Evaluation of nondestructive assay characterization methods for pipe-over-pack containers
- Canberra Instruments Inc., Meriden, CT (United States)
Nondestructive assay (NDA) measurements of Transuranic (TRU) waste at Los Alamos National Laboratory (LANL) packed in Pipe-Over-Pack Containers or POC's exhibit a number of complexities. The POC is highly attenuating to both gamma rays and neutrons which presents a difficult waste matrix for correct quantification of material in the container. Also, chemical and matrix properties of the Pu contaminated waste in the POCs that may affect the measurement result are generally unknown in advance of the measurement. Currently there are a number of POC containers at LANL that require evaluation for shipment to the Waste Isolation Pilot Plant (WIPP) in Carlsbad, NM. At LANL, a single instrument has been used to explore the appropriateness of both passive neutron and quantitative gamma ray methods for measuring POC's. The instrument, a High Efficiency Neutron Counter (HENC) with an integrated high purity germanium detector incorporates both passive neutron and high resolution gamma counting capabilities. The passive neutron approach uses the Reals coincidence count rate to establish plutonium mass and other parameters of interest for TRU waste. The quantitative gamma ray method assumes a homogeneous distribution of matrix and source material and assays the drum with a calibration based on the known density of the matrix. Both methods are supplemented by a simultaneous gamma isotopic measurement using Multi-Group Analysis (MGA) software to determine the plutonium isotopic composition. If MGA fails to provide a viable isotopic result Fixed energy Response function Analysis with Multiple efficiencies (FRAM) could be used to replace MGA results. Acceptable knowledge (AK) may also be used in certain instances. This report will discuss the two measurement methods in detail for POC analysis. Included in the discussion will be descriptions of the setup parameters and calibration techniques for the instrument. A number of test measurements have been performed to compare HENC data with certified safeguards data. Empty POCs loaded with known sources have also been measured to determine the viability of the technique. Finally, a brief discussion of the conclusions that can be drawn from the tests will be offered. (authors)
- Research Organization:
- WM Symposia, 1628 E. Southern Avenue, Suite 9 - 332, Tempe, AZ 85282 (United States)
- OSTI ID:
- 21290787
- Report Number(s):
- INIS-US-09-WM-07172; TRN: US10V0112038198
- Resource Relation:
- Conference: WM'07: 2007 Waste Management Symposium - Global Accomplishments in Environmental and Radioactive Waste Management: Education and Opportunity for the Next Generation of Waste Management Professionals, Tucson, AZ (United States), 25 Feb - 1 Mar 2007; Other Information: Country of input: France; 5 refs
- Country of Publication:
- United States
- Language:
- English
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