitions that fought in ...
of
World War I
World War I (28 July 1914 11 November 1918), often abbreviated as WWI, was one of the deadliest global conflicts in history. Belligerents included much of Europe, the Russian Empire, the United States, and the Ottoman Empire, with fightin ...
as a substitute for materials they could no longer import due to the British naval blockade. At the time both sides of the Ore Mountains were contained in territory controlled by the Central Powers, as the northern flank belonged to the German Empire whereas the southern flank belonged to
Austria-Hungary
Austria-Hungary, often referred to as the Austro-Hungarian Empire,, the Dual Monarchy, or Austria, was a constitutional monarchy and great power in Central Europe between 1867 and 1918. It was formed with the Austro-Hungarian Compromise of ...
. Given that uranium was mostly seen as a "waste product" in radium-mining at the time, a plentiful supply was available even without scaling up mining. While radium has legitimate evidence based applications in
nuclear medicine
Nuclear medicine or nucleology is a medical specialty involving the application of radioactive substances in the diagnosis and treatment of disease. Nuclear imaging, in a sense, is " radiology done inside out" because it records radiation emi ...
, the availability of other
radionuclides
A radionuclide (radioactive nuclide, radioisotope or radioactive isotope) is a nuclide that has excess nuclear energy, making it unstable. This excess energy can be used in one of three ways: emitted from the nucleus as gamma radiation; transferr ...
with more desirable properties has all but eliminated the market for radium.
In the United States, the first radium/uranium ore was discovered in 1871 in
gold mines
Gold mining is the extraction of gold resources by mining. Historically, mining gold from alluvial deposits used manual separation processes, such as gold panning. However, with the expansion of gold mining to ores that are not on the surface, ...
near Central City, Colorado. This district produced about 50 tons of high grade ore between 1871 and 1895. Most American uranium ore before World War II came from vanadium deposits on the Colorado Plateau of Utah and Colorado.
In Cornwall, England, the South Terras Mine near St. Stephen opened for uranium production in 1873, and produced about 175 tons of ore before 1900. Other early uranium mining occurred in
Autun
Autun () is a subprefecture of the Saône-et-Loire department in the Bourgogne-Franche-Comté region of central-eastern France. It was founded during the Principate era of the early Roman Empire by Emperor Augustus as Augustodunum to give a Ro ...
ois in France's
Massif Central
The (; oc, Massís Central, ; literally ''"Central Massif"'') is a highland region in south-central France, consisting of mountains and plateaus. It covers about 15% of mainland France.
Subject to volcanism that has subsided in the last 10,0 ...
(whence the name
Autunite
Autunite (hydrated calcium uranyl phosphate), with formula Ca(UO2)2(PO4)2·10–12H2O, is a yellow-greenish fluorescent phosphate mineral with a hardness of 2–. Autunite crystallizes in the orthorhombic system and often occurs as tabular square ...
for a uranium-bearing mineral once mined in the area),
Oberpfalz
The Upper Palatinate (german: Oberpfalz, , ) is one of the seven administrative districts of Bavaria, Germany, and is located in the east of Bavaria.
Geography
The Upper Palatinate is a landscape with low mountains and numerous ponds and lakes ...
in
Bavaria
Bavaria ( ; ), officially the Free State of Bavaria (german: Freistaat Bayern, link=no ), is a state in the south-east of Germany. With an area of , Bavaria is the largest German state by land area, comprising roughly a fifth of the total lan ...
Shinkolobwe
Shinkolobwe, or Kasolo, or Chinkolobew, or Shainkolobwe, was a radium and uranium mine in the Haut-Katanga Province of the Democratic Republic of the Congo (DRC), located 20 km west of Likasi (formerly Jadotville), 20 km south of Kamb ...
Belgian Congo
The Belgian Congo (french: Congo belge, ; nl, Belgisch-Congo) was a Belgian colony in Central Africa from 1908 until independence in 1960. The former colony adopted its present name, the Democratic Republic of the Congo (DRC), in 1964.
Colo ...
(now
Shaba Province
Katanga was one of the four large provinces created in the Belgian Congo in 1914.
It was one of the eleven provinces of the Democratic Republic of the Congo between 1966 and 2015, when it was split into the Tanganyika, Haut-Lomami, Lualaba, a ...
Union Minière du Haut Katanga
Union commonly refers to:
* Trade union, an organization of workers
* Union (set theory), in mathematics, a fundamental operation on sets
Union may also refer to:
Arts and entertainment
Music
* Union (band), an American rock group
** ''Un ...
. Other important deposits mined early in the history of uranium mining include
Port Radium
Port Radium is a mining area on the eastern shore of Great Bear Lake, Northwest Territories, Canada.
It included the settlement of Cameron Bay as well as the Eldorado (also called Port Radium) and Echo Bay mines. The name Port Radium did n ...
, near
Great Bear Lake
Great Bear Lake ( den, Sahtú; french: Grand lac de l'Ours) is a lake in the boreal forest of Canada. It is the largest lake entirely in Canada (Lake Superior and Lake Huron are larger but straddle the Canada–US border), the fourth-largest ...
, Canada, discovered in 1931; along with
Beira Province
Beira () was one of the six traditional provinces or '' comarcas'' of Portugal.
The territorial extension is different from that of the area called ''the Beiras'', which refers to three provinces of 1936, Beira Alta, Beira Baixa and Beira Lit ...
Uzbekistan
Uzbekistan (, ; uz, Ozbekiston, italic=yes / , ; russian: Узбекистан), officially the Republic of Uzbekistan ( uz, Ozbekiston Respublikasi, italic=yes / ; russian: Республика Узбекистан), is a doubly landlocked co ...
(whence
Tyuyamunite
Tyuyamunite (pronounced tuh-YOO-ya-moon-ite) is a very rare uranium mineral with formula Ca(UO2)2V2O8·(5-8)H2O. It is a member of the carnotite group. It is a bright, canary-yellow color because of its high uranium content. Also, because of tyuyam ...
); and
Radium Hill
Radium is a chemical element with the symbol Ra and atomic number 88. It is the sixth element in group 2 of the periodic table, also known as the alkaline earth metals. Pure radium is silvery-white, but it readily reacts with nitrogen (rather t ...
, Australia.
Atomic age
Because of the need for the uranium for bomb research during World War II, the
Manhattan Project
The Manhattan Project was a research and development undertaking during World War II that produced the first nuclear weapons. It was led by the United States with the support of the United Kingdom and Canada. From 1942 to 1946, the project w ...
used a variety of sources for the element. The Manhattan Project initially purchased uranium ore from the Belgian Congo, through the
Union Minière du Haut Katanga
Union commonly refers to:
* Trade union, an organization of workers
* Union (set theory), in mathematics, a fundamental operation on sets
Union may also refer to:
Arts and entertainment
Music
* Union (band), an American rock group
** ''Un ...
. Later the project contracted with vanadium mining companies in the American Southwest. Purchases were also made from the
Eldorado Mining and Refining Limited
Eldorado Resources was a Canadian mining company active between 1926 and 1988. The company was originally established by brothers Charles and Gilbert LaBine as a gold mining enterprise in 1926, but transitioned to focus on radium in the 1930s an ...
company in Canada. This company had large stocks of uranium as waste from its radium refining activities.
The smaller scale
German nuclear program
The Uranverein ( en, "Uranium Club") or Uranprojekt ( en, "Uranium Project") was the name given to the project in Germany to research nuclear technology, including nuclear weapons and nuclear reactors, during World War II. It went through seve ...
likewise tried to acquire uranium, putting the Berlin based Auergesellschaft, which had been taken from previous Jewish-German owners, in charge of acquisition. A substantial amount of uranium from the Belgian Congo (and thus the same source as the one used by the Americans) fell into German hands when the Wehrmacht conquered Belgium. Another important source was mining in the Ore Mountains (mostly on the Czech side, which had been annexed after the Munich treaty of 1938). While incompetence, bad luck, lack of resources and infighting kept the Germans from ever assembling enough uranium and neutron moderator in a single " pile" to achieve criticality, by the end of the war more than enough uranium had been in German hands to theoretically allow for the construction of a crude reactor on the scale of Chicago Pile-1 or the Soviet F-1 (nuclear reactor) if it had all been assembled in a single place. The
Haigerloch
Haigerloch is a town in the north-western part of the Swabian Alb in Germany.
Geography Geographical location
Haigerloch lies at between 430 and 550 metres elevation in the valley of the Eyach river, which forms two loops in a steep shelly limes ...
research reactor ( :de:Forschungsreaktor Haigerloch) assembled months before the end of the war in Southwestern Germany was an extremely subcritical assembly which lacked both sufficient uranium and sufficient moderator to produce significant amounts of plutonium, let alone heat. A uranium cube thought to have belonged to
Werner Heisenberg
Werner Karl Heisenberg () (5 December 1901 – 1 February 1976) was a German theoretical physicist and one of the main pioneers of the theory of quantum mechanics. He published his work in 1925 in a breakthrough paper. In the subsequent serie ...
was analyzed decades later, confirming that the Germans were nowhere near plutonium production.
American uranium ores mined in Colorado were mixed ores of vanadium and uranium, but because of wartime secrecy, the Manhattan Project would publicly admit only to purchasing the vanadium, and did not pay the uranium miners for the uranium content. In a much later lawsuit, many miners were able to reclaim lost profits from the U.S. government. American ores had much lower uranium concentrations than the ore from the Belgian Congo, but they were pursued vigorously to ensure nuclear self-sufficiency. Similar efforts were undertaken in the
Soviet Union
The Soviet Union,. officially the Union of Soviet Socialist Republics. (USSR),. was a List of former transcontinental countries#Since 1700, transcontinental country that spanned much of Eurasia from 1922 to 1991. A flagship communist state, ...
, which did not have native stocks of uranium when it started developing its own atomic weapons program.
While the Soviet Republics of
Kazakhstan
Kazakhstan, officially the Republic of Kazakhstan, is a transcontinental country located mainly in Central Asia and partly in Eastern Europe. It borders Russia to the north and west, China to the east, Kyrgyzstan to the southeast, Uzbeki ...
and the RSFSR would later become some of the leading uranium producers in the world, immediately after the end of World War II the availability of large uranium deposits in the USSR wasn't yet known and thus the Soviets developed immense mining operations in their
satellite state
A satellite state or dependent state is a country that is formally independent in the world, but under heavy political, economic, and military influence or control from another country. The term was coined by analogy to planetary objects orbitin ...
s East Germany and Czechoslovakia which had known uranium deposits in the Ore Mountains. The deliberately opaquely named
SDAG Wismut
SAG/SDAG Wismut was a uranium mining company in East Germany
Germany,, officially the Federal Republic of Germany, is a country in Central Europe. It is the second most populous country in Europe after Russia, and the most populo ...
(the German term "Wismut" for
Bismuth
Bismuth is a chemical element with the symbol Bi and atomic number 83. It is a post-transition metal and one of the pnictogens, with chemical properties resembling its lighter group 15 siblings arsenic and antimony. Elemental bismuth occurs ...
should give the illusion of prospection for a metal the Soviets definitely ''weren't'' after) became the biggest employer in the Saxon Ore Mountains and remote mining towns like
Johanngeorgenstadt
Johanngeorgenstadt () is a mining town in Saxony’s Ore Mountains, 17 km south of Aue, and 27 km northwest of Karlovy Vary. It lies in the district of Erzgebirgskreis, on the border with the Czech Republic, is a state-recognized heal ...
swelled to ten times their population in a few years. The mining cost immense amounts of money and miners were on the one hand subject to heavier repression and surveillance but on the other hand allowed more generous supply with consumer goods than other East Germans. While production was never able to compete with global
uranium market
The uranium market, like all commodity markets, has a history of volatility, moving with the standard forces of supply and demand as well as geopolitical pressures. It has also evolved particularities of its own in response to the unique nature and ...
prices, the
dual use
In politics, diplomacy and export control, dual-use items refers to goods, software and technology that can be used for both civilian and military applications.
nature of the mined material as well as the possibility to pay miners in soft currency but sell uranium for
hard currency
In macroeconomics, hard currency, safe-haven currency, or strong currency is any globally traded currency that serves as a reliable and stable store of value. Factors contributing to a currency's ''hard'' status might include the stability and ...
or substitute imports which would've had to be paid for in hard currency tipped the scales in favor of continuing mining operations throughout the Cold War. After German reunification, mining was wound down and the arduous task of rehabilitating the land impacted by mining was begun. In the course of this, some remaining deposits had to be mined to reduce the potential harm from material leaching into groundwater, but this has since ceased as well, making the area in which uranium had been discovered two centuries prior entirely devoid of uranium mining.
In the 20th century, the United States was the world's largest uranium producer. Grants Uranium District in northwestern New Mexico was the largest United States uranium producer. The Gas Hills Uranium District was the second largest uranium producer. The famous Lucky Mc Mine is located in the Gas Hills near Riverton, Wyoming. Canada has since surpassed the United States as the cumulative largest producer in the world. In 1990, 55% of world production came from underground mines, but this shrank to 33% by 1999. From 2000, new Canadian mines again increased the proportion of underground mining, and with Olympic Dam it is now 37%. In situ leach (ISL, or ISR) mining has been steadily increasing its share of the total, mainly due to Kazakhstan. Unlike with coal, particularly lignite, where the biggest producers tend to also be the biggest consumers, the biggest uranium producers, Kazakhstan, Australia and Canada contain only one nation –
Canada
Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by tot ...
