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Originally Posted by ninty9
That's why I said ignore the pictures. oOo:
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I caught that, which is why I also discounted whatever source he used to gather his information on the effects of depleted uranium ammunition. About the only fact in his cute little presentation was the half-life of depleted uranium.
Some information on why DU ammunition isn't harmful:
[quote:25b78]
An alpha particle consists of two protons and two neutrons and is positively charged (+2). Most alpha particles are not energetic enough to penetrate skin and are not considered an external hazard.[/quote:25b78]
[quote:25b78]
238U—which by weight makes up almost 99.8 percent of DU—is an alpha emitter. The radiological half-life of 238U or the time required for 238U to lose 50 percent of its activity by decay is 4.5 x 109 years. 238U decays into two short-lived "daughters:" thorium-234 (234Th, half-life of 24.1 days) and protactinium-234m (234mPa, half-life of 1.17 minutes)—which are beta and gamma emitters. Because of this constant nuclear decay process, very small amounts of these "daughters" are always present in DU. 235U (half-life of 7.0 x 108 years) decays into thorium-231 (231Th, half-life 25.5 hours), which decays into protactinium-231 (231Pa, half-life of 3.25 x 104 years) and then to actinium with a half-life of 21.8 years, resulting in alpha and beta particles and gamma rays.[196] The 238U and 235U chains continue through a series of isotopes before terminating in stable, non-radioactive lead isotopes 206Pb and 207-Pb, respectively.[/quote:25b78]
[quote:25b78]
"Depleted uranium," the byproduct of the enrichment process, has about 0.002 percent 234U, 0.2 percent 235U and 99.8 percent 238U, and about 60 percent of natural uranium’s radioactivity. In the gaseous diffusion process, uranium hexafluoride (UF6), a gaseous compound of uranium and fluorine, is separated into two fractions—one enriched in 235U and one depleted in 235U. The depleted fraction is then chemically transformed into a uranium metal stock. This is the first stage at which the depleted material is in the state necessary for further processing by ammunition manufacturers.
The Nuclear Regulatory Commission (NRC) defines "depleted uranium" as uranium in which the percentage of the 235U isotope’s weight is less than 0.711 percent. Military specifications mandated by the Department of Defense (DoD) require that the percentage of 235U be less than 0.3 percent, but in actual practice, DoD uses DU with a 235U content of approximately 0.2 percent.[197] DU is 40 percent less radioactive than the uranium in the raw uranium-bearing ores found in nature; but its material content is still uranium. The specific activity of DU is, therefore, about 0.4 µCi/g. All isotopes of uranium are essentially identical chemically and, since depleted and natural uranium are just different mixtures of the same three isotopes, they have the same chemical properties.
The Department of Energy has recently reported that the DU used by DOD in its armor plates (found only on "Heavy Armor" Abrams tank models) may contain trace levels of transuranics (neptunium, plutonium, and americium) and fission products (technetium-99). The DU used in munitions may also contain these materials. The military services are testing the stocks of DU munitions and parts. The levels of transuranics and fission products found during testing of the material used for producing armor packages are in minute quantities (the picocurie/gram range) and result in less than a one percent increase in the internal radiation dose. These evaluations indicate that measures designed to protect personnel from the DU itself are adequate to protect them from the traces of transuranics and fission products as well.[/quote:25b78]
08-27-2004, 07:34 PM
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