[ RadSafe ] Radon Travel in Granite

Kai Kaletsch eic at shaw.ca
Thu Jul 31 10:48:51 CDT 2008


Hi Don (you are pronouncing it right),

The problem with the junkscience article is that it makes it sound like 
elevated radiation levels can only be fount at the Capitol. Around here, 90% 
of all commercial buildings are made with brown brick, which approximately 
doubles the background radiation level. Ironically, all the meetings where 
the antis are condemning the dangers of increasing BG radiation by 
0.00...001% are held in these buildings.

On the positive side, my kids can find their way to school, even in a good 
Saskatchewan blizzard, by using a Geiger counter.

Regards,
Kai

----- Original Message ----- 
From: <dckosloff at firstenergycorp.com>
To: "Kai Kaletsch" <eic at shaw.ca>
Cc: <radsafe at radlab.nl>; <radsafe-bounces at radlab.nl>; "al gerhart" 
<webmaster at solidsurfacealliance.org>
Sent: Thursday, July 31, 2008 6:50 AM
Subject: Re: [ RadSafe ] Radon Travel in Granite


> Hi Kai ( I like the sound of that, but I am probably pronouncing it 
> wrong),
> Al and all,
>
> This seems to be related to any discussion of the radioactivity from
> granite:
> http://www.junkscience.com/apr01/crstudy.htm
>
> "Radiation Sources at the U.S. Capitol and Library of Congress Buildings"
>
> Unfortunately, I don't have any granite counter tops.  How about marble
> window ledges?
>
> Enjoy,
> Don Kosloff, License Renewalist
> 6310 N. Harris Harbor Drive
> Oak Harbor OH 43449
>
>
>
>
>
>             "Kai Kaletsch"
>             <eic at shaw.ca>
>             Sent by:                                                   To
>             radsafe-bounces at r         "al gerhart"
>             adlab.nl                  <webmaster at solidsurfacealliance.org
>                                       >, <radsafe at radlab.nl>
>                                                                        cc
>             07/30/2008 09:51
>             PM                                                    Subject
>                                       Re: [ RadSafe ] Radon Travel in
>                                       Granite
>
>
>
>
>
>
>
>
>
>
> Hi Al and all,
>
> Aside from any incremental increase in radon or gamma exposure (which I
> don't tend to get too excited about), 0.25% U ore would NOT be my first
> choice of food preparation surface. If those numbers are correct, then it
> is
> important that a sample of the same material be made available for testing
> by the other stake holders in this (by now somewhat politicized) issue.
>
> 0.25% U is quite high and, at least in Canada, there are several
> regulations
> dealing with radioactive materials that kick in at much lower levels. For
> example, 0.05% U (5 times lower than your rock) is considered 'source
> material' and is a 'controlled nuclear substance' (even if it is contained
> in a granite countertop) and a license is required to export the material
> from Canada. So, if your slab of granite came from Canada, and the 
> exporter
>
> didn't approach our nuclear regulator to get a license ... You can see our
> Nuclear Non-proliferation Import and Export Control Regulations here:
> http://laws.justice.gc.ca/en/n-28.3/sor-2000-210/153934.html?noCookie
>
> Before, you asked if there is a quick and dirty way of getting from cpm or
> mR/Hr to ppm. You can get in the right ballpark if you take readings on a
> bunch of  normal granite, average the readings, assume that corresponds to
> Dan's value of ~ 10 ppm and scale the result of your sample.
>
> You can also calculate a dose rate for a given geometry as a function of
> uranium content. I have a program on my website that does this (see
> http://members.shaw.ca/eic/Tools/JavaShield/Index.html , read the
> documentation and use the rectangular source geometry). If you are using a
> pancake probe, these are not energy compensated and your reading will be
> off
> by a bit. More importantly, make sure you put ~ 1 mm sheet of aluminum (or
> similar) between the source and the pancake. Otherwise, your detector will
> see alpha and beta radiation and your mR/Hr reading will be meaningless
> (you
> want to see gamma). That is probably how you got your 10.5 mR/Hr reading,
> which is too high, even for 0.25%U.
>
> Regards,
> Kai
>
> Kai Kaletsch
> Environmental Instruments Canada Inc
>
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