Re: Found Source

["Ron L. Kathren" <rkathren@beta.tricity.wsu.edu>]

Randy --

In the good old days (before my time, of course), radium, frequently 
incorporated into a lucite or other plastic matrix, was supplied along 
with various instruments as a 'calibration' or check source.  Sometimes 
these took the form of little disks of plastic about the size of a silver 
dollar (pre-Susan B. Anthony size) with a bit of Ra about 5 mm in 
diameter in the center.  The idea was to provide a means of assessing the 
instrument performance in the field, as well as, in some cases, of 
providing a crude but effective calibration tool.

Most likely the material is RaCl2; I suggest you treat same as 
radioactive waste and contact the state health department or, 
alternatively, Paul Frame at ORISE (formerly ORAU) who is acquiring a 
very fine collection of such materials for his museum of health physics 
(and, the answer is no, he not asked me to be put on display).

Ron Kathren

P.S.  Radium shows up in many places -- vacuum tubes (very old -- rember, 
these were the transistors of our founding fathers) sometimes contain 
appreciable (even mg quantities!) of radium, and may leak.  Old 
electronic equipment had not only radium dials, but also switches and 
markings that were radium bearing.  Finally, not meaning to be preachy, 
but 'contact' readings (especially with a GM) don't mean a lot absent the 
geometry and energy response of the detector; some Ra sources emit 
appreciable amounts of beta (from daughters, or progeny if you prefer the 
politically correct term) as well as soft x-rays.

The little prof.   

On Tue, 11 Oct 1994, Randy Ross, rnross@bscsc02.gov.bc.ca wrote:

> I got a call from a man who received a radium source from a thrift shop.  They
>  were asking $1.00 for it but gave it to him free since he bought a number of
> other things.  He had it for a year until he suspected it was radioactive.
> I picked it up from him but do not know what it is or where it came from.
> 
> Let me describe it:  Its a metal yellowish orange rectangular container with a
> hinged lid.  On a black metal plate on the side it says" Calibration source and
>  jig for ___ meters.  Contamination No.1 S CatNo. 6665-110099  Serial #113
> Year ____  Code_____    Ra source probe 100uC      meter reading to be 4 mR/hr"
> 
> And someone had written upon the case in black marker "Source 13943".That #
> was also printed on the source.The source was inside the box on a hinge
>  that enabled one to lift the source up or rotate it down to a horizontal
> position centered (roughly) in the box.
> There was a diagram on the box that showed how  nother instrument fit into the
>  open lid in away that fixed the distance between the source and it.
> 
> Its' Ra 226 and not leaking.  But what is it?
> Approx readings (end window GM): 1.5 m  bg, on contact with case 18 mR/hr,
> 5mm from source 100 mR/hr.
> The metal box is not shielded and is roughly 2.5 by 2.5 by 6 inches.
> 
> ===============================================================
> The opinions contained within are solely those of the author
> and do not represent those of BC Systems Corp. BC Min. of Health
> ================================================================
>