AW: [ RadSafe ] Feds puzzled by gamma radiation higher thannormalnear wildfire -Cs-137, K-40 data

Tue Jul 17 09:52:01 CDT 2007

Stewart, Dan, Mike and others,

You might be interested that there has been research done in the province of
Upper Austria about 10 years ago on that (and related) topics to check the
influence of the Chernobyl accident on the Cs-137 concentrations. Result: No
concern. There has been research in Sweden on the Cs-137 concentration in
wood and in materials from various stages in the pulp and paper industry.
Other investigations were carried out on wood exported from Eastern European
Countries. In Finland there was shortly after the Chernobyl accident a
discussion about Cs-137 in peat, because in some areas peat is used for
electricity generation. 

I could try to find some papers, but I will fly tomorrow to Estonia and also
visit my friends in Finland, so I will be back only after about three weeks!

I did not really follow this thread tightly, maybe I missed something: The
first thing I would do in this case, would be to put samples on top of a
HPGe-detector and determine the nature and the concentration of the
radionuclides. I cannot believe that no such detectors would be available in
a country which spends billions of $$$ on homeland security and now even
wants to encircle New York with radiation detectors!

Best regards,

Franz

Franz Schoenhofer, PhD
MinRat i.R.
Habicherg. 31/7
A-1160 Wien/Vienna
AUSTRIA

-----Ursprüngliche Nachricht-----
Von: radsafe-bounces at radlab.nl [mailto:radsafe-bounces at radlab.nl] Im Auftrag
von stewart farber
Gesendet: Dienstag, 17. Juli 2007 16:25
An: Dan McCarn; Michael McNaughton; Emer,Dudley
Cc: radsafe at radlab.nl
Betreff: Re: [ RadSafe ] Feds puzzled by gamma radiation higher
thannormalnear wildfire -Cs-137, K-40 data

Hi all,

I've mentioned aspects of the woodash survey I conducted back in the  1990s 
on radsafe before. Based on actual measurements, from this survey of Cs-137 
in woodash, the typical K-40 content of woodash is about 120,000 picoCuries 
per kg of ash.  Woodash is 10 to 15% potassium by weight --thus it's use as 
a feedstock to the early US potash industry in colonial times.

Ash samples from burning mature hardwoods in the East in my survey had 
Cs-137 as high as 20,000 [in many parts of New England] to 25,000 picoCuries

kg of ash [in oak ash from FL].

At these latter levels, the  Cs-137 peak dwarfed the K-40 peak due to gamma 
abundance in K-40 being relatively low vs. Cs-137 and Cs-137 efficiency in 
gamma counting being much higher than K-40. Thus total counts from Cs-137 at

say 20,000 pCi/kg ash showed a peak on a gamma spec that was much, much 
higher than that from K-40 at 120,000 pCi/kg ash. Every other peak in the U 
and Th decay series in woodash faded to the baseline vs. the K-40 and Cs-137

peak heights.

I received  data in this survey on Cs-137 in wood ash from Idaho which was 
about 1,000 pCi/kg in pine ash. Wood ash samples from trees in CA showed 
Cs-137 at only about 300 pCi/kg ash. Cs-137 content in woodash varies by 
factors of up to 100 despite relatively even Cs-137 areal deposition from 
airborne nuclear bomb testing, due to soil factors:  stable Cs in soil 
[higher stable Cs leads to higher Cs-137 in biomass per unit deposition], 
stable potassium levels in soil [inverse relationship  --more stable K, 
lower Cs-137 per unit deposition], and more.

A wild fire can throw up  2 to 3% or more of the mass of biomass burned as 
airborne ash particulates which might contribute to elevated activity 
measured on filters due to K-40 and Cs-137 [residual from generalized 
weapon's test fallout].

Stewart Farber, MS Public Health
Consulting Scientist
Farber Technical Services
1285 Wood Ave.
Bridgeport, CT 06604
[203] 441-8433 [office]
[203] 522-2817 [cell]
email: radproject at sbcglobal.net

==========================

----- Original Message ----- 
From: "Dan McCarn" <hotgreenchile at gmail.com>
To: "Michael McNaughton" <mcnaught at lanl.gov>; "Emer,Dudley" 
<EMERDF at nv.doe.gov>; <HotGreenChile at gmail.com>
Cc: <radsafe at radlab.nl>
Sent: Monday, July 16, 2007 3:13 PM
Subject: Re: [ RadSafe ] Feds puzzled by gamma radiation higher than 
normalnear wildfire

Hi Michael:

As you probably already know, Bi-214 is the most significant gamma
emitter of the Ra-226 daughters (dominantly the 609 KeV gamma photopeak),
but the early part of the chain has quite short half-lives.  Perhaps the
"gamma" detectors *during* the fire were seeing the gamma from the Bi-214
which decayed to the three radionuclides - Pb-210, Bi-210, and Po-210.

