update on contaminated lead products

["M. Woo" <melissa@zelda.ehs.uiuc.edu>]

                               June 4, 1997

This information is a followup to the notice distributed by
the Illinois Department of Nuclear Safety (IDNS) or the
Conference of Radiation Control Program Directors, Inc.
(CRCPD) that was sent to you within the last 24 hours.  If you
have further questions, please contact Steve Collins at 217-785-9935
or fax 217- 782-1328 or at collins@idns.state.il.us.

Based on results of analyses from the IDNS Radiochemistry
Laboratory for five samples, the radionuclides are lead-210
and its daughters bismuth-210 and polonium- 210.  The half-life
of lead-210 is approximately 22 years, bismuth-210 is
approximately 5 days, and polonium-210 is approximately 138 days.

The total activity is approximately 4 + 2 nanocuries per gram
of lead material. The bismuth 1.16 MeV beta is the primary
contributor to dose followed by the k-shell x-rays.  The energy
of the x-rays is 88 keV or less with most less than 50 keV.

The estimated dose rate is approximately 0.6 to 3 millirad per
hour at contact. If a film badge/tld is near an apron made of
the contaminated material for a long period of time with the
window of the film badge/tld holder toward the source of radiation,
there may be a reading that is significantly above the actual
dose received by the individual assigned the personnel dosimeter.

The IDNS has notified each state Radiation Control Program in
which there is a company that received contaminated lead (Pb)
material from the Illinois supplier of lead.  Each state agreed
to support the effort to track the distribution of the products. 
Each of the companies has also been requested to provide a description
of the company's process for use of the lead, a description of the
company's products made with the lead, and a distribution list
for the company's potentially contaminated products.


--
Melissa Woo, Health Physicist                    |m-woo@uiuc.edu
University of Illinois at Urbana-Champaign       |ofc 1.217.244.7233
DEHS, MC225, 101 S. Gregory St., Urbana, IL 61801|fax 1.217.244.6594
http://www.uiuc.edu/ph/www/m-woo                 |