[ RadSafe ] Natural Uranium - Isotope Abundance

[Geo>K0FF]

"(1) Natural uranium means uranium with the naturally occurring distribution 
of uranium isotopes (approximately 0.711 weight percent uranium-235, and the 
remainder by weight essentially uranium-238)."



http://www.nrc.gov/reading-rm/doc-collections/cfr/part071/part071-0004.html



George Dowell

NLNL
New London Nucleonics Lab

----- Original Message ----- 
From: "Redmond, Randy (RXQ)" <redmondrr at y12.doe.gov>
To: <radsafe at radlab.nl>
Sent: Tuesday, October 23, 2007 9:30 AM
Subject: [ RadSafe ] Natural Uranium - Isotope Abundance


Background

- NRC regulations define depleted uranium as uranium with U-235
abundance less than 0.711 percent.
- DOE STD 1136-2000 Table 2-1 gave U-235 weight percent as 0.72 and
stated that the range of the weight percent of U-235 in the natural
environment could vary from 0.61 to 0.81 percent.
- The range stated in 1136 was deleted - DOE STD 1136-2004.

My dilemma

To prove that I have not technology enhanced (added radioactivity to)
the uranium in various substances (my facility deals with DU and EU), I
am being currently held to 0.711 percent.  If my results are greater
than  0.711 percent U-235, then it's enriched; if my results are less
than 0.711 percent, then it's depleted.  Does anyone know of a NRC or
DOE document that can be cited which establishes a range for U-235 in
natural uranium?  Establishing baseline information on every material is
not an option..

Thank you,

Randy Redmond
BWXT Y-12
Radiological Engineering
865-574-5640


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