Screening for contaminated dosimeters

["Jim F. Herrold" <Herrold@UWyo.Edu>]

Hello.

We got our dosimetry report back from last month with a higher number of
low x- or gamma-ray exposures (10 to 20 mrem) where we shouldn't have
seen any. The control badge was returned, and, as far as I know,
subtracted. The possibility of one or more contaminated badges sent back
with the group came up. The dosimetry company routinely screens incoming
badges for contamination and did not see anything unusual (they didn't
report it to us, anyway). It raised a question, however. We are not in
the practice of checking our badges for contamination before sending
them off. In the past ten years I can't recall this being a problem. 

My question is: Do other institutions check their badges routinely for
contamination? If so, or if not, why? What else could have caused
abnormal counts on maybe 10 percent of the badges?

Thanks in advance for your help.

Jim F. Herrold
Radiation Safety Officer
University of Wyoming
Environmental Health & Safety
312 Merica Hall
Laramie, WY 82071

herrold@uwyo.edu
(307) 766-3277

DISCLAIMER: Nothing I say, write, or think (including this disclaimer)
represents the positions held by the University of Wyoming, Trustees,
President or his designee.