Re: Contaminated Lead Products Update

[Al Tschaeche <antatnsu@pacbell.net>]

Tupin, Edward A. 301-827-1230 Fax 594-4760 wrote:

> Attached is an official FDA notice on lead-containing radiation=20
> protection devices (primarily aprons, thyroid shields and gonad shiel=
> ds)=20
> which have been identified as having radioactivity.

A later post pointed to a June 27, 1997 DOE letter on this subject
written by Andy Wallo.  The attachment to that letter states: "Beginning
in November/December, 1996, the smelter's import agent apparently
arranged the import of a smelter byproduct (described a solder-like
material) that was 65% Sn, 34.5% Pb and 0.5% Bi, containing the leat 210
contamination.  The contamination concentration is stated as 4 plus or
minus 2 nanocuries per gram of lead material.  Apparently there was no
Ra-226 or other precursor of the lead 210.  The question I have is:
where and how did so much lead-210 get separated from Ra-226??  When I
was making radioactive counting sources eons ago, we searched all over
the world for radium that had been sealed long enough for the lead 210
to build up so we could separate it and use it for counting standards. 
I never heard of any one or any place that had so much lead 210
separated from Ra-226.  Can anyone enlighten me as to how so much lead
210 could have been separated from Ra-226 and why anyone would want to
do that?  Do we have another oklo-type phenomenon?  Al Tschaeche
antatnsu@pacbell.net