[ RadSafe ] Gamma measurements in planes

Aad van der Kooij A.vanderKooij at TUDelft.nl
Mon Dec 18 14:11:02 CST 2006

>From the way this discussion is evolving I get the impression that my
previous post about DU use in commercial aircraft has been lost in
cyberspace. But yes, there are still DU counterweights around, mainly in
aging aircraft. I remember vivid discussions about this subject a couple of
years ago, when it would be perfectly legal to fly around in a 747 (with a
couple of hundreds kilograms of DU in the structure) that became a licensing
problem the moment it was retired to the desert wreckers yard. The use was
not limited to the 747 other types are DC-10, L-1010, C-140 and there are
also examples of the use of DU in helicopter rotor counterweights.
I think the US license exemption is still in existence as long as you keep
the DU counterweights in good condition (i.e. no corrosion, other damage and
It might be for that reason that FAA advisory circular 20-123:
is still valid.

Further information about the use of DU in aircraft can be found in NUREG
1717 (3.17) !!!!warning this is a large document, some 800 pages!!!:

Aad van der Kooij
Ass.RPO TU Delft

-----Original Message-----
From: radsafe-bounces at radlab.nl [mailto:radsafe-bounces at radlab.nl] On Behalf
Of Otto Raabe
Sent: Monday, 18 December 2006 18:33
To: Ellars, Charles; Olsson Mattias :MSO; radsafe at radlab.nl
Subject: RE: [ RadSafe ] Gamma measurements in planes

At 07:24 AM 12/18/2006, Ellars, Charles wrote:
>On a recent trip to FL from Boston, my RadEyeG measured 0.01 mr/hr on
>the ground and 0.40 mr/hr at 35Kft during the day.  On the return flight
>the next night it measured 0.01 on the ground and 0.30 mr/hr.
December 18, 2006

I presume that the "on the ground" measurements were from inside the plane 
so that any radioactive sources on the plane would be accounted.

Does anyone know for sure whether commercial airliners have stopped using 
depleted uranium for ballast?


Prof. Otto G. Raabe, Ph.D., CHP
Center for Health & the Environment
University of California
One Shields Avenue
Davis, CA 95616
E-Mail: ograabe at ucdavis.edu
Phone: (530) 752-7754   FAX: (530) 758-6140
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