– who derives a significant proportion of electricity from nuclear power. On the other hand, big users of nuclear power like
France
France (), officially the French Republic ( ), is a country primarily located in Western Europe. It also comprises of overseas regions and territories in the Americas and the Atlantic, Pacific and Indian Oceans. Its metropolitan area ...
,
South Korea
South Korea, officially the Republic of Korea (ROK), is a country in East Asia, constituting the southern part of the Korean Peninsula and sharing a land border with North Korea. Its western border is formed by the Yellow Sea, while its eas ...
,
India
India, officially the Republic of India (Hindi: ), is a country in South Asia. It is the seventh-largest country by area, the second-most populous country, and the most populous democracy in the world. Bounded by the Indian Ocean on the so ...
or Japan import most or all of the uranium used in their power plants as they have no or negligible domestic uranium resources. India in particular has been interested in the
Thorium fuel cycle
The thorium fuel cycle is a nuclear fuel cycle that uses an isotope of thorium, , as the fertile material. In the reactor, is transmuted into the fissile artificial uranium isotope which is the nuclear fuel. Unlike natural uranium, natural ...
for decades, as India has much larger thorium reserves than it does uranium reserves. France historically derived significant shares of its uranium needs from its African colonies and continues to be politically and economically active in those African countries to ensure its uranium supply.
Deposit types
Many different types of uranium deposits have been discovered and mined.
There are mainly three types of uranium deposits including unconformity-type deposits, namely paleoplacer deposits and sandstone-type also known as roll front type deposits.
Uranium deposits are classified into 15 categories according to their geological setting and the type of rock in which they are found. This geological classification system is determined by the International Atomic Energy Agency (IAEA).
Uranium is also contained in
seawater
Seawater, or salt water, is water from a sea or ocean. On average, seawater in the world's oceans has a salinity of about 3.5% (35 g/L, 35 ppt, 600 mM). This means that every kilogram (roughly one liter by volume) of seawater has appr ...
but at present prices on the
uranium market
The uranium market, like all commodity markets, has a history of volatility, moving with the standard forces of supply and demand as well as geopolitical pressures. It has also evolved particularities of its own in response to the unique nature and ...
, costs would have to be lowered by a factor of 3–6 to make its recovery economical.
Sedimentary
Uranium deposits in sedimentary rocks include those in sandstone (in Canada and the
western US
The Western United States (also called the American West, the Far West, and the West) is the region comprising the westernmost states of the United States. As American settlement in the U.S. expanded westward, the meaning of the term ''the Wes ...
),
Precambrian
unconformities
An unconformity is a buried erosional or non-depositional surface separating two rock masses or strata of different ages, indicating that sediment deposition was not continuous. In general, the older layer was exposed to erosion for an interval ...
(in Canada),
phosphate
In chemistry, a phosphate is an anion, salt, functional group or ester derived from a phosphoric acid. It most commonly means orthophosphate, a derivative of orthophosphoric acid .
The phosphate or orthophosphate ion is derived from phosph ...
, Precambrian
quartz
Quartz is a hard, crystalline mineral composed of silica ( silicon dioxide). The atoms are linked in a continuous framework of SiO4 silicon-oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall chemical ...
breccia pipe
A breccia pipe, also referred to as a chimney, is a mass of breccia (rock composed of broken fragments of minerals or rock cemented together by a fine-grained matrix), often in an irregular and cylindrical shape.
Characteristics
When exposed a ...
s (see Arizona breccia pipe uranium mineralization),
and calcrete
Sandstone uranium deposits are generally of two types. ''Roll-front'' type deposits occur at the boundary between the up dip and oxidized part of a sandstone body and the deeper down dip reduced part of a sandstone body. ''Peneconcordant'' sandstone uranium deposits, also called ''Colorado Plateau''-type deposits, most often occur within generally oxidized sandstone bodies, often in localized reduced zones, such as in association with carbonized wood in the sandstone.
Precambrian quartz-pebble conglomerate-type uranium deposits occur only in rocks older than two billion years old. The conglomerates also contain pyrite. These deposits have been mined in the Blind River- Elliot Lake district of Ontario, Canada, and from the gold-bearing
Witwatersrand
The Witwatersrand () (locally the Rand or, less commonly, the Reef) is a , north-facing scarp in South Africa. It consists of a hard, erosion-resistant quartzite metamorphic rock, over which several north-flowing rivers form waterfalls, which ...
conglomerates of South Africa.
Unconformity-type deposits make up about 33% of the World Outside Centrally Planned Economies Areas (WOCA)'s uranium deposits.
Igneous or hydrothermal
Hydrothermal uranium deposits encompass the vein-type uranium ores. Vein-type hydrothermal uranium deposits represent epigenetic concentrations of uranium minerals that typically fill breccias, fractures, and shear zones. Many studies have sought to identify the source of uranium with hydrothermal vein-type deposits and the potential sources still remains a mystery, but are thought to include preexisting rocks that have been broken down by weathering and force that come from areas of long-term sediment build up. The South Chine Block is an example of a region that has been relying on vein-type hydrothermal uranium deposit demand for the past half century. Igneous deposits include
nepheline syenite
Nepheline syenite is a holocrystalline plutonic rock that consists largely of nepheline and alkali feldspar. The rocks are mostly pale colored, grey or pink, and in general appearance they are not unlike granites, but dark green varieties are al ...
Greenland
Greenland ( kl, Kalaallit Nunaat, ; da, Grønland, ) is an island country in North America that is part of the Kingdom of Denmark. It is located between the Arctic and Atlantic oceans, east of the Canadian Arctic Archipelago. Greenland i ...
; the disseminated uranium deposit at Rossing, Namibia; uranium-bearing pegmatites, and the Aurora
crater lake
Crater Lake ( Klamath: ''Giiwas'') is a volcanic crater lake in south-central Oregon in the western United States. It is the main feature of Crater Lake National Park and is famous for its deep blue color and water clarity. The lake partly fill ...
deposit of the
McDermitt Caldera
The McDermitt Caldera is a large, oval-shaped caldera west of McDermitt in southeastern Oregon and northern Nevada in the United States. It is about long north–south and wide east–west. The western part of the caldera is in the Trout Cre ...
in Oregon. Disseminated deposits are also found in the states of Washington and Alaska in the US.
Breccia
Breccia uranium deposits are found in rocks that have been broken due to tectonic fracturing, or weathering. Breccia uranium deposits are most common in India, Australia and the United States. A large mass of breccia is called a breccia pipe or chimney and is composed of the rock forming an irregular and almost cylinder like shape. The origin of breccia pipe is uncertain but it is thought that they form on intersections and faults. When the formations are found solid in ground host rock called rock flour, it usually is often a site for copper or uranium mining. Copper Creek, Arizona is home to approximately 500 mineralized breccia pipes and Cripple Creek, Colorado also is a site that contains breccia pipe ore deposits that is associated with a volcanic pipe.
Olympic Dam mine
The Olympic Dam mine is a large poly-metallic underground mine located in South Australia, NNW of Adelaide. It is the fourth largest copper deposit and the largest known single deposit of uranium in the world. Copper is the largest contributor ...
, the world's largest uranium deposit, was discovered by
Western Mining Corporation
Western may refer to:
Places
*Western, Nebraska, a village in the US
* Western, New York, a town in the US
* Western Creek, Tasmania, a locality in Australia
* Western Junction, Tasmania, a locality in Australia
*Western world, countries that ...
in 1975 and is owned by
BHP
BHP Group Limited (formerly known as BHP Billiton) is an Australian multinational mining, metals, natural gas petroleum public company that is headquartered in Melbourne, Victoria, Australia.
The Broken Hill Proprietary Company was founded ...
.
Exploration
Uranium prospecting is similar to other forms of mineral exploration with the exception of some specialized instruments for detecting the presence of radioactive isotopes.
The Geiger counter was the original radiation detector, recording the total count rate from all energy levels of radiation. Ionization chambers and Geiger counters were first adapted for field use in the 1930s. The first transportable Geiger–Müller counter (weighing 25 kg) was constructed at the
University of British Columbia
The University of British Columbia (UBC) is a public research university with campuses near Vancouver and in Kelowna, British Columbia. Established in 1908, it is British Columbia's oldest university. The university ranks among the top thre ...
in 1932. H.V. Ellsworth of the GSC built a lighter weight, more practical unit in 1934. Subsequent models were the principal instruments used for uranium prospecting for many years, until geiger counters were replaced by scintillation counters.
The use of airborne detectors to prospect for radioactive minerals was first proposed by G.C. Ridland, a geophysicist working at
Port Radium
Port Radium is a mining area on the eastern shore of Great Bear Lake, Northwest Territories, Canada.
It included the settlement of Cameron Bay as well as the Eldorado (also called Port Radium) and Echo Bay mines. The name Port Radium did n ...
in 1943. In 1947, the earliest recorded trial of airborne
radiation detector
In experimental and applied particle physics, nuclear physics, and nuclear engineering, a particle detector, also known as a radiation detector, is a device used to detect, track, and/or identify ionizing particles, such as those produced by nuc ...
s (ionization chambers and Geiger counters) was conducted by
Eldorado Mining and Refining Limited
Eldorado Resources was a Canadian mining company active between 1926 and 1988. The company was originally established by brothers Charles and Gilbert LaBine as a gold mining enterprise in 1926, but transitioned to focus on radium in the 1930s an ...
. (a Canadian Crown Corporation since sold to become
Cameco Corporation
Cameco Corporation (formerly Canadian Mining and Energy Corporation) is the world's largest publicly traded uranium company, based in Saskatoon, Saskatchewan, Canada. In 2015, it was the world's second largest uranium producer, accounting for 18 ...
). The first patent for a portable
gamma-ray
A gamma ray, also known as gamma radiation (symbol γ or \gamma), is a penetrating form of electromagnetic radiation arising from the radioactive decay of atomic nuclei. It consists of the shortest wavelength electromagnetic waves, typically sh ...
spectrometer
A spectrometer () is a scientific instrument used to separate and measure spectral components of a physical phenomenon. Spectrometer is a broad term often used to describe instruments that measure a continuous variable of a phenomenon where the ...
was filed by Professors Pringle, Roulston & Brownell of the
University of Manitoba
The University of Manitoba (U of M, UManitoba, or UM) is a Canadian public research university in the province of Manitoba.Saskatchewan
Saskatchewan ( ; ) is a province in western Canada, bordered on the west by Alberta, on the north by the Northwest Territories, on the east by Manitoba, to the northeast by Nunavut, and on the south by the U.S. states of Montana and North Dak ...
.
Airborne gamma-ray spectrometry is now the accepted leading technique for uranium prospecting with worldwide applications for geological mapping, mineral exploration & environmental monitoring. Airborne gamma-ray spectrometry used specifically for uranium measurement and prospecting must account for a number of factors like the distance between the source and the detector and the scattering of radiation through the minerals, surrounding earth and even in the air. In Australia, a Weathering Intensity Index has been developed to help prospectors based on the Shuttle Radar Topography Mission (SRTM) elevation and airborne gamma-ray spectrometry images.
A deposit of uranium, discovered by geophysical techniques, is evaluated and sampled to determine the amounts of uranium materials that are extractable at specified costs from the deposit.
Uranium reserves
Uranium is a chemical element with the Symbol (chemistry), symbol U and atomic number 92. It is a silvery-grey metal in the actinide series of the periodic table. A uranium atom has 92 protons and 92 electrons, of which 6 are valence electrons. ...
are the amounts of ore that are estimated to be recoverable at stated costs. As prices rise or technology allows for lower cost of recovery of known, previously uneconomic, deposits, reserves increase. For uranium this effect is particularly pronounced as the biggest currently uneconomic reserve – uranium extraction from
seawater
Seawater, or salt water, is water from a sea or ocean. On average, seawater in the world's oceans has a salinity of about 3.5% (35 g/L, 35 ppt, 600 mM). This means that every kilogram (roughly one liter by volume) of seawater has appr ...
– is bigger than all known land based resources of uranium combined.
Mining techniques
As with other types of
hard rock mining
Underground hard-rock mining refers to various underground mining techniques used to excavate "hard" minerals, usually those containing metals, such as ore containing gold, silver, iron, copper, zinc, nickel, tin, and lead. It also involves the ...
there are several methods of extraction. In 2016, the percentage of the mined uranium produced by each mining method was:
in-situ leach
In-situ leaching (ISL), also called in-situ recovery (ISR) or solution mining, is a mining process used to recover minerals such as copper and uranium through boreholes drilled into a deposit, ''in situ''. In situ leach works by artificially disso ...
(49.7 percent),
underground mining
Mining is the extraction of valuable minerals or other geological materials from the Earth, usually from an ore body, lode, vein, seam, reef, or placer deposit. The exploitation of these deposits for raw material is based on the economic vi ...
