From: Michael M. Butler (mmb@spies.com)
Date: Sat Jun 07 2003 - 19:10:28 MDT
On Sat, 7 Jun 2003 16:05:00 -0700 (PDT), Robert J. Bradbury
<bradbury@aeiveos.com> wrote:
>
> Though I do not like to bring this up....
>
>> More than 500 tons of natural uranium and 1.8 tons of low-enriched
>> uranium were stored at Tuwaitha, international inspectors have said
>
> Article:
> http://www.nytimes.com/2003/06/08/international/worldspecial/08IRAQ.html?pagewanted=print
>
> Please note the scales involved -- *TONS*. It takes only a few
> tens of kg to make a nuclear weapon (of enriched uranium)
> and less than that to make a weapon out of plutonium.
Excuse me, Robert; you might be making a quantity error here. The NYTimes
might have their info correct here, or they might not. Assuming they didn't
get mixed up and call ore "natural uranium" and yellowcake "low enriched
uranium", there is still enough to be a matter of some concern.
But see http://www.fas.org/nuke/intro/nuke/uranium.htm for info, including
the following:
<<
"In a typical sample of natural uranium, only 0.72 percent of the atoms are
235 U atoms, and it can be assumed that all of the remaining atoms are 238
U atoms. 8 Natural uranium typically has a composition of 0.0055 atom % 234
U, 0.7205 atom % 235 U, and 99.274 atom % 238 U. For most purposes, the
tiny fraction of 234 U can be neglected. Higher concentrations of 235 U are
required for many applications, and the use of uranium isotope separation
processes to increase the assay of 235 U above its natural value of 0.72
percent is called uranium enrichment.
"While low-enriched uranium (LEU) could technically mean uranium with an
assay anywhere between slightly greater than natural (0.72 percent) and 20
percent 235 U, it most commonly is used to denote uranium with an assay
suitable for use in a light-water nuclear reactor (i.e., an assay of <5
percent). Similarly, the term “highly enriched” uranium (HEU) could be used
to describe uranium with an assay >20 percent, but it is commonly used to
refer to uranium enriched to 90 percent 235 U or higher (i.e., weapons-
grade uranium). The term “oralloy” was used during World War II as a
contraction of “Oak Ridge alloy,” and it denoted uranium enriched to 93.5
percent 235U."
>>
So there are a wide range of possible numbers from the sketchy description
provided by the NYT. If they *did* mean 1.8 tonnes of 0.72 percent 235U,
that's 13 kg of pure 235U. At 5% that obviously turns into 90 kg; at 20%,
360 kg. Not whistling past the graveyard here, just saying I can't tell.
> Any extropian in a major population center should be attempting
> to determine whether it is a good idea to relocate out of said
> population center.
This has been true for quite some time, friend Robert.
MMB
-- I am not here to have an argument. I am here as part of a civilization. Sometimes I forget.
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