Calibrating and training of neutron based NSA techniques with less SNM standards

Conference · Fri Jan 01 00:00:00 EST 2010

OSTI ID:1018692

Geist, William H ^[1]; Swinhoe, Martyn T ^[1]; Bracken, David S ^[1]; Freeman, Corey R ^[1]; Newell, Matthew R ^[1]

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1. Los Alamos National Laboratory

Accessing special nuclear material (SNM) standards for the calibration of and training on nondestructive assay (NDA) instruments has become increasingly difficult in light of enhanced safeguards and security regulations. Limited or nonexistent access to SNM has affected neutron based NDA techniques more than gamma ray techniques because the effects of multiplication require a range of masses to accurately measure the detector response. Neutron based NDA techniques can also be greatly affected by the matrix and impurity characteristics of the item. The safeguards community has been developing techniques for calibrating instrumentation and training personnel with dwindling numbers of SNM standards. Monte Carlo methods have become increasingly important for design and calibration of instrumentation. Monte Carlo techniques have the ability to accurately predict the detector response for passive techniques. The Monte Carlo results are usually benchmarked to neutron source measurements such as californium. For active techniques, the modeling becomes more difficult because of the interaction of the interrogation source with the detector and nuclear material; and the results cannot be simply benchmarked with neutron sources. A Monte Carlo calculated calibration curve for a training course in Indonesia of material test reactor (MTR) fuel elements assayed with an active well coincidence counter (AWCC) will be presented as an example. Performing training activities with reduced amounts of nuclear material makes it difficult to demonstrate how the multiplication and matrix properties of the item affects the detector response and limits the knowledge that can be obtained with hands-on training. A neutron pulse simulator (NPS) has been developed that can produce a pulse stream representative of a real pulse stream output from a detector measuring SNM. The NPS has been used by the International Atomic Energy Agency (IAEA) for detector testing and training applications at the Agency due to the lack of appropriate SNM standards. This paper will address the effect of reduced access to SNM for calibration and training of neutron NDA applications along with the advantages and disadvantages of some solutions that do not use standards, such as the Monte Carlo techniques and the NPS.

• Research Organization: Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC52-06NA25396
• OSTI ID: 1018692
• Report Number(s): LA-UR-10-03922; LA-UR-10-3922; TRN: US1103438
• Resource Relation: Conference: Institute of Nuclear Materials Management 51st Annual Meeting ; July 11, 2010 ; Baltimore, MD
• Country of Publication: United States
• Language: English

Related Subjects

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
98 NUCLEAR DISARMAMENT, SAFEGUARDS, AND PHYSICAL PROTECTION
CALIBRATION
CALIFORNIUM
DESIGN
FUEL ELEMENTS
IAEA
INDONESIA
MONTE CARLO METHOD
NEUTRON SOURCES
NEUTRONS
NUCLEAR MATERIALS MANAGEMENT
PERSONNEL
REGULATIONS
SAFEGUARDS
SECURITY
SIMULATION
SIMULATORS
TEST REACTORS
TESTING
TRAINING