Gamma and neutron detector performance in a MOX fuel fabrication plant environment

Effectively implementing safeguards in fuel reprocessing and fuel fabrication plants requires the extensive use of state-of-the-art instrumentation for accurate material characterization. The ability to rapidly and continuously determine the material balance in a large facility is essential to control and reduce the risk of diversion. Multiple detection technologies are implemented that provide the necessary Continuity of Knowledge (CoK) and inventory control required for effective safeguards. In a Pu/U-oxide (MOX) fuel processing facility, much of the detection technology is based on moderated
³
He neutron detectors. Recent concerns with respect to the possible lack of sufficient quantities of
³
He has resulted in the interest in developing alternative detection technologies for current and future needs and applications. To address this situation, we have begun a series of experiments at a MOX fuel fabrication facility to determine the performance and suitability of liquid scintillator neutron detectors. MOX fuel in the form of reactor fuel assembly fuel rods and large volume MOX powder containers typically found in such production facilities were measured. In addition, high-purity Germanium (HPGe) and cadmium zinc telluride (CZT) detectors will be included to determine their respective performance characteristics in a large and complex fuel production environment. The results of these experiments will be used for consideration in the development and deployment of new safeguards systems in large, complex facilities such as the Japan Mixed-Oxide Fuel Fabrication Facility (J-MOX) or the Rokkasho Reprocessing Plant (RRP). This paper will present and discuss the results of the first series of experiments, conducted at PPFF (Plutonium Fuel Development Center Plutonium Fuel Facility) of JAEA, as well as describe the next steps in this process.