Development and Demonstration of a Pu NDA System using ZnS/10B2O3 Ceramic Scintillator Detectors

Year
2014
Author(s)
Kazuhiko Soyama - J-PARC Center
Akira Ohzu - Nuclear Science and Engineering Directorate
Tatsuya Nakamura - J-PARC Center
Kaoru Sakasai - J-PARC Center
Hironobu Nakamura - Tokai Reprocessing Development Center
M. Seya - Integrated Support Center for Nuclear Nonproliferation and Nuclear Security, Japan Atomic Energy Agency
Tsutomu Kurita - Reprocessing Technology Development Center, Japan Atomic Energy Agency
Nozomi Kobayashi - Nuclear Science and Engineering Directorate
Abstract
To establish an alternative technique of He-3 neutron detector that is used for nuclear material accountancy and safeguards, we have started an R&D project to develop a new type of neutron detector (Pu NDA system) using ZnS/10B2O3 ceramic scintillator with support of Japanese government. The design of the alternative system (ASAS: Alternative Sample Assay System) refers basically to the INVS (INVentory Sample assay system) which is passive neutron assay system of plutonium and capable of measuring the small amount of Pu in the MOX powder or Pu nitrate solution in a vial with total 18 He-3 tubes (about 42% of counting efficiency). In order to certify the technology and performance after the fabrication of the new detector progresses, we are planning to conduct demonstration activity in the early 2015 experimentally. The demonstration activity implements the confirmation of reproducibility about sample positioning, optimization of detector parameters, counting statistical uncertainty, stability (temperature and gamma-ray change) check and figure of merit (FOM) using check source and actual MOX powder. In addition, performance comparison between the current INVS and the ASAS is also planned In this paper, we present some analytical study results using Monte-Carlo simulation code (MCNP), entire ASAS design and demonstration plan to prove technology and performance.