Re: Radium Smoke Detector Sources

[NSSIHOU@aol.com]

The form of the smoke detector foil depends on when it was made and who made 
it. Some of the foils were fabricated in a manner similar to the current 
Am-241 foils. The radionuclide is blended with a metal powder and rolled 
until the powder becomes a metal foil which is placed between other metal 
foils and rolled again. At the end of rolling, the radionuclide is bound in 
the metal matrix with a very thin layer of foil over the surface. The foils 
used were at one time Silver but I would guess that it would pass the TCLP 
with no difficulty. 

Other foils were made by electroplating the Radium onto foils and 
electroplating a thin metal surface over the top of the base metal.

In both cases the foils are prepared in large pieces with the detector foils 
stamped from this large piece. The stamping also wipes the cover foil down 
over the edges and helps seal the foil from leaking.

I would guess that the smoke detector foil is of less hazard than the Lead 
contained in the solder of the circuit board.

If I can be of further assitance, please contact me directly.

Bob Gallagher
NSSI
713 641-0391