[ RadSafe ] Natural Uranium - Isotope Abundance

[bobcherry at satx.rr.com]

>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.
To quote the great Lee Corso, "Not so fast, my friend."
Be sure to consider uncertainty in your results and uncertainty in the natural variation in relative abundance of uranium isotopes. Choose acceptable values for type I and type II errors and then see what you have.
Bob

----- Original Message ----- 
From: "Redmond, Randy (RXQ)" <redmondrr at y12.doe.gov> 
Date: Wednesday, October 24, 2007 10:37 am 
Subject: [ RadSafe ] Natural Uranium - Isotope Abundance 
To: radsafe at radlab.nl 

> 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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