Gamma ray scanner systems for nondestructive assay of heterogeneous waste barrels Page: 11 of 16
16 p.View a full description of this article.
Extracted Text
The following text was automatically extracted from the image on this page using optical character recognition software:
system monitors density as well as activity distribution in each segment. The system gives a
warning in cases of conditions exceeding the capability of the SGS system, otherwise the
expected error will be higher than the threshold set in advance.
The second mode is a computed tomography imaging measurement. In the case of a
warning following an SGS measurement, another measurement in the tomo operational mode
should be made to provide the accuracy level needed. This mode can be invoked manually by
the operator or automatically. Depending on the accuracy required, the tomography
measurement mode usually needs a longer measurement time than the SGS mode. For waste
management purposes a factor of 1.5-2 is typical. For safeguards purposes it can be longer.
Generally, the total amount of radioactivity is needed and not the image. Sometimes
localization of hot spots is required in those case where removal of some activity would
characterize the barrel as a lower category of waste.
3.3 Summary of INT Efforts
Waste management and safeguards have different needs for the assay of 200-L barrels. Very
large errors can be introduced in measurements made by a standard SGS system. A modular
system developed by INT seems to be capable of making measurements that fulfill the
different waste assay and safeguards requirements. The cost factor should also be considered
when building a low-spatial resolution, low cost monitoring system attached to a standard
SGS system.
4. REFERENCES
[1] ROBERSON, G. PATRICK, et al., "Nondestructive Assay of TRU Waste Using
Gamma-ray Active and Passive Computed Tomography," Proceedings of the
Nondestructive Assay and Nondestructive Examination Waste Characterization
Conference, Salt Lake City, Utah, October 24-26, (1995) 73-84.
[2] BERNARDI, RICHARD T. AND MARTZ, JR., HARRY E., "Nuclear Waste Drum
Characterization with 2 MeV X-ray and Gamma-ray Tomography," Proceedings of the
SPIE's 1995 International Symposium on Optical Science, Engineering, and
Instrumentation, 2519 San Diego, CA, July 13-14, 1995.
[3] PRETTYMAN, T.H., et al., "A maximum-likelihood reconstruction algorithm for
tomographic gamma-ray nondestructive assay," Nucl. Inst. Meth. A356(1995)470-475.
[4] GOODMAN, DENNIS, "Maximum Likelihood Estimation with Poisson (Counting)
Statistics for Waste Drum Inspection," UCRL-ID-127361, Lawrence Livermore
National Laboratory, Livermore, Calif, May 1997.
[5] TRANSURANIC WASTE CHARACTERIZATION QUALITY ASSURANCE
PROGRAM PLAN, U.S. Department of Energy, Carlsbad Area Office, National TRU
Program Office, CAO-94-1010, Interim Change, November 15, 1996.
[6] PERFORMANCE DEMONSTRATION PROGRAM PLAN FOR
NONDESTRUCTIVE ASSAY FOR THE TRU WASTE CHARACTERIZATION
PROGRAM, U.S. Department of Energy, Carlsbad Area Office, National TRU
Program Office, CAO-94-1045, Revision 1, May 1997.9
Upcoming Pages
Here’s what’s next.
Search Inside
This article can be searched. Note: Results may vary based on the legibility of text within the document.
Tools / Downloads
Get a copy of this page or view the extracted text.
Citing and Sharing
Basic information for referencing this web page. We also provide extended guidance on usage rights, references, copying or embedding.
Reference the current page of this Article.
Martz, H. E.; Roberson, G. P.; Decman, D. J.; Camp, D. C. & Levai, F. Gamma ray scanner systems for nondestructive assay of heterogeneous waste barrels, article, August 1, 1997; California. (https://digital.library.unt.edu/ark:/67531/metadc693863/m1/11/: accessed July 17, 2024), University of North Texas Libraries, UNT Digital Library, https://digital.library.unt.edu; crediting UNT Libraries Government Documents Department.