Re: Uranium Analyses

[Holloway3 <Holloway3@aol.com>]

<< An excerpt reads:  "In the 1991 proposal EPA solicited comment on use of a
 conversion factor of 1.38 pCi/g or 0.67 pCi/g.... In today's rule the Agency
 is selecting the lower conversion factor, 0.67 pCi/g, because it is a
 conservative factor that is based on the 1:1 activity ratio of U-234 to U-238
 characteristic of
 naturally occurring uranium." >>

Any conversion factor such as the one above can be considered only as a gross
approximation, because the actual ratio of U-234 to U-238 in water can vary
enormously, usually from 1 to 10 (activity ratio).  From what I have seen, it
is more often nearer to 2, than to 1.   If one is willing to accept an
uncertainty of 100% or more, then I suppose the above conversion factor is
acceptable.