H-3 Exit Signs

[jmueller@ucla.edu (Jeff Mueller)]

The majority of responses I have seen regarding my original posting on the
problems associated with H-3 exit signs concerns me greatly, since these
signs evidently exist in many applications from libraries to movie theaters
to aircraft.

Contrary to what is commonly thought and what is promoted by the sign
manufacturers/vendors, when a gas-filled sign is broken, the 5 Ci to 50 Ci
(= 2 x 25 Ci back-to-back) of H-3 doesn't just escape and dilute harmlessly
into the environment.

I don't know the mechanism, but the fact is that a single gas-filled H-3
exit sign can create removable contamination in excess of 2,000 dpm/100 sq.
cm over hundreds of square feet.  In my opinion, this constitutes a
significant HP concern because of the contamination problem in an
unrestricted area (even if the dose is "insignificant").

To those HPs who still don't see this as a problem, let's just say one
broken sign can create the need for a $10K to $30K clean-up using outside
consultants and/or significant resources if handled in-house, not to mention
the negative PR.



>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
  Jeffrey S. Mueller, M.S., CHP                  E-mail = jmueller@ucla.edu
  UCLA Radiation Safety Office                Telephone = 310/206-8204
  1010 Veteran Avenue, 2195 WMB                     FAX = 310/206-9051
  Box 951765                                      Pager = 800/233-7231 #93565
  Los Angeles, CA 90095-1765
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