Feasibility study of technology for Pu solution monitoring including FP; Design of GAGG detector and gamma spectrum measurement

Sekine, Megumi ; Matsuki, Takuya ; Tokoro, Hayate; Tsutagi, Koichi ; Tomikawa, Hirofumi; Nakamura, Hironobu 

In a reprocessing facility, it is necessary to develop a detector which is measurable plutonium (Pu) amount in the Pu solution containing the Fission Product (FP) in order to expand the application of Pu monitoring. To investigate rays which is applicable for Pu monitoring, Ce:GAGG (Ce: GdAlGaO) scintillator which can measure a wide range of energy at high dose and has high resolution (Target: High Active Liquid Waste (HALW)) was newly designed and developed in deal with aim for Pu quantitativeness. ray measurement was performed to the HALW in the concrete cell using the detector, and it was confirmed that high energy rays (9.5 MeV) could be measured and high energy rays spectra over 3 MeV without deriving from FP at the first time. In this presentation, detector design, results of ray spectra measurement, applicability evaluation to Pu monitoring and the future plan are presented. This project has been carried out under the support of the Ministry of Education, Culture, Sports, Science and Technology (MEXT) of the Japanese government.