re: beta monitoring - added comment

[slaback@micf.nist.gov]

There are a number of situations where
beta dose rates might need to be monitored,
e.g., a plated source, where contamination
is not an issue and where general area dose
rates are not an issue.  Hence a 'member of the
public' could be in the area and not be monitored
as a person who is occupationally exposed.
This is not as uncommon as you might expect, 
particularly at research facilities.

Also remember that it does not take much activity
to have a significant contact dose rate concern,
and hence a control (if not a monitoring) concern.
So the issue is not just contamination and area
dose rates.

A little risk adds spice to life.
Lester.Slaback@NIST.gov