Depleted uranium (DU) is uranium which contains a reduced proportion of the fissile isotope U-235 and (usually) the highly radioactive but rare isotope U-234, compared to natural uranium. During the Manhattan Project depleted uranium had the codename tuballoy, a term that is still occasionally used.

Natural uranium contains 0.720% U-235 and 99.2745% U-238 (and 0.0055% U-234), while depleted uranium contains only 0.2 to 0.4 weight-percent U-235.

The U-235 is concentrated into enriched uranium through the process of isotope separation for use in nuclear reactors and nuclear weapons:

• Nuclear weapons usually use uranium containing perhaps 85% or more of U-235 (a lower grade is possible but makes the weapon less efficient).
• Commercial nuclear reactor fuel is usually enriched to 5% or less.

The enrichment process does not create U-235, the isotopes of uranium are merely separated. Therefore the process leaves large amounts of depleted uranium as a waste product. For example producing 1kg of 5% enriched uranium requires 11.8kg of natural uranium, leaving about 10.8 kg of depleted uranium with 0.3% U-235.

The United States Department of Energy currently has an inventory of 704,000 tonnes of depleted uranium hexafluoride (stored in 58,000 metal cylinders), corresponding to 476,000 tonnes of uranium [1] (http://web.ead.anl.gov/uranium/). It encourages the use of DU as a means of disposing of the stock, and plans to eventually convert the remaining inventory to a less toxic form, probably either uranium metal or oxide.

As a product otherwise requiring long term storage as low level radioactive waste, depleted uranium can be obtained cheaply. It is useful for its extremely high density, which is only slightly less than that of tungsten. As well as a lower initial cost, depleted uranium is easier to roll, machine and cast than tungsten. However since it is radioactive the facilities for processing it need to monitor and filter dust and airborne particles. One disadvantage of DU is that it needs to be correctly handled when an object containing it is scrapped. The uranium is normally leased from the manufacturer and subsequently returned at the end of the object's life.

Contents

1 Military applications 1.1 Projectile weapons 1.2 Armour plate 2 Civilian applications 3 Health concerns 3.1 Depleted uranium and Gulf War Syndrome 4 Legal status of military use 5 External links 5.1 United Nations 5.2 Scientific bodies 5.3 Other

Military applications

Projectile weapons

A major use of DU is for high-kinetic energy penetrators for the anti-tank role. Depleted uranium is very dense: at 19050 kg/m³, it is 70% denser than lead thus each round is heavier, and therefore carries more kinetic energy. DU is pyrophoric: if it penetrates steel or other metal armour, the impact and heat energy released causes it to disintegrate to dust and combust when it reaches air. Against an armoured vehicle this is devastating, piercing the hull to create an extremely hot ball of dust and gas in the interior, killing the crew and igniting fuel and ammunition.

The US Army uses the DU in an alloy with around 3.5% titanium. It is used by the US Army in 120mm or 105mm calibre by the M1 Abrams and M60A3 tanks and in 25mm calibre by the M242 mounted on the M2 Bradley and the LAV-AT.

The US Navy used it in its 20mm Phalanx CIWS guns (though it has now switched to tungsten for this application). The Air Force uses the 30mm PGU-14/B amour-piercing round in the GAU-8 Avenger cannon of the A-10 Thunderbolt II and the Marine Corps in the 25mm PGU-20 fired by the GAU-12 Equalizer cannon of the AV-8B Harrier, and also in the 20mm M197 gun mounted on AH-1 helicopter gunships.

The Russian military has used DU munitions in tank main gun ammunition since the late 1970s, mostly for the 115mm guns in the T-62 tank and the 125mm guns in the T-64, T-72, T-80, and T-90 tanks.

DU munitions (in the form of tank and naval artillery rounds) are also deployed by the armed forces of the UK, Israel, France, Japan, China, Russia, Pakistan, and many more. DU rounds are manufactured in 18 countries.

Armour plate

Because of its high density, depleted uranium can also be used in tank armour, sandwiched between sheets of steel armor plate. For instance, some late-production M1A1HA and M1A2 Abrams tanks built after 1998 have DU reinforcement as part of its armour plating in the front of the hull and the front of the turret and there is a program to upgrade the rest.

