RE: Question on Specific Activity

["Edwards, Richard W" <Richard.Edwards@PSS.Boeing.com>]

I beg to differ...

Per 49 CFR (IATA/ICAO uses similar wording)

"Specific activity of a radionuclide" means the activity of the
radionuclide per unit mass of that nuclide.  The specific activity of a
material in which the radionuclide is essentially uniformly distributed
is the activity per unit mass of the material.

Tossing a single source small source into a package of heavier,
non-radioactive items does not render the item nonradioactive from the
perspective of the DOT. They might not catch it, but that doesn't make
it legal. From a practical standpoint, I think you can only average the
activity with the weight of that smallest divisible component carrying
the activity. For example, for a device containing a small encapsulated
source, I would use the weight of the source rather than the weight of
the entire device.

Rick Edwards, Analyst

The Boeing Company, Radiation Protection Technical Services Group
richard.w.edwards@boeing.com         (425) 393-8250