[ RadSafe ] Alpha Check Sources

[Kai Kaletsch]

Dear Radsafers,

I am looking for a supplier of check sources that can be used for alpha counters. These can be very low activity. About 400 Bq would be ideal, but even much lower would be acceptable. The actual activity is not very important. These are to be used as check sources, rather than calibration standards. I am looking for the thin 25 mm disk sources.

This is how I understand the situation (and PLEASE correct me if I'm wrong): Small quantities of Am-241 are exempt from licensing requirements in most of the world, but not in the US. This makes it difficult for organizations in the US to get these sources. Up to 4% Thorium in tungsten does not need to be licensed in the US, but nobody makes check sources out of this material. So, what can organizations in the US use as an alpha check source?

The main supplier of Am-241 sources ( http://www.ipl.isotopeproducts.com/new_ipl_site/ ) is located in the US. Suppliers in the US are often not aware of regulations in other countries and are reluctant to ship these sources to unlicensed entities outside the US. Even if you can explain the situation and they ship the source, it gets to customs with a whole bunch of paperwork and the customs people don't know what to do with it. So, it is difficult to get an alpha check source outside the US, as well.

All of this adds to the cost. The price of a small Am-241 source is ~ $1000 USD even before the paper burden, for a source that is several orders of magnitude smaller than what is contained in a $5 smoke detector.

My question is: Does anyone have a suggestion of how an unlicensed entity, either in the US or outside the US, can get a small alpha emitting check source for a reasonable price and without a lot of paperwork? (... that does not involve taking apart a smoke detector.)

Background:

To avoid having my door kicked in by various security agencies, I should probably explain the reason for this request. 

We manufacture the TM372 portable alpha counter, which has become the standard instrument for measuring radon progeny and Long Lived Radioactive Dust in Canadian uranium mines. The uranium mining companies are licensed to have radioisotopes. They have the budget to pay $1000 for a check source and they have the staff that is accustomed to dealing with the paper burden related to getting radioactive material. So, this issue is not so difficult for them.

However, there are other entities who do not necessarily have a radioisotope license, who want to (and should!) measure radon progeny and use the TM372. These include other mines (e.g. zinc, gold, tin, molybdenum...) as well as consultants. Getting an alpha check source becomes a real difficulty for them.

Off-list responses welcome.

Thanks in advance,
Kai

Kai Kaletsch
Environmental Instruments Canada Inc.
http://www.eic.nu/