[ RadSafe ] Texsport Item #14210 - Lantern Mantles

Dan McCarn hotgreenchile at gmail.com
Wed Jul 11 22:41:56 CDT 2012

Dear Stewart and group:

Aside from Stewart's humor...

The term "radioactive material" (DOT, IAEA, IATA) requires a two-part
test: 1) the concentration of the radionuclides or collection of
radionuclides must exceed a certain level AND the total activity must
exceed a specified limit.  Lantern mantles do not qualify for either
test.  Thus, they are NOT RADIOACTIVE MATERIALS and need not be

Dan ii

On Wed, Jul 11, 2012 at 12:10 PM, Stewart Farber <SAFarber at optonline.net> wrote:
> Using "real" lantern mantles for a calibration is neat. I recall using two
> of the major peaks in the complex decay series of Th-232 and its daughters
> to do a two point energy calibration of a portable Ge detector I was using
> away from home.  Plus despite the prohibition of carrying "radioactive"
> materials on a plane I would think you won't end up in Guantanamo being
> mistaken for a terrorist by bringing a lantern mantle on-board, or trying to
> create a dirty bomb.
> However, the total gamma activity in a lantern mantle changes with time.
> After being made with fresh Th, the activity declines for the first 5 years
> or so, and then increases from 5 to 20 years before reaching equilibrium.
> See the following for some good general info on Thorium put together by
> ORAU's Paul Frame:
> http://www.orau.org/ptp/collection/consumer%20products/thoriumgeneralinfo.ht
> m
> I recall seeing a paper 30 years ago by a Professor from a small NYState
> college regarding determining the age of a lantern mantle based on the ratio
> of various isotopes present.
> But no matter what, a lantern mantle does make a great item to demonstrate
> aspects of natural radioactivity.  And if it is a "standard" real mantle, it
> should be do problem in counting contrary to what Chris Alston happened to
> see. Several Coleman mantles I have show 20,000 cpm or more with a standard
> pancake GM [ Ludlum 44-9 for example] on contact. If you don't see 15K cpm
> or more, you've been give a substandard Th mantle. Bear in mind that there
> are non-Th mantles on the market. However, the non-Th mantles are not as
> good, and a black market has sprung up among people who want to get their
> hands on the real stuff yielding max brightness so they don't walk into
> trees at night while camping,  on their way to the bathrooms.
> Perhaps you can file a complaint with your State AG Consumer Protection
> division that you've been victimized in purchasing a substandard Chinese
> product as a consumer and have NOT received the full amount of radioactivity
> you've paid for!! :-) And please, I'm kidding about being cheated of your
> radioactivity. It's been shown previously on this List that an attempt at
> humor is sometimes not recognized as being facetious.
> Stewart Farber, MSPH
> Farber Medical Solutions, LLC
> Bridgeport, CT 06604
> SAFarber at optonline.net
> 203-441-8433
> -----Original Message-----
> From: radsafe-bounces at health.phys.iit.edu
> [mailto:radsafe-bounces at health.phys.iit.edu] On Behalf Of John R Johnson
> Sent: Wednesday, July 11, 2012 12:30 PM
> To: The International Radiation Protection (Health Physics) Mailing List
> Subject: Re: [ RadSafe ] Texsport Item #14210 - Lantern Mantles
> Mike
> Mantle containing Th are useful because they can be used for calibrations.
> Just make sure that they are left in the package they were sold in.
> John
> On Wed, Jul 11, 2012 at 8:02 AM, Brennan, Mike (DOH) <
> Mike.Brennan at doh.wa.gov> wrote:
>> My take, only somewhat flip, is that you can't trust a Chinese product
>> contains what it is supposed to and only what it is supposed to, even
>> if what it is supposed to contain is something that would freak out
>> many environmentalists.
>> -----Original Message-----
>> From: radsafe-bounces at health.phys.iit.edu
>> [mailto:radsafe-bounces at health.phys.iit.edu] On Behalf Of Chris Alston
>> Sent: Tuesday, July 10, 2012 3:38 PM
>> To: The International Radiation Protection (Health Physics) Mailing
>> List
>> Subject: [ RadSafe ] Texsport Item #14210 - Lantern Mantles
>> Folks
>> The packets of these mantles, the which are Made in China, give as the
>> primary ingredients nitrates and hydroxides of Th.  Another
>> ingredient, for what it is worth, is cerium.  They are also labelled
>> with all sorts of cautionary messages in re proper handling, including
>> warnings that they emit radioactive materials, and that California
>> knows them to be carcinogenic.  I see no significant readings, i.e.,
>> there may be a slight excursion above background with a pancake GM at
>> contact, but certainly not the check-source-worthy output one would
>> expect.  Does anyone have a take on this?  It has occurred to me that
>> the packet may be intended for use with mantles from one supplier, but
>> was filled in the factory with mantles of the same spec from a
>> different supplier.
>> TIA and
>> Cheers
>> cja
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Dan ii

Dan W McCarn, Geologist
108 Sherwood Blvd
Los Alamos, NM 87544-3425
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HotGreenChile at gmail.com (Private email) HotGreenChile at gmail dot com

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