(30.8 percent),
open pit
Open-pit mining, also known as open-cast or open-cut mining and in larger contexts mega-mining, is a surface mining technique of extracting rock or minerals from the earth from an open-air pit, sometimes known as a borrow.
This form of minin ...
(12.9 percent),
heap leaching
Heap leaching is an industrial mining process used to extract precious metals, copper, uranium, and other compounds from ore using a series of chemical reactions that absorb specific minerals and re-separate them after their division from other e ...
(0.4 percent), co-product/by-product (6.1%). The remaining 0,1% was derived as miscellaneous recovery.
Open pit
In open pit mining,
overburden
In mining, overburden (also called waste or spoil) is the material that lies above an area that lends itself to economical exploitation, such as the rock, soil, and ecosystem that lies above a coal seam or ore body. Overburden is distinct from tai ...
is removed by drilling and blasting to expose the ore body, which is then mined by blasting and excavation using loaders and dump trucks. Workers spend much time in enclosed cabins thus limiting exposure to radiation. Water is extensively used to suppress airborne dust levels. Groundwater is an issue in all types of mining, but in open pit mining, the usual way of dealing with it - i.e. when the target mineral is found below the natural water table - is to lower the water table by pumping off the water. The ground may settle considerably when groundwater is removed and may again move unpredictably when groundwater is allowed to rise again after mining is concluded. Land reclamation after mining takes different routes, depending on the amount of material removed. Due to the high energy density of uranium, it is often sufficient to fill in the former mine with the overburden, but in case of a mass deficit exceeding the height difference between the previous surface level and the natural water table, artificial lakes develop when groundwater removal ceases. If sulfites, sulfides or sulfates are present in the now-exposed rocks
acid mine drainage
Acid mine drainage, acid and metalliferous drainage (AMD), or acid rock drainage (ARD) is the outflow of acidic water from metal mines or coal mines.
Acid rock drainage occurs naturally within some environments as part of the rock weathering ...
can be a concern for those newly developing bodies of water. Mining companies are now required by law to establish a fund for future reclamation while mining is ongoing and those funds are usually deposited in such a way as to be unaffected by bankruptcy of the mining company.
Underground
If the uranium is too far below the surface for open pit mining, an underground mine might be used with tunnels and shafts dug to access and remove uranium ore.
Underground uranium mining is in principle no different from any other
hard rock mining
Underground hard-rock mining refers to various underground mining techniques used to excavate "hard" minerals, usually those containing metals, such as ore containing gold, silver, iron, copper, zinc, nickel, tin, and lead. It also involves the ...
and other ores are often mined in association (e.g., copper, gold, silver). Once the ore body has been identified a shaft is sunk in the vicinity of the ore veins, and crosscuts are driven horizontally to the veins at various levels, usually every 100 to 150 metres. Similar tunnels, known as drifts, are driven along the ore veins from the crosscut. To extract the ore, the next step is to drive tunnels, known as raises when driven upwards and winzes when driven downwards, through the deposit from level to level. Raises are subsequently used to develop the stopes where the ore is mined from the veins.
The stope, which is the workshop of the mine, is the excavation from which the ore is extracted. Three methods of stope mining are commonly used. In the "cut and fill" or "open stoping" method, the space remaining following removal of ore after blasting is filled with waste rock and cement. In the "shrinkage" method, only sufficient broken ore is removed via the chutes below to allow miners working from the top of the pile to drill and blast the next layer to be broken off, eventually leaving a large hole. The method known as "room and pillar" is used for thinner, flatter ore bodies. In this method the ore body is first divided into blocks by intersecting drives, removing ore while so doing, and then systematically removing the blocks, leaving enough ore for roof support.
The health effects discovered from
radon
Radon is a chemical element with the symbol Rn and atomic number 86. It is a radioactive, colourless, odourless, tasteless noble gas. It occurs naturally in minute quantities as an intermediate step in the normal radioactive decay chains through ...
exposure in unventilated uranium mining prompted the switch away from uranium mining via tunnel
mining
Mining is the extraction of valuable minerals or other geological materials from the Earth, usually from an ore body, lode, vein, seam, reef, or placer deposit. The exploitation of these deposits for raw material is based on the economic ...
towards open cut and
in-situ leaching
In-situ leaching (ISL), also called in-situ recovery (ISR) or solution mining, is a mining process used to recover minerals such as copper and uranium through boreholes drilled into a deposit, ''in situ''. In situ leach works by artificially diss ...
technology, a method of extraction that does not produce the same occupational hazards, or mine tailings, as conventional mining.
With regulations in place to ensure the use of high volume ventilation technology if any confined space uranium mining is occurring, occupational exposure and mining deaths can be largely eliminated. The Olympic Dam and Canadian underground mines are ventilated with powerful fans with radon levels being kept at a very low to practically "safe level" in uranium mines. Naturally occurring radon in other, non-uranium mines, also may need control by ventilation.
Heap leaching
Heap leaching
Heap leaching is an industrial mining process used to extract precious metals, copper, uranium, and other compounds from ore using a series of chemical reactions that absorb specific minerals and re-separate them after their division from other e ...
is an extraction process by which chemicals (usually sulfuric acid) are used to extract the economic element from ore which has been mined and placed in piles on the surface. Heap leaching is generally economically feasible only for oxide ore deposits. Oxidation of sulfide deposits occurs during the geological process called weathering. Therefore, oxide ore deposits are typically found close to the surface. If there are no other economic elements within the ore a mine might choose to extract the uranium using a leaching agent, usually a low molar sulfuric acid.
If the economic and geological conditions are right, the mining company will level large areas of land with a small gradient, layering it with thick plastic (usually
HDPE
High-density polyethylene (HDPE) or polyethylene high-density (PEHD) is a thermoplastic polymer produced from the monomer ethylene. It is sometimes called "alkathene" or "polythene" when used for HDPE pipes. With a high strength-to-density ratio, ...
or
LLDPE
Linear low-density polyethylene (LLDPE) is a substantially linear polymer (polyethylene), with significant numbers of short branches, commonly made by copolymerization of ethylene with longer-chain olefins. Linear low-density polyethylene differs ...
), sometimes with clay, silt or sand beneath the plastic liner. The extracted ore will typically be run through a crusher and placed in heaps atop the plastic. The leaching agent will then be sprayed on the ore for 30–90 days. As the leaching agent filters through the heap, the uranium will break its bonds with the oxide rock and enter the solution. The solution will then filter along the gradient into collecting pools which will then be pumped to on-site plants for further processing. Only some of the uranium (commonly about 70%) is actually extracted.
The uranium concentrations within the solution are very important for the efficient separation of pure uranium from the acid. As different heaps will yield different concentrations, the solution is pumped to a mixing plant that is carefully monitored. The properly balanced solution is then pumped into a processing plant where the uranium is separated from the sulfuric acid.
Heap leach is significantly cheaper than traditional milling processes. The low costs allow for lower grade ore to be economically feasible (given that it is the right type of ore body). US environmental law requires that the surrounding ground water is continually monitored for possible contamination. The mine will also have to have continued monitoring even after the shutdown of the mine. In the past mining companies would sometimes go bankrupt, leaving the responsibility of
mine reclamation
Mine reclamation is the process of modifying land that has been mined to ecologically functional or economically usable state. Although the process of mine reclamation occurs once mining is completed, the planning of mine reclamation activiti ...
to the public. 21st century additions to US mining law require that companies set aside the money for reclamation before the beginning of the project. The money will be held by the public to insure adherence to environmental standards if the company were to ever go bankrupt.
''In-situ'' leaching
In-situ leaching (ISL), also known as solution mining, or in-situ recovery (ISR) in North America, involves leaving the ore where it is in the ground, and recovering the minerals from it by dissolving them and pumping the pregnant solution to the surface where the minerals can be recovered. Consequently, there is little surface disturbance and no tailings or waste rock generated. However, the orebody needs to be permeable to the liquids used, and located so that they do not contaminate ground water away from the orebody.
Uranium ISL uses the native groundwater in the orebody which is fortified with a complexing agent and in most cases an oxidant. It is then pumped through the underground orebody to recover the minerals in it by leaching. Once the pregnant solution is returned to the surface, the uranium is recovered in much the same way as in any other uranium plant (mill).
In Australian ISL mines (
Beverley
Beverley is a market and minster town and a civil parish in the East Riding of Yorkshire, England, of which it is the county town. The town centre is located south-east of York's centre and north-west of City of Hull.
The town is known fo ...
, Four Mile and Honeymoon Mine) the oxidant used is hydrogen peroxide and the complexing agent sulfuric acid. Kazakh ISL mines generally do not employ an oxidant but use much higher acid concentrations in the circulating solutions. ISL mines in the USA use an alkali leach due to the presence of significant quantities of acid-consuming minerals such as gypsum and limestone in the host aquifers. Any more than a few percent carbonate minerals means that alkali leach must be used in preference to the more efficient acid leach.
The Australian government has published a best practice guide for in situ leach mining of uranium, which is being revised to take account of international differences.
Seawater recovery
The uranium concentration in sea water is low, approximately 3.3
parts per billion
In science and engineering, the parts-per notation is a set of pseudo-units to describe small values of miscellaneous dimensionless quantities, e.g. mole fraction or mass fraction. Since these fractions are quantity-per-quantity measures, they ...
or 3.3 micrograms per liter of seawater. But the quantity of this resource is gigantic and some scientists believe this resource is practically limitless with respect to world-wide demand. That is to say, if even a portion of the uranium in seawater could be used the entire world's nuclear power generation fuel could be provided over a long time period. Some anti-nuclear proponents claim this statistic is exaggerated. Although research and development for recovery of this low-concentration element by inorganic adsorbents such as
titanium oxide
Titanium oxide may refer to:
* Titanium dioxide (titanium(IV) oxide), TiO2
* Titanium(II) oxide (titanium monoxide), TiO, a non-stoichiometric oxide
* Titanium(III) oxide (dititanium trioxide), Ti2O3
* Ti3O
* Ti2O
* δ-TiOx (x= 0.68–0.75)
* T ...
compounds has occurred since the 1960s in the United Kingdom, France, Germany, and Japan, this research was halted due to low recovery efficiency.
At the Takasaki Radiation Chemistry Research Establishment of the Japan Atomic Energy Research Institute (JAERI Takasaki Research Establishment), research and development has continued culminating in the production of adsorbent by irradiation of polymer fiber. Adsorbents have been synthesized that have a functional group ( amidoxime group) that selectively adsorbs heavy metals, and the performance of such adsorbents has been improved. Uranium adsorption capacity of the polymer fiber adsorbent is high, approximately tenfold greater in comparison to the conventional titanium oxide adsorbent.
One method of extracting uranium from seawater is using a uranium-specific nonwoven fabric as an adsorbent. The total amount of uranium recovered from three collection boxes containing 350 kg of fabric was >1 kg of
yellowcake
Yellowcake (also called urania) is a type of uranium concentrate powder obtained from leach solutions, in an intermediate step in the processing of uranium ores. It is a step in the processing of uranium after it has been mined but before f ...
after 240 days of submersion in the ocean. The experiment by Seko ''et al.'' was repeated by Tamada et al. in 2006. They found that the cost varied from ¥15,000 to ¥88,000 depending on assumptions and "The lowest cost attainable now is ¥25,000 with 4g-U/kg-adsorbent used in the sea area of Okinawa, with 18 repetitionuses." With the May, 2008 exchange rate, this was about $240/kg-U.
In 2012,
ORNL
Oak Ridge National Laboratory (ORNL) is a U.S. multiprogram science and technology national laboratory sponsored by the U.S. Department of Energy (DOE) and administered, managed, and operated by UT–Battelle as a federally funded research and ...
researchers announced the successful development of a new adsorbent material dubbed "HiCap", which vastly outperforms previous best adsorbents, which perform surface retention of solid or gas molecules, atoms or ions. "We have shown that our adsorbents can extract five to seven times more uranium at uptake rates seven times faster than the world's best adsorbents," said Chris Janke, one of the inventors and a member of ORNL's Materials Science and Technology Division. HiCap also effectively removes toxic metals from water, according to results verified by researchers at Pacific Northwest National Laboratory.
In 2012 it was estimated that this fuel source could be extracted at 10 times the current price of uranium.
In 2014, with the advances made in the efficiency of seawater uranium extraction, it was suggested that it would be economically competitive to produce fuel for light water reactors from seawater if the process was implemented at large scale. Uranium extracted on an industrial scale from seawater would constantly be replenished by both river erosion of rocks and the natural process of uranium dissolved from the surface area of the ocean floor, both of which maintain the solubility equilibria of seawater concentration at a stable level. Some commentators have argued that this strengthens the case for nuclear power to be considered a renewable energy.
Co-product/by-product
Uranium can be recovered as a by-product along with other co-products such as molybdenum, vanadium, nickel, zinc and petroleum products. Uranium is also often found in
phosphate
In chemistry, a phosphate is an anion, salt, functional group or ester derived from a phosphoric acid. It most commonly means orthophosphate, a derivative of orthophosphoric acid .
The phosphate or orthophosphate ion is derived from phosph ...
minerals, where it has to be removed because phosphate is mostly used for fertilizers.
