Re: Uranium Analyses

[Bobshann <Bobshann@aol.com>]

In a message dated 3/13/98 20:51:48, you wrote:

<<dale_dusenbury@mail.enr.state.nc.us>>

While I have returned a specific reply to Dale, I discovered a typo in the
Federal Register regarding conversions between gravimetric and radiometric
uranium results.  

The EPA has promulgated a conversion factor to be used for natural uranium in
drinking water in 40 CFR  Part 141 (actually look in the Federal Register from
March 5, 1997, "National Public Drinking Water Regulations: Analytical Methods
for Radionuclides; Final and Proposed Rule" at
http://www.epa.gov/fedrgstr/EPA-WATER/1997/March/Day-05/w4889.htm) .   

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."

The units for the conversion factor listed are incorrectly printed as pCi/g !
The correct conversion factor should read 0.67 pCi/ug Nat U.  

Otherwise there are quite a few factors that should be considered when trying
to compare the two types of results.  Feel free to reply to me personally, if
you are interested.

Maybe that EPA number refers to the recently discovered "non-radioactive form
of uranium..."


Standard disclaimers apply...

Bob Shannon
Radiochemistry Technical Manager
Paragon Analytics, Inc.
Fort Collins, CO
(970)490-1511
Bobshann@aol.com