[ RadSafe ] Re: attn. Landauer Customers

[Sandy Perle]

Hi Dale,

This all has to do with source geometry, is it a point source, several point sources, or more like a line source. location of source(s), distance, angle, etc. This is not an unusual observation.

Regards,

Sandy


On 24 Aug 2005 at 18:01, Dale Boyce wrote:

> John's point is definitely a real one. While I have personally seen
> doses as high as 300 mrem from intransit, I have seen a report come
> back for a couple of thousand badges, several hundred of which had
> exposures reported between 10 and 50 mrem with most in the 20 to 30
> mrem category.
> 
> Since these films were all shipped in the same box, one wonders why
> the spread in reported exposure. Even though it is a lot of badges
> when shipped as the film only the box is pretty small.
> 
> Also, what correction could be applied in such a case if the control
> showed 0, 10, 20, 30, 40, or 50 mrem?
> 
> I guess one solution is to not use carriers that also handle isotopes.
> The second best would be to not use the same carrier(s) that deliver
> isotopes to your facility, since the most probable place for the
> badges to be placed near a source in transit is during final delivery.
> However, in the case mentioned different carriers were used, but the
> one delivering the badges also does or at least did transport RAM.
> 
> Dale
> 
> 
> ----- Original Message ----- 
> From: "Wright, Will (DHS-PSB)" <WWright2 at dhs.ca.gov>
> To: "Flood, John" <FloodJR at nv.doe.gov>; <sandyfl at earthlink.net>;
> <jblute at NITON.com>; <radsafe at radlab.nl>; "Neill Stanford"
> <stanford at stanforddosimetry.com> Sent: Wednesday, August 24, 2005 5:03
> PM Subject: RE: [ RadSafe ] Re: attn. Landauer Customers
> 
> 
> i believe i deleted the initial strings, could someone briefly
> describe the issue or was this simply a discussion about the
> inconvenience of maintaining a control. controls are critical as
> indicated in all objective science endeavors/ bench top science as
> well as others will teach this the hard way.
> 
> -----Original Message-----
> From: radsafe-bounces at radlab.nl [mailto:radsafe-bounces at radlab.nl]On
> Behalf Of Flood, John Sent: Wednesday, August 24, 2005 2:52 PM To:
> 'sandyfl at earthlink.net'; jblute at NITON.com; radsafe at radlab.nl; Neill
> Stanford Subject: RE: [ RadSafe ] Re: attn. Landauer Customers
> 
> 
> Perhaps I missed a post on this subject, but the discussion seems to
> be overlooking the in-transit exposure that a control dosimeter also
> monitors. There is no doubt that accurate background subtraction is
> important to low dose measurements, but the absence of background
> measurements can be a horrifying experience if every dosimeter in the
> shipment to the processor shows a few hundred mrem from irradiation
> in-transit.  This is a very real, modern problem - if your dosimeters
> sit next to some clinic's radionuclide shipment on the truck or in the
> warehouse, expect to see 50-300 mrem on every dosimeter (how would I
> know this?).  Without control dosimeters, life certainly gets more
> complicated.
> 
> Bob Flood
> Nevada Test Site

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Sandy Perle 
Senior Vice President, Technical Operations 
Global Dosimetry Solutions, Inc. 
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