Re: The Sun, The Wind and Nuclear Power?

[Susan L Gawarecki <loc@icx.net>]

Ruth's estimate of 3% uranium in coal is high--perhaps she meant to 

write 3 ppm?  I've reprinted a relevant message from Phil Egidi with 

more details below.



--Susan Gawarecki



> Subject: Re: Coal ash in concrete

> Date: Wed, 12 Jan 2000 17:07:20 -0700

> From: "Phil V. Egidi" 

>  

> Susan,

> 

> EPA has a fact sheet - EPA Guideline for Purchasing Cement and Concrete

> Containing Fly Ash, EPA/530-SW-91-086, January 1992.  I don't have it

> personally, so I can't comment on it.

> 

> The amounts of TENORM that may be present in fly ash and bottom ash can

> vary, depending on the source coal.  According to the National Academy of

> Sciences Report, Evaluation of Guidelines for Exposures to Technologically

> Enhanced Naturally Occurring Radioactive Materials (1999), typical coal has

> uranium concentrations about 0.05 - 3 ppm and thorium at 1 - 10 ppm.  The

> resulting ash from combustion (fly ash and bottom ash) average about 3.7

> pCi/g Ra-226.  There could be strong enrichment of Po210 and Pb210 due to

> volatization and subsequent condensation on the fly ash particles (bottom

> ash would be depleted).  But since these are volatilized particles, the

> radon emanation fraction should be very low.  The EPA, in their 1993 report

> of TENORM reported average concentrations in fly ash for U-238 and Th232 at

> 1.5 to 8.6 pCi/g and 0.4 to 7.5 pCi/g respectively.  They report enrichment

> factors (from coal to fly ash) from 1.3 and 1.4 for U238 and Th232, up to a

> factor of 2 for Ra-226, and 5 to 11 for Po210 and Pb210.

> So there is variability in the amount of enrichment, depending on the

> source and the process.





-- 

.....................................................

Susan L. Gawarecki, Ph.D., Executive Director

Oak Ridge Reservation Local Oversight Committee

102 Robertsville Road, Suite B, Oak Ridge, TN 37830

Toll free 888-770-3073 ~ www.local-oversight.org

.....................................................





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