Uranium mining in the United States

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Uranium mining in the United States declined drastically in the 1980s, but has revived since 2001 due to higher uranium prices. The average spot price of uranium oxide (U₃O₈) increased from $7.92 in 2001 to $39.48 in 2006.[1]

Regular production of uranium-bearing ore in the United States began in 1898 with the mining of carnotite-bearing sandstones of the Colorado Plateau in Colorado and Utah, for their vanadium content.

The late 1940s and early 1950s saw a boom in uranium mining in the western US, spurred by the fortunes made by prospectors such as Charlie Steen. The United States was the world's leading producer of uranium from 1953 until 1980, when annual US production peaked at 16,810 tonnes U₃O₈.^[1] Until the early 1980s, there were active uranium mines in Arizona, Colorado, New Mexico, South Dakota, Texas, Utah, Washington, and Wyoming.^[2]

Price declines in the late 1970s and early 1980s forced the closure of numerous mines. Most uranium ore in the United States comes from deposits in sandstone, which tend to be of lower grade than those of Australia and Canada. Because of the lower grade, many uranium deposits in the United States became uneconomic when the price of uranium declined sharply in the late 1970s. By 2001, there were only three operating uranium mines (all in-situ leaching operations) in the United States. Annual production reached a low of 779 tonnes of uranium oxide in 2003, but then more than doubled in three years to 1672 tonnes in 2006, from 10 mines.[2] The US Energy Information Administration reported that 90% of US uranium production in 2006 came from in-situ leaching.[3]

Uranium is used primarily for nuclear power. In 2001 the United States had 104 operating nuclear power plants generating 20% of the nation's electrical power supply. Although the United States had the most nuclear power plants of any country, it generated a much lower percentage of electricity from nuclear power than did France (76% from nuclear) or Japan (34% from nuclear). In 2001 the United States mined only 5% of the uranium consumed by its nuclear power plants. The remainder was imported, principally from Canada and Australia.^[3]

Although uranium production has declined to low levels, the United States has the fourth-largest uranium resource in the world, behind Australia, Canada, and Kazakhstan.^[4] Rising uranium prices since 2001 have increased interest in uranium mining in Arizona, Colorado, Texas and Utah.[4][5] The states with the largest known uranium ore reserves (not counting byproduct uranium from phosphate) are (in order) Wyoming, New Mexico, and Colorado.^[5]

Contents 1 By state 1.1 Alabama 1.2 Alaska 1.3 Arizona 1.4 California 1.5 Colorado 1.6 Florida 1.7 Idaho 1.8 Nebraska 1.9 Nevada 1.10 New Jersey 1.11 New Mexico 1.12 North Dakota 1.13 Oklahoma 1.14 Oregon 1.15 Pennsylvania 1.16 South Dakota 1.17 Texas 1.18 Utah 1.19 Virginia 1.20 Washington 1.21 Wyoming 2 Health and environmental issues 3 References 4 See also 5 External links

[edit] By state

[edit] Alabama

Uranium in Alabama is found in the Coosa Block of the Northern Alabama Piedmont. Metamorphic uranium occurrences have been found in the Higgins Ferry Group in Coosa and Clay Counties. Some exploration has been done, but no economic deposits have been found to date.

[edit] Alaska

Uranium was discovered at the Ross-Adams deposit in 1955 by an airborne gamma radiation survey. The deposit is at Bokan Mountain on Prince of Wales Island. The principal ore mineral was uranothorite, whick occurred in veinlets in granite. Accessory minerals were primarily hematite and calcite, with lesser amounts of fluorite, pyrite, galena, and quartz. The only mining was done in 1957, when ore was removed from an open pit 25 to 75 feet (23 m) wide, 370 feet (110 m) long, and 30 feet (9.1 m) deep.^[6]

[edit] Arizona

See main article: Uranium mining in Arizona

Uranium mining in Arizona has taken place since 1918. Prior to the uranium boom of the late 1940s, uranium in Arizona was a byproduct of vanadium mining of the mineral carnotite. There are currently no producing uranium mines in Arizona.

