Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!cwjcc!tut.cis.ohio-state.edu!rutgers!att!cbnews!military
From: pwcs.sbc.com!royf@cs.utexas.edu (Roy Forsstrom)
Newsgroups: sci.military
Subject: Re: What is a "depleted uranium round"
Keywords: uranium
Message-ID: <8233@cbnews.ATT.COM>
Date: 13 Jul 89 03:09:26 GMT
References: <8076@cbnews.ATT.COM>
Sender: military@cbnews.ATT.COM
Organization: City of Saint Paul, Dept. of Public Works
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Approved: military@att.att.com



From: pwcs.sbc.com!royf@cs.utexas.edu (Roy Forsstrom)

In article <8076@cbnews.ATT.COM> military@cbnews.ATT.COM (William B. Thacker) writes:
>
>
>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

U-235 is just a few percent of natural uranium ore. It is separated out
and used in military power reactors because it has a higher probability
of fissioning with thermal "low kinetic energy" neutrons than U-238. 
A military power reactor may be enriched to over 90% U-235. 

The fission process produces more thermal neutrons, ~2.54, than fast
neutrons giving a higher density within the reactor. It is also easier
to moderate thermal neutrons--using plain water--than fast neutrons.

Civilian reactors use slightly enriched U-238 for economic reasons. Late
in life, a civilian reactor's power is mainly the result of plutonium
fission.

The unique requirements of a ship's power reactor, small, powerful, easy
and accurate control, reliability and maintainability at sea, prompt the
use of expensive and rare U-235.

Formerly a nuclear reactor operator aboard the USS California, I'm now at-
-----------------------------------+-------------------------------------------
Roy Forsstrom 612-298-5569         |   What are the Rights of Man and the
Public Works Computer Services     |   Liberties of the World but Loose-Fish?
pwcs!royf  royf@pwcs.StPaul.GOV    |         - Moby Dick
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_______________________________________________________________________________
Roy Forsstrom                          What are the Rights of Man and the
Public Works Computer Services         Liberties of the World but Loose-Fish?
pwcs!royf  royf@pwcs.StPaul.GOV              - Ishmael in Moby Dick