Re: Radon Control During Remediation

[huntjb@ornl.gov (Jerry Hunt)]

Bates--

You shouldn't have much of a radon problem with the DU since the progenitor
of the radon (226-radium) has been chemically removed before the uranium
was processed (the reason that mill tailings are such a problem with
radon).  The nearest parent isotope left after the chemical processing is
234-U which is mostly stripped away in the gaseous diffusion process (goes
with the enriched uranium).  The remaining 234-U (~0.2%) has a long enough
half-life (~250,000 yrs.) to preclude the ingrowth of daughters below 234-U.

Your primary radon problem will probably be with the Colorado soil.

                                  Jerry 

At 09:28 AM 1/8/98 -0600, you wrote:
>          Hello Radsafers;
>          
>          Rocky Flats will shortly begin remediation of an area known as 
>          Trench 1 (T1) where ~125 drums of depleted uranium (DU) chips 
>          and lathe coolant were buried from 1954 until 1962.
>          
>          The work will involve excavating the drums and stabilizing the 
>          potentially pyrophoric DU, in place.  All work will be 
>          performed inside a very large tent to be constructed over the 
>          site.
>          
>          My question concerns the generation of Radon and decay 
>          products from the DU (primarily U238) during the work. Are 
>          there any regulatory drivers, etc. to require monitoring 
>          worker exposure to the Radon products, as would be the case in 
>          a uranium mine, since the Radon is being generated from 
>          man-made materials?
>          
>          We intend to air-sample and monitor (with CAMs) for uranium.
>          
>          Thanks for any input Radsafers might have.
>          
>          Bates Estabrooks
>          bates.estabrooks@rfets.gov  
>

*******************************************
Jerry Hunt, CHP
Office of Radiation Protection
Oak Ridge National Laboratory
P.O. Box 2008
Bldg. 4500-S, MS-6099
Oak Ridge, TN  37831-6099
Ph.-(423)576-5117, Mailto:huntjb@ornl.gov
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