Main Page | See live article | Alphabetical index

Depleted uranium

Depleted uranium (DU) is uranium which has had most of the fissile isotope U-235 removed, and consists of mostly U-238. The U-235 is concentrated into enriched uranium through the process of isotope separation for use in nuclear reactors and nuclear weapons. The remaining, less radioactive (40% as radioactive as natural uranium), U-238 is waste material from this enrichment process. During the Manhattan Project depleted uranium had the codename tubealloy, a term that is still occasionally used. Uranium is mined mainly for its U-235 content, so the excess U-238 can be obtained cheaply and is used for its extremely high density, only slightly less than that of tungsten.

Table of contents
1 Military Applications
2 Civilian Applications
3 Health concerns
4 Bibliography, external links and references

Military Applications

A major use of DU is as the head of a kinetic projectile fired to penetrate armour, so it is used by tanks and other military platforms. Depleted uranium is very dense: at 19.05 g/cm³ it is 70% denser than lead, allowing it to penetrate most conventional armor. A DU projectile burns and melts as it penetrates steel, becoming 'sharper' rather than blunting. As the projectile passes through armor, the heat build-up causes it to catch fire and disintegrate into fine particles on re-encountering air. DU is also used as a form of vehicular armour.

The US military is the primary user of DU. It uses the DU in an alloy with around 3.5% titanium. It is used by the US Army in 120 mm or 105 mm caliber by the M1 Abrams tanks and in 25 mm by the M919 mounted on the M2 Bradley and the LAV-AT; the Abrams contains DU as part of its armour plating. The US Navy use it in their 20 mm CIWS and the 25mm Mk 38 machine gun. The Air Force uses it in 30 mm caliber on the A-10 Thunderbolt II and the Marine Corps in 25 mm on their AV-8B Harrier. DU munitions (in the form of tank and naval artillery rounds) are also deployed by the armed forces of the UK.

Civilian Applications

Depleted uranium is also used in sailboat keels, as counterweights in oil drills, and in other places where there is a need to place a weight that occupies as little space as possible, such as in aircraft ballast.

Health concerns

Environmental groups have raised concerns about the use of this material; arguing that not only is it dangerously radioactive, but it is also as toxic as lead. Such issues are of concern to those fired upon by DU weapons, to those protected by DU armour-plating; and to civilians and troops operating in a theatre where DU is used. The health effects of depleted uranium have been postulated to be one of the possible causes of Gulf war syndrome. This possibility has been widely denied by a number of government officials, most of whom deny that DU is dangerously radioactive.

Studies of scientific bodies have resulted in mixed conclusions. Studies showing detrimental health affects have claimed the following:

"The most important concern is the potential for future groundwater contamination by corroding penetrators (ammunition tips made out of DU). The penetrators recovered by the UNEP team had decreased in mass by 10-15% due to corrosion. This rapid corrosion speed underlines the importance of monitoring the water quality at the DU sites on an annual basis." These facts together may indicate, that DU ammunition is actually quite of a health problem, and endangers the civilian population if left on the battlefield. However, other studies have shown that DU ammunition has no measurable detrimental health effects, either in the short or long term. Critics of these studies point to the fact that they come primarily from the US and UK -- both supporters of DU. However, the Geneva-based International Atomic Energy Agency also reports, "based on credible scientific evidence, there is no proven link between DU exposure and increases in human cancers or other significant health or environmental impacts" [1].

Bibliography, external links and references

  1. IEAE Information on Depleted Uranium - Includes a fact sheet with information about health hazards.
  2. "Evidence for a lack of DNA double-strand break repair in human cells exposed to very low x-ray doses", Vol. 100, Issue 9, 5057-5062, April 29, 2003, Proceedings of the National Academy of Sciences [1]
  3. "Clustered DNA damages induced in isolated DNA and in human cells by low doses of ionizing radiation", Vol. 97, Issue 1, 103-108, January 4, 2000, Proceedings of the National Academy of Sciences
  4. "Mutagenesis and repair by low doses of radiation in mammalian cells" published on August 27, 2002, Proceedings of the National Academy of Sciences
  5. Post Conflict Assessment Iraq by the United Nations Environment Programme
  6. Depleted Uranium article from The Royal Society
  7. Report about the DU conference in Prague at 24.-25.11.01 (in German)