Hitachi-Ge Nuclear Energy, Ltd.

Jfe Steel Corporation

Ryo Hamada

Hideyuki Hosokawa

Nobuyuki Ota

Satoshi Oouchi

Takashi Oohira

Motohiro Aizawa

Naobumi Tsubokawa

Masahiko Kazama

Hiroo Yoshikawa

Shunichi Kamezaki

Shintaro Yanagisawa

Takuya Akasaki

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.

Chemical decontamination method and chemical decontamination apparatus

A chemical decontamination method capable of improving the decontamination efficiency of chemical decontamination of a steam dryer in the RPV is provided. In particular, the decontamination method includes feeding a chemical decontamination aqueous solution into a reactor pressure vessel in which a steam dryer is arranged, and after chemical decontamination of the steam dryer, the water level of the chemical decontamination aqueous solution existing in the reactor pressure vessel is lowered to a first water level below the lower end of the steam dryer.

Chemical decontamination method

A coke extrusion force estimation method includes: measuring irregularities on an inner wall surface of a carbonization chamber to acquire an oven wall profile; estimating an outer shape of a coke produced in the carbonization chamber based on the oven wall profile; defining an active state for a side surface position of the coke at which a coke width is smaller than an oven width and defining a passive state for a side surface position of the coke at which a coke width is larger than an oven width based on the oven wall profile and the estimated outer shape; and calculating oven wall friction force for each side surface position of the coke using a previously set apparent Young's modulus of the coke in accordance with definition of the active state or the passive state to estimate the extrusion force based on the oven wall friction force.

Coke extrusion force estimation method and coke oven repairing method

Growing community of inventors

Tokyo, Japan

Ryo Hamada