Phosphogypsum
Phosphogypsum (PG) is the calcium sulfate hydrate formed as a by-product of the production of fertilizer from phosphate rock. It is mainly composed of gypsum (CaSO4·2H2O). Although gypsum is a widely used material in the construction industry, p ...
is a waste product from phosphate mining that can contain significant amounts of uranium and radium.
Coal fly ash
Fly ash, flue ash, coal ash, or pulverised fuel ash (in the UK) plurale tantum: coal combustion residuals (CCRs)is a coal combustion product that is composed of the particulates (fine particles of burned fuel) that are driven out of coal-fired b ...
also contains significant amounts of uranium and has been suggested as a source for uranium extraction.
Resources
Uranium occurs naturally in many rocks, and even in seawater. However, like other metals, it is seldom sufficiently concentrated to be economically recoverable.
Like any resource, uranium cannot be mined at any desired concentration. No matter the technology, at some point it is too costly to mine lower grade ores.
Mining companies usually consider concentrations greater than 0.075% (750 ppm) as ore, or rock economical to mine at current uranium market prices.
There is around 40 trillion tons of uranium in Earth's crust, but most is distributed at low parts per million trace concentration over its mass.American Geophysical Union, Fall Meeting 2007, abstract #V33A-1161 Mass and Composition of the Continental Crust /ref>
Estimates of the amount concentrated into ores affordable to extract for under $130 per kg can be less than a millionth of that total.
Uranium-235, the fissile isotope of uranium used in nuclear reactors, makes up about 0.7% of uranium from ore. It is the only naturally occurring isotope capable of directly generating nuclear power.
While Uranium-235 can be "bred" from , a natural decay product of present at 55 ppm in all natural uranium samples, Uranium-235 is ultimately a finite
non-renewable resource
A non-renewable resource (also called a finite resource) is a natural resource that cannot be readily replaced by natural means at a pace quick enough to keep up with consumption. An example is carbon-based fossil fuels. The original organic mat ...
.
Due to the currently low price of uranium, the majority of commercial
light water reactor
The light-water reactor (LWR) is a type of thermal-neutron reactor that uses normal water, as opposed to heavy water, as both its coolant and neutron moderator; furthermore a solid form of fissile elements is used as fuel. Thermal-neutron react ...
s operate on a "once through fuel cycle" which leaves virtually all the energy contained in the original - which makes up over 99% of natural uranium - unused. Nuclear reprocessing can recover part of that energy by producing
MOX fuel
Mixed oxide fuel, commonly referred to as MOX fuel, is nuclear fuel that contains more than one oxide of fissile material, usually consisting of plutonium blended with natural uranium, reprocessed uranium, or depleted uranium. MOX fuel is an al ...
or
Remix Fuel Remix Fuel was developed in Russia to make use of Mixed Recycled Uranium and Plutonium from spent nuclear fuel to manufacture fresh fuel suitable for widespread use in Russian reactor designs. Compared to "conventional" MOX-fuel
MOX or Mixed Oxid ...
for use in conventional power generating light water reactors. This technology is currently used at industrial scale in France, Russia and Japan. However, at current uranium prices, this is widely deemed uneconomical if only the "input" side is considered.
Breeder reactor
A breeder reactor is a nuclear reactor that generates more fissile material than it consumes. Breeder reactors achieve this because their neutron economy is high enough to create more fissile fuel than they use, by irradiation of a fertile mate ...
technology could allow the current reserves of uranium to provide power for humanity for billions of years, thus making nuclear power a sustainable energy.
Reserves
Reserves are the most readily available resources.
About 96% of the global uranium reserves are found in these ten countries: Australia, Canada, Kazakhstan, South Africa, Brazil, Namibia, Uzbekistan, the United States, Niger, and Russia.
The known uranium resources represent a higher level of assured resources than is normal for most minerals. Further exploration and higher prices will certainly, on the basis of present geological knowledge, yield further resources as present ones are used up. There was very little uranium exploration between 1985 and 2005, so the significant increase in exploration effort that we are now seeing could readily double the known economic resources. On the basis of analogies with other metal minerals, a doubling of price from price levels in 2007 could be expected to create about a tenfold increase in measured resources, over time.
Known conventional resources
Known conventional resources are resources that are known to exist and easy to mine.
In 2006, there were about 4 million tons of conventional resources.
In 2011, this increased to 7 million tonnes.
Exploration for uranium has increased: from 1981 to 2007, annual exploration expenditures grew modestly, from US$4 million to US$7 million. This increased to US$11 million in 2011.
The world's largest deposits of uranium are found in three countries.
Australia has just over 30% of the world's reasonably assured resources and inferred resources of uranium – about .
Kazakhstan has about 12% of the world's reserves, or about .
Canada has of uranium, representing about 9%.
Undiscovered conventional resources
Undiscovered conventional resources are resources that are thought to exist but have not been mined.
It will take a significant exploration and development effort to locate the remaining deposits and begin mining them. However, since the entire earth's geography has not been explored for uranium at this time, there is still the potential to discover exploitable resources.
The OECD Redbook cites areas still open to exploration throughout the world. Many countries are conducting complete aeromagnetic gradiometer radiometric surveys to get an estimate the size of their undiscovered mineral resources. Combined with a gamma-ray survey, these methods can locate undiscovered uranium and thorium deposits.
The U.S. Department of Energy conducted the first and only national uranium assessment in 1980 – the National Uranium Resource Evaluation (NURE) program.
Secondary resources
Secondary resources are essentially recovered uranium from other sources such as nuclear weapons, inventories, reprocessing and re-enrichment. Since secondary resources have exceedingly low discovery costs and very low production costs, they may have displaced a significant portion of primary production. Secondary uranium was and is available essentially instantly. However, new primary production will not be. Essentially, secondary supply is a "one-time" finite supply, with the exception of the re-processed fuel.
In 2017, about 7% of uranium demand was met from secondary resources.
Due to reduction in nuclear weapons stockpiles, a large amount of former weapons uranium was released for use in civilian nuclear reactors. As a result, starting in 1990, a significant portion of uranium nuclear power requirements were supplied by former weapons uranium, rather than newly mined uranium. In 2002, mined uranium supplied only 54 percent of nuclear power requirements. But as the supply of former weapons uranium has been used up, mining has increased, so that in 2012, mining provided 95 percent of reactor requirements, and the OCED Nuclear Energy Agency and the International Atomic Energy Agency projected that the gap in supply would be completely erased in 2013.
Inventories
Inventories are kept by a variety of organizations – government, commercial and others.
The US DOE keeps inventories for security of supply in order to cover for emergencies where uranium is not available at any price.
Decommissioning nuclear weapons
Both the US and Russia have committed to recycle their nuclear weapons into fuel for electricity production. This program is known as the
Megatons to Megawatts Program The Megatons to Megawatts Program, also called the United States-Russia Highly Enriched Uranium Purchase Agreement, was an agreement between Russia and the United States. The official name of the program is the "Agreement between the Government of t ...
.
Down blending of Russian weapons high enriched uranium (HEU) will result in about of low enriched uranium (LEU) over 20 years. This is equivalent to about of natural U, or just over twice annual world demand. Since 2000, of military HEU is displacing about of uranium oxide mine production per year which represents some 13% of world reactor requirements.
The Megatons to Megawatts program came to an end in 2013.
Plutonium recovered from nuclear weapons or other sources can be blended with uranium fuel to produce a mixed-oxide fuel. In June 2000, the US and Russia agreed to dispose of each of weapons-grade plutonium by 2014. The US undertook to pursue a self-funded dual track program (immobilization and MOX). The G-7 nations provided US$1 billion to set up Russia's program. The latter was initially MOX specifically designed for VVER reactors, the Russian version of the Pressurized Water Reactor (PWR), the high cost being because this was not part of Russia's fuel cycle policy. This MOX fuel for both countries is equivalent to about of natural uranium.
The U.S. also has commitments to dispose of of non-waste HEU.
Reprocessing and recycling
Nuclear reprocessing (or recycling) can increase the supply of uranium by separating the uranium from
spent nuclear fuel
Spent nuclear fuel, occasionally called used nuclear fuel, is nuclear fuel that has been irradiated in a nuclear reactor (usually at a nuclear power plant). It is no longer useful in sustaining a nuclear reaction in an ordinary thermal reactor and ...
.
Spent nuclear fuel is primarily composed of uranium, with a typical concentration of around 96% by mass.
The composition of reprocessed uranium depends on the time the fuel has been in the reactor, but it is mostly uranium-238, with about 1%
uranium-235
Uranium-235 (235U or U-235) is an isotope of uranium making up about 0.72% of natural uranium. Unlike the predominant isotope uranium-238, it is fissile, i.e., it can sustain a nuclear chain reaction. It is the only fissile isotope that exi ...
, 1%
uranium-236
Uranium-236 (236U) is an isotope of uranium that is neither fissile with thermal neutrons, nor very good fertile material, but is generally considered a nuisance and long-lived radioactive waste. It is found in spent nuclear fuel and in the re ...
and smaller amounts of other isotopes including
uranium-232
Uranium-232 () is an isotope of uranium. It has a half-life of around
69 years and is a side product in the thorium cycle. It has been cited as an obstacle to nuclear proliferation using 233U as the fissile material, because the intense gamm ...
.
Currently, there are eleven reprocessing plants in the world. Of these, two are large-scale commercially operated plants for the reprocessing of spent fuel elements from light water reactors with throughputs of more than of uranium per year. These are La Hague, France with a capacity of per year and Sellafield, England at uranium per year.
The rest are small experimental plants.
The two large-scale commercial reprocessing plants together can reprocess 2,800 tonnes of uranium waste annually.
The United States had reprocessing plants in the past but banned reprocessing in the late 1970s due to the high costs and the risk of nuclear proliferation via plutonium.
The main problems with uranium reprocessing are the cost of mined uranium compared to the cost of reprocessing,
At present, reprocessing and the use of plutonium as reactor fuel is far more expensive than using uranium fuel and disposing of the spent fuel directly – even if the fuel is only reprocessed once.
Reprocessing is most useful as part of a
nuclear fuel cycle
The nuclear fuel cycle, also called nuclear fuel chain, is the progression of nuclear fuel through a series of differing stages. It consists of steps in the ''front end'', which are the preparation of the fuel, steps in the ''service period'' in w ...
using
fast-neutron reactor
A fast-neutron reactor (FNR) or fast-spectrum reactor or simply a fast reactor is a category of nuclear reactor in which the fission chain reaction is sustained by fast neutrons (carrying energies above 1 MeV or greater, on average), as oppose ...
s since
reprocessed uranium
Reprocessed uranium (RepU) is the uranium recovered from nuclear reprocessing, as done commercially in France, the UK and Japan and by nuclear weapons states' military plutonium production programs. This uranium makes up the bulk of the material s ...
and
reactor-grade plutonium Reactor-grade plutonium (RGPu) is the isotopic grade of plutonium that is found in spent nuclear fuel after the uranium-235 primary fuel that a nuclear power reactor uses has burnt up. The uranium-238 from which most of the plutonium isotopes der ...
both have isotopic compositions not optimal for use in today's
thermal-neutron reactor
A thermal-neutron reactor is a nuclear reactor that uses slow or thermal neutrons. ("Thermal" does not mean hot in an absolute sense, but means in thermal equilibrium with the medium it is interacting with, the reactor's fuel, moderator and struct ...
s.
Unconventional resources
Unconventional resources are occurrences that require novel technologies for their exploitation and/or use. Often unconventional resources occur in low-concentration. The exploitation of unconventional uranium requires additional research and development efforts for which there is no imminent economic need, given the large conventional resource base and the option of reprocessing spent fuel.
Phosphates, seawater, uraniferous coal ash, and some type of
oil shale
Oil shale is an organic-rich fine-grained sedimentary rock containing kerogen (a solid mixture of organic chemical compounds) from which liquid hydrocarbons can be produced. In addition to kerogen, general composition of oil shales constitut ...
s are examples of unconventional uranium resources.
Phosphates
Uranium occurs at concentrations of 50 to 200 parts per million (ppm) in phosphate-laden earth or
phosphate rock
Phosphorite, phosphate rock or rock phosphate is a non-detrital sedimentary rock that contains high amounts of phosphate minerals. The phosphate content of phosphorite (or grade of phosphate rock) varies greatly, from 4% to 20% phosphorus pentox ...
. As uranium prices increase, there has been interest in extraction of uranium from phosphate rock, which is normally used as the basis of phosphate fertilizers.
There are 22 million tons of uranium in phosphate deposits. Recovery of uranium from phosphates is a
mature technology
A mature technology is a technology that has been in use for long enough that most of its initial faults and inherent problems have been removed or reduced by further development. In some contexts, it may also refer to technology that has not se ...
; it has been utilized in Belgium and the United States, but high recovery costs limit the utilization of these resources, with estimated production costs in the range of US$60–100/kgU including capital investment, according to a 2003 OECD report for a new 100 tU/year project.
Historical operating costs for the uranium recovery from phosphoric acid range from $48–$119/kg U3O8.
In 2011, the average price paid for U3O8 in the United States was $122.66/kg.
