x-ray units and dosimeters

["Sandy Perle" <sandyfl@earthlink.net>]

While at FPL, there were many occasions where the dosimeters being 
shipped to the plants, were inadvertently x-rayed. The specific 
process they followed was to open up the shipment and do a visual 
inspection, and not to pass the shipment through the security x-ray 
unit. As Roy stated, the added exposure was miniscule. However, the 
plant always required that all dosimeters be re-annealed, and shipped 
back to the plant.

Other situations needing clients to be aware of are shipping 
overnight, office x-ray units and mail security in general.

(1) FedEx is the only major over night shipper that also ships 
radiopharmaceuticals. Using a label stating that the shipment should 
not be x-rayed, or be stored next to a radiopharmaceutical doesn't 
gain the attention of the sorter. FedEx employees look for a FedEx 
specific green label, and if you ship via FedEx, you better use this 
label to help mitigate inadvertent irradiation of your dosimeters. 

(2) Mail shipments are sometimes irradiated. We know this since the 
film dosimeters all show a distinctive x-ray dose, generally 70 to 11 
kvP. This happens less frequently that FedEx irradiations. Somehow, 
the Post Office must selectively determine what packages they will x-
ray.

(3) Office building are increasingly x-raying all packages entering 
the facility. Depending on the type of unit, there may or may not be 
an inadvertent exposure.

The key indicator is assessing the Control Dosimeters for any unusual 
dose or filter patterns. If the entire shipment is irradiated 
uniformly, the task is simplified. If there is a non-uniform 
irradiation .. well, the assessment becomes more difficult, unless 
the exposure is low enough to be considered not statistically higher 
and therefore, can be assumed to be acceptable.

Sandy Perle
E-Mail: sandyfl@earthlink.net 
Personal Website: http://www.geocities.com/scperle

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