Depleted uranium sources

World Health Organization (WHO) (2001) Depleted Uranium Sources, Exposure and Health Effects. Geneva Department of the Protection of the Human Environment, World Health Organization. 

WHO, 2001. In W.H.O. Department of Protection of the Human EnvironmenL Depleted Uranium Sources, Exposures, and Health Effects World Health Organization, Geneva, Switzerland. 

One of the most significant sources of change in isotope ratios is caused by the small mass differences between isotopes and their effects on the physical properties of elements and compounds. For example, ordinary water (mostly Ej O) has a lower density, lower boiling point, and higher vapor pressure than does heavy water (mostly H2 0). Other major changes can occur through exchange processes. Such physical and kinetic differences lead to natural local fractionation of isotopes. Artificial fractionation (enrichment or depletion) of uranium isotopes is the basis for construction of atomic bombs, nuclear power reactors, and depleted uranium weapons. 

Nuclear weapons which usually use nuclear fusion, have far greater yields than weapons, which use only fission, as fusion releases more energy per kilogram and can also be used as a source of fast neutrons to cause fission in depleted uranium. 

UNSCEAR has considered that limits for natural (and depleted) uranium in food and drinking water (the most important sources of human exposure) should be based on the chemical toxicity rather than on a hypothetical radiological toxicity, which has not been observed in either humans or animals (UNSCEAR 1993 Wrenn et al. 1985). 

Walsh M Department of Veterans Affairs Medical Center, Boston MA Follow-up and monitoring of gulf war veterans with fragments of depleted uranium and other sources of depleted uranium. Department of Veterans Affairs Research and Development... 

Japan s nuclear source materials and nuclear fuel materials, which support this nuclear power generation, are all subject to safeguards under the Nuclear Regulation Law and the NPT. At the end of 1992, Japan held roughly 35001 of natural and depleted uranium, about 94001 of low enriched uranium (LEU) and 33.5 t of plutonium. Figure... 

A few parts from the ion sources and collectors of the calutrons were brought back to Laboratories in Seibersdorf for analysis. In addition, samples were taken from the declared product batches, covering a range of uranium-235 enrichment from depleted uranium less than 0.1 wt% up to around 6 wt%. 

Nuclear reactors use and produce materials that are carefully regulated. Special nuclear materials include uranium-233, uranium-235, enriched uranium, and plutonium. Source materials include natural uranium, thorium, and depleted uranium that cannot be used as reactor fuel. By-product material is generated from nuclear materials these by-products include any radioactive material or waste products produced by the reactor system. In 2004, there were approximately 104 nuclear facilities in the United States the majority of these systems are located in states east of the Mississippi River. Only 19 nuclear reactors are operated west of the Mississippi. 

DEPLETED URANIUM (DU). Uranium that is depleted of the specific isotope uranium-235. DU has a smaller percentage of uranium-235 than is found in naturally occurring uranium. It is used for military purposes because it is very dense, can be machined at relatively low cost, and is available as a by-product of producing nuclear fuel aud nuclear weapons. However, because it is low in uranium-235, it cannot be used as a fuel source for a nuclear weapon and has little or no radioactivity, making it unusable as a source in a radiological dispersal device (RDD). 

TAILINGS. In the nuclear context, the depleted stream remaining from a uranium enrichment process or from uranium milling. In relative terms, the tailings (also occasionally referred to as tails ) are depleted uranium reduced in uranium-235, while the enrichment process is enriched in that Isotope. In general, tailings make poor sources for development of nuclear weapons or for use in radlolt ical dispersal devices (RDD) because they are low in radioactive uranium-235. 

De-enrichment of HEU from approximately 93% to 3% can be accompHshed using the depleted tails from the original enrichment process. These tails contain on the average 0.20% U. The de-enrichment of 11 of HEU uses 32 t of tads, yielding approximately 33 t of fuel having an enrichment of 3% U. Producing the same amount of 3% enriched uranium from natural sources would requite approximately 180 t of natural uranium metal. Therefore, 1 t of HEU is equivalent to 180 t of natural uranium. 

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