Worldwide, approximately 400 wet-process
phosphoric acid
Phosphoric acid (orthophosphoric acid, monophosphoric acid or phosphoric(V) acid) is a colorless, odorless phosphorus-containing solid, and inorganic compound with the chemical formula . It is commonly encountered as an 85% aqueous solution, w ...
plants were in operation. Assuming an average recoverable content of 100 ppm of uranium, and that uranium prices do not increase so that the main use of the phosphates are for
fertilizers
A fertilizer (American English) or fertiliser (British English; see spelling differences) is any material of natural or synthetic origin that is applied to soil or to plant tissues to supply plant nutrients. Fertilizers may be distinct from ...
, this scenario would result in a maximum theoretical annual output of U3O8.
Seawater
Unconventional uranium resources include up to of uranium contained in sea water. Several technologies to extract uranium from sea water have been demonstrated at the laboratory scale.
According to the OECD, uranium may be extracted from seawater for about US$300/kgU.
In 2012,
ORNL
Oak Ridge National Laboratory (ORNL) is a U.S. multiprogram science and technology national laboratory sponsored by the U.S. Department of Energy (DOE) and administered, managed, and operated by UT–Battelle as a federally funded research and ...
researchers announced the successful development of a new absorbent material dubbed HiCap, which vastly outperforms previous best adsorbents, which perform surface retention of solid or gas molecules, atoms or ions. "We have shown that our adsorbents can extract five to seven times more uranium at uptake rates seven times faster than the world's best adsorbents", said Chris Janke, one of the inventors and a member of ORNL's Materials Science and Technology Division. HiCap also effectively removes toxic metals from water, according to results verified by researchers at Pacific Northwest National Laboratory.
Uraniferous coal ash
According to a study by
Oak Ridge National Laboratory
Oak Ridge National Laboratory (ORNL) is a U.S. multiprogram science and technology national laboratory sponsored by the U.S. Department of Energy (DOE) and administered, managed, and operated by UT–Battelle as a federally funded research an ...
, the theoretical maximum energy potential (when used in
breeder reactor
A breeder reactor is a nuclear reactor that generates more fissile material than it consumes. Breeder reactors achieve this because their neutron economy is high enough to create more fissile fuel than they use, by irradiation of a fertile mate ...
s) of trace uranium and thorium in coal actually exceeds the energy released by burning the coal itself. This is despite very low concentration of uranium in coal of only several parts per million average before combustion.
From 1965 to 1967
Union Carbide
Union Carbide Corporation is an American chemical corporation wholly owned subsidiary (since February 6, 2001) by Dow Chemical Company. Union Carbide produces chemicals and polymers that undergo one or more further conversions by customers befo ...
operated a mill in
North Dakota
North Dakota () is a U.S. state in the Upper Midwest, named after the indigenous Dakota Sioux. North Dakota is bordered by the Canadian provinces of Saskatchewan and Manitoba to the north and by the U.S. states of Minnesota to the east, So ...
, United States, burning uraniferous lignite and extracting uranium from the ash. The plant produced about 150 metric tons of U3O8 before shutting down.
An international consortium has set out to explore the commercial extraction of uranium from uraniferous coal ash from coal power stations located in Yunnan province, China. The first laboratory scale amount of yellowcake uranium recovered from uraniferous coal ash was announced in 2007. The three coal power stations at Xiaolongtang, Dalongtang and Kaiyuan have piled up their waste ash. Initial tests from the Xiaolongtang ash pile indicate that the material contains (160–180 parts per million uranium), suggesting a total of U3O8 could be recovered from that ash pile alone.
Oil shales
Some oil shales contain uranium, which may be recovered as a byproduct. Between 1946 and 1952, a marine type of
Dictyonema
''Dictyonema'' is a genus of mainly tropical basidiolichens in the family Hygrophoraceae.
The ''Dictyonema'' symbiosis
Most lichens are a symbiosis between an ascomycete fungus and a photosynthetic green alga. However, a small percentage of ...
shale was used for
uranium
Uranium is a chemical element with the symbol U and atomic number 92. It is a silvery-grey metal in the actinide series of the periodic table. A uranium atom has 92 protons and 92 electrons, of which 6 are valence electrons. Uranium is weak ...
production in
Sillamäe
Sillamäe (Estonian for 'Bridge Hill'; also known by the Germanised names of ''Sillamäggi'' or ''Sillamägi'') is a town in Ida-Viru County in the northern part of Estonia, on the southern coast of the Gulf of Finland. It has a population of ...
, Estonia, and between 1950 and 1989 alum shale was used in Sweden for the same purpose.
Breeding
A breeder reactor produces more nuclear fuel than it consumes and thus can extend the uranium supply. It typically turns the dominant isotope in natural uranium, uranium-238, into fissile plutonium-239. This results in hundredfold increase in the amount of energy to be produced per mass unit of uranium, because U-238, which constitute 99.3% of natural uranium, is not used in conventional reactors which instead use U-235 which only represent 0.7% of natural uranium. In 1983, physicist Bernard Cohen proposed that the world supply of uranium is effectively inexhaustible, and could therefore be considered a form of renewable energy.
He claims that
fast breeder reactor
A breeder reactor is a nuclear reactor that generates more fissile material than it consumes. Breeder reactors achieve this because their neutron economy is high enough to create more fissile fuel than they use, by irradiation of a fertile mater ...
s, fueled by naturally-replenished uranium-238 extracted from seawater, could supply energy at least as long as the sun's expected remaining lifespan of five billion years.
There are two types of breeders: Fast breeders and thermal breeders.
Efforts at commercializing breeder reactors have been largely unsuccessful, due to higher costs and complexity compared to LWR, as well as political opposition.
A few commercial breeder reactors exists. In 2016, the Russian BN-800 fast-neutron breeder reactor started producing commercially at full power (800 MWe), joining the previous
BN-600
The BN-600 reactor is a sodium-cooled fast breeder reactor, built at the Beloyarsk Nuclear Power Station, in Zarechny, Sverdlovsk Oblast, Russia. Designed to generate electrical power of 600 MW in total, the plant dispatches 560 MW ...
. , the Chinese CFR-600 is under construction after the success of the
China Experimental Fast Reactor
The China Experimental Fast Reactor (CEFR) is China's first fast nuclear reactor, and is located outside Beijing at the China Institute of Atomic Energy.
It aims to provide China with fast-reactor design, construction, and operational experienc ...
, based on the BN-800. These reactors are currently generating mostly electricity rather than new fuel because the abundance and low price of mined and reprocessed uranium oxide makes breeding uneconomical, but they can switch to breed new fuel and close the cycle as needed.
The CANDU reactor, which was designed to be fueled with natural uranium, is capable of using
spent fuel
Spent nuclear fuel, occasionally called used nuclear fuel, is nuclear fuel that has been irradiated in a nuclear reactor (usually at a nuclear power plant). It is no longer useful in sustaining a nuclear reaction in an ordinary thermal reactor a ...
from Light Water Reactors as fuel, since it contains more fissile material than natural uranium. Research into "DUPIC" - direct use of PWR spent fuel in CANDU type reactors - is ongoing and could increase the usability of fuel without the need for reprocessing.
Fast breeder
A fast breeder, in addition to consuming U-235, converts fertile U-238 into
Pu-239
Plutonium-239 (239Pu or Pu-239) is an isotope of plutonium. Plutonium-239 is the primary fissile isotope used for the production of nuclear weapons, although uranium-235 is also used for that purpose. Plutonium-239 is also one of the three main ...
, a
fissile
In nuclear engineering, fissile material is material capable of sustaining a nuclear fission chain reaction. By definition, fissile material can sustain a chain reaction with neutrons of thermal energy. The predominant neutron energy may be t ...
fuel. Fast breeder reactors are more expensive to build and operate, including the reprocessing, and could only be justified economically if uranium prices were to rise to pre-1980 values in real terms. In addition to considerably extending the exploitable fuel supply, these reactors have an advantage in that they produce less long-lived
transuranic
The transuranium elements (also known as transuranic elements) are the chemical elements with atomic numbers greater than 92, which is the atomic number of uranium. All of these elements are unstable and decay radioactively into other elements. ...
wastes, and can consume nuclear waste from current
light water reactor
The light-water reactor (LWR) is a type of thermal-neutron reactor that uses normal water, as opposed to heavy water, as both its coolant and neutron moderator; furthermore a solid form of fissile elements is used as fuel. Thermal-neutron react ...
s, generating energy in the process.
Uranium turned out to be far more plentiful than anticipated, and the price of uranium declined rapidly (with an upward blip in the 1970s). This is why the United States halted their use in 1977, and the UK abandoned the idea in 1994.
Significant technical and materials problems were encountered with FBRs, and geological exploration showed that scarcity of uranium was not going to be a concern for some time. By the 1980s, due to both factors, it was clear that FBRs would not be commercially competitive with existing light water reactors. The economics of FBRs still depend on the value of the plutonium fuel which is bred, relative to the cost of fresh uranium.
At higher uranium prices
breeder reactor
A breeder reactor is a nuclear reactor that generates more fissile material than it consumes. Breeder reactors achieve this because their neutron economy is high enough to create more fissile fuel than they use, by irradiation of a fertile mate ...
s may be economically justified. Many nations have ongoing breeder research programs. China, India, and Japan plan large scale utilization of breeder reactors during the coming decades. 300 reactor-years experience has been gained in operating them.
Thermal breeder
Fissile uranium can be produced from
thorium
Thorium is a weakly radioactive metallic chemical element with the symbol Th and atomic number 90. Thorium is silvery and tarnishes black when it is exposed to air, forming thorium dioxide; it is moderately soft and malleable and has a high ...
in thermal breeder reactors. Thorium is three times more plentiful than uranium. Thorium-232 is in itself not fissile, but it can be made into fissile
uranium-233
Uranium-233 (233U or U-233) is a fissile isotope of uranium that is bred from thorium-232 as part of the thorium fuel cycle. Uranium-233 was investigated for use in nuclear weapons and as a reactor fuel. It has been used successfully in exp ...
in a breeder reactor. In turn, the uranium-233 can be fissioned, with the advantage that smaller amounts of
transuranic
The transuranium elements (also known as transuranic elements) are the chemical elements with atomic numbers greater than 92, which is the atomic number of uranium. All of these elements are unstable and decay radioactively into other elements. ...
s are produced by
neutron capture
Neutron capture is a nuclear reaction in which an atomic nucleus and one or more neutrons collide and merge to form a heavier nucleus. Since neutrons have no electric charge, they can enter a nucleus more easily than positively charged protons, ...
, compared to
uranium-235
Uranium-235 (235U or U-235) is an isotope of uranium making up about 0.72% of natural uranium. Unlike the predominant isotope uranium-238, it is fissile, i.e., it can sustain a nuclear chain reaction. It is the only fissile isotope that exi ...
and especially compared to
plutonium-239
Plutonium-239 (239Pu or Pu-239) is an isotope of plutonium. Plutonium-239 is the primary fissile isotope used for the production of nuclear weapons, although uranium-235 is also used for that purpose. Plutonium-239 is also one of the three mai ...
.
Despite the
thorium fuel cycle
The thorium fuel cycle is a nuclear fuel cycle that uses an isotope of thorium, , as the fertile material. In the reactor, is transmuted into the fissile artificial uranium isotope which is the nuclear fuel. Unlike natural uranium, natural ...
having a number of attractive features, development on a large scale can run into difficulties, mainly due to the complexity of fuel separation and reprocessing.
Advocates for liquid core and
molten salt reactor
A molten salt reactor (MSR) is a class of nuclear fission reactor in which the primary nuclear reactor coolant and/or the fuel is a molten salt mixture. Only two MSRs have ever operated, both research reactors in the United States. The 1950's ...
s such as LFTR claim that these technologies negate the above-mentioned thorium's disadvantages present in solid-fueled reactors.
The first successful commercial reactor at the
Indian Point Energy Center
Indian Point Energy Center (I.P.E.C.) is a three-unit nuclear power plant station located in Buchanan, just south of Peekskill, in Westchester County, New York. It sits on the east bank of the Hudson River, about north of Midtown Manhattan. ...
in
Buchanan, New York
Buchanan is a village located in the town of Cortlandt in Westchester County, New York, United States. The population was 2,230 as of the 2010 census.
The now decommissioned Indian Point nuclear power facility is located in Buchanan. The 2000 R ...
(Indian Point Unit 1) ran on thorium. The first core did not live up to expectations.
Production
The world's top uranium producers are
Kazakhstan
Kazakhstan, officially the Republic of Kazakhstan, is a transcontinental country located mainly in Central Asia and partly in Eastern Europe. It borders Russia to the north and west, China to the east, Kyrgyzstan to the southeast, Uzbeki ...
(39% of world production), Canada (22%) and Australia (10%). Other major producers include
Namibia
Namibia (, ), officially the Republic of Namibia, is a country in Southern Africa. Its western border is the Atlantic Ocean. It shares land borders with Zambia and Angola to the north, Botswana to the east and South Africa to the south and ea ...
