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Industrial Minerals and Uranium Section For information: contact Robert W. Gregory Email: bgregory@uwyo.edu Phone: (307) 766-2286 Ext. 237

Uranium Page

Revised, 7/15/2005

Highland

Located in Wyoming, CAMECO's Highland is the largest production center in the United States.

Wyoming has been the nations leading producer of uranium ore since 1995. Wyoming also contains the nation's largest reserves of uranium. All uranium produced in Wyoming since 1991 has been by the in-situ extraction method. In early 2005, two in-situ mining operations were producing uranium in Wyoming. These are CAMECO's Highland / Morton Ranch and Smith Ranch operations. Recently CAMECO consolidated these properties into one. The recent production of in-situ uranium is given in the table below:

Wyoming Annual In-Situ Uranium Production (Pounds of Yellowcake)

Sources: Wyoming State Inspector of Mines and Wyoming Department of Revenue

Figure 1: Schematic diagram of in-situ mining of uranium. Courtesy COGEMA

Figure 3: Yellowcake solution recovered from in-situ processing, Highland operation, Converse County, Wyoming. Solution from this vat is dried and shipped in barrels to enrichment plants in France. Photo by Ray E. Harris, 1998

Figure 2: Recovery of yellowcake from solutions recovered from wells in ore body, Christensen Ranch operation. Photo courtesy COGEMA

A roll-front occurrence of uranium minerals (black) in host sandstone, Gas Hills, Wyoming. The sandstone contains reduced forms of minerals on the convex side of the roll-front, while the minerals exist in the oxidized state inside or on the concave side of the roll-front. Photo from C. L. VanAlstine, Office of the U. S. Atomic Energy Commission, Casper, Wyoming, donated to the Wyoming State Geological Survey by W. L. Chenoweth. Date of photo unknown

As of February 2005, the only other large scale production of yellowcake in the United States was from the Crow Butte in-situ operation in Nebraska also by CAMECO. Small amounts of uranium are being produced from the historic mining areas on the Colorado Plateau of Utah and Colorado. No uranium is being mined in the former mining areas in New Mexico, Arizona, the Texas coastal plain, or hardrock mining areas in Washington State. A major deep in situ mine in Texas is planned to start up in 2005

The in situ leaching process involves pumping an environmentally benign solution of water and sodium bicarbonate down an injection well where it flows through the deposit, dissolving the uranium. The uranium-bearing solution is pumped back to the surface through extraction wells, leaving the underground rock formation intact. The uranium is extracted at a central processing facility and the mining solution recycled. This mining technique produces no tailings and has significant operational and environmental advantages over conventional mining methods.

The spot market price of yellowcake has been increasing recently. For the latest price go here.

Uranium-bearing ore was first mined in Wyoming in 1920 from the Silver Cliff Mine near Lusk in Niobrara County. This ore was processed for its radium content and it is reported that some of this material from Wyoming was used by Madame Curie in her pioneering experiments with radiation.

Uranium was first discovered in Tertiary sandstones in Wyoming by Dr. J. D. Love on October 15, 1951, at the Pumpkin Buttes, Campbell County. Following this discovery uranium was discovered in Tertiary sandstones in the Gas Hills, Red Desert, southern Powder River Basin, Shirley Basin, and other areas in the state. Uranium in Tertiary sandstones occurs in what have been termed roll-front deposits. These were named by miners on the Colorado Plateau uranium mining area in Utah and Colorado where they constituted minor and unusual occurrences. However, in Wyoming, roll-fronts are the most common type of occurrence.

Prior to 1994, Wyoming historically ranked 2^nd in uranium production and 2^nd in uranium reserves after New Mexico. Annual production of mined uranium from Wyoming is shown in the graph below.

As seen in the production graph to the right, Wyoming has experienced three uranium production peaks. The first peak in 1961 represents uranium produced for the Atomic Energy Commission for ultimate use in atomic weapons. Production peaked again in 1973 when uranium was processed for fuel during the first phase of domestic nuclear power plant construction. Production peaked in Wyoming in 1980 as nuclear fuel was being stockpiled for future worldwide nuclear power plant operations. Most production contracts terminated within a month of the Three Mile Island power plant malfunction March 28, 1979.

Yellowcake, an oxidized form of uranium, is the product produced by Wyoming's current producers. Wyoming's yellowcake may be sold to a variety of enrichment operations.

The source of nuclear fuel used in nuclear powered electrical generating stations in the United States is varied. According to an article in the February, 2004 issue of Pay Dirt, 20% of all electricity generated in the United States is nuclear. Under the terms of a 1993 agreement between USEC, Inc., and a Russian firm, Techsnabexport, the equivalent of 8000 Russian nuclear warheads have been converted to nuclear reactor fuel. This requires the reduction of the percentage of fissionable isotope U235 from over 90% to around 3%. According to Pay Dirt, about 10% of the electricity now used in the U.S. is generated from former Russian warhead uranium. That means half of the nuclear fuel used in the U.S. is this material. The amount is decreasing as this supply is being exhausted. This is a large part of the reason the price of yellowcake is increasing on the spot market.

The other half comes from a variety of sources. USEC also produces nuclear power plant grade fuel from conventional sources (mined uranium converted to yellowcake) at its Paducah, Kentucky plant. This material comes from a variety of sources that may include Wyoming-produced yellowcake, or foreign suppliers. According to www.usec.com nuclear power plant fuel from both Paducah and diluted Russian warhead uranium is sold to 14 countries. USEC also operates facilities at Oak Ridge, Tennessee, Portsmouth, Ohio, and has offices in Bethesda, Maryland.

It is generally not known exactly where Wyoming's yellowcake is sold, though reliable sources say some is sold to French enrichment companies, and some is sold to Duke Power in North Carolina.

Other uses for uranium include medical and research materials, and depleted uranium (uranium metal depleted in the fissionable isotope ²³⁵U) is used in weights such as elevator counterweights, armor, and armor-piercing shells.

For a detailed overview of uranium in Wyoming, read:

Harris, R.E., and King, J. K., 1993, Geological classification and origin of radioactive mineralization in Wyoming: in Snoke, A. W., Steidtmann, J. R., and Roberts, S. M., editors, Geology of Wyoming: Wyoming State Geological Survey Memoir 5, p. 898 – 916.

Uranium mining in the Gas Hills of Wyoming in the late 1960s. Most mining was by open pit methods. Photo from the collection of C. L. VanAlstine, U. S. Atomic Energy Commission Casper, Wyoming office, donated to the Wyoming State Geological Survey by W. L. Chenoweth.

Information about Wyoming's uranium producers may be found at this company site:

• CAMECO (http://www.cameco.com)

Useful information about atomic energy and the nuclear fuel cycle may be found at the following sites:

• The Virtual Nuclear Tourist(http://www.nucleartourist.com/)
• The Nuclear Energy Institute (http://www.nei.org/)
• The International Atomic Energy Agency (http://www.iaea.org/)
• U.S. Department of Energy nuclear power page (http://www.eia.doe.gov/fuelnuclear.html)
• World Nuclear Association (http://www.world-nuclear.org/)