Re: A couple off-the-wall (unrelated) questions

["Wesley M. Dunn" <WDUNN@brc1.tdh.state.tx.us>]

Jim,

I'll give my opinion on #1:

Assuming the diffraction units are using Copper targets, no dosimetry
should be necessary unless and except they bypass the interlocks to
realign the target while the power is on.  Ring dosimeters are
appropriate for that case.  If non-copper targets are used (e.g.,
tungsten), than a wholebody badge/TLD would be appropriate.

Most regulations require dosimetry for all x-ray diffraction units.
However, it is really unnecessary for the majority of uses.  It is
very difficult to get a significant dose from the new, interlocked
units, even if you do stick your finger in the beam (do the calcs if
you doubt it: pencil beam and a wavering hand makes a difficult
combination).  The old Norelco's could and did leak a lot of
radiation when people played with the housing, so badging was
certainly appropriate.

Wes

> Date:          Fri, 20 Oct 95 15:42:58 -0500
> Reply-to:      radsafe@romulus.ehs.uiuc.edu
> From:          "Jim F. Herrold" <HERROLD@UWYO.EDU>
> To:            Multiple recipients of list <radsafe@romulus.ehs.uiuc.edu>
> Subject:       A couple off-the-wall (unrelated) questions

> Hello out there in RadSafe land...
>
> I have a couple things which are puzzling me on this Friday afternoon an dwould
> appreciate some insight. These are two ares in which I am sadly ignorant, so
> any answer, no matter how basic it may seem, is probably not too basic for me.
>
> #1.  What recommendations do other research institutions follow for monitoring
> technicians in x-ray diffraction labs. We have a couple units on campus made by
> Scintag (an XDS2000 and a PADII), which are fully enclosed and shielded, so
> that exposures to all users have been less than detectable. In fact, the area
> monitors do not even register any exposures. Now, before you go telling me to
> talk to my state regulatory agency, you should know that here in Wyoming we
> don't HAVE one. It was eliminated three years back and no one over there at the
> Capital has a clue. What I am looking for, then, is the accepted guidelines in
> OTHER states who still care about x-ray safety. I've been meaning to go get
> some exposure levels with a portable PIC (as soon as I get a round TUIT). Based
> on that information, I'm inclined to leave the area monitors there but stop
> badging the people individually. Following the NRC guidelines (my only source
> of inspiration on radiation protection) I would say monitoring of individuals
> is not required. Feedback, please.
>
> #2.  Can pancake geiger detectors be set off by high electromagnetic fields?

*********************************************************************
Wesley M. Dunn, C.H.P., Administrator      512-834-6688
Licensing Branch                           512-834-6690 (fax)
(Texas) Bureau of Radiation Control        wdunn@brc1.tdh.state.tx.us
*********************************************************************