(6.7%),
Niger
)
, official_languages =
, languages_type = National languages
Uranium production in 2017 was 59,462 tonnes, 93% of the demand. The balance came from inventories held by utilities and other fuel cycle companies, inventories held by governments, used reactor fuel that has been reprocessed, recycled materials from military nuclear programs and uranium in depleted uranium stockpiles.
Demand
Uranium demand was in 2017.
As some countries are not able to supply their own needs of uranium economically, countries have resorted to importing uranium ore from elsewhere. For example, owners of U.S. nuclear power reactors bought of natural uranium in 2006. Out of that 84%, or , were imported from foreign suppliers, according to the Energy Department.
Because of the improvements in
gas centrifuge
A gas centrifuge is a device that performs isotope separation of gases. A centrifuge relies on the principles of centrifugal force accelerating molecules so that particles of different masses are physically separated in a gradient along the radiu ...
technology in the 2000s, replacing former
gaseous diffusion
Gaseous diffusion is a technology used to produce enriched uranium by forcing gaseous uranium hexafluoride (UF6) through semipermeable membranes. This produces a slight separation between the molecules containing uranium-235 (235U) and uranium-2 ...
enriched uranium
Enriched uranium is a type of uranium in which the percent composition of uranium-235 (written 235U) has been increased through the process of isotope separation. Naturally occurring uranium is composed of three major isotopes: uranium-238 (238U ...
from a given amount of natural uranium, by re-enriching tails ultimately leaving a depleted uranium tail of lower enrichment. This has somewhat lowered the demand for natural uranium.
Demand forecasts
According to Cameco Corporation, the demand for uranium is directly linked to the amount of electricity generated by nuclear power plants. Reactor capacity is growing slowly, reactors are being run more productively, with higher capacity factors, and reactor power levels. Improved reactor performance translates into greater uranium consumption.
Nuclear power stations of 1000 megawatt electrical generation capacity require around of natural uranium per year. For example, the United States has 103 operating reactors with an average generation capacity of 950 MWe demanded over of natural uranium in 2005. As the number of nuclear power plants increase, so does the demand for uranium.
As nuclear power plants take a long time to build and refuelling is undertaken at sporadic, predictable intervals, uranium demand is rather predictable in the short term. It is also less dependent on short-term economic boom-bust cycles as nuclear power has one of strongest fixed costs to variable costs ratios (i.e. The
marginal costs
In economics, the marginal cost is the change in the total cost that arises when the quantity produced is incremented, the cost of producing additional quantity. In some contexts, it refers to an increment of one unit of output, and in others it r ...
of running, rather than leaving idle an already constructed power plant are very low, compared to the
capital cost
Capital costs are fixed, one-time expenses incurred on the purchase of land, buildings, construction, and equipment used in the production of goods or in the rendering of services. In other words, it is the total cost needed to bring a projec ...
s of construction) and it is thus nearly never advisable to leave a nuclear power plant idle for economic reasons. However, nuclear policy can lead to short term fluctuations in demand, as evidenced by the German
nuclear phaseout
A nuclear power phase-out is the discontinuation of usage of nuclear power for energy production. Often initiated because of concerns about nuclear power, phase-outs usually include shutting down nuclear power plants and looking towards fossil ...
, which was decided upon by the government of
Gerhard Schröder
Gerhard Fritz Kurt "Gerd" Schröder (; born 7 April 1944) is a German lobbyist and former politician, who served as the chancellor of Germany from 1998 to 2005. From 1999 to 2004, he was also the Leader of the Social Democratic Party of Germa ...
(1998-2005) reversed during the
second Merkel cabinet
The Second Merkel cabinet (German: ''Kabinett Merkel II'') was the Government of the Federal Republic of Germany during the 17th legislative session of the Bundestag. Installed after the 2009 federal election, it left office on 17 December 2013 ...
(2009-2013) only for a reversal of that reversal to occur as a consequence of the
Fukushima nuclear accident
The was a nuclear accident in 2011 at the Fukushima Daiichi Nuclear Power Plant in Ōkuma, Fukushima, Japan. The proximate cause of the disaster was the 2011 Tōhoku earthquake and tsunami, which occurred on the afternoon of 11 March 2011 an ...
, which also led to the temporary shutdown of several German nuclear power plants.
Prices
Generally speaking, in the case of nuclear energy the cost of fuel has the lowest share in total energy costs of all fuel consuming energy forms (i.e. Fossil fuels, biomass and nuclear). Furthermore, given the immense energy density of nuclear fuel (particularly in the form of enriched uranium or high grade plutonium), it is easy to stockpile amounts of fuel material to last several years at constant consumption. Power plants that do not have
online refuelling In nuclear power technology, online refuelling is a technique for changing the fuel of a nuclear reactor while the reactor is critical. This allows the reactor to continue to generate electricity during routine refuelling, and therefore improve th ...
capabilities, as is the case for the vast majority of commercial power plants in operation, will refuel as seldom as possible to avoid costly downtime and usually plan refuelling shutdowns long in advance so as to allow maintenance and inspection to use the scheduled downtime as well. As such power plant operators tend to have long-term contracts with fuel suppliers that are – if at all – only minorly affected by the fluctuations of uranium prices. The effect on electricity price for end consumers is negligible even in countries like France, which derive a majority of their electric energy from nuclear power. Nonetheless, short term price developments like the
2007 uranium bubble
The uranium bubble of 2007 was a period of nearly exponential growth in the price of natural uranium, starting in 2005 and peaking at roughly $300/kg (or ~$135/lb) in mid-2007. This coincided with significant rises of stock price of uranium mining ...
, can have drastic effects on mining companies, prospection and the economic calculations as to whether a certain deposit is worthwhile for commercial purposes.
Since 1981 uranium prices and quantities in the US are reported by the
Department of Energy A Ministry of Energy or Department of Energy is a government department in some countries that typically oversees the production of fuel and electricity; in the United States, however, it manages nuclear weapons development and conducts energy-re ...
.
The import price dropped from 32.90 US$/lb-U3O8 in 1981 down to 12.55 in 1990 and to below 10 US$/lb-U3O8 in the year 2000. Prices paid for uranium during the 1970s were higher, 43 US$/lb-U3O8 is reported as the selling price for Australian uranium in 1978 by the Nuclear Information Centre. Uranium prices reached an all-time low in 2001, costing US$7/lb, but in April 2007 the price of Uranium on the spot market rose to US$113.00/lb, a high point of the
uranium bubble of 2007
The uranium bubble of 2007 was a period of nearly exponential growth in the price of natural uranium, starting in 2005 and peaking at roughly $300/kg (or ~$135/lb) in mid-2007. This coincided with significant rises of stock price of uranium mining ...
. This was very close to the all time high (adjusted for inflation) in 1977.
Following the 2011
Fukushima nuclear disaster
The was a nuclear accident in 2011 at the Fukushima Daiichi Nuclear Power Plant in Ōkuma, Fukushima, Japan. The proximate cause of the disaster was the 2011 Tōhoku earthquake and tsunami, which occurred on the afternoon of 11 March 2011 ...
, the global uranium sector remained depressed with the uranium price falling more than 50%, declining share values, and reduced profitability of uranium producers since March 2011 and into 2014. As a result, uranium companies worldwide are reducing costs, and limiting operations. As an example, Westwater Resources (previously Uranium Resources), has had to cease all uranium operations due to unfavorable prices. Since then, Westwater has tried branching out into other markets, namely
lithium
Lithium (from el, λίθος, lithos, lit=stone) is a chemical element with the symbol Li and atomic number 3. It is a soft, silvery-white alkali metal. Under standard conditions, it is the least dense metal and the least dense solid ...
and
graphite
Graphite () is a crystalline form of the element carbon. It consists of stacked layers of graphene. Graphite occurs naturally and is the most stable form of carbon under standard conditions. Synthetic and natural graphite are consumed on lar ...
.
As of July 2014, the price of uranium concentrate remained near a five-year low, the uranium price having fallen more than 50% from the peak spot price in January 2011, reflecting the loss of Japanese demand following the 2011
Fukushima nuclear disaster
The was a nuclear accident in 2011 at the Fukushima Daiichi Nuclear Power Plant in Ōkuma, Fukushima, Japan. The proximate cause of the disaster was the 2011 Tōhoku earthquake and tsunami, which occurred on the afternoon of 11 March 2011 ...
. As a result of continued low prices, in February 2014 mining company
Cameco
Cameco Corporation (formerly Canadian Mining and Energy Corporation) is the world's largest publicly traded uranium company, based in Saskatoon, Saskatchewan, Canada. In 2015, it was the world's second largest uranium producer, accounting for 18 ...
deferred plans to expand production from existing Canadian mines, although it continued work to open a new mine at Cigar Lake. Also in February 2014, Paladin energy suspended operations at its mine in Malawi, saying that the high-cost operation was losing money at current prices.
Effect of price on mining and nuclear power plants
In general short term fluctuations in the price of uranium are of more concern to operators and owners of mines and potentially lucrative deposits than to power plant operators. Due to its high energy density, uranium is easy to stockpile in the form of
strategic reserve
A strategic reserve is the reserve of a commodity or items that is held back from normal use by governments, organisations, or businesses in pursuance of a particular strategy or to cope with unexpected events.
A document issued by the US Departm ...
s and thus a short term increase in prices can be compensated by accessing those reserves. Furthermore, many countries have ''de facto'' reserves in the form of
reprocessed uranium
Reprocessed uranium (RepU) is the uranium recovered from nuclear reprocessing, as done commercially in France, the UK and Japan and by nuclear weapons states' military plutonium production programs. This uranium makes up the bulk of the material s ...
spent fuel
Spent nuclear fuel, occasionally called used nuclear fuel, is nuclear fuel that has been irradiated in a nuclear reactor (usually at a nuclear power plant). It is no longer useful in sustaining a nuclear reaction in an ordinary thermal reactor a ...
is - as of the 2020s - done commercially primarily to use the fissile material still contained in spent fuel. The commonly employed
PUREX
PUREX (plutonium uranium reduction extraction) is a chemical method used to purify fuel for nuclear reactors or nuclear weapons. PUREX is the ''de facto'' standard aqueous nuclear reprocessing method for the recovery of uranium and plutonium ...
process recovers uranium and plutonium which can then be converted into MOX-fuel for use in the same light water reactors that produced the spent fuel. Whether reprocessing is economical is subject to much debate and depends in part on assumptions as to the price of uranium and the cost of disposal via
deep geological repository
A deep geological repository is a way of storing hazardous or radioactive waste within a stable geologic environment (typically 200–1000 m deep). It entails a combination of waste form, waste package, engineered seals and geology that is suite ...
or nuclear transmutation. Reactors that can run on natural uranium consume less mined uranium per unit of power produced but can have higher capital costs to build due to the need for heavy water as moderator. Furthermore they need to be capable of
online refueling In nuclear power technology, online refuelling is a technique for changing the fuel of a nuclear reactor while the reactor is critical. This allows the reactor to continue to generate electricity during routine refuelling, and therefore improve t ...
because the
burnup
In nuclear power technology, burnup (also known as fuel utilization) is a measure of how much energy is extracted from a primary nuclear fuel source. It is measured as the fraction of fuel atoms that underwent fission in %FIMA (fissions per ini ...
achievable with natural uranium is lower than that achievable with enriched uranium - having to shut down the entire reactor for every refueling would quickly make such a reactor uneconomic.
Breeder reactor
A breeder reactor is a nuclear reactor that generates more fissile material than it consumes. Breeder reactors achieve this because their neutron economy is high enough to create more fissile fuel than they use, by irradiation of a fertile mate ...
s also become more economical as uranium prices rise and it was among other things a decline in uranium prices in the 1970s that led to a decline in interest in breeder reactor technology. The
thorium fuel cycle
The thorium fuel cycle is a nuclear fuel cycle that uses an isotope of thorium, , as the fertile material. In the reactor, is transmuted into the fissile artificial uranium isotope which is the nuclear fuel. Unlike natural uranium, natural ...
is a further alternative if and when uranium prices remain at a sustained high level and consequently interest in this alternative to current "mainstream" light water reactor technology is dependent in no small part on uranium prices.
Politics
In the beginning of the Cold War, to ensure adequate supplies of uranium for national defense, the United States Congress passed the U.S. Atomic Energy Act of 1946, creating the Atomic Energy Commission (AEC) which had the power to withdraw prospective uranium mining land from public purchase, and also to manipulate the price of uranium to meet national needs. By setting a high price for uranium ore, the AEC created a uranium "boom" in the early 1950s, which attracted many prospectors to the Four Corners region of the country. Moab, Utah became known as the Uranium-capital of the world, when geologist
Charles Steen
Charles Augustus Steen (December 1, 1919 – January 1, 2006) was a geologist who made and lost a fortune after discovering a rich uranium deposit in Utah during the uranium boom of the early 1950s.
Early years
Charlie Steen was born in 1919 ...
discovered such an ore in 1952, even though American ore sources were considerably less potent than those in the Belgian Congo or
South Africa
South Africa, officially the Republic of South Africa (RSA), is the Southern Africa, southernmost country in Africa. It is bounded to the south by of coastline that stretch along the Atlantic Ocean, South Atlantic and Indian Oceans; to the ...
