Re: NDA

[CHAPMANJA@oax.a1.ornl.gov]

In the interest of the RADSAFE community, here's a list of the technologies 
we're either developing/improving or are familiar with in regard to the Non 
Destructive Assay of radioactive waste:

1.  Passive gamma-ray spectroscopy.
2.  Segmented gamma-ray spectroscopy.
3.  Segmented gamma-ray spectroscopy with attenuation correction via the use 
of a Eu152 transmission source.
4.  Transmission computed tomography.
5.  Emission computed tomography.
6.  Analog real-time radiography.
7.  Digital real-time radiography.
8.  Differential Dieaway Time method for the characterization of fissile 
waste.  This method uses a pulsed 14-MeV (DT) generator to induce fissions in 
fissile nuclei and then detects the resulting fission neutrons.
9.  Neutron coincidence counting.
    {Recent upgrade to 8 and 9 includes neutron "imaging"}
10. Pulsed 14-MeV neutron interrogation coupled with prompt/delayed gamma-ray 
detection.
11. Cf252 interrogation coupled with time-integrated gamma-ray detection.


Our colleagues at LANL have developed improved methods for detecting fissile 
material:  nuetron multiplicity measurements and the Cf252 shuffler method---a 
Cf252 source is shuffled in and out of a chamber and the resulting delayed 
neutrons are measured.

There is an ASTM committee that has provided several standards for NDA and 
we're currently working on 4 new standards:  Californium Shuffler, 
Differential Dieaway Time Method, Holdup Measurements, and a Good Practices 
Guide to NDA.

Additionally, there is a DOE NDA/NDE Interface Working Group that provides a 
platform for NDA experts to discuss new developments in NDA/NDE.

If you have any questions please give me a call.

Jeff Chapman
Oak Ridge National Laboratory
615-574-5729
chapmanja@ornl.gov