Civilian applications

Depleted uranium is also used in a number of civilian applications, generally where a high density weight is needed.

Such applications include sailboat keels, as counterweights and sinker bars in oil drills, gyroscope rotors, and in other places where there is a need to place a weight that occupies as little space as possible. Tungsten could be used instead, but it is much more expensive.

Aircraft may also contain depleted uranium counterweights (a Boeing 747 may contain 400–1,500kg). However there is some controversy about its use in this application because of concern about the uranium entering the environment should the aircraft crash, particularly as the metal is pyrophoric. This was highlighted by the collision of two Boeing 747s at Tenerife Airport in 1977 when the resulting fire consumed 3000kg of the material. Consequently its use has been phased out in many newer aircraft, for example both Boeing and McDonnell-Douglas discontinued using DU counterweights in the 1980s.

An unexpected application is in Formula 1 racing cars. The rules state a minimum weight of 600kg but builders strive to get the weight as low as possible and then bring it up to the 600kg mark by placing depleted uranium where needed to achieve a better balance.

DU is also used as a radiation shield — its alpha radiation is easily stopped by the non-radioactive casing of the shielding and the uranium's high atomic weight is effective in absorbing gamma radiation.

Health concerns

Environmental groups have raised concerns about the use of this material, particularly in munitions because it is dangerously radioactive, and also it is toxic in the same manner as lead and other heavy metals.

Such issues are of concern to those attacked with DU weapons, those firing DU weapons, those protected by DU armour-plating, civilians and troops operating in a theatre where DU is used, and to people who will live at any time after in such areas or breathing air or drinking water from these areas (DU lasts forever in the environment, in any practical sense).

The health effects of depleted uranium have been postulated to be one of the possible causes of Gulf war syndrome (see below). US Government officials have disputed this claim.

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

• Toxic material from depelete uranium ammunition disperses into the air much more easily and widely than expected. Also DU disperses into the water, as mentioned in a United Nations Environment Programme (UNEP) study [2] (http://www.unep.org/pdf/iraq_ds_lowres.pdf):

"The most important concern is the potential for future groundwater contamination by corroding penetrators (ammunition tips made out of DU). The munition tips recovered by the UNEP team had already decreased in mass by 10-15% in this way. This rapid corrosion speed underlines the importance of monitoring the water quality at the DU sites on an annual basis."

• Military DU studies mainly evaluated external exposure, but newer studies take inhalation risk into consideration. These studies indicate that DU passes into humans far easier than thought after battlefield use, and that use of DU ammunition may have grave consequences, especially if used near population centers.
• Since low levels of radiation may cause cell damage less easy for the body to detect and repair, small increases in background radiation may be more dangerous than large increases. Others state that these claims have little merit, as natural levels of background radiation are often surprisingly high. However, it is important to note that there is a major difference between general radiation levels outside the body, and radiation from particles absorbed into the body structure itself.
• While DU is minimally radioactive, its decay products - Thorium 234 and Protactinium 234 - are beta particle emitters with half-lives of several weeks (Pa 234 decays to Uranium 234, with a half-life of hundreds of millennia, and this isotope does not build to equilibrium concentration for a very long time. When the two first isotopes in the decay chain reach their (tiny) equilibrium concentrations, a DU fragment will emit 3 times the radiation due to DU itself, and most of this will be beta radiation - which can penetrate the skin or cause damage if ingested or inhaled.

These facts together indicate that DU ammunition may actually be a serious health problem, as asserted in a 1997 report by the European Committee on Radiation Risk (ECRR), which found that DU posed serious health risks. 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 either "Green" groups who are opposed to anything vaguely nuclear, or the US and UK governments -- both supporters of DU.

An important aspect of DU poisoning is that radiation levels inside the structure of the body are in general far more dangerous that the same level outside the body, due to their immediate proximity to delicate cells such as bone marrow and blood, and to DNA. In addition, uranium carries the same risk as lead and other heavy metal poisoning, that is, it becomes embedded in the bones and other organs.

By contrast, the Vienna-based International Atomic Energy Agency 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." [3] (http://www.iaea.org/NewsCenter/Features/DU/faq_depleted_uranium.shtml) The US military watchdog group Federation of American Scientists has come to similar conclusions.

