Depleted Uranium





Depleted Uranium (DU) is uranium remaining after removal of the isotope uranium-235. It is primarily composed of the isotope uranium-238. In the past it was called by the names Q-metal, depletalloy, and D-38, but these have fallen into disuse. Since depleted uranium contains less than one third as much uranium-235 and uranium-234 as natural uranium, it is weakly radioactive and an external radiation dose from depleted uranium is about 60% of that from the same mass of uranium with a natural isotopic ratio.

At standard temperature and pressure (Standard conditions for temperature and pressure) it is a very dense metal solid. Due to its high density the main uses of depleted uranium include counterweights in aircraft, radiation shields in medical radiation therapy machines and containers for the transport of radioactive materials. The military uses depleted uranium for defensive armor plate and its pyrophoricity has made it a valued component in other military applications, particularly in the form of Armor-piercing shot and shell projectiles.

Its use in ammunition is controversial because of its release into the environment. Besides its residual radioactivity, U-238 is a heavy metal whose compounds are known from laboratory studies to be toxic to mammals. However, there has never been a definitive toxicological link established in humans and it is believed that low and moderate exposures to depleted uranium pose little if any toxicological threat.

Sources Depleted uranium is produced as a byproduct during the process of forming enriched uranium from natural uranium. Enriched uranium is used in nuclear reactors. When the majority of nuclear fission radioactive isotopes of uranium are removed from natural uranium, what remains is called depleted uranium. Another, less common, source of Depleted Uranium is Nuclear reprocessing spent reactor fuel. DU created by enrichment can be distinguished from DU created in a reactor by the percentage of Isotopes of uranium, produced by neutron capture from uranium-235 in nuclear reactors, present in the material.

DU is considered both a Toxicity and radioactive hazard that requires long term storage as low level nuclear waste. DU is relatively expensive to store but relatively inexpensive to produce or obtain. Generally the only real costs are those associated with conversion of uranium hexafluoride (UF6) to metal. DU is extremely Density#Density of substances, 67% denser than lead, only slightly less than tungsten and gold, and just 16% less dense than osmium or iridium, the densest naturally occurring substances known. Its low cost makes it attractive for a variety of industrial and military uses. However, the material is prone to corrosion and small particles are pyrophoric.

History Depleted uranium was first stored in stockpiles in the 1940s when the U.S. and Soviet Union began their nuclear weapons and nuclear power programs. While it is possible to design Pressurised Heavy Water Reactor, only about 10% of reactors ever built utilize that technology, and both nuclear weapons production and Nuclear marine propulsion require the concentrated isotope. Originally, DU was conserved in the hope that more efficient enrichment techniques would allow further extraction of the fissile isotope; however, those hopes have not materialized.

In the 1970s, The Pentagon reported that the Red Army had developed armor plating for Warsaw Pact tanks that North Atlantic Treaty Organisation ammunition couldn't penetrate. The Pentagon began searching for material to make Density bullets. After testing various metals, ordnance researchers settled on depleted uranium. DU was useful in ammunition not only because of its unique physical properties and effectiveness, but also because it was cheap and readily available. Tungsten, the only other candidate, had to be sourced from China. With DU stockpiles estimated to be more than 500,000 tons, the financial burden of housing this amount of low-level radioactive waste was very apparent. It was therefore more economical to use depleted uranium rather than storing it. Thus, from the late 1970s, the U.S., the Soviet Union, United Kingdom and France, began converting their stockpiles of depleted uranium into kinetic energy penetrators.

Photographic evidence of destroyed equipment suggests that DU was first used during the 1973 Arab-Israeli war. Various written reports cite information that was obtained as a consequence of that use.Doug Rokke Depleted Uranium: Uses and Hazards (PDF) an updated version of the paper presented in the British House of Commons on December 16, 1999 However, while clearing the decades-old Hawaii Stryker firing range, workers have found depleted uranium ammunition from the 1960s.

