Re: Posting of "Beta" Radiation Areas

["Sandy Perle" <sandyfl@earthlink.net>]

Ray Weedon stated the following:

> Beta dose could be considered a risk issue for DDE for the eyes.  In most
> power plants, workers typically wear safety glasses or other types of eye
> protection which provide sufficient shielding that DDE to the eyes is not of
> concern. 

While the question concerns posting requirements, the issue of 
potential risk should be addressed, as stated by Ray above. For there 
to be a risk from beta exposure to penetrate the cornea and lens of 
the eye, the beta energy has to be very high. Per 10 CFR 20, the LDE 
dose limit is 15 rem/yr at a depth of 0.3 cm. In a study conducted at 
FPL years ago, we determined that 95% of all beta dose found from 
normal plant work around valves and other beta source components was 
attenuated by 70 mg/cm^3. While I am not positive, I believe that the 
thickness of the lens of the eye exceeds this value.

In my opinion, it is a rare occurrence where the eye becomes a 
critical entity when working around beta sources, unless the energy 
is high enough to not only penetrate the 0.3 cm, but also 1 cm.

Sandy Perle
E-Mail: sandyfl@earthlink.net 
Personal Website: http://www.geocities.com/capecanaveral/1205

"The object of opening the mind, as of opening 
the mouth, is to close it again on something solid"
              - G. K. Chesterton -
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