[1J09-12] Corrosion, Electrochemistry, Radiolysis 2

[1J10] Measures against deterioration of ion exchange resin in decommissioning chemical decontamination

*Hideyuki Hosokawa¹, Kazushige Ishida¹, Tsuyoshi Ito², Ohira Takashi², Shintaro Yanagisawa² (1. Hitachi, Ltd. Research & Development Group, 2. Hitachi-GE Nuclear Energy, Ltd)

Keywords:Decommissioning chemical decontamination, Radiolysis, Hydrogen peroxide, Ion exchange resin, Oxidative decomposition

In the chemical decontamination of the reactor pressure vessel in the decommissioning process of a boiling water reactor (BWR), the decontamination solution comes into contact with the activated structural material. Hydrogen peroxide is produced by the radiolysis of water by gamma rays from the activated material. When the generated hydrogen peroxide circulates in the decontamination system and reaches the ion exchange resin, the resin is oxidatively decomposed and the decomposition component of the polymer containing the sulfate group flows out into the decontamination solution. Therefore, in order to prevent oxidative decomposition of the ion exchange resin, the water quality conditions that suppress the residual hydrogen peroxide were examined.