The U.S. military used DU shells in the 1991 Gulf War, Bosnia war, Operation Allied Force, and the 2003 Iraq War.(Associated Press, August 12, 2006, free archived copy at: http://www.commondreams.org/headlines06/0812-06.htm most recently visited November 1, 2006)

Production and availability Natural uranium metal contains about 0.71% Uranium-235, 99.28% Uranium-238, and about 0.0054% Uranium-234. In order to produce enriched uranium, the process of isotope separation removes a substantial portion of the U-235 for use in nuclear power, weapons, or other uses. The remainder, depleted uranium, contains only 0.2% to 0.4% U-235. Because natural uranium begins with such a low percentage of U-235, the enrichment process produces large quantities of depleted uranium. For example, producing 1 kg of 5% enriched uranium requires 11.8 kg of natural uranium, and leaves about 10.8 kg of depleted uranium with only 0.3% U-235 remaining.

The Nuclear Regulatory Commission (NRC) defines depleted uranium as uranium with a percentage of the 235U isotope that is less than 0.711% by weight (See 10 CFR 40.4.) The military specifications designate that the DU used by DoD contain less than 0.3% 235U (AEPI, 1995). In actuality, DoD uses only DU that contains approximately 0.2% 235U (AEPI, 1995).

:::::::World Depleted Uranium Inventory ::::{| class="wikitable" |-! Country! Organization! DU Stocks (in tonnes)! Reported|-||||United States Department of Energy||480,000||2002|-||||[FAEA||190,000||2001|-||||[BNFL||16,000||1999|-||||[JNFL||2,000||2000|-||||[KAERI||73||2001|-||TOTAL||||1,188,273||2002|-|} :::: Source: WISE Uranium Project

Military applications

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Depleted uranium is very ]; at 19050 kg/m³, it is almost 70% denser than lead. Thus a given weight of it has a smaller diameter than an equivalent lead projectile, with less external ballistics and deeper terminal ballistics due to a higher pressure at point of impact. DU projectile ordnance is often incendiary because of its pyrophoric property.

===Armor plate===Because of its high density, depleted uranium can also be used in tank armor, sandwiched between sheets of steel armor plate. For instance, some late-production M1 Abrams tanks built after 1998 have DU reinforcement as part of its armor plating in the front of the hull and the front of the turret and there is a program to upgrade the rest, for example Chobham armour#Heavy metal modules.

Nuclear weapons Depleted uranium is used as a tamper in fission bombs and as a nuclear fuel in hydrogen bombs.

Ammunition Most military use of depleted uranium has been as 30 mm and smaller Ammunition, primarily the 30 mm PGU-14/B armour-piercing incendiary round from the GAU-8 Avenger cannon of the A-10 Thunderbolt II used by the USAF. 25 mm DU rounds have been used in the M242 gun mounted on the U.S. Army's M2 Bradley and LAV-AT. The United States Marine Corps uses DU in the 25 mm PGU-20 round fired by the GAU-12 Equalizer cannon of the AV-8 Harrier II, and also in the 20 mm M197 gun mounted on AH-1 Cobra. The US Navy's Phalanx CIWS's M61 Vulcan gatling gun used 20 mm armor-piercing penetrator rounds with discarding plastic sabots which were made using depleted uranium, later changed to tungsten.

Another use of depleted uranium is in kinetic energy penetrators anti-armor role. Kinetic energy penetrator rounds consist of a long, relatively thin penetrator surrounded by discarding sabot. Two materials lend themselves to penetrator construction: tungsten and depleted uranium, the latter in designated alloys known as staballoys. Staballoys are metal alloys of depleted uranium with a very small proportion of other metals, usually titanium or molybdenum. One formulation has a composition of 99.25% by weight of depleted uranium and 0.75% by weight of titanium. Another variant can have 3.5% by weight of titanium. Staballoys are about twice as dense as lead and are designed for use in kinetic energy penetrator armor-piercing ammunition. The United States Army uses DU in an alloy with around 3.5% titanium.

