[ RadSafe ] Pepto-Bismol

[Michael McNaughton]

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