Re: To Bioassay or not to Bioassay!!

[fegallag@uci.edu (Frank E. Gallagher, III)]

>I am re-writing the Radiation Procedures Manual (which is actually more
>policy than procedures) for my University and am attempting to set
>guidelines on when a routine bioassay program is required.[Additional stuff
>DELETED]

Alex,

I am a member of ANSI Working Group N13.39 of the Health Physics Society
Standards Committee.  We are writing a standard on Internal Dosimetry
Programs which should provide guidance on when to perform bioassays, how to
interpret results, how to record results, etc.  We are in the early stages
of reviewing our first ROUGH draft, so look for the standard in about 5-7 years.

My experience is as an RSO for a state broad-scope licensee that has
monitored many workers over many years, and not found much radioactivity in
many of the urine and thyroid counts.  We have recently convinced our state
regulatory agency to relax their former "unrealistic" requirements, and I
would recommend that you do not tie yourself into a heavy bioassay workload
with very little chance for positive results.

In looking at Charles Meyer's reply to your question, I reviewed NRC Reg.
Guides 8.9 and 8.25.  In 8.25, it seems to indicate that routine bioassay
monitoring would be "required" by the NRC regulations for anyone handling

        >0.1/E-6 = >E5 times the ALI for inhalation.

This seems to be a good starting point for routine bioassays where the
frequencies are set looking at the effective half lives.  Our working group
is considering a voluntary category of confirmatory bioassays that may be
done on an occasional basis (perhaps quarterly, for example) to confirm that
radiation safety procedures are satisfactory.  This might be set at a factor
of 5 or 10 less than for routine "required" bioassays.

Two other factors need to be considered:

        1) Is the material handled on an open bench, in a fume hood, or in a
glove box?  Perhaps the basic criteria should be modified by a factor of 10
or so between each type of containment.

        2) Is the material reactive or volatile such that airborne
radioactivity is very likely to be released (e.g., labeling with H-3
borohydrides, iodinations with I-125).  Perhaps an extra factor of 10
reduction in quantity handled for bioassays to be needed should be included
for these compounds/procedures.

I feel like a lone wolf on my working group, surrounded by US DOE types who
look at bioassays for hundreds upon hundreds of workers as the "norm".  I am
trying to help write a standard that could be useful to universities as well
as nuclear reservations covering 1,000 square kilometers or more.

I plan to report on my experiences at the CRSO Conference at USC in Los
Angeles at the end of June. 
  

Frank E. Gallagher, III, CHP
RSO, Univ. of California, Irvine   92717-2725
Voice: (714) 824-6904, Fax: (714) 824-8539
E-mail: fegallag@uci.edu