DEVELOPMENT OF IMPROVED HOLD-UP MEASUREMENT SYSTEM AT PLUTONIUMU FUEL PRODUCTION FACILITY

Year
1997
Author(s)
Tracy R. Wenz - Los Alamos National Laboratory
Howard Menlove - Los Alamos National Laboratory
H. Kobayashi - Power Reactor and Nuclear Fuel Development Corporation
Takashi Asano - Power Reactor and Nuclear Fuel Dev. Corp.
H. Maruyama - Power Reactor and Nuclear Fuel Dev. Corp.
J. Ninagawa - Power Reactor and Nuclear Fuel Dev. Corp.
Abstract
GBAS (Glove Box Assay System), which is a neutron coincidence counting system, was developed under the agreement between PNC and DOE(LANL) in order to measure plutonium hold-up in the glove box at the Plutonium Fuel Production Facility(PFPF) in Japan. This system was introduced in May 1990 and afterwards it was used for material accountancy by operator and verification by inspectorate during inspection. However, in conjunction with the increase of the amount of hold-up, an improvement in measurement accuracy was needed to achieve accurate material accountancy. An improved GBAS called Super GBAS (SBAS) was developed under the agreement between PNC and DOE(LANL). The target in this development was to improve measurement accuracy to better than 10%. SBAS was designed to improve measurement error caused by influence of the distribution of hold-up in the glove box and the influence of neutron from neighbor glove boxes. This system was introduced to PFPF in June 1996. And then, the performance tests and the calibrations were carried out. As a result of these tests, the initial target of the measurement accuracy was achieved and this system was recognized as the inspection equipment by JNSB and IAEA. The improvement points of SBAS and the results of the performance tests are described in this paper.