Method for relieving corrosive environment of boiling water reactor, nuclear power plant, and method for injecting noble