Re: table 2 appendix b

[ELMCGUIRE@life.uams.edu]

Les, I thought you were Mr. Part 20 (or is it Bob Alexander) and were 
supposed to be answering questions rather than asking! Nevertheless...

IMHO, in response to your query, I think it's clear for inhalation that the
factor of 2 is the age adjustment factor.  If you look in e.g. ICRP53,
the dose difference per unit intake is ~2 for an adult to that of the 10year
old. For submersion in a semi-infinite medium, as for noble gases, the size
of the target really doesn't matter, so there's no age adjustment fudge 
factor.

I don't think 50 mrem was intended to be the basic public dose limit; 
100 mrem is the limit. In 1302 (b)(1) , you are allowed to show that you 
are exposing the individual publican to less than 100 mrem (and may use
occupancy factors).  In 1302(b)(2), you may use the 50 mrem limit for 
compliance, assuming constant occupancy. In either case, 1302 is intended 
as a compliance method, whereas 1301 is the basic dose limit = 100 mrem.

In a medical institution, using the 1302(b)(2) option is out of the question.
How do you show dose rates <(50 mrem*y^-1/8760hr*y^-1=.006 mR*h^-1? Env.
monitoring with TLD I suppose can be used, but we are not blessed with
previous baseline studies, etc. It is a technical problem for medical/academic 
sites, one of many when reactor rules are applied to facilities whose 
basic purposes are different.    

Lynn McGuire 
Univ. of Arkansas Medical Sciences