[ RadSafe ] Pepto-Bismol

[Bernard L. Cohen]

       Many thanks. I get it now.

Michael McNaughton wrote:

> There is a series of stages, each of which enriches the uranium by a 
> small step. The enrichment depends on the number of stages in the 
> enrichment direction of the series; whereas the depletion depends on 
> the number of stages in the depletion direction. The depletion series 
> stops when the U-235/U238 is 0.002. In the other direction, the 
> enrichment continues for as many stages are used, e.g., to >90%.
>
> At 12:24 PM 12/14/2006, Bernard L. Cohen wrote:
>
>> Natural uranium should have the same alpha activity from U-238 and 
>> U-234 (they are in secular equilibrium).. The enrichment process 
>> takes U-235 from 0.7% to about 3.5% so the DU should have 1/5 as much 
>> U-235 as natural uranium. Enrichment shoud remove a  somewhat larger 
>> fraction of U-234 (it is lower in mass) than of U-235, so the U-234 
>> alpha activity in DU should be somewhat less than 20% of that in 
>> natural uranium. Even if it was 20%, it would be 0.2/ (1+0.2) = 17% 
>> of the total alpha activity. How can it be as much as 28%?
>
>
> Mike McNaughton
> Los Alamos National Lab.
> email: mcnaught at LANL.gov or mcnaughton at LANL.gov
> phone: 505-667-6130; page: 505-664-7733
>
>

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