[edit] California

Uranium was discovered in 1954 in the Sierra Nevada of Kern County, along the Kern River about 30 miles (48 km) northeast of Bakersfield. Two mines, the Kergon mine and the Miracle mine, made small shipments in 1954 and 1955. Uranium occurs as uraninite and autunite in shear zones in granodiorite. Accessory minerals include fluorite and the molybdenum minerals ilsemanite and jordisite.^[7]

[edit] Colorado

See main article, Uranium mining in Colorado

The first uranium identified in the USA was pitchblende from the Wood gold mine at Central City, Colorado in 1871. Uranium mining in southwest Colorado goes back to 1898. The Uravan district of Colorado and Utah supplied about half the world's radium from 1910 to 1922, and vanadium and uranium were byproducts. The only currently active uranium mine in the state is the Sunday mine near Uravan, Colorado, owned by Denison Mines.^[8]

[edit] Florida

The central-Florida phosphorite deposits are considered to contain the largest known uranium resource (one million tonnes of uranium oxide) in North America (but note that resources are not the same as ore reserves). Uranium has been produced as a byproduct of phosphate mining and the production of phosphoric acid fertilizer. The uranium is contained in the phosphate minerals francolite, crandallite, millisite, wavellite, and vivianite, found in Miocene and Pliocene sediments of the Bone Valley Formation. The average uranium content is 0.009%.^[9] However, because the recovery process costs an estimated $22 to $54 per pound of U₃O₈, more than the price of uranium from the 1980s through the early 2000s, uranium has not been recovered from Florida phosphate since 1998.^[10] Because of the high price of uranium since 2003, uranium recovery may be reactivated.[6]

[edit] Idaho

From 1955 to 1960, uranium was extracted from placer black sand deposits derived from the Idaho Batholith in southwest Idaho. The deposits were mined for uranium, thorium, and rare earths. Uranium and thorium were in the monazite grains; rare earths were in columbite and euxenite. Production was 365 thousand pounds (165 tonnes) of U₃O₈.^[11]

Uranium was mined at the Stanley district in Custer County, Idaho from 1957 to 1962. Deposits occur as veins in granite of the Cretaceous Idaho Batholith, and in strataform deposits in possibly Paleocene arkosic conglomerates and sandstones between the underlying Idaho Batholith and overlying Challis Volcanic Group (Eocene). The USGS has estimated production to be less than 170 thousand pounds (78 tonnes) of U₃O₈.^[12]

[edit] Nebraska

The only uranium mine in Nebraska has been the Crow Butte mine, operated by Cameco. The mine is five miles (8 km) southeast of Crawford in Dawes County, western Nebraska.^[13] The roll-front deposit in the Oligocene Chadron formation was discovered in 1980 by Wyoming Fuel Co.^[14] Mining began in 1991. The uranium is being mined by in-situ leaching.

• Nuclear Regulatory Commission (13 Feb. 1998): Crow Butte resources Inc., Final finding of no significant impact
• Mining News (16 Feb 2006): Crow Butte gets ISO certified

[edit] Nevada

The uranium deposit of the Apex mine (also called the Rundberg mine or the Early Day mine) was discovered in 1953, three miles south of Austin, Nevada, in Lander County. The mine produced 45 tonnes of U₃O₈ from 1954 until the mine was closed in 1966. Uranium occurs as autunite and meta-autunite in fractured Cambrian quartzite and argillite, adjacent to Jurassic quartz monzonite.^[15]

The McDermitt Caldera in Humboldt County was the site of intense uranium exploration in the late 1970s. Western Uranium Corporation is currently drilling exploratory boreholes in the area.[7]

[edit] New Jersey

A uranium exploration project in northern New Jersey was halted in 1980 when the local government passed an ordinance preventing uranium mining.[8]

[edit] New Mexico

See main article: Uranium mining in New Mexico

New Mexico was a significant uranium producer since the discovery of uranium by Navajo sheepherder Paddy Martinez in 1950. Uranium in New Mexico is almost all in the Grants mineral belt, along the south margin of the San Juan Basin in McKinley and Cibola counties, in the northwest part of the state.^[16] No mining has been done since 2002, even though the state has second-largest known uranium ore reserves in the U.S.