If the 'ingrowth" chain is broken during the fire, then perhaps the only
R/Ns to survive on an air filter would begin with Pb-210 and the ingrowth
daughters Bi-210 and Po-210.  After only a few hours (4.46 hours), the
Pb-214 would have decayed (10 half lifes) to 1/1024 of the original value
and may be undetectable along with the Bi-214.

Another gamma emitter that would certainly be lofted during the fire would
be K-40, which accumulates in soils and wood as a macronutrient in plants.
SInce the soils "burn" in forest fires as well as the trees (similar caloric
value), the K-40 could easily be lofted with the ash from the forest floor.
The name "potash" comes from the use of wood ash from the firepalace as a
fertilizer, since it is significantly enriched in potassium.

Rn-222 3.8235 d
Po-218 164.3 µS
Pb-214 26.8 m
Bi-214 19.9 m
Po-214 164.3 µS
Pb-210 22.20 y
Bi-210 5.012 d
Po-210 138.376 d

Best regards!

Dan ii

Dan W McCarn, Geologist
Houston & Albuquerque

On 7/16/07, Michael McNaughton <mcnaught at lanl.gov> wrote:
>
> Following the Cerro-Grande fire at Los Alamos, I and my colleagues
> investigated the increased airborne radiation measured during the fire.
> Almost all the increased radioactivity we detected is from the long-lived
> radon decay product, lead-210, and its progeny: bismuth-210 and
> polonium-210. However, I am puzzled by the word "gamma" that appears
> several times in the article below. Pb-210, Bi-210, and Po-210 emit few
> gammas, mostly of low energy. Does anyone on this list have more
> information?
>
> mike
>
> At 01:35 PM 07/13/2007, Sandy Perle wrote:
> >Feds puzzled by gamma radiation higher than normal near wildfire
> >
> >The Salt Lake Tribune, Jul 13 -  A puzzle has sprung from the flames
> >of the Milford Flat Fire: What's pumping radiation into the air? The
> >National Nuclear Security Administration said Thursday its radiation
> >monitors in the area are showing gamma radiation spikes seven times
> >higher than the normal background. But before anyone runs to the
> >doctor, it's worth pointing out that even those spikes, if someone
> >breathed them for seven hours straight, produce less than one-2,000th
> >of the radiation dose a Utahn normally gets in a year. "You're
> >talking about a very small dose," said NNSA spokesman Darwin Morgan.
> >The agency, which had proposed a massive, non-nuclear explosion
> >experiment at the Nevada Test Site last year, monitors the air for
> >radiation at 29 monitoring stations in Utah, California and Nevada.
> >The agency canceled the so-called Divine Strake test after hearing
> >from thousands of Utahns who complained that the explosion would send
> >radiation-tainted debris into their air and onto their landscape. "We
> >heard loud and clear from the people of Utah they are concerned about
> >radiation," said Morgan, explaining his agency's reasons for
> >publicizing the radiation-meter findings. Morgan said filters from
> >the Milford monitoring station are being analyzed at a laboratory.
> >The agency thinks that naturally occurring radon is being released
> >from the ground, but only study of the material captured on the air
> >filters will tell them for sure. Dane Finerfrock, director of the
> >Utah Division of Radiation Control, said the fact that radiation is
> >released during combustion is no secret. "There's a radioactivity in
> >that forest and brush," he said, "and some of it stays in the ash and
> >some of it goes into the atmosphere." Morgan said there is no data
> >about the radiation from the Neola North Fire in eastern Utah. The
> >agency does not have monitors in that part of the state.
> >----------------------
>
> Mike McNaughton
> Los Alamos National Lab.
> email: mcnaught at LANL.gov or mcnaughton at LANL.gov
> phone: 505-667-6130; page: 505-664-7733
>
>
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-- 
Dan W McCarn
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