Re: Screening for contaminated dosimeters

[Patrick Duffy <prduffy@foxberry.net>]

What kind of dosimeter?  Couls it be Bi (or other) contamination of Pb
shielding?

Could have been airport or other security devices (x-rays and explosive
detectors).  Or shipment may have been located adjacent to another rad
materials shipment.

In my laboratory, all TLDs (we process Panasonic UD-802/807/814) are frisked
for contamination upon receipt - the risk of contaminating our TLD readers
is too great (not to mention strict contamination control issues).



Jim F. Herrold wrote:

> 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.