[edit] North Dakota

Some lignite coal in southwest North Dakota contains economic quantities of uranium. From 1965 to 1967 Union Carbide operated a mill near Belfield in Stark County to burn uraniferous lignite and extract uranium from the ash. The plant produced about 150 tonnes of U₃O₈ before shutting down.[9]

North Dakota Geological Survey: Uranium

[edit] Oklahoma

A small amount of uranium ore was mined in the mid-1950s from a surface exposure at Cement in Caddo County. The uranium occurred as carnotite and tyuyamunite in fracture fillings in the Rush Springs Sandstone over the Cement anticline, where the sandstone is bleached.^[17] The mined area was 150 feet (46 m) long, 3 to 5 feet (1.5 m) wide, and extended 3 to 5 feet (1.5 m) below ground surface.^[18]

[edit] Oregon

Uranium was discovered in Oregon in 1955, near Lakeview in Lake County. The White King mine and the Lucky Lass mine shipped uranium from 1955 until 1965. At the White King mine, uranium was mined by both underground and open-pit methods from a low-temperature hydrothermal deposit in Pliocene volcanic rocks, associated with opal realgar, stibnite, cinnabar, and pyrite. At the Lucky Lass mine, the uranium without the associated minerals was mined from an open pit.^[19]

A minor amount of uranium was mined in 1960 from a deposit at Bear Creek Butte in Crook County. The uranium was present as autunite at the contact between a rhyolite dike and tuffs of the Oligocene-Miocene John Day Formation.

[edit] Pennsylvania

The uranium mineral autunite was reported in 1874 near the town of Mauch Chunk (present-day Jim Thorpe) in Carbon County, eastern Pennsylvania.^[20] A small amount of test mining was done in 1953 at the Mount Pisgah deposit. The uranium at the Mount Pisgah deposit is primarily in an unidentified black mineral in pods and rolls in the basal conglomerate of the Mauch Chunk Formation (Mississippian). Also present are the secondary uranium and uranium-vanadium minerals carnotite, tyuyamunite, liebigite, uranophane, and betauranophane.^[21]

[edit] South Dakota

Uranium was discovered near Edgemont, South Dakota in 1951, quickly followed by mining. The uranium occurs in Cretaceous sandstones of the Inyan Kara group, where it outcrops along the southern edge of the Black Hills in Fall River County, South Dakota. Minerals in unoxidized sandstone are uraninite and coffinite; minerals in oxidized zones include carnotite and tyuyamunite.^[22]

An airborne gamma radiation survey flown by the US Atomic Energy Commission in 1954 discovered high radiation readings over the Cave Hills area in Harding County, in the northwest corner of the state. Claims were immediately staked over uranium-bearing lignite beds in the area. The lignite was strip-mined, probably starting that same year, and continuing until the mines closed in 1964.[10]

No uranium is currently mined in South Dakota.

In January 2007 Powertech Uranium Corporation received a state permit to drill boreholes to evaluate their Dewey-Burdock project, in Custer and Fall River counties northwest of Edgemont.[11][12] Previous work at the property in the early 1980s defined a resource of 10 million pounds (4500 tonnes) of uranium, of which 5 million pounds (2300 tonnes) were estimated recoverable by conventional underground mining.[13] Powertech hopes to bring the property into production as an in-situ leaching mine in 2009.[14]

South Dakota Department of Environment & Natural Resources: In Situ Leach Mine Regulations

[edit] Texas

The uranium district of south Texas was discovered by accident in 1954 by an airborne gamma radiation survey looking for petroleum deposits. The coastal plain had previously been regarded as highly unfavorable for uranium deposits.^[23] The uranium occurs in roll-front type deposits in sandstones of Eocene, Oligocene and Miocene age.^[24] The deposits are distributed along about 200 miles (320 km) of coastal plain, from Panna Maria in the north, south into Mexico. Uranium production began in 1958, from open-pit and in situ leach mines.

