RE: Leak Testing Sealed Sources

["Sorensen, Scott" <ssorensen@doeal.gov>]

Rad Safers,

I've noticed that numerous regulatory-based sealed source leak-test
thresholds have been provided in response to Mr. Haleem's request.  I
think some discussion of dose-based thresholds would also be
interesting...  I'm aware of one published methodology for deriving
leak-test thresholds:

Kerr, G.D. and Ekerman, K.F. Source Inventory Limits. Health Physics.
Vol.59 No. 6, 1990.

Radionuclides are partitioned into eight leak-test thresholds, ranging
from a nCi to a mCi, based on relative dose derived from the limiting
pathway (external radiation or inhalation).  Most of the actinides are
in the sub-uCi range.  This reference appears to be the basis behind
current U.S. Department of Energy (DOE) sealed source accountability
requirements (although not identical to the author's recommendations).

I believe that the DOE is considering revising dose-based methodology to
be somewhat similar to a Los Alamos National Laboratory (LANL) sealed
source accountability proposal (is this published?).  The proposed new
DOE thresholds may end up codified in a revised 10 CFR 835.  Are any of
the other quoted regulatory thresholds (State, NRC licensed) derived
from a health-protection basis?

Regards,
Scott Sorensen
ssorensen@doeal.gov