Re: Request for Information

[Christopher Dixon <cdixon@interlog.com>]

Sam:

The most common type of contaminated material that I have encountered in my
dealings with scrap companies are:

Airplane dials: Ra-226, <100 kBq
Contaminated pipe: U-238 (mining) , Ra-226 (radium sulfide from fertilizer
production), highest = 40 MBq
Aircraft Engines: Th-232, specific activity x % abundance (usually 0.05% of
mass)

Possibly present but unlikely and never observed:

Industrial Sources: Cs-137, Co-60, Am-241, Kr-85, Fe-55, Ni-63, Am-241/Be,
Pu-238/Be, Ra-226/Be, 10 mCi to 2 Ci
Teletherapy Sources: Cs-137, Co-60, >50Ci?
Gamma Cells: Co-60 >1000 Ci?

Smoke detectors use primarily Am-241 (although some use Ra-226), with
activities ranging from 0.8 uCi to 40 uCi.  It is unlikely that they would
be sent for scrap due to the low volume of metal that they usually contain.
They pose a larger threat to landfill instead.

Christopher Dixon
Radiation Protection Manager
Monserco Limited
190 Wilkinson Road
Brampton, Ontario
L6T 4W3
Tel: (905) 450-3507
Fax (905) 450-8523
email: cdixon@interlog.com