[ RadSafe ] Chino Airport to clean radium contamination

[Dukelow, James S Jr]

Franz Schoenhofer and John R Johnson wrote:
-----Original Message-----
From: radsafe-bounces at radlab.nl [mailto:radsafe-bounces at radlab.nl] On Behalf Of Franz Schönhofer
Sent: Friday, April 15, 2005 1:54 PM
To: 'John R Johnson'; 'Susan Gawarecki'; 'RADSAFE'
Cc: 'John R Johnson (TRIUMF)'
Subject: AW: [ RadSafe ] Chino Airport to clean radium contamination


John,

Since I have done an interesting research on the transfer of tritium from wrist watches to the body I have looked after radium dials as well.


At the age of about 10 (I am 60 now) I received a wrist watch which (of
course) had radium dials and the hours were marked with radium "points". I still have it, but it lacks after so many years most of the "points", an effect which showed up already after a few years. It therefore is not unlikely that the radium-paint might loosen from the dial. 

But this would not be a problem, because these instruments had a glass cover. The only problem being possible would be for persons repairing these instruments. This has also been put forward to me by a person dealing with the repair of instruments used in trains. It was found that the working benches of these persons were contaminated by radium. Unfortunately I was not able to finish this research, but it seemed to me that the dose to the staff was below the ones acceptable for radiation workers. 

Concern is not at all on radon progeny - there is enough Rn-222 present in all corners of this world. What makes the radon dials measurable is the external gamma-dose rate, otherwise nobody would have been able to state a "radiation protection problem". 

    <snip>

Best regards,

Franz

Franz Schoenhofer
PhD, MR iR
Habicherg. 31/7
A-1160 Vienna
AUSTRIA
phone -43-0699-1168-1319


> -----Ursprüngliche Nachricht-----
> Von: radsafe-bounces at radlab.nl [mailto:radsafe-bounces at radlab.nl] Im 
> Auftrag von John R Johnson
> Gesendet: Donnerstag, 14. April 2005 23:48
> An: Susan Gawarecki; RADSAFE
> Cc: John R Johnson (TRIUMF)
> Betreff: RE: [ RadSafe ] Chino Airport to clean radium contamination
> 
> Susan and other radsafers
> 
> My experience with radium dials is that the radium stays on the dials.
I
> therefore assume that the contamination is radon progeny and need see
if
> that is stated in the bulliten.
> 
> Has anyone reviewed it?
> 
> John
>  _________________
> John R Johnson, Ph.D.
> *****

================

In 1962 I traveled to Europe and purchased a Tissot watch with a radium dial.

In 1974, while studying nuclear engineering, I held a counter to the face of my watch (which I had worn more or less continuously in the intervening years).  2 mrem/hr!  I chose some other way to know what time it was from then on.

McDowell and his colleagues at Oak Ridge researched alpha-recoil spalling in the 70s, establishing conclusively that coincident alpha decays in actinides can eject small (on the order of a million atoms) particles from the surface of the material and investigating some of the interesting consequences of this phenomenon.  The shorter the half-life the stronger the effect.  Actinides just want to get out and see the world.  Since the half-life of Ra is days or a few years or about 1600 years, the effect should be significant for Ra.  Franz' radium "points" probably really did turn into dispersed radium particles.

Best regards.

Jim Dukelow
Pacific Northwest National Laboratory
Richland, WA
jim.dukelow at pnl.gov

These comments are mine and have not been reviewed and/or approved by my management or by the U.S. Department of Energy.