aboard USS Missouri (BB-63).Staballoys, along with lower raw material costs, have the advantage of being easy to melt and cast into shape; a difficult and expensive process for tungsten. Note also that according to recent research, at least some of the most promising tungsten alloys which have been considered as replacement for depleted uranium in penetrator ammunitions, such as tungsten-cobalt or tungsten-nickel-cobalt alloys, possess extreme carcinogenic properties, which by far exceed those (confirmed or suspected) of depleted uranium itself: 100% of rats implanted with a pellet of such alloys developed lethal rhabdomyosarcoma within a few weeks. On more properly military grounds, depleted uranium is favored for the penetrator because it is self-sharpening and pyrophoric. On impact with a hard target, such as an armoured vehicle, the nose of the rod fractures in such a way that it remains sharp. The impact and subsequent release of heat energy causes it to disintegrate to dust and burn when it reaches air because of its pyrophoric properties (compare to ferrocerium). When a DU penetrator reaches the interior of an armored vehicle, it catches fire, often igniting ammunition and fuel, killing the crew, and possibly causing the vehicle to explode. DU is used by the United States Army in 120 mm or 105 mm cannons employed on the M1 Abrams and M60A3 tanks. The Russian military has used DU ammunition in tank main gun ammunition since the late 1970s, mostly for the 115 mm guns in the T-62 tank and the 125 mm guns in the T-64, T-72, T-80, and T-90 tanks.

The DU content in various ammunition is 180 g in 20 mm projectiles, 200 g in 25 mm ones, 280g in 30 mm, 3.5 kg in 105 mm, and 4.5 kg in 120 mm penetrators. It is used in the form of Staballoy. The US Navy used DU in its 20 mm Phalanx CIWS guns, but switched in the late 1990s to armor-piercing tungsten for this application, because of the fire risk associated with stray pyrophoric rounds. DU was used during the mid-1990s in the U.S. to make 9 mm and similar caliber armor piercing bullets, grenades, cluster bombs, and land mine, but those applications have been discontinued, according to Alliant Techsystems. Whether or not other nations still make such use of DU is difficult to determine.

It is thought that between 17 and 20 states have weapons incorporating depleted uranium in their arsenals. They include the United States, the United Kingdom, France, Russia, Greece, Turkey, Israel, Saudi Arabia, Bahrain, Egypt, Kuwait, Pakistan, Thailand, Iraq and Taiwan. DU ammunition is manufactured in 18 countries. Only the US and the UK have acknowledged using DU weapons.The International Legality of the Use of Depleted Uranium Weapons: A Precautionary Approach, Avril McDonald, Jann K. Kleffner and Brigit Toebes, eds. (TMC Asser Press Fall-2003)

Legal status in weapons In 1996 the International Court of Justice (ICJ) gave an advisory opinion on the "legality of the threat or use of nuclear weapons". legality of the threat or use of nuclear weapons This made it clear, in paragraphs 54, 55 and 56, that international law on poisonous weapons, – the Second Hague Declaration of 29 July 1899, Hague Convention IV of 18 October 1907 and the Geneva Protocol of 17 June 1925 – did not cover nuclear weapons, because their prime or exclusive use was not to poison or asphyxiate. This ICJ opinion was about nuclear weapons, but the sentence "The terms have been understood, in the practice of States, in their ordinary sense as covering weapons whose prime, or even exclusive, effect is to poison or asphyxiate." also removes depleted uranium weaponry from coverage by the same treaties as their primary use is not to poison or asphyxiate, but to destroy materiel and kill soldiers through kinetic energy.

The Sub-Commission on Prevention of Discrimination and Protection of Minorities of the United Nations Human Rights Commission, Citizen Inspectors Foiled in Search for DU Weapons passed two motions Depleted Uranium UN Resolutions the first in 1996 Sub-Commission resolution 1996/16 and the second in 1997. Sub-Commission resolution 1997/36 They listed weapons of mass destruction, or weapons with indiscriminate effect, or of a nature to cause superfluous injury or unnecessary suffering and urged all states to curb the production and the spread of such weapons. Included in the list was weaponry containing depleted uranium. The committee authorized a working paper, in the context of human rights and humanitarian norms, of the weapons. The requested UN working paper was delivered in 2002 E/CN.4/Sub.2/2002/38 Human rights and weapons of mass destruction, or with indiscriminate effect, or of a nature to cause superfluous injury or unnecessary suffering ( backup) "In its decision 2001/36 of 16 August 2001, the Sub‑Commission, recalling its resolutions 1997/36 and 1997/37 of 28 August 1997, authorized Mr. Y.K.J. Yeung Sik Yuen to prepare, without financial implications, in the context of human rights and humanitarian norms, the working paper originally assigned to Ms. Forero Ucros." by Y.K.J. Yeung Sik Yuen in accordance with United Nations Commission on Human Rights#Sub-Commission on Promotion and Protection of Human Rights resolution 2001/36. He argues that the use of DU in weapons, along with the other weapons listed by the Sub‑Commission, may breach one or more of the following treaties: The Universal Declaration of Human Rights; the Charter of the United Nations; the Convention on the Prevention and Punishment of the Crime of Genocide; the United Nations Convention Against Torture; the Geneva Conventions including Protocol I; the Convention on Conventional Weapons of 1980; and the Chemical Weapons Convention. Yeung Sik Yuen writes in Paragraph 133 under the title "Legal compliance of weapons containing DU as a new weapon":

