AW: [ RadSafe ] TLD Readings in Checked Luggage

[Sandy Perle]

Hi Doug,

You pretty much said it all. What makes a dose attributable to the checked
baggage scan is when the individual typically does not receive measurable
exposure or not much more than minimum reportable from their routine
occupational work where very little exposure is received. If an individual
typically receives between 0.1 and 0.5 mSv each badging period, takes a trip
and the dosimeter when processed reads 1.5 mSv, one can hypothesize that the
exposure was due to the checked baggage scan. The higher the exposure that a
worker receives, and especially if there is fluctuation in the exposure
received from period to period, the actual quantity of exposure due to the
checked baggage scan, will be difficult to determine. Yes, one would be
aware of the fact that the X-Ray unit caused a dose, it just can't be
quantified whereby the total dose on the dosimeter can be parsed, and an
estimate used for the period where there was this non-occupational exposure.
In the NPP there is always a secondary dosimeter worn along with the TLD or
other dose of record dosimeter, and that can always be sued in lieu of the
primary dosimeter.

In conclusion, checked baggage X-Ray Scanners do put out a significant
exposure, each and every time a dosimeter goes through one of them. If the
individual never received dose or very little, one can subtract out the
estimated scanned dose. If one typically receives higher doses that is
variable, relying on the secondary dosimeter for the time occupational dose
is received, assigning that, would be the most prudent thing. Trying to
parse out a dose is nearly impossible, unless the dosimeter is only used for
the specific trip in question.

Hope this helps!

Regards,

Sandy

----------------------------------------------------------------
Sander C. Perle 
President
Global Dosimetry Solutions, Inc. 
2652 McGaw Avenue
Irvine, CA 92614
 
Tel: (949) 296-2306 / (888) 437-1714 Extension 2306 
Fax:(949) 296-1144
 
E-Mail: sperle at dosimetry.com
E-Mail: sandyfl at cox.net 
 
Global Dosimetry Website: http://www.dosimetry.com/ 
 

-----Original Message-----
From: radsafe-bounces at radlab.nl [mailto:radsafe-bounces at radlab.nl] On Behalf
Of Doug Aitken
Sent: Thursday, September 06, 2007 9:21 AM
To: Rainer.Facius at dlr.de; LMS1 at pge.com; radsafe at radlab.nl
Subject: Re: AW: [ RadSafe ] TLD Readings in Checked Luggage

I'm not sure that this is totally correct, given the vast range of 
inspection equipment being used around the world, including heavy dose 
X-ray machines in some less up-to date places. In the US (I guess this is 
the focus of Linda's query), we have seen some higher than normal doses on 
TLD (L!7) and OSL (Al2O3) badges that have been attributed to airport 
security scans. However, as these are quarterly badges of workers 
performing source manipulations, it is a little difficult to attribute 
actual doses to airport exposures. Perhaps Sandy can give some more 
coherent information?

Regards
Doug

At 07:02 AM 9/6/2007, Rainer.Facius at dlr.de wrote:
>Linda:
>
>Unless you remove your TLD chips after passing the (hand-) luggage check 
>and read them out before take-off of your plane, the dose received during 
>the flight (several micro-Sv) may well dwarf the dose from the check 
>(approx. 1 - 2 micro-Sv).
>
>Best regards, Rainer
>
>Dr. Rainer Facius
>German Aerospace Center
>Institute of Aerospace Medicine
>-----Ursprüngliche Nachricht-----
>
>Has anyone had any experience with the TLD doses to expect if a TLD is 
>placed in checked luggage? If so, please give me a call or send me an 
>e-mail with the dose received and the estimated energies.
> > Linda Sewell, CHP
>Senior Health Physicist
> > Diablo Canyon Power Plant

Doug Aitken                     Cell Phone    713 562-8585
QHSE Advisor
D&M Operations Support
Schlumberger Technology Corporation