Uranium production stopped in 1999, but restarted in 2004.^[25] By 2006, three mines were active: Kingsville Dome in Kleberg County, the Vasquez mine in Duval County, and the Alta Mesa mine in Brooks County. 2007 production was 1.34 million pounds (607 tonnes) of U₃O₈.^[26]

Energy Metals Corp. is applying for permits to begin mining the La Palangana deposit in Duval County; the company hopes to begin mining in 2008.[15]

Handbook of Texas Online: Uranium Mining

[edit] Utah

See main article: Uranium mining in Utah.

Mining of uranium-vanadium ore in southeast Utah goes back to the late 1800s. All of Utah’s numerous uranium mines closed prior to 2000, because of low prices. In late 2006, Denison Mines reopened the Pandora mine in the La Sal mining district of southeastern Utah.

[edit] Virginia

Marline Uranium Corp. announced in July 1982 that it had discovered 30 million pounds of uranium in the Coles Hill deposit, on land that it had leased near Chatham in Pittsylvania County. In response, the state of Virginia imposed a moratorium on uranium mining in the state.[16] Marline dropped its remaining mineral leases and closed its local exploration office in 1990.[17] The deposits occur as breccia-fill and veins in gneiss bordering the Triassic Danville Basin. Ore minerals are coffinite, uraninite, and uranium-bearing apatite.[18]

In October 2007, Walter Coles, who owns the land over the Coles Hill deposit, announced that he and some other landowners had formed Virginia Uranium Inc. to mine the deposit themselves, if it can be done safely.[19][20] In November 2007, the state issued an exploration permit to Virginia Uranium, to allow drilling test holes into the deposit. Drilling began in mid-December.

The state-imposed moratorium on uranium mining is still in effect. A bill proposed in the state General Assembly in January 2008 would have created a Virginia Uranium Mining Commission to determine if uranium mining could be done in a manner protective of human health and the environment, and to recommend regulatory controls.[21] However, opponents of uranium mining succeeded in stopping the bill on March 3, 2008, when a committee to the House of Delegates delayed consideration of the bill until 2009.[22]

• Virginia Uranium Inc. website
• Virginia Department of Mines, Minerals, and Energy: Uranium Exploration Permit Approved

[edit] Washington

Uranium was discovered at the Midnite Mine deposit on the Spokane Indian Reservation, Stevens County, Washington in 1954. The deposit was mined from an open pit 1956-1962 and 1969-1982.^[27] Production through 1975 was 8 million pounds of U₃O₈. The uranium is contained in autunite, uraninite, and coffinite, with gangue minerals pyrite and marcasite. The ore occurs as disseminations, replacements, and stockworks in Precambrian metamorphic rocks of the Togo formation, in a roof pendant in Cretaceous porphyritic quartz monzonite.^[28]

Western Nuclear discovered the Spokane Mountain uranium deposit in 1975, two miles (3 km) northeast of the Midnite Mine, and in a similar geologic setting.^[29]

Uranium was also mined at the Sherwood mine, a few miles south of the Midnite mine.

[edit] Wyoming

See main article Uranium mining in Wyoming

Wyoming once had many operating uranium mines, and has the largest known uranium ore reserves of any state in the U.S. The Wyoming uranium mining industry was hard-hit in the 1980s by the drop in the price of uranium. The uranium-mining boom town of Jeffrey City lost 95% of its population in three years. By 2006, the only active uranium mine in Wyoming was the Smith Ranch-Highland in-situ leaching operation in the Powder River Basin, owned by a subsidiary of Cameco. The mine produced 907 tonnes of yellowcake (uranium concentrate) in 2006, making it the leading uranium producer in the United States.^[30]

[edit] Health and environmental issues

The radiation hazards of uranium mining and milling were not appreciated in the early years, resulting in workers exposed to high levels of radiation. Inhalation of radon gas caused sharp increases in lung cancers among underground uranium miners employed in the 1940s and 1950s.^[31][32][33]

Uranium mining and milling has left a legacy of environmental problems. Out of 50 present and former uranium milling sites in 12 states, 24 have been abandoned, and are the responsibility of the US Department of Energy.[23]

[edit] References

[edit] See also

• Nuclear power in the United States
• Uranium mining
• List of uranium mines
• Anti-nuclear movement in the United States

[edit] External links

• Uranium Producers of America