Feasibility Study of Technology for Pu Solution Monitoring including FP -Development of Gamma Spectra Detector for High Active Liquid Waste -

Year
2018
Author(s)
Hironobu Nakamura - Japan Atomic Energy Agency
Hirofumi Tomikawa - Japan Atomic Energy Agency
Megumi Sekine - Japan Atomic Energy Agency
Takuya Matsuki - Japan Atomic Energy Agency
Koichi Tsutagi - Japan Atomic Energy Agency
Hayate Tokoro - Japan Atomic Energy Agency
Abstract
In a reprocessing facility, it is necessary to develop a detector which can measure plutonium (Pu) content in the Pu solutions containing fission products (FP) in order to expand the application of Pu monitoring. In order to establish this technology, JAEA has studied a system measure gamma-rays was utilized since it applicable for Pu monitoring. Ce:GAGG (Ce:Gd3Al2Ga3O12) scintillator detector can measure a wide energy range in a high-dose environment and has reasonable resolution. Gamma-ray measurements were performed inside of the concrete cell containing the High Active Liquid Waste tank at the Tokai reprocessing plant. In the spectra, the two significant peaks were measured by the GAGG above 800 keV and were considered to be from Eu-154. There gamma-ray measurements will be combined with previous neutron measurements and both will be compared to MCNP models for future Pu monitoring technology. Future measurements will be made inside the concrete cell with modified detectors. This presentation will describe the detector selection, the design system, the results of gamma-ray spectral measurements and the applicability for Pu monitoring. This project has been carried out under the support of the Ministry of Education, Culture, Sports, Science and Technology (MEXT) of the Japanese government.