.
In the 1950s methods for extracting diluted uranium and
thorium
Thorium is a weakly radioactive metallic chemical element with the symbol Th and atomic number 90. Thorium is silvery and tarnishes black when it is exposed to air, forming thorium dioxide; it is moderately soft and malleable and has a high ...
, found in abundance in granite or seawater, were pursued. Scientists speculated that, used in a
breeder reactor
A breeder reactor is a nuclear reactor that generates more fissile material than it consumes. Breeder reactors achieve this because their neutron economy is high enough to create more fissile fuel than they use, by irradiation of a fertile mate ...
, these materials would potentially provide limitless source of energy.
American military requirements declined in the 1960s, and the government completed its uranium procurement program by the end of 1970. Simultaneously, a new market emerged: commercial nuclear power plants. In the U.S. this market virtually collapsed by the end of the 1970s as a result of industrial strains caused by the
energy crisis
An energy crisis or energy shortage is any significant bottleneck in the supply of energy resources to an economy. In literature, it often refers to one of the energy sources used at a certain time and place, in particular, those that supply n ...
, popular opposition, and finally the Three Mile Island nuclear accident in 1979, all of which led to a ''de facto'' moratorium on the development of new nuclear reactor power stations.
In Europe a mixed situation exists. Considerable nuclear power capacities have been developed, notably in Belgium, Finland, France, Germany, Spain, Sweden, Switzerland, and the UK. In many countries development of
nuclear power
Nuclear power is the use of nuclear reactions to produce electricity. Nuclear power can be obtained from nuclear fission, nuclear decay and nuclear fusion reactions. Presently, the vast majority of electricity from nuclear power is produced ...
has been stopped and phased out by legal actions. In Italy the use of nuclear power was barred by a
referendum
A referendum (plural: referendums or less commonly referenda) is a direct vote by the electorate on a proposal, law, or political issue. This is in contrast to an issue being voted on by a representative. This may result in the adoption of a ...
in 1987; this is now under revision. Ireland in 2008 also had no plans to change its non-nuclear stance.
The years 1976 and 1977 saw uranium mining become a major political issue in Australia, with the Ranger Inquiry (Fox) report opening up a public debate about uranium mining.Bauer, Martin (ed) (1995). ''Resistance to New Technology'', Cambridge University Press, p. 173. The Movement Against Uranium Mining group was formed in 1976, and many protests and demonstrations against uranium mining were held.Drew Hutton and Libby Connors, (1999). ''A History of the Australian Environmental Movement'', Cambridge University Press. Concerns relate to the health risks and environmental damage from uranium mining. Notable Australian anti-uranium activists have included
Kevin Buzzacott
Kevin Buzzacott (born 1947), often referred to as Uncle Kev as an Aboriginal elder, is an Indigenous Australian from the Arabunna nation in northern South Australia. He has campaigned widely for cultural recognition, justice and land rights fo ...
,
Jacqui Katona
Jacqui Katona is a western-educated Aboriginal Australian woman who led the campaign to stop the Jabiluka uranium mine in the Northern Territory. In 1998 the Mirrar Aboriginal people, together with environmental groups, used peaceful on-site c ...
,
Yvonne Margarula
Yvonne Margarula is an Aboriginal Australian environmentalist who won the 1998 Friends of the Earth International Environment Award and the 1998 Nuclear-Free Future Award. She also won the 1999 US Goldman Environmental Prize, with Jacqui Katon ...
, and
Jillian Marsh
Jillian is both a feminine given name and a surname. A spelling variant of Gillian, it originates as a feminine form of the given name Julian, Julio, Julius, and Julien.
Notable people with the name include:
Given name
* Jillian Armenante (bo ...
.
The
World Uranium Hearing
The World Uranium Hearing was held in Salzburg, Austria in September 1992. Anti-nuclear speakers from all continents, including indigenous speakers and scientists, testified to the health and environmental problems of uranium mining and processing ...
was held in
Salzburg, Austria
Salzburg (, ; literally "Salt-Castle"; bar, Soizbuag, label=Austro-Bavarian) is the fourth-largest city in Austria. In 2020, it had a population of 156,872.
The town is on the site of the Roman settlement of ''Iuvavum''. Salzburg was founded ...
in September 1992.
Anti-nuclear
The anti-nuclear movement is a social movement that opposes various nuclear technologies. Some direct action groups, environmental movements, and professional organisations have identified themselves with the movement at the local, nationa ...
speakers from all continents, including indigenous speakers and scientists, testified to the health and environmental problems of uranium mining and processing,
nuclear power
Nuclear power is the use of nuclear reactions to produce electricity. Nuclear power can be obtained from nuclear fission, nuclear decay and nuclear fusion reactions. Presently, the vast majority of electricity from nuclear power is produced ...
nuclear tests
Nuclear weapons tests are experiments carried out to determine nuclear weapons' effectiveness, yield, and explosive capability. Testing nuclear weapons offers practical information about how the weapons function, how detonations are affected by ...
Thomas Banyacya
Thomas Banyacya, Sr. (June 2, 1909 – February 6, 1999) was a Hopi Native American traditional leader.
Biography
Thomas Banyacya was born on June 2, 1909 and grew up in the village of Moenkopi, Arizona. He was a member of the Wolf, Fox, ...
,
Katsumi Furitsu has a doctorate in medical genetics and radiation biology from Japan's Osaka University and currently works in the genetics department of the Hyogo College of Medicine. She became involved in peace and anti-nuclear movement activities as a student ...
,
Manuel Pino
Manuel may refer to:
People
* Manuel (name)
* Manuel (Fawlty Towers), a fictional character from the sitcom ''Fawlty Towers''
* Charlie Manuel, manager of the Philadelphia Phillies
* Manuel I Komnenos, emperor of the Byzantine Empire
* M ...
and Floyd Red Crow Westerman. They highlighted the threat of radioactive contamination to all peoples, especially indigenous communities and said that their survival requires self-determination and emphasis on spiritual and cultural values. Increased renewable energy commercialization was advocated.
The Kingdom of Saudi Arabia with the help of China has built an extraction facility to obtain uranium yellowcake from uranium ore. According to Western officials with information regarding the extraction site, the process is conducted by the oil-rich kingdom to champion nuclear technology. However, Saudi Energy Minister denied having built a uranium ore facility and claimed that the extraction of minerals is a fundamental part of the kingdom’s strategy to diversify its economy.
Despite sanctions on Russia some countries still buy its uranium in 2022, and some argue the EU should stop. S&P Global Commodity Insights, S&P Global say non-Russian miners await more certainty before deciding whether to invest in new mines.
Health risks
Uranium ore emits
radon
Radon is a chemical element with the symbol Rn and atomic number 86. It is a radioactive, colourless, odourless, tasteless noble gas. It occurs naturally in minute quantities as an intermediate step in the normal radioactive decay chains through ...
gas. The health effects of radon, health effects of high exposure to radon are a particular problem in the mining of uranium; significant excess lung cancer deaths have been identified in epidemiology, epidemiological studies of uranium miners employed in the 1940s and 1950s.
The first major studies with radon and health occurred in the context of uranium mining, first in the Joachimsthal region of Bohemia and then in the Southwestern United States during the early Cold War. Because radon is a product of the radioactive decay of uranium, underground uranium mines may have high concentrations of radon. Many uranium miners in the Four Corners region contracted lung cancer and other pathologies as a result of high levels of exposure to radon in the mid-1950s. The increased incidence of lung cancer was particularly pronounced among Navajo and Mormon (who generally have low rates of lung cancer) miners. This is in part due to the religious prohibition on smoking in Mormonism.
Safety standards requiring expensive ventilation were not widely implemented or policed during this period. While radon exposure is the main source of lung cancer in non-smokers who aren't exposed to asbestos, there is evidence that the combination of smoking and radon exposure increases the risk above the combined risks of either harmful substance.
In studies of uranium miners, workers exposed to radon levels of 50 to 150 picocuries of radon per liter of air (2000–6000 Bq/m3) for about 10 years have shown an increased frequency of lung cancer.Toxological profile for radon , Agency for Toxic Substances and Disease Registry, U.S. Public Health Service, In collaboration with U.S. Environmental Protection Agency, December 1990. Statistically significant excesses in lung cancer deaths were present after cumulative exposures of less than 50 WLM. There is unexplained heterogeneity in these results (whose confidence interval do not always overlap). The size of the radon-related increase in lung cancer risk varied by more than an order of magnitude between the different studies.
Since that time, ventilation and other measures have been used to reduce radon levels in most affected mines that continue to operate. In recent years, the average annual exposure of uranium miners has fallen to levels similar to the concentrations inhaled in some homes. This has reduced the risk of occupationally induced cancer from radon, although it still remains an issue both for those who are currently employed in affected mines and for those who have been employed in the past.
The power to detect any excess risks in miners nowadays is likely to be small, exposures being much smaller than in the early years of mining. Coal mining in addition to other health risks can also expose miners to radon as Uranium (and its decay product radon) are often found in and near coal deposits and can accumulate underground as radon is denser than air.
In the USA, the ''Radiation Exposure Compensation Act'' provides compensation to sufferers of various health problems linked to radiation exposure, or to their surviving relatives. Uranium miners, uranium mill workers and uranium transport workers have been compensated under the scheme.
United States clean-up efforts
Despite efforts made in cleaning up uranium sites, significant problems stemming from the legacy of uranium development still exist today on the territory of the Navajo Nation and in the states of Utah, Colorado, New Mexico, and Arizona. Hundreds of abandoned mines have not been cleaned up and present environmental and health risks in many communities. At the request of the U.S. House Committee on Oversight and Government Reform in October 2007, and in consultation with the Navajo Nation, the Environmental Protection Agency (EPA), along with the Bureau of Indian Affairs (BIA), the Nuclear Regulatory Commission (NRC), the Department of Energy (DOE), and the Indian Health Service (IHS), developed a coordinated Five-Year Plan to address uranium contamination. Similar interagency coordination efforts are beginning in the State of New Mexico as well.
In 1978, Congress passed the Uranium Mill Tailings Radiation Control Act (UMTRCA), a measure designed to assist in the cleanup of 22 inactive ore-processing sites throughout the southwest. This also included constructing 19 disposal sites for the tailings, which contain a total of 40 million cubic yards of low-level radioactive material. The Environmental Protection Agency estimates that there are 4000 mines with documented uranium production, and another 15,000 locations with uranium occurrences in 14 western states, most found in the Four Corners area and Wyoming.
The ''Uranium Mill Tailings Radiation Control Act'' is a United States environmental law that amended the Atomic Energy Act of 1954 and gave the United States Environmental Protection Agency, Environmental Protection Agency the authority to establish health and environmental standards for the stabilization, Environmental remediation, restoration, and disposal of uranium mill tailings. Title 1 of the Act required the EPA to set environmental protection standards consistent with the Resource Conservation and Recovery Act, including groundwater protection limits; the
Department of Energy A Ministry of Energy or Department of Energy is a government department in some countries that typically oversees the production of fuel and electricity; in the United States, however, it manages nuclear weapons development and conducts energy-re ...
to implement EPA standards and provide perpetual care for some sites; and the Nuclear Regulatory Commission to review cleanups and license sites to states or the DOE for perpetual care. Title 1 established a uranium mill remedial action program jointly funded by the federal government and the state. Title 1 of the Act also designated 22 inactive uranium mill sites for remediation, resulting in the containment of 40 million cubic yards of low-level radioactive material in UMTRCA Title 1 holding cells.
Peak uranium
Peak uranium is the point in time that the maximum global
uranium
Uranium is a chemical element with the symbol U and atomic number 92. It is a silvery-grey metal in the actinide series of the periodic table. A uranium atom has 92 protons and 92 electrons, of which 6 are valence electrons. Uranium is weak ...
production rate is reached. Predictions of peak uranium differ greatly.
Pessimistic predictions of future high-grade uranium production operate on the thesis that either the peak has already occurred in the 1980s or that a second peak may occur sometime around 2035. Optimistic predictions claim that the supply is far more than demand and do not predict peak uranium.
, identified uranium reserves recoverable at US$130/kg were 6.14 million tons (compared to 5.72 million tons in 2015). At the rate of consumption in 2017, these reserves are sufficient for slightly over 130 years of supply. The identified reserves as of 2017 recoverable at US$260/kg are 7.99 million tons (compared to 7.64 million tons in 2015).
The expected amount of usable uranium for nuclear power that is recoverable depends greatly on how it is used. The main factor is the nuclear technology: light-water reactors, which comprise the great majority of reactors today, only consume about 0.5% of their uranium fuel, leaving over 99% of it as spent fuel waste. Fast breeder reactors instead consume closer to 99% of uranium fuel. Another factor is the ability to extract uranium from seawater. About 4.5 billion tons of uranium are available from seawater at about 10 times the current price of uranium with current extraction technology, which is about a thousand times the known uranium reserves. The Earth's crust contains approximately 65 trillion tons of uranium, of which about 32 thousand tons flow into oceans per year via rivers, which are themselves fed via geological cycles of erosion, subduction and uplift. The ability to extract uranium from seawater economically would therefore make uranium a renewable resource in practice.