In 2001, Carla Del Ponte, the chief prosecutor for the International Criminal Tribunal for the Former Yugoslavia, said that NATO's use of depleted uranium in former Yugoslavia could be investigated as a possible war crime.The Associated Press & Reuters contributed to this report: Use of DU weapons could be war crime CNN January 14, 2001 Louise Arbour, Del Ponte's predecessor as chief prosecutor, had created a small, internal committee, made up of staff lawyers, to assess the allegation. Their findings, that were accepted and endorsed by Del Ponte,Joe Sills et al Environmental Crimes in Military Actions and the International Criminal Court (ICC)-United Nations Perspectives (PDF) ( HTML) of American Council for the UN University, April 2002. Page 28 concluded that:

Requests for a general moratorium of military use Some states and a coalition of over 80 non-governmental organizations have asked for a ban on the production and military use of depleted uranium weapons. The European Parliament has repeatedly passed resolutions requesting an immediate moratorium on the further use of depleted uranium ammunition, but France and Britain – the only EU states that are also permanent members of the United Nations Security Council – have consistently rejected calls for a ban, maintaining that its use continues to be legal, and that the health risks are entirely unsubstantiated.

Civilian applications Civilian applications for depleted uranium are fairly limited and are typically unrelated to its radioactive properties. It primarily finds application as ballast because of its high density. 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. However other high density materials are sometimes preferred because uranium is prone to corrosion.

Other relatively minor consumer product uses have included: incorporation into dental porcelain used for false teeth to simulate the fluorescence of natural teeth; and in uranium-bearing reagents used in chemistry laboratories (eg. uranyl acetate, used in analytical chemistry and as a staining in electron microscopy).

Uranium was widely used as a coloring matter for Fiestaware and Uranium glass in the 19th century. The practice was believed to be a matter of history, however in 1999 concentrations of 10% depleted uranium were found in "jaune no.17" a yellow Vitreous enamel powder that was being produced in France by Cristallerie de Saint-Paul, a manufacturer of enamel pigments. The depleted uranium used in the powder was sold by Cogéma's Pierrelatte facility. Cogema has since confirmed that it has made a decision to stop the sale of depleted uranium to producers of enamel and glass.

DU is also used for radiation shielding for radiation sources used in medical and industrial radiography.

U.S. Nuclear Regulatory Commission regulations at 10 CFR 40.25 establish a general license for the use of depleted uranium contained in industrial products or devices for mass-volume applications. This general license allows anyone to possess or use Depleted Uranium for authorized purposes. Generally, a registration form is required, along with a commitment to not abandon the material. Agreement States may have similar, or more stringent, regulations.

Trim weights in aircraft Aircraft may also contain depleted uranium trim weights (a Boeing 747 may contain 400 to 1,500 kg). This application of DU is controversial. If an aircraft crashes there is concern that the uranium would enter the environment: the metal can oxidize to a fine powder in a fire. Its use has been phased out in many newer aircraft; Boeing and McDonnell-Douglas discontinued using DU counterweights in the 1980s. Some amount of depleted uranium was released eg. during the Bijlmer disaster, when 152 kg was 'lost'. Counterweights are manufactured with cadmium plating and are considered non-hazardous while the plating is intact.