Depleted uranium and Gulf War Syndrome

Unresolved disputes exist about the role (if any) played by depleted uranium in the Gulf, either its effects on the forces using it, or on people living in the areas it was used. Those who claim there are no proven effects point to lack of confirmed agreed reports, those who believe there are effects point to medical statistics and investigations which they claim have been "swept under the carpet".

In 1991, the Allies fired 944,000 DU rounds or some 2700 tons of DU tipped bombs. The Pentagon states that around 320 metric tons of DU were left on the battlefield after the first Gulf war, although Russian military experts say 1000 metric tons is more accurate. Some reports note that a large part of this landed in and around populous areas, such as Bhagdad, a city of 5 million people. A UK Atomic Energy Authority report said that some 500,000 people would die before the end of this century, due to radioactive debris left in the desert.

The use of DU is also associated with a sudden surge in the rate of birth defects in the children of Allied veterans and is believed to be the cause of the 'worrying number of anophthalmos cases -- babies born without eyes' in Iraq. Only one in 50 million births should be anophthalmic, yet one Baghdad hospital had eight cases in just two years. Seven of the fathers had been exposed to American DU anti-tank rounds in 1991. There have also been cases of Iraqi babies born without the crowns of their skulls, a deformity also linked to DU shelling.

In 1989 there were 11 birth defects per 100,000 births; in 2001 there were 116 per 100,000 births. A sixfold increase in child leukaemia since 1992 has been attributed to the presence of depleted uranium in the missiles used by the Allied forces in the first Gulf War. (Lancet Medical Journal, Feb.98). Birth defects and cancers in Iraq mirror those expected from radiation poisoning and uranium exposure. "Cancer appears to have increased between seven and 10 times and deformities between four and six times," according to the UN subcommission cited above.

The U.S. Army acknowledges the hazards in a training manual, in which it requires that anyone who comes within 25 meters of any DU-contaminated equipment or terrain wear respiratory and skin protection, and states that "contamination will make food and water unsafe for consumption."

The Uranium Medical Research Centre in Canada and the United States, and center research associates Patricia Horan and Leonard Dietz, published a unique study in the August issue of Military Medicine medical journal. The study is believed to be the first to look at inhaled DU among Gulf War veterans, using the ultrasensitive technique of thermal ionization mass spectrometry, which enabled them to easily distinguish between natural uranium and DU. The study, which examined British, Canadian and U.S. veterans, all suffering typical Gulf War Syndrome ailments, found that, nine years after the war, 14 of 27 veterans studied had DU in their urine. DU also was found in the lung and bone of a deceased Gulf War veteran.

Dr. Doug Rokke, an Army health physicist assigned in 1991 to clean up DU, reports that ten years on, 30% of his team are dead, and most of the others (himself included) now suffer serious health issues. He says:

"Verified adverse health effects from personal experience, physicians and from personal reports from individuals with known DU exposures include reactive airway disease, neurological abnormalities, kidney stones and chronic kidney pain, rashes, vision degradation and night vision losses, lymphoma, various forms of skin and organ cancer, neuropsychological disorders, uranium in semen, sexual dysfunction and birth defects in offspring."

Sources: ** The Sunday Herald (Scotland), Mar.30 2003 [4] (http://www.sundayherald.com/32522), ** [5] (http://www.blackherbals.com/iraqi_cancers.htm)

Legal status of military use

In 1996 and 1997, the United Nations Human Rights Commission in Geneva, passed a resolution to ban the use of depleted uranium weapons. The Subcommission adopted resolutions which include depleted uranium weaponry amongst "weapons of mass and indiscriminate destruction, ... incompatible with international humanitarian or human rights law." (Secretary General's Report, 24 June 1997, E/CN. 4/Sub.2/1997/27)

A UN report of 2002 states that DU weapons also potentially breach each of the following laws: The Universal Declaration of Human Rights; the Charter of the United Nations; the Genocide Convention; the Convention Against Torture; the four Geneva Conventions of 1949; the Conventional Weapons Convention of 1980; and the Hague Conventions of 1899 and 1907. All of these laws are designed to spare civilians from unwarranted suffering in or after armed conflicts.

