[ RadSafe ] Feds puzzled by gamma radiation higher than normal near wildfire

[Emer, Dudley]

The data were taken from the Community Environmental Monitoring Program
(CEMP) stations http://www.cemp.dri.edu/cemp/ which are deployed around
the Nevada Test Site and measure met data as well as gamma radiation
(using a PIC). These stations take weekly air samples as well. 
 
Go to the DOE CEMP web site and lookup the gamma and met data for the
period July 5 - July 15, 2007.
http://www.cemp.dri.edu/cgi-bin/cemp_stations.pl?prod=7&stn=milu

They will calibrate the gamma detector once a month and you will see a
spike during those cals but these events have been persistent over the
period July 5 - 15.  Note the level shift on July 15 jumping from 20 to
17uR/hr which may indicate an equipment problem.  The barometric
pressure and winds have been steady and calm and none of the surrounding
stations show these spikes so I don't think its local atmospheric
pumping.  The gamma spikes don't seem to correlate with wind direction
although in talking with DRI they said the mass loadings on the air
filter is approximately double the normal load indicating the filtered
particulates may be smoke derived. 

DRI/UNLV is running the air samples now and should have some gamma spec
data later today or tomorrow which will tell the tale.  
  
Dudley Emer
Geophysicist
National Security Technologies
702-295-7808 office
702-794-5824 pager
702-521-8577 cell


-----Original Message-----
From: radsafe-bounces at radlab.nl [mailto:radsafe-bounces at radlab.nl] On
Behalf Of Michael McNaughton
Sent: Monday, July 16, 2007 8:12 AM
To: Sandy Perle; radsafe at radlab.nl; powernet at hps1.org
Subject: [ RadSafe ] Feds puzzled by gamma radiation higher than normal
near wildfire

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


_______________________________________________
You are currently subscribed to the RadSafe mailing list

Before posting a message to RadSafe be sure to have read and understood
the RadSafe rules. These can be found at:
http://radlab.nl/radsafe/radsaferules.html

For information on how to subscribe or unsubscribe and other settings
visit: http://radlab.nl/radsafe/