Uranium can also be bred from
thorium
Thorium is a weakly radioactive metallic chemical element with the symbol Th and atomic number 90. Thorium is silvery and tarnishes black when it is exposed to air, forming thorium dioxide; it is moderately soft and malleable and has a high ...
(which is itself 3–4 times as abundant as uranium) in certain breeder reactors, although there are currently no commercially practical thorium reactors in the world and their development would require substantial financial investment which is not justified given the current low prices of natural uranium.
Thirteen countries have hit peak and exhausted their economically recoverable uranium resources at current prices according to the Energy Watch Group.
In a similar manner to every other natural metal resource, for every tenfold increase in the cost per kilogram of uranium, there is a three-hundredfold increase in available lower quality ores that would then become economical. The theory could be observed in practice during the Uranium bubble of 2007 when an unprecedented price hike led to investments in the development of uranium mining of lower quality deposits which mostly became stranded assets after uranium prices returned to a lower level.
Uranium supply
There is around 40 trillion tons of uranium in Earth's crust, but most is distributed at low parts per million trace concentration over its mass. Estimates of the amount concentrated into ores affordable to extract for under $130 per kg can be less than a millionth of that total.
One highly criticized life cycle study by Jan Willem Storm van Leeuwen suggested that below 0.01–0.02% (100–200 ppm) in ore, the energy required to extract and process the ore to supply the fuel, operate reactors and dispose properly comes close to the energy gained by using the uranium as a fissible material in the reactor. Researchers at the Paul Scherrer Institute who analyzed the Jan Willem Storm van Leeuwen paper however have detailed the number of incorrect assumptions of Jan Willem Storm van Leeuwen that led them to this evaluation, including their assumption that all the energy used in the mining of Olympic Dam is energy used in the mining of uranium, when that mine is predominantly a copper mine and uranium is produced only as a co-product, along with gold and other metals. The report by Jan Willem Storm van Leeuwen also assumes that all enrichment is done in the older and more energy intensive
gaseous diffusion
Gaseous diffusion is a technology used to produce enriched uranium by forcing gaseous uranium hexafluoride (UF6) through semipermeable membranes. This produces a slight separation between the molecules containing uranium-235 (235U) and uranium-2 ...
technology, however the less energy intensive
gas centrifuge
A gas centrifuge is a device that performs isotope separation of gases. A centrifuge relies on the principles of centrifugal force accelerating molecules so that particles of different masses are physically separated in a gradient along the radiu ...
technology has produced the majority of the world's enriched uranium now for a number of decades.
In the early days of the nuclear industry, uranium was thought to be very scarce, so a closed fuel cycle would be needed. Fast breeder reactors would be needed to create nuclear fuel for other power producing reactors. In the 1960s, new discoveries of reserves, and new uranium enrichment techniques allayed these concerns.
An appraisal of nuclear power by a team at MIT in 2003, and updated in 2009, have stated that:
Production
According to Robert Vance of the OECD's Nuclear Energy Agency, the world production rate of uranium has already reached its peak in 1980, amounting to of U3O8 from 22 countries. However, this is not due to lack of production capacity. Historically, uranium mines and mills around the world have operated at about 76% of total production capacity, varying within a range of 57% and 89%. The low production rates have been largely attributable to excess capacity. Slower growth of nuclear power and competition from secondary supply significantly reduced demand for freshly mined uranium until very recently. Secondary supplies include military and commercial inventories, enriched uranium tails, reprocessed uranium and mixed oxide fuel.
According to data from the International Atomic Energy Agency, world production of mined uranium has peaked twice in the past: once, circa 1960 in response to stockpiling for military use, and again in 1980, in response to stockpiling for use in commercial nuclear power. Up until about 1990, the mined uranium production was in excess of consumption by power plants. But since 1990, consumption by power plants has outstripped the uranium being mined; the deficit being made up by liquidation of the military (through decommissioning of nuclear weapons) and civilian stockpiles. Uranium mining has increased since the mid-1990s, but is still less than the consumption by power plants.
Primary sources
Various agencies have tried to estimate how long uranium primary resources will last, assuming a Nuclear fuel cycle#Once-through nuclear fuel cycle, once-through cycle. The European Commission said in 2001 that at the current level of uranium consumption, known uranium resources would last 42 years. When added to military and secondary sources, the resources could be stretched to 72 years. Yet this rate of usage assumes that nuclear power continues to provide only a fraction of the world's energy supply. If electric capacity were increased six-fold, then the 72-year supply would last just 12 years. The world's present measured resources of uranium, economically recoverable at a price of US$130/kg according to the industry groups Organisation for Economic Co-operation and Development (OECD), Nuclear Energy Agency (NEA) and International Atomic Energy Agency (IAEA), are enough to last for "at least a century" at current consumption rates. According to the World Nuclear Association, yet another industry group, assuming the world's current rate of consumption at 66,500 tonnes of uranium per year and the world's present measured resources of uranium (4.7–5.5 Mt) are enough to last for some 70–80 years.
Predictions
There have been numerous predictions of peak uranium in the past. In 1943, Alvin M. Weinberg et al. believed that there were serious limitations on nuclear energy if only U-235 were used as a nuclear power plant fuel. They concluded that breeding was required to usher in the age of nearly endless energy.
In 1956, M. King Hubbert declared world fissionable reserves adequate for at least the next few centuries, assuming breeding and reprocessing would be developed into economical processes.
In 1975 the US Department of the Interior, Geological Survey, distributed the press release "Known US Uranium Reserves Won't Meet Demand". It was recommended that the US not depend on foreign imports of uranium.
Pessimistic predictions
Many analysts predicted a uranium peak and exhaustion of uranium reserves in the past or the near future.
Edward Steidle, Dean of the School of Mineral Industries at Pennsylvania State College, predicted in 1952 that supplies of fissionable elements were too small to support commercial-scale energy production.
Michael Meacher, the former environment minister of the UK 1997–2003, and UK Member of Parliament, reports that peak uranium happened in 1981. He also predicts a major shortage of uranium sooner than 2013 accompanied with hoarding and its value pushed up to the levels of precious metals.
M. C. Day projected that uranium reserves could run out as soon as 1989, but, more optimistically, would be exhausted by 2015.
Jan Willem Storm van Leeuwen, an independent analyst with Ceedata Consulting, contends that supplies of the high-grade uranium ore required to fuel nuclear power generation will, at current levels of consumption, last to about 2034. Afterwards, he expects the cost of energy to extract the uranium will exceed the price the electric power provided.
The Energy Watch Group has calculated that, even with steep uranium prices, uranium production will have reached its peak by 2035 and that it will only be possible to satisfy the fuel demand of nuclear plants until then.
Various agencies have tried to estimate how long these resources will last.
The European Commission said in 2001 that at the current level of uranium consumption, known uranium resources would last 42 years. When added to military and secondary sources, the resources could be stretched to 72 years. Yet this rate of usage assumes that nuclear power continues to provide only a fraction of the world's energy supply. If electric capacity were increased six-fold, then the 72-year supply would last just 12 years.
According to the industry groups OECD, Nuclear Energy Agency, NEA and IAEA, the world's present measured resources of uranium, economically recoverable at a price of US$130/kg, are enough to last for 100 years at current consumption. According to the Australian Uranium Association, another industry group, assuming the world's current rate of consumption at 66,500 tonnes of uranium per year and the world's present measured resources of uranium (4.7 Mt) are enough to last for 70 years.
Optimistic predictions
All the following references claim that the supply is far more than demand. Therefore, they do not predict peak uranium.
In his 1956 paper, M. King Hubbert wrote that nuclear energy would last for the 'foreseeable future.'" Hubbert's study assumed that breeder reactors would replace
light water reactor
The light-water reactor (LWR) is a type of thermal-neutron reactor that uses normal water, as opposed to heavy water, as both its coolant and neutron moderator; furthermore a solid form of fissile elements is used as fuel. Thermal-neutron react ...
s and that uranium would be bred into plutonium (and possibly thorium would be bred into uranium). He also assumed that economic means of reprocessing would be discovered. For political, economic and nuclear proliferation reasons, the plutonium economy never materialized. Without it, uranium is used up in a once-through process and will peak and run out much sooner. However, at present, it is generally found to be cheaper to mine new uranium out of the ground than to use reprocessed uranium, and therefore the use of reprocessed uranium is limited to only a few nations.
The OECD estimates that with the world nuclear electricity generating rates of 2002, with LWR, once-through fuel cycle, there are enough conventional resources to last 85 years using known resources and 270 years using known and as yet undiscovered resources. With breeders, this is extended to 8,500 years.
If one is willing to pay $300/kg for uranium, there is a vast quantity available in the ocean. It is worth noting that since fuel cost only amounts to a small fraction of nuclear energy total cost per kWh, and raw uranium price also constitutes a small fraction of total fuel costs, such an increase on uranium prices wouldn't involve a very significant increase in the total cost per kWh produced.
In 1983, physicist Bernard Cohen proposed that uranium is effectively inexhaustible, and could therefore be considered a renewable source of energy. He claims that
fast breeder reactor
A breeder reactor is a nuclear reactor that generates more fissile material than it consumes. Breeder reactors achieve this because their neutron economy is high enough to create more fissile fuel than they use, by irradiation of a fertile mater ...
s, fueled by naturally replenished uranium extracted from seawater, could supply energy at least as long as the sun's expected remaining lifespan of five billion years. While uranium is a finite mineral resource within the earth, the hydrogen in the sun is finite too – thus, if the resource of nuclear fuel can last over such time scales, as Cohen contends, then nuclear energy is every bit as sustainable as solar power or any other source of energy, in terms of sustainability over the time scale of life surviving on this planet.
His paper assumes extraction of uranium from seawater at the rate of per year of uranium. The current demand for uranium is near per year; however, the use of breeder reactors means that uranium would be used at least 60 times more efficiently than today.
James Hopf, a nuclear engineer writing for American Energy Independence in 2004, believes that there is several hundred years' supply of recoverable uranium even for standard reactors. For breeder reactors, "it is essentially infinite".
The IAEA estimates that using only known reserves at the current rate of demand and assuming a once-through nuclear cycle that there is enough uranium for at least 100 years. However, if all primary known reserves, secondary reserves, undiscovered and unconventional sources of uranium are used, uranium will be depleted in 47,000 years.
Kenneth S. Deffeyes estimates that if one can accept ore one tenth as rich then the supply of available uranium increased 300 times. His paper shows that uranium concentration in ores is log-normal distributed. There is relatively little high-grade uranium and a large supply of very low grade uranium.
Ernest Moniz, a professor at the Massachusetts Institute of Technology and the former United States Secretary of Energy, testified in 2009 that an abundance of uranium had put into question plans to reprocess spent nuclear fuel. The reprocessing plans dated from decades previous, when uranium was thought to be scarce. But now, "roughly speaking, we’ve got uranium coming out of our ears, for a long, long time," Professor Moniz said.
Possible effects and consequences
As uranium production declines, uranium prices would be expected to increase. However, the price of uranium makes up only 9% of the cost of running a nuclear power plant, much lower than the cost of coal in a coal-fired power plant (77%), or the cost of natural gas in a gas-fired power plant (93%).
Uranium is different from conventional energy resources, such as oil and coal, in several key aspects. Those differences limit the effects of short-term uranium shortages, but most have no bearing on the eventual depletion. Some key features are:
* The uranium market is diverse, and no country has a monopoly influence on its prices.
* Thanks to the extremely high energy density of uranium, stockpiling of several years' worth of fuel is feasible.
* Significant secondary supplies of already mined uranium exist, including decommissioned nuclear weapons, depleted uranium tails suitable for reenrichment, and existing stockpiles.
* Vast amounts of uranium, roughly 800 times the known reserves of mined uranium, are contained in extremely dilute concentrations in seawater.
* Introduction of fast neutron reactors would increase the uranium utilization efficiency by about 100 times.
Substitutes
An alternative to uranium is
thorium
Thorium is a weakly radioactive metallic chemical element with the symbol Th and atomic number 90. Thorium is silvery and tarnishes black when it is exposed to air, forming thorium dioxide; it is moderately soft and malleable and has a high ...
which is three times more common than uranium. Fast breeder reactors are not needed. Compared to conventional uranium reactors, thorium reactors using the
thorium fuel cycle
The thorium fuel cycle is a nuclear fuel cycle that uses an isotope of thorium, , as the fertile material. In the reactor, is transmuted into the fissile artificial uranium isotope which is the nuclear fuel. Unlike natural uranium, natural ...
may produce about 40 times the amount of energy per unit of mass. However, creating the technology, infrastructure and know-how needed for a ''thorium-fuel economy'' is uneconomical at current and predicted uranium prices.
See also
* Botanical prospecting for uranium
* Energy development
* Energy security
* Isotopes of uranium
* List of uranium projects
* Nuclear fuel cycle
* Uranium metallurgy
* Uranium tile
* Uranium in the environment
* Uranium mining debate
* World energy supply and consumption
References
Further reading
;Books
* Herring, J.: ''Uranium and Thorium Resource Assessment, Encyclopedia of Energy'', Boston University, Boston, 2004, .
;Articles
*