Uranium hexafluoride About 95% of the depleted uranium produced is stored as uranium hexafluoride, (D)UF6, in steel cylinders in open air yards close to enrichment plants. Each cylinder contains up to 12.7 tonnes (or 14 US tons) of UF6. In the U.S. alone, 560,000 tonnes of depleted UF6 had accumulated by 1993. In 2005, 686,500 tonnes in 57,122 storage cylinders were located near Portsmouth, Ohio, Oak Ridge, Tennessee, and Paducah, Kentucky. , The long-term storage of DUF6 presents environmental, health, and safety risks because of its chemical instability. When UF6 is exposed to moist air, it reacts with the water in the air to produce UO2F2 (uranyl fluoride) and HF (hydrofluoric acid) both of which are highly soluble and toxic. Storage cylinders must be regularly inspected for signs of corrosion and leaks. The estimated life time of the steel cylinders is measured in decades.



There have been several accidents involving uranium hexafluoride in the United States. The U.S. government has been converting DUF6 to solid uranium oxides for disposal. Such disposal of the entire DUF6 inventory could cost anywhere from 15 to 450 million dollars.

Health considerations Radiological hazards Depleted uranium is not a significant health hazard unless it is taken into the body. External exposure to radiation from depleted uranium is generally not a major concern because the alpha particle emitted by its isotopes travel only a few centimeters in air or can be stopped by a sheet of paper. Also, the uranium-235 that remains in depleted uranium emits only a small amount of low-energy gamma radiation. According to the World Health Organization, a Ionizing radiation dose from it would be about 60% of that from purified natural uranium with the same mass. Approximately 90 µg (micrograms) of natural uranium, on average, exist in the human body as a result of normal intakes of water, food and air. The majority of this is found in the skeleton, with the rest in various organs and tissues.

The radiological dangers of pure depleted uranium are relatively low, lower (60%) than those of naturally-occurring uranium due to the removal of the more radioactive isotopes, as well as due to its long half-life (4.46 billion years). Depleted uranium differs from natural uranium in its Isotopic signature, but its biochemistry is for the most part the same. For further details see Actinides in the environment.

Chemical hazards Health effects of DU are determined by factors such as the extent of exposure and whether it was internal or external. Three main pathways exist by which internalization of uranium may occur: inhalation, ingestion, and embedded fragments or shrapnel contamination. Properties such as the solubility of uranium and its compounds influence their absorption, Distribution (pharmacology), translocation, Clearance (medicine) and the resulting toxicity. The chemical toxicity of uranium salts is greater than their radiological toxicity.

Uranium is pyrophoric when finely divided. It will corrode under the influence of air and water producing insoluble uranium(IV) and soluble uranium(VI) salts. Soluble uranium salts are toxic. Uranium accumulates in several organs, such as the liver, spleen, and kidneys. The World Health Organization has established a daily "tolerated intake" of soluble uranium salts for the general public of 0.5 µg/kg body weight, or 35 µg for a 70 kg adult.

While epidemiological studies on laboratory animals have exposed to high levels of depleted uranium point to it as being a possible Teratogenesis ,, neurotoxic , and carcinogen and leukaemia potential , there has not been any link between these possible health effects in laboratory animals and humans.

Studies of depleted uranium aerosol exposure have concluded that uranium combustion product particles would quickly settle out of the air . Measurements made in areas where depleted uranium munitions were used extensively did not find significantly higher than average uranium concentrations in the soil, just a few months after contamination. Henryk Bema, Firyal Bou-Rabeeb. Environmental and health consequences of depleted uranium use in the 1991 Gulf War Most studies have shown that DU ammunition has no measurable detrimental health effects, either in the short or long term. The International Atomic Energy Agency, for example, reported in 2003 that, "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," although "Like other heavy metals, DU is potentially poisonous. In sufficient amounts, if DU is ingested or inhaled it can be harmful because of its chemical toxicity. High concentration could cause kidney damage". A Rand Corporation has also studied the health effects on Depleted Uranium and has concluded that the debate around the issue is more political than technical. The study commented that “the full and unbiased presentation of the facts to governments around the world has resulted in the continued use of DU — even in the face of concerted actions by some to distort the facts and media often more interested in shock value than in presenting the truth”. Bernard D. Rostker . Depleted Uranium, A Case Study of Good and Evil. RAND Corporation

