First Tests of a Portable Plutonium Mass Verification System

Conference · Wed Aug 01 04:00:00 EDT 2001

OSTI ID:15005293

Swanson, J; Buckley, B; Kreek, S; Wang, T F

Special Nuclear Material (SNM) accounting at some DOE facilities requires removal of samples from storage, transport to a counting facility, removal of the sample from its storage container, counting, repackaging, and transport back to the storage facility until selected in the next physical inventory. This procedure requires personnel time, radiation exposure, and increases the potential for diversion. If a verification can be performed within the storage vault or bunker and not require removal of the SNM from the container, personnel time and radiation exposure could be reduced, the sample would not have to leave the security of the storage vault, and costs for performing inventories could be reduced. Lawrence Livermore National Laboratory (LLNL) is developing an instrument, based on established coincidence counting techniques, to yield a semi-portable Pu mass verification solution to the problem of in-vault verification. Commercially available instrumentation is being tested that will enable in-situ verification of Pu masses in sealed containers. The detector assembly includes both neutron and gamma detectors. The device will operate on battery power, and will be mounted on a cart for portability. For mass verification of plutonium, two types of signal are analyzed. A gamma spectrum is analyzed for isotopic ratios using LLNL's MGAHI code. Neutron count rates and coincidence rates are measured to quantify the spontaneous fission rate within the Pu. Corrections for neutron scattering, alpha-neutron reaction sources, and induced fission rate must be made to establish the necessary accuracy for this analysis. The system is intended to be easy to set-up and operate.

• Research Organization: Lawrence Livermore National Lab., CA (US)
• Sponsoring Organization: US Department of Energy (US)
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 15005293
• Report Number(s): UCRL-JC-143824
• 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
CONTAINERS
COUNTING TECHNIQUES
GAMMA DETECTION
NEUTRON DETECTORS
NUCLEAR MATERIALS MANAGEMENT
PLUTONIUM
PORTABLE EQUIPMENT
RADIATION DETECTORS