January 20, 2006
By: Evgenia Misenzhnikova, Legislative Intern
You asked for information on companies that produce depleted uranium (DU) and its disposal. You also asked what would happen if a DU projectile hit a tank with depleted uranium armor.
DU is a by-product of the uranium enrichment process. There are two plants in the United States that enrich uranium — one in Kentucky, the other in Ohio. Several companies use DU to manufacture munitions.
DU is considered to be a low-level radioactive material and is disposed of in the form of hexafluoride. It is stored in carbon steel cylinders in the open air on gravel or concrete in “cylinder yards” located adjacent to the enrichment plants.
The main characteristics of DU are its flammability and high density, which make DU projectiles good armor-piercing devices. When a DU projectile hits a tank with depleted uranium armor, there is an explosion that releases numerous fine insoluble uranium oxide particles. They remain in the human body for extended periods of time and are hazardous to health. Uranium levels in ground water increase sharply if the particles end up in the soil.
MANUFACTURERS OF DEPLETED URANIUM
DU is a by-product of the uranium enrichment process. (It contains 0.2% to 0.4% of uranium-235.) Throughout the global nuclear industry, uranium is enriched by one of two methods: gaseous diffusion or gas centrifuge. Currently, according to the U.S. Nuclear Regulatory Commission, there are two operating enrichment plants in the United States: in Paducah, Kentucky and Piketon, Ohio. Both are operated by the United States Enrichment Corporation (USEC), which was created as a government corporation under the 1992 Energy Act and privatized by legislation in 1996 (http://www.nrc.gov/reading-rm/doc-collections/fact-sheets/enrichment.html).
Several companies use depleted uranium in production of armor-piercing shells, bomb casings, missiles, tank armor plating, aircraft ballast, and tank rounds. The major manufacturers of DU ammunition in the United States are:
1. Aerojet Ordnance Co. (formerly Aerojet Heavy Metals Co.) in Jonesborough, Tennessee
2. Alliant Ammunition and Powder Co. in Radford, Virginia
3. General Dynamics Ordnance and Tactical Systems (formerly Primex Technologies) in St. Petersburg, Florida
4. Oak Ridge Centers for Manufacturing Technology in Oak Ridge, Tennessee
5. Radford Army Ammunition Plant in Radford, Virginia
6. Rocky Flats Environmental Technology Site (formerly Rocky Flats Nuclear Weapons Plant) near Boulder, Colorado
7. Starmet Corp. (formerly Nuclear Metals) in Concord, Massachusetts
8. Twin Cities Army Ammunition Plant in New Brighton, Minnesota (http://vzajic.tripod.com/4thchapter.html )
DISPOSAL OF DEPLETED URANIUM
DU is considered a low-level radioactive material under both Department of Energy (DOE) orders and Nuclear Regulatory Commission regulations. It is stored and disposed of in the form of uranium hexafluoride (UF6), the chemical form used in the enrichment process.
The U.S. DOE is the agency responsible for managing most of the DU produced in the U.S. Currently DOE has about 750,000 metric tonnes of depleted uranium, which is stored in carbon steel cylinders. They are stacked two-high in the open air on gravel or concrete in so-called cylinder yards located adjacent to the enrichment plants. The cylinders contain up to 12.7 metric tonnes of UF6. According to DOE, the major disposal sites of depleted uranium are:
1. Nevada Test Site — 65 miles northwest of Las Vegas
2. Hanford Site — south-central Washington
3. Waste Isolation Pilot Plant -- New Mexico
4. Portsmouth Gaseous Diffusion Plant Site — Ohio
5. Peducah Gaseous Diffusion Site — Kentucky
6. East Tennessee Technology Park — Tennessee (www.doe.gov)
DEPLETED URANIUM PROJECTILES
The most common DU round is a high kinetic energy projectile. The main characteristics of DU are flammability (uranium can spontaneously ignite and then burn at temperatures of above 10,832 degrees Fahrenheit) and high density (twice the density of lead) (http://www.fpx.de). Upon impact, concentration of high kinetic energy allows DU projectile to ignite and penetrate armor. As it goes through armor, it “self-sharpens” and often has enough momentum to penetrate the opposite wall of the tank. Contact temperature between the projectile and the armor is 2,069 degrees Fahrenheit. Usually the burning projectile will ignite ammunition or the fuel within the tank. So, if a DU projectile hit a tank with depleted uranium, the tank would explode immediately because of the high temperature. The projectile would burn on impact, releasing fine insoluble uranium oxide particles that can then be spread by the wind, inhaled and absorbed into the human body or by animals and plants. The particles remain in the body system for extended periods of time. Uranium oxide particles are highly toxic for the soil. They pollute the environment and create up to a 100% increase in uranium levels in ground water (U.N. Environmental Program, http://seattlepi.nwsource.com).