According to the UN, the resolutions in 1996-97 were passed because DU breaches several international laws concerning inhumane weapons: it is not limited in time or space to the legal field of battle, or to military targets; it continues to act after the war; it is "inhumane" by virtue of its ability to cause prolonged or long term death by cancer and other serious health issues, it causes harm to future civilians and passers by (including unborn children and those breathing the air or drinking water); and it has an "unduly negative" and long term effect on the natural environment and food chain. In detail:

1. Weapons may only be used in the legal field of battle, defined as legal military targets of the enemy in war. Weapons may not have an adverse effect off the legal field of battle. DU shells burn into fine particles which remain in the air or the environment. So they infect others over a wide range, and future passers-by, with uranium poisoning.
2. Weapons can only be used for the duration of an armed conflict. A weapon that is used or continues to act after the war is over violates this criterion.
3. Weapons may not be unduly inhumane. Weapons that cause cancer and illness long after the war are widely considered to be legally "inhumane". Health issues to unborn children and civilians may also be crimes against humanity under international law.
4. Weapons may not have an "unduly negative" effect on the natural environment. The dust from DU impact becomes widespread in the environment, and (as with other heavy metals) becomes highly concentrated within living beings and the food chain.

External links

United Nations

• Sub-Commission resolution 1996/16 (http://ap.ohchr.org/documents/E/SUBCOM/resolutions/E-CN_4-SUB_2-RES-1996-16.doc)
  (resolves and states DU to be "incompatible" with human rights and international law; lists DU as "particularly" one "weapon of mass destruction or indiscriminate effect")
• UN High Commission for Human Rights, 1998 (http://www.unhchr.ch/tbs/doc.nsf/(Symbol)/7afeec7003489bb7802567550045e27a?Opendocument)
  (statement that DU is prohibited and contravenes prior UN resolutions)
• "Human rights and weapons of mass destruction, or with indiscriminate effect, or of a nature to cause superfluous injury or unnecessary suffering" (http://www.unhchr.ch/Huridocda/Huridoca.nsf/(Symbol)/E.CN.4.Sub.2.2002.38.En?Opendocument)
  (The UN 2002 report)
• Post Conflict Assessment Iraq (http://www.unep.org/pdf/iraq_ds_lowres.pdf) by the United Nations Environment Programme.

Scientific bodies

• Depleted Uranium (http://www.royalsoc.ac.uk/du/intro.htm) article from the Royal Society.
• Depleted Uranium Human Health Fact Sheet (http://www.ead.anl.gov/pub/doc/Depleted-Uranium.pdf) from Summary Fact Sheets for Selected Environmental Contaminants to Support Health Risk Analyses (http://www.ead.anl.gov/pub/doc/Cover-Intro-Linked.pdf) by Argonne National Laboratory Environmental Assessment Division.

Other

• Is The Pentagon Giving Our Soldiers Cancer? (http://feedthefish.org/blog/materials/johnson.html) - Rolling Stone, October 2, 2003
• Rise in birth deformities blamed on Allies' deadly weaponry (http://www.independent-media.tv/itemprint.cfm?fmedia_id=7131&fcategory_desc=Under%20Reported) - The Independent, May 13, 2004
• U.S. Soldiers Contaminated With Depleted Uranium Speak Out (http://www.democracynow.org/article.pl?sid=04/04/05/1356248&mode=thread&tid=25) - Democracy Now!, April 5, 2004
• Depleted uranium: Dirty bombs, dirty missiles, dirty bullets (http://www.sfbayview.com/081804/Depleteduranium081804.shtml) - San Francisco Bay View article by Leuren Moret
• Metal of Dishonor (http://www.iacenter.org/depleted/metalpvn.htm) - documentary film by Peoples Video Network.
• Depleted UF6 Management Information Network (http://web.ead.anl.gov/uranium/), Online repository of information about the U.S. Department of Energy's inventory of depleted uranium hexafluoride.
• "After the Dust Settles" (http://www.thebulletin.org/article.php?art_ofn=nd99fetter) (Bulletin of the Atomic Scientists report from 1999)

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