FGR 13 math check

[Andrew Karam <karam.1@osu.edu>]

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)
Office of Radiation Safety					"The mind is not a vessel to
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(karam.1@osu.edu)