Hazards of Depleted Uranium Contamination Training Video; Between October and December 1995, the U.S. Army's Depleted Uranium (DU) Project completed a series of training videos and manuals about depleted uranium munitions. This training regimen was developed as the result of recommendations made in the January 1993 General Accounting Office (GAO) report, Army Not Adequately Prepared to Deal with Depleted Uranium Contamination. The training materials were intended to instruct servicemen and women about the use and hazards of depleted uranium munitions. In addition, the training regimen included instructions for soldiers who repair and recover vehicles contaminated by depleted uranium. Metallic uranium (U) is a silver-white, lustrous, dense, weakly radioactive element. It is ubiquitous throughout the natural environment, and is found in varying but small amounts in rocks, soils, water, air, plants, animals and in all human beings. Natural uranium consists of a mixture of three radioactive isotopes which are identified by the mass numbers 238U (99.27% by mass), 235U (0.72%) and 234U (0.0054%). On average, approximately 90 µg (micrograms) of uranium exists in the human body from normal intakes of water, food and air. About 66% is found in the skeleton, 16% in the liver, 8% in the kidneys and 10% in other tissues. Uranium is used primarily in nuclear power plants. However, most reactors require uranium in which the 235U content is enriched from 0.72% to about 1.5-3%. Depleted uranium: The uranium remaining after removal of the enriched fraction contains about 99.8% 238U, 0.2% 235U and 0.001% 234U by mass; this is referred to as depleted uranium or DU. The main difference between DU and natural uranium is that the former contains at least three times less 235U than the latter. DU, consequently, is weakly radioactive and a radiation dose from it would be about 60% of that from purified natural uranium with the same mass. The behaviour of DU in the body is identical to that of natural uranium. Spent uranium fuel from nuclear reactors is sometimes reprocessed in plants for natural uranium enrichment. Some reactor-created radioisotopes can consequently contaminate the reprocessing equipment and the DU. Under these conditions another uranium isotope, 236U, may be present in the DU together with very small amounts of the transuranic elements plutonium, americium and neptunium and the fission product technetium-99. However, the additional radiation dose following intake of DU into the human body from these isotopes would be less than 1%. Applications of depleted uranium: Due to its high density, about twice that of lead, the main civilian uses of DU include counterweights in aircraft, radiation shields in medical radiation therapy machines and containers for the transport of radioactive materials. The military uses DU for defensive armour plate. DU is used in armour penetrating military ordnance because of its high density, and also because DU can ignite on impact if the temperature exceeds 600°C. Public Domain video.
Tags: depleted uranium DU nuclear radiation radioactive radioactivity health effects safety exposure contamination spent war
