Patent ID: 7811392

Claim:
A method for suppressing radionuclide deposition on a metallic reactor component of a nuclear power plant comprising the steps of: connecting a pipe having a pump pressurizing a treatment solution to a piping, which is made of stainless steel and is the metallic reactor component, during a time that the nuclear power plant is stopped; adding a first agent containing iron (II) ions, a second agent for oxidizing the iron (II) ions to iron (III) ions, and a third agent for adjusting a pH, in this order, into the pipe; supplying the treatment solution containing the first, second and third agents and adjusting a pH to within 5.5-9.0 by the addition of the third agent into the piping through the pipe; adsorbing the iron (II) ions on an inner surface of the piping by contacting the treatment solution with the inner surface of the piping; and forming a ferrite film on the inner surface of the piping by oxidizing the adsorbed iron (II) ions through an oxidation action of the second agent, during the time that the nuclear power plant is stopped.