Re: FGR 13 math check

[Bernard L Cohen <blc+@pitt.edu>]

	Your calculation leaves out the effects of radon, which are far
larger than those of all the others combined.

Bernard L. Cohen
Physics Dept.
University of Pittsburgh
Pittsburgh, PA 15260
Tel: (412)624-9245
Fax: (412)624-9163
e-mail: blc+@pitt.edu


On Thu, 19 Mar 1998, Andrew Karam wrote:

> I have just completed a few preliminary calculations based on number given
> in FGR 13.  Before putting these into a letter to my representatives, I'd
> like to ask anyone out there to check a sample calculation, just to make
> sure I'm doing this correctly, given the information provided in the report.
> 
> For U-238 homogeneously distributed in soil at a concentration of 1 pCi/gm
> I come up with an annual risk of 3.16e-11 and a lifetime risk (70 year) of
> 2.21e-9.  Summing all of the U-238 progeny nuclides gives an annual risk of
> 1.18e-5 and a lifetime risk of 8.26e-4 (again, for 1 pCi/gm homogeously
> distributed.  I would not ask for anyone to check the entire series, but I
> set it up on a spreadsheet and, if U-238 is correct, they all ought to be.
> 
> FYI, I come up with lifetime risks of 8.19e-4 for U-238+progeny (accounting
> for abundance), 2.22e-6 for U-235+progeny (again, accounting for
> abundance), and 1.13e-3 for Th-232+progeny.  These are all for 1 pCi/gm in
> soil.  Total lifetime risk (per FGR 13) is 1.95e-3 for soil containing 1
> pCi/gm each of U and Th.
> 
> Thanks in advance for your help.
> 
> Andy
> 
> The opinions expressed above are well-reasoned and insightful.  Needless to
> say, they are not those of my employer. (with apologies to Michael Feldman)		
> 
> Andrew Karam, MS, CHP					(614) 292-1284 (phone)
> The Ohio State University 					(614) 292-7002 (fax)
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