US 12,283,386 B2
Chemical decontamination method and chemical decontamination apparatus
Takashi Oohira, Hitachi (JP); Satoshi Oouchi, Hitachi (JP); Motohiro Aizawa, Hitachi (JP); Nobuyuki Ota, Hitachi (JP); Hideyuki Hosokawa, Tokyo (JP); Ryo Hamada, Tokyo (JP); Hiroo Yoshikawa, Osaka (JP); Naobumi Tsubokawa, Osaka (JP); and Masahiko Kazama, Osaka (JP)
Assigned to Hitachi-GE Nuclear Energy, Ltd., Hitachi (JP)
Filed by Hitachi-GE Nuclear Energy, Ltd., Hitachi (JP)
Filed on Mar. 10, 2021, as Appl. No. 17/197,437.
Claims priority of application No. 2020-046084 (JP), filed on Mar. 17, 2020.
Prior Publication US 2021/0296019 A1, Sep. 23, 2021
This patent is subject to a terminal disclaimer.
Int. Cl. G21F 9/00 (2006.01); B01D 15/12 (2006.01); B01D 15/36 (2006.01); B01J 39/24 (2017.01); G21F 9/12 (2006.01)
CPC G21F 9/004 (2013.01) [B01D 15/12 (2013.01); B01D 15/362 (2013.01); B01J 39/24 (2013.01); G21F 9/12 (2013.01)] 8 Claims
OG exemplary drawing
 
1. A chemical decontamination method comprising:
a reduction decontamination step of supplying a reduction decontamination solution to a decontamination target portion made of stainless steel;
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 by using a hydrogen peroxide decomposition device which is directly connected to the decontamination target portion via a temporary circulation pipes downstream of the decontamination target portion that decomposes hydrogen peroxide, when an iron concentration in the reduction decontamination solution becomes a predetermined concentration or less; and
a metal ion removing step of removing a metal ion contained in the reduction decontamination solution after the hydrogen peroxide decomposition step by using a metal ion exchange resin tower that removes metal ions, which is installed downstream of the hydrogen peroxide decomposition device and upstream of the decontamination target portion.