The Basra hospital data ]Following the first war], scientists at the Basra hospital and university have monitored the incidence of leukaemias and other malignancies among children in the Basra area, and of congenital malformations in newborn children. The data for the period 1990–2001 show an incidence increase of 426% for general malignancies, 366% for leukemias and of over 600% for birth defects, with all series showing a roughly increasing pattern with time. These data, being the largest set of epidemiology data available for the Iraqi population, have received considerable attention; and since it reported a very large increase in those pathologies which are known or strongly suspected to be related to uranium poisoning, it has been natural to consider the possibility that such increase had indeed been caused by depleted uranium contamination. The connection, however, is far from being obvious or proven: first of all, there is a considerable delay (at least ten years) between the occurrence of contaminations and the peak of incidence of malformations and malignancies, which leads to speculative hypotheses about the process of accumulation of uranium in the human body; and secondarily, there could be other causes or concurrent causes, for example different kinds of pollution related or unrelated to the war (e.g. burning oil wells), or the 1990–2003 Iraq sanctions which led to a collapse of the Iraqi economy and in general to a dramatic impoverishment of the population with a sharp decrease of nutritional and hygienic conditions (which alone, however, cannot explain why the increase in congenital defects is the highest observed). In general, the prevailing scientific view on the matter ,, is that such data, and other scarce data available, do not conclusively prove a poisoning effect of depleted uranium; but that the possibility exists and cannot be ruled out either, and so a precautionary principle would suggest to suspend the use of such weapons.

Other relevant contamination cases On October 4, 1992, an El Al Boeing 747 cargo aircraft El Al Flight 1862, crashed into an apartment building in Amsterdam. After reports of local residents and rescue workers complaining of health issues related to the release of depleted uranium used as counterbalance in the plane, authorities began an epidemiological study in 2000 of those believed to be affected by the accident. The study concluded that because exposure levels were so low, it was improbable that exposure to depleted uranium was the cause of the reported health complaints.

Gulf War syndrome and soldier complaints Increased rates of immune system disorders and other wide-ranging symptoms, including chronic pain, fatigue and memory loss, have been reported in over one quarter of combat veterans of the 1991 Gulf War . It has not always been clear whether these were related to Gulf War service, but combustion products from depleted uranium munitions are still being considered as one of the potential causes by the Research Advisory Committee on Gulf War Veterans' Illnesses, as DU was used in tank kinetic energy penetrator and machine-gun bullets on a large scale for the first time in the Gulf War.

A two year study headed by Sandia National Laboratory Al Marshall analyzed potential health effects associated with accidental exposure to depleted uranium during the 1991 Gulf War. Marshall’s study concluded that the reports of serious health risks from DU exposure are not supported by veteran medical statistics and were consistent with earlier studies from Los Alamos and the New England Journal of Medicine. An Analysis of Uranium Dispersal and Health Effects Using a Gulf War Case Study, Albert C. Marshall, Sandia National Laboratories

Some American soldiers more recently employed are also complaining of symptoms or illnesses which they attribute to exposure to depleted uranium. The correlation has not been confirmed and the hypothesis ignores the multitude of other exposures that soldiers in a war situation are likely to receive.Associated Press via Wired. U.S. Soldiers Are Sick of It. August 12, 2006

The U.S. Army has commissioned ongoing research into potential risks of depleted uranium and other projectile weapon materials like tungsten. Studies by the Armed Forces Radiobiology Research Institute have concluded that even though it was unlikely that future studies will alter the view that moderate exposures to either depleted uranium or uranium present a significant toxicological threat, the research was still useful to quantify risk exposure. Status of Health Concerns about Military Use of Depleted Uranium and Surrogate Metals in Armor-Penetrating Munitions A similar study from the Australian defense ministry concluded that “there has been no established increase in mortality or morbidity in workers exposed to uranium in uranium processing industries”, and that “studies of Gulf War veterans show that, in those who have retained fragments of depleted uranium following combat related injury, it has been possible to detect elevated urinary uranium levels, but no kidney toxicity or other adverse health effects related to depleted uranium after a decade of follow-up.” Military medical aspects of depleted uranium munitions

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