US Stocking Uranium-Rich Bombs?U.S. forces in the Persian Gulf may be armed with radioactive bombs and missiles hundreds of times more potent than similar weapons used during the Gulf War and the U.N. military campaign in Bosnia.
As evidence that the United States is expanding its use of depleted uranium weapons beyond the relatively small 30-millimeter to 120-millimeter armor-piercing bullets and shells used by tanks and tank-killer aircraft in the Gulf and Balkans, weapons watchdogs cite the so-called "bunker-buster" bombs and missiles unleashed on Afghanistan.
The Pentagon has not confirmed the use of uranium or depleted uranium in the bunker-busters, and it has refused to identify the composition of the dense-metal warheads that enable the missiles to penetrate structures deeply buried under earth, steel and reinforced concrete.
But critics such as British researcher Dai Williams contend that only uranium -- in one form or another -- possesses the density and other characteristics necessary to achieve the penetration levels attributed to such weapons as the 2,000-pound AGM 130C air-to-ground cruise missile, and the guided bomb unit, or GBU, series of laser-guided hard-target penetrators intended to pierce bunkers and other reinforced structures
http://www.wired.com/news/conflict/0,2100,57959,00.html?tw=wn_story_related And just for the record, while U-238 (which comprises > 99% of depleted uranium) is an alpha emitter, two of the daughter elements produced by the decay process of U-238, Thorium Th-234 and Protactinium Pa-234, do emit Beta radiation. The decay process is such that within 6 months the Thorium and Protactinium content in any sample of formerly 100% U238 are in equilibrium and adding significantly to the original alpha radiation from the U-238.
Contamination of Persian Gulf War Veterans and Others by Depleted Uraniumby Leonard A. Dietz
July 19, 1996 (last updated Feb. 21, 1999)
The U-238 decay chain is broken during the chemical reduction of uranium hexafluoride into DU metal and is broken again during the melting and processing of the metal into a penetrator. To determine the maximum time it takes to regain equilibrium in the partial decay chain, we assume a solid sample of uranium that initially contains only the U-238 isotope, i.e. no decay progeny. Using Bateman's equations, (Ref. 13), we calculate the growth of Th-234 and Pa-234 activities as a function of elapsed time in weeks. The results are given in Table II.
Table II. Radioactivity (disintegrations/second) in 1 gram of
U-238 with no decay progeny initially present.
Half lives used:
U-238 = 4.47e9 years
Th-234 = 24.10 days
Pa-234 = 1.17 minutes, 6.69 hours (two decay states)
U-234 = 2.46e5 years (Ref. 14).
Scientific notation is used, i.e. 2.46e5 = 246000.
Weeks U-238 ---> Th-234 ---> Pa-234 ---> U-234
------------------------------------------------------------
0 12,430 0 0 0.000
1 12,430 2,270 2,150 0.000
5 12,430 7,890 7,840 0.001
10 12,430 10,770 10,750 0.004
15 12,430 11,830 11,820 0.007
20 12,430 12,210 12,210 0.010
25 12,430 12,350 12,350 0.013
30 12,430 12,400 12,400 0.017
After 25 weeks, Th-234 and Pa-234 have reached 99.4% of the decay rate of U-238 and for practical purposes have reached secular equilibrium with U-238, their parent isotope. Secular equilibrium means that the decay progeny of U-238 are being replaced at the same rate they are decaying; after 25 weeks all three isotopes are decaying at approximately the same rate. This is a maximum time; in reality, equilibrium will be reached much faster, since these two isotopes can never be separated totally from U-238. The isotope U-238 emits alpha particles and also emits some gamma rays. Its decay progeny Th-234 and Pa-234 each emit beta particles and gamma rays. An alpha particle is a fast helium atom with its two electrons removed, a beta particle is a high-speed electron and a gamma ray is like an X-ray.
From this analysis we conclude that in a solid sample of DU, six months at most after manufacture of a DU penetrator, or DU armor for a tank, or DU particles in a person's body, substantial additional radiation in the form of beta particles and gamma rays always will be present. In fact, most of the penetrating gamma radiation and all of the penetrating beta radiation from DU comes, not from uranium, but from the decay progeny of U-238 (Ref. 15). In a year, only one-thousandth of a gram (1 milligram or mg) of DU generates more than a billion alpha particles, beta particles and gamma rays. The U.S. Army has investigated the generation of DU aerosols in armored vehicles hit by DU cannon rounds. Their investigators report "...that personnel inside DU struck vehicles could receive a dose in the `tens of milligrams' range due to inhalation" (Ref. 16). This exposure results in an acute dose of uranium.
http://www.wise-uranium.org/dgvd.html Edited to ad: The table above showing the disintigrations/sec for the U-238, Th-234, Pa-234 and U-234 is clearer in the original. The column formatting was lost in posting.
From www.wikipedia.com
While uranium-238 is minimally radioactive, its decay products - Thorium 234 and Protactinium 234 - are beta particle emitters with half-lives about 20 days and one minute respectively (Pa 234 decays to Uranium 234, which has 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 sample of initially pure uranium-238 will emit three times the radiation due to uranium-238 itself, and most of this will be beta radiation. (my emphasis /jc) After all the beta radiation is almost over, the by-product of uranium-238 would be (Pb) lead.
http://en.wikipedia.org/wiki/U238
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