公开(公告)号：US20240071640A1

公开(公告)日：2024-02-29

申请号：US18269305

申请日：2021-10-29

申请人： Hitachi-GE Nuclear Energy, Ltd.

发明人： Tsuyoshi ITOU ,  Kazushige ISHIDA ,  Hideyuki HOSOKAWA ,  Shintaro YANAGISAWA ,  Takashi OOHIRA

IPC分类号： G21F9/00

CPC分类号： G21F9/002

摘要： Provided is a chemical decontamination method that shortens the decomposition time of a reduction decontamination agent. An oxidization decontamination, a decomposition of an oxidization decontamination agent, and reduction decontamination using an oxalic acid aqueous solution are performed on a target piping of a BWR plant. After that, the oxalic acid is decomposed (S7). That is, a part of the oxalic acid is decomposed by irradiating the oxalic acid aqueous solution with ultraviolet rays upstream of a decomposition device (S8), and Fe3+ in the aqueous solution is converted to Fe2+. Hydrogen peroxide is supplied to the decomposition device (S9). In the decomposition device, the oxalic acid is decomposed by a catalyst and hydrogen peroxide, Fe2+ and hydrogen peroxide react to produce Fe3+ and OH*, and the oxalic acid is decomposed by OH*. A corrosion potential of the aqueous solution flowing out from the decomposition device is measured (S11). A concentration ratio calculation device obtains Fe3+/Fe2+ (concentration ratio) based on the corrosion potential (S12), and A control device controls the supply amount of hydrogen peroxide to the decomposition device based on Fe3+/Fe2+ (S14 and S16).).

公开(公告)号：US20210296019A1

公开(公告)日：2021-09-23

申请号：US17197437

申请日：2021-03-10

申请人： Hitachi-GE Nuclear Energy, Ltd.

发明人： Takashi OOHIRA ,  Satoshi OOUCHI ,  Motohiro AIZAWA ,  Nobuyuki OTA ,  Hideyuki HOSOKAWA ,  Ryo HAMADA ,  Hiroo YOSHIKAWA ,  Naobumi TSUBOKAWA ,  Masahiko KAZAMA

IPC分类号： G21F9/00 ,  G21F9/12 ,  B01D15/12 ,  B01D15/36 ,  B01J39/24

摘要： Provided are a chemical decontamination method and a chemical decontamination apparatus capable of preventing deterioration of a metal ion exchange resin and performing decontamination at a low cost in a short time.
The chemical decontamination method of the invention includes: a reduction decontamination step of supplying a reduction decontamination solution to a decontamination target portion and performing reduction decontamination on a surface of a member constituting the decontamination target portion; a hydrogen peroxide decomposition step of decomposing hydrogen peroxide contained in the reduction decontamination solution after the reduction decontamination step; and a metal ion removing step of removing a metal ion contained in the reduction decontamination solution after the hydrogen peroxide decomposition step.