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AssigneeHitachi GE Vernova Nuclear Energy, Ltd.
InventorsTsuyoshi Itou, Kazushige Ishida, Hideyuki Hosokawa, Shintaro Yanagisawa, Takashi Oohira
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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).).
A chemical decontamination method comprising a step of performing a reduction decontamination of a constituent member of a nuclear power plant by bringing an aqueous solution of a reduction decontamination agent into contact with a surface of the constituent member which is to be in contact with a reactor water, and thereby decomposing the reduction decontamination agent contained in the aqueous solution,
A chemical decontamination method comprising the steps of:
A chemical decontamination apparatus comprising:
Dependencies are inferred from the claim text.