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From: MT666_VINARC@kcgl1.eng.ohio-state.edu
Newsgroups: sci.military
Subject: Depleted Uranium
Message-ID: <15438@cbnews.ATT.COM>
Date: 11 Apr 90 03:16:34 GMT
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From: MT666_VINARC@kcgl1.eng.ohio-state.edu
Based on the discussion so far, I assume that so-called "depleted uranium" is
actually U-238, the stable isotope of Uranium. (Please correct me if I am
wrong).  U-238 is mostly useles as fuel in atomic reactors, since it is 
difficult to impossible to get sustained chain reactions with it.  However,
it can be placed in a "breeder" reactor to form Plutonium 239, which is
a lot more usefull (so we need more breeder reactors to prevent any shortages 
of fissionable material).  

Anyway, U-238 forms about 99.7% of all Uranium present on Earth (maybe it's a 
little less, but it's the predominant isotope).  It has a half-life of
4.5 x 10^9 years......that means that after 4.5 x 10^9 years, one-half of it
will have decayed into by-products.  So I would say it's pretty stable, and 
does not have a high amount of radioactivity associated with it. (consider that
some elements have half-lives measured in x10^-7 seconds!)


So while DP shells are radioactive, I wouldn't think it is something a thin
lead coating wouldn't stop....maybe they are lead-coated, since that shouldn't
degrade performance appreciably, and it would increase the safety effect.

My reference for this is "Nuclear Fission Reactors", by I.R. Cameron, and
Prof. R. Bailey (I'm taking a course in Nuclear Engineering this quarter).

Michael J. Vinarcik
The Ohio State University
Metallurgical Engineering
Standard disclaimers apply!