Re: Coal Fired Plants and Release of Radioactivity

[SENES Consultants Limited <senes@senes.on.ca>]

I believe that the quoted Pu-239/U-238 radiotoxicity ratio of 3.4 x 10E11 is in error.

The Pu-239/U-238 ratio of  dose conversion factors  for inhaled insoluble material (type S) is only 2.0 for adult members of the public (ICRP Publication 72).   Even considering the relatively higher specific activity of Pu-239 due to its shorter half-life ( 2.41E4 y compared to 4.47E9 y for U-238), the Pu-239/U-238 radiotoxicity ratio would be less than 4E5 on a mass basis.  The ratio is higher (but less than 5E7) for the more soluble type F materials. 

The Pu-239/U-238 radiotoxicity ratio for ingested material is less than 2E6 on a mass basis.   All  these ratios are much less than the quoted value.


Leo M. Lowe, Ph.D.
Principal, Senior Health and
Environmental Physicist

SENES Consultants Limited
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