Re: Posting of "Beta" Radiation Areas

[Bob Flood <bflood@SLAC.Stanford.EDU>]

At 09:44 AM 9/10/1999 -0500, you wrote:
>
>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.

I agree with Sandy (not unusual). The typical mix of beta emitters at a
power reactor has a low average energy, dominated by Co-60 (<100 keV avg).
That mix offers no real hazard since the energy is insufficient to
penetrate to a depth of 300 mg/cm2 in tissue. Only if a reactor has
significant failed fuel problems can contamination include beta emitters
that offer an opportunity for meaningful lens of eye doses. And in that
situation, a quantity of such contamintion large enough to yield a
meaningful lens of eye dose rate will also mean the facility has
contamination control and airborne radioactivity problems of overwhelming
importance, probably requiring bubble suits to get anywhere near the area.
The shielding over the eyes from the suit would preclude lens of eye dose.
Sort of a problem that corrects itself for all the worst reasons.

===================================
Bob Flood
Dosimetry Group Leader
Stanford Linear Accelerator Center
(650) 926-3793
bflood@slac.stanford.edu
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