Radioactive Lightning Rods in Brazil ??? -Reply

[FRAMEP@ORAU.GOV]

Mark Mattheiss wrote:

>II am trying to gather information on radioactive lightning rods used on
>buildings in Brazil??  Specifically what isotope would they be, what is
>theapproximate activity of a rod, and how are they disposed of ??  Any
>information would be greatly appreciated.

The info I have is old: 1978 NUREG CP-0001 "Radioactivity in Consumer
Products"

The idea for radioactive lighteneing rods came from Szillard. The first
patent seems to have been 1932. The first devices  used Ra-226. Since
then Kr-85, Co-60, Am-241 and Po-210 have been used. In the late 70s,
Am-241 and Po-210 were the most popular i.e. alpha emiters with little
gamma activity. It seems the activities can vary quite a bit depending,
among other things, on the number of individual sources used by the
rods. The best I can acertain, the activities range from 0.1 uCi to tens of
mCi. 

200,000 were estimated to be in use worldwide in 1976. I know that they
were in use in New York City about ten years ago and that doing leak
checks on these things, high above Manhattan, was not especially fun.
The sort of task you'd give the new hires.

I'm interested in learning some more up to date info so I'd appreciate
seeing any responses posted on the list.

Best wishes

Paul Frame
Professional Training Programs
ORISE
framep@orau.gov