Re: neutron radiography

[jgbarnes@ix.netcom.com (JAMES BARNES)]

A question:

Are you looking for a portable unit that you can take to the pipe, or a 
free standing unit that you can take the pipe to.

If the latter, an industrial CAT scanner would be able to see pieces of 
wood without too much trouble (we have seen KimWipes in 55 gallon waste 
drums with ours).  Unfortunately, they are not very portable, thus could not be 
used in the field.

As an offshoot of this, you might try taking X-rays of the line using different 
kVp settings, and then comparing the films one to another.  You'll probably need 
something in the range of 320 Kv to get through the line; this may not be 
available in a portable unit.

We used to operate a neutron radiography system here at Rockwell.  Unfortunately, 
the two gents who are the guru's on it are not here today.  I checked with 
several other old-timers, and they said that to their recollection, all the 
radiographs they saw were of low-Z materials.  So trying to see through the pipe 
wall with any degree of resolution may be very tricky.  Additionally, one has the 
consideration of activation, scatter, etc.

I will check around with these gents when they return to work.  If any additional 
info turns up, I'll post it to RadSafe.

Jim Barnes, CHP
Rockwell Aerospace/Rocketdyne Division
Radiation Safety Officer
---------------------
You wrote: 
>
>Dear RADSAFERS:
>
>Please consider the following as a matter of urgency.
>The thing I'm looking for is rather speculative.  
>I was thinking about gathering infos, ideas, or tips 
>on various methods (need not to be based directly on 
>ionizing radiation principles). 
>
>Question:  ..???
>
>I would like to detect/localize pieces of wooden material inside of an 
iron 
>pipes/tubes filled with heavy water.
>
>Pipe/tubes with inner diameter is 1.75" - 2.00".
>Wall thickness approximatelly  0.25".
>
>One of my ideas would be something in lines of
>"neutron radiography" to take advantage of different neutron
>scattering/absorption on deuterium in the D2O versus 
>on hydrogen in the wood.
>
>The method should be simple to use in a complex industrial 
>environment with limited access to the area around the pipes,
>considerable hazards of ambient gamma fields and/or contamination and 
>the main trick, I guess, would be to have the application available 
almost
>immediately.
>The method should yield in results with good resolution confirm the 
location
>and 
>the size of the wooden piece.
>
>If there is any feasible way, or hopefully, a service for 
>this task, or should anyone have anything to add on how
>to deal with this, please e-mail me.
>Thank you in advance.
>Miroslav Lieskovsky
>
>e-mail: 
>mirolies@nbnet.nb.ca
>
>or
>
>miroslav@mi.net
>
>
>     Miroslav
>
>PS. Standard disclaimers apply.
>-----------------------------------------------------------------------
----
>If I had an opinion, it sure wouldn't be mine... or my employer's!
>Nazory nemusia v ziadnom pripade vyjadrovat postoj mojho 
zamestnavatela, 
>ba niekedy ani moje vlastne.
>-----------------------------------------------------------------------
----
>Miroslav Lieskovsky                               Health Physics 
Department
>mirolies@nbnet.nb.ca                       Point Lepreau Generating 
Station
>Phone  bus: (506) 659 2220 ext. 7421                    New Brunswick 
Power
>Fax    bus: (506) 659 2003                             P.O. Box 10, 
Hwy 790
>Phone  res: (506) 636 7629                                    Lepreau, 
N.B.
>e-mail res: miroslav@mi.net                                 Canada, 
E0G 2H0
>
>