Re: quarterly vs. monthly TLDs revisited

[Keith <WELCH@CEBAF.GOV>]

I would add the following to what Erick and Mike said about quarterly
monitoring:

Many nuc plants have been using quarterly monitoring for years due (among other
things) to the old NRC quarterly dose limits.  For the bulk of their workers
this is adequate. Those who get significant exposures need supplemental
dosimetry and more frequent processing, but assuming we're looking at a group
of people who are receiving near background doses, consider this -

(with TLDs) monthly monitoring gives you 12 times a year to either (1) generate
a false positive of say 10 mrem, or (2) generate a false negative of zero. I
would expect to see the following from going to quarterly monitoring.

1. Your total person rem (among the low dose group) may drop due to fewer
   false positives, and
2. For those who receive a positive (real) dose (now a smaller group),
   their exposures may average slightly higher than with monthly monitoring.

Personally, I think quarterly monitoring is preferable for all the reasons
others said and for the potential in reducing false positives/negatives.
This and fifty cents still buys you a soda in most states.

This concept was extracted directly from several orifices on my body, and I
have no idea whether it is valid.  Anyone care to comment?