Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!tut.cis.ohio-state.edu!att!cbnews!military
From: military@cbnews.ATT.COM (William B. Thacker)
Newsgroups: sci.military
Subject: Re: What is a "depleted uranium round"
Message-ID: <8076@cbnews.ATT.COM>
Date: 8 Jul 89 04:34:43 GMT
Organization: AT&T Bell Laboratories
Lines: 23
Approved: military@att.att.com



From: ulysses!smb
> It consists of the relatively
> stable uranium isotope, and so is only mildly radioactive.  DU is
> extremely hard, and denser than tungsten (or lead); these two properties
> make it an excellent choice for kinetic energy armor penetrators.


Anyway -- DU may or may not be ``mildly radioactive'' compared to the
natural stuff.  The issue is that U-235, the isotope separated out for
use in bombs and reactors, fissions much more easily when bombarded
by neutrons; U-238 has much more of a tendency to turn into plutonium
(eventually, and via several indirect steps).  The natural level of
radioactivity of either -- that is, the spontaeous decay rate -- is
of no particular interest militarily; the ability to fission, and to
emit neutrons of the appropriate energy level during fission, thus
causing a chain reaction, is what's interesting.

I don't think uranium per se is that radioactive; it has quite a long
half-life, which translates directly into ``not many atoms split per
unit time''.  Stuff with a short half life is much nastier, since you
then get lots of radiation.