Feasibility study of advanced measurement technology for solution monitoring at reprocessing plant; Dose rate measurement for the solution including Pu with FP

Matsuki, Takuya ; Yamanaka, Atsushi ; Sekine, Megumi ; Suzuki, Satoshi*; Yasuda, Takeshi; Tsutagi, Koichi ; Tomikawa, Hirofumi; Nakamura, Hironobu ; LaFleur, A. M.*; Browne, M. C.*

The Tokai Reprocessing Plant (TRP) has been developing a new detector from 2015 to 2017 for purpose to monitor Pu amount in High Active Liquid Waste (HALW) containing FP. It can make a contribution to an advanced approach to effectively and efficiently conduct safeguards for reprocessing facilities because it becomes available to monitor and verify nuclear material movement continuously by a new detector, which has proposed by IAEA. For the second step of this project, we conducted dose rate measurement on the guide rail installing in the cell storing the HALW tank and comparison between measured dose rate distribution and calculation result by MCNP simulation in order to investigate the dose rate distribution which is needed for shielding design of a new detector that is used for radiation (neutron/ spectrum) measurement in the cell and inquest on the monitoring position of the detector for Pu monitoring. In this paper, we report the result of the dose rate measurement in the cell, improvement of the simulation model which is cleared by comparison between measurement result and calculation result and our future plan.