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public dose, restricted area comments



a bit of history (how time flies)...
The BIG revision of Part 20, effective 1/1/94, defined public dose differently. As noted the added 1995 adjustment to Part 20 made a number of corrections, one of which was to allow public dose to be received in a restricted area. Hence the previous Q&As on this topic are no longer correct.
The vital argument for this change was the a person (i.e., a member of the public) should not be subject to the occupational dose limits simply because of geographic circumstances. The PR reason was that certain facilities that do educational activities did not want persons entering their restricted areas for simple tours to be classed as radiation workers (i.e., be subject to occupational dose limits) simply because of geography.
As an added thought: The definition of occupational dose used to be one of two (or so) major uses of the resticted area concept. It is now defunct. The other is source security (10CFR20.1801/2) and recent events have blurred the boundary for that rule (i.e., NRC seems to treat security the same regardless of where the sources are). The 2 mr/h limit for unrestricted areas was almost thrown out during the revision process (and with the fundamental basis of the rule being annual dose it should have been, IMHO). Part 19 in now keyed to occupational dose (I was a minority objector to the change). Little else would appear to use this concept. Perhaps it is no longer needed?

From: Carl_A._Tarantino@vapower.com (Carl A. Tarantino)
The interpretation by ICN Biomedicals based on the NUREG/CR-6204, Q/A
#33, is correct. Individuals entering a restricted area are subject
to the occupational dose limits, which in the case of minors, would be
10% of the adult occupational dose limits. The licensee has
discretionary action in determining prospectively if these individuals
require monitoring, however.




Disclaimer: the above are the personal musings of the author, and do not represent any past, present, or future position of NIST, the U.S. government, or anyone else who might think that they are in a position of authority.
Lester Slaback, Jr. [Lester.Slaback@NIST.GOV]
NBSR Health Physics
Center for Neutron Research
NIST
Gaithersburg, MD 20899
301 975-5810