[ RadSafe ] Best technique to detect DU in huge area!!!

Sat Nov 20 18:04:49 CST 2010

Dan

FYI, the FIDLER is an NaI detector with a 5" x 1mm crystal (5" PMT).  It does not see much but what is directly in front of it, and directly above it.  One would use it to look for the 63 and 93 keV emissions from Th-234, plus bremsstrahlung from the Pa betas, natch.

Cheers
cja

________________________________________
From: Rich, John [John.Rich at fpl.com]
Sent: Friday, November 19, 2010 5:11 PM
To: 'The International Radiation Protection (Health Physics) MailingList'
Cc: 'Abujarad'
Subject: Re: [ RadSafe ] Best technique to detect DU in huge area!!!

One last comment before the w'end.

Dan raised some excellent points.  Are these issues of detectability the same ones that are addressed in MARRSIM and MARLAP?  It would seem that the site release criteria could be applicable for setting "discovery" criteria.  I'm guessing that if something isn't present in quantities greater than natural background, then the site can be declared free of contamination (because if it can't be measured it can't be declared present).  Kind of a tautology, but it might work.

Have a good w'end everybody  - -jmr

-----Original Message-----
From: radsafe-bounces at health.phys.iit.edu [mailto:radsafe-bounces at health.phys.iit.edu] On Behalf Of Dan W McCarn
Sent: Friday, November 19, 2010 4:55 PM
To: 'The International Radiation Protection (Health Physics) MailingList'
Cc: 'Abujarad'
Subject: Re: [ RadSafe ] Best technique to detect DU in huge area!!!

Dear Dr. Abu-Jarad:

Area of Analysis

1) Speaking as a geologist, 10km X 30km is not that large an area for
exploration. I think that a with a radiation survey, it would be very
difficult to distinguish between natural background radiation and dispersed
DU except in areas of known battle damage (destroyed tanks, etc.)

2) Assuming that in the intervening 20 years, the dispersed uranium has
migrated vertically into the soil profile, masking any DU (1001 KeV gammas
from 234Pa), and making this material virtually indistinguishable from
natural uranium.

3) The naturally occurring mineralized uranium in the rocks and soils at the
surface should display not only the 234Pa signature, but also the 226Ra
daughters such as 214Bi (a number of emission lines), 40K and Th-series
gamma thus making gross-gamma measurements unrevealing.

4) Possibly a series of soil transects might be more revealing, with
vertically stratified soil samples, submitted for analysis by
high-resolution gamma and mass-spec instruments might be able to direct your
search. Perhaps 300-1000 locations might be selected and for each, a set of
stratified samples submitted for analysis. The locations could be optimized
for the wind patterns of the area, or perhaps the assumption of a downwind
"gauss plume" dispersion from known battle-damage locations.

5) Use of geostatistical techniques to interpret the resulting spatial data
(variography & kriging) might reveal structures in the data and locations
where follow-up sampling might be indicated.

6) A towed array of NaI crystals is certainly possible. They would be useful
for initially characterizing the background radiation, but I think that a
set of soil samples, because they can be analyzed more rigorously in a lab,
might be more effective in time and money.

Interferences:

1) It is doubtful that gross-gamma methods would reveal very much,
especially with so small a crystal (2x2inch NaI). Any elevated radiation
that you might find might also be (likely) attributable to the geology or
pedogenic processes (caliches, duracrusts, silcretes, etc.) that naturally
occur in an arid environment or the geometry of the measuring point with
respect to the surround topographic relief. Interference from K-U-Th series
is also likely.

2) The leaching of natural uranium may cause the U-234 fraction to increase,
masking any changes in 238U/234U ratios. Natural leaching tends to
selectively remove 234U from natural uranium minerals because it has been
dislodged in the crystal lattice during alpha decay of 238U to 234Th,
imparting about 100KeV of kinetic energy to the 234Th.

3) Sample geometry: measurements taken in a swale or crater will show
increased radiation because of the geometry of the measurement. Serious
mistakes have been made in the past with the assumption that the increased
radiation in a shell crater is the result of DU.  High-explosive mortar or
cannon fire (with no DU) will typically show increased radiation because of
the geometry of the measurement. A set of uniform soil samples analyzed in a
lab will eliminate this source of potential misinterpretation of a gamma
survey.

4) I suspect that the addition of aerosol DU, compared to the natural
uranium background, may cause significant difficulties in identification of
zones, beyond those already identified with battle damage, very difficult.

If I can be of any assistance, please do not hesitate to contact me.

Dan ii

--

Dan W McCarn, Geologist

108 Sherwood Blvd

Los Alamos, NM 87544-3425

+1-505-672-2014 (Home - New Mexico)

+1-505-670-8123 (Mobile - New Mexico)

HotGreenChile at gmail.com (Private email) HotGreenChile at gmail dot com

-----Original Message-----
From: radsafe-bounces at health.phys.iit.edu
[mailto:radsafe-bounces at health.phys.iit.edu] On Behalf Of Haleem, Mahmoud S.
Sent: Friday, November 19, 2010 11:15
To: The International Radiation Protection (Health Physics) Mailing List
Subject: Re: [ RadSafe ] Best technique to detect DU in huge area!!!

Dear Dr. Abu-jarad,

You should ask the DOD to clean it up since they caused it in the first
place.  I doubt it the Saudis have weapons with DU. Anyway, DOD have the
means and resources for such work.  If I was you I would seek their help and
guidance.  Best of luck.

Mahmoud Haleem

 \\-----Original Message-----

From: radsafe-bounces at health.phys.iit.edu
[mailto:radsafe-bounces at health.phys.iit.edu] On Behalf Of Abujarad

Sent: Friday, November 19, 2010 12:22 PM

To: radsafe at health.phys.iit.edu

Subject: [ RadSafe ] Best technique to detect DU in huge area!!!

Dear All

Your advice is greatly appreciated:

There is a potential to perform Radiation survey in huge area 10 km x 30 km

or more for possible contamination with DU as a result of Gulf war.

The area is desert, sandy and not uniform.

What is the best technique to perform that?

Is movable FIDLER (NaI 2inx2in) with GPS and data timing is the best?

Any advice about the cost (individually and array as example 6 with trailer)

Suitable manufacturer and contact. for complete system..

Best regards

Dr. Falah Abu-Jarad

Dr.fabujarad at gmail.com

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