RE: [ RadSafe ] Martin Tondel´s thesis - Sweden a nd Chernobyl

[Brennan, Mike (DOH)]

Thanks, Cindy.  Interesting information.  It does, if anything, make it seem MORE likely that any identification or U-236 in the environment is an error (intentional or not), as the concentrations are so small, and so much of the DU inventory remains at the facilities where it was produced.  

I have to admit to being suspicious of any time an activist claims to have found an unusual isotope, which is then blamed on whatever the activist is activating against at that moment.  I've seen activists claim to have found radioactive cadmium in sediment, and conclude it was from a Navy control rod that had been dropped in the water and left there.  He declined to change his mind even after it was pointed out to him that (a) the gamma energy he used to identify the radioactive cadmium is the same as that from one of the radon daughters, (b) the Navy would never either drop a control rod into the water or leave it there if it did get dropped and (c) Navy control rods don't contain cadmium.

I've seen an activist claim to have found a particular isotope based on one hit in an energy bin on his gamma spec in a 10 hour long count.

I've seen a lab used by activists tell a reporter they found plutonium when the results were about half of the LLD (and the lab that REALLY did the work said that it was not a positive result).

I realize that there are a lot of people out there who feel so strongly about the dangers of nuclear anything that they feel justified in speaking from a higher Truth, even if it is counter to the mundane truth.  But it doesn't enhance their credibility, as far as I am concerned. 

-----Original Message-----
From: radsafe-bounces at radlab.nl [mailto:radsafe-bounces at radlab.nl] On Behalf Of Cindy Bloom
Sent: Monday, June 11, 2007 6:21 PM
To: radsafe at radlab.nl
Subject: RE: [ RadSafe ] Martin Tondel´s thesis - Sweden a nd Chernobyl

Beginning in the 1950s, uranium used in enrichment plants was derived from irradiated uranium (aka recycled uranium), as well as from uranium ore.  The U-236 is a component of the irradiated uranium.  During U-235 enrichment of recycled uranium, some of the U-236 ends up in the enriched material, but some also remains in the depleted uranium.

The following is one of many references (you can do a search on recycled uranium or U-236) that mentions U-236 in recycled (and depleted) uranium.
http://www.wise-uranium.org/pdf/duinve.pdf

To this novice, a review of the decay scheme for U-236 indicates that U-236 might be challenging to detect by radiological methods in low levels in the presence of other uranium isotopes.  By mass, U-236 is likely to be a very small percentage of a depleted uranium source term.

At 05:05 PM 6/11/2007 -0700, Brennan, Mike  \(DOH\) wrote:
>How would the U-236 get into the DU?  DU is produced when U-235 is 
>concentrated.  Are you saying that the uranium from the reactor was 
>mixed with natural uranium, and then U-235 was concentrated to the 
>desired enrichment level?  Do you have any references on this?
>
>I think a more likely explanation for a lab finding U-236 in a sample 
>is that they don't know what they are doing, and misidentified 
>something.  I've seen that a number of times, particularly when 
>activists are involved.
>
>-----Original Message-----
>From: radsafe-bounces at radlab.nl [mailto:radsafe-bounces at radlab.nl] On 
>Behalf Of Michael McNaughton
>Sent: Monday, June 11, 2007 2:21 PM
>To: edmond0033; radsafe at radlab.nl
>Subject: Re: [ RadSafe ] Martin Tondel´s thesis - Sweden and Chernobyl
>
>At 07:14 PM 06/10/2007, edmond0033 wrote:
> >I have a question which has puzzled me of late.  There is a feeling 
> >that the DU contains Uranium-236
>
>Long ago, some enriched uranium was reprocessed. Enriched uranium that 
>has been in a reactor contains U-236, and during the re-enrichment some 
>of this
>U-236 ended up in DU.
>
>mike
>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/
>_______________________________________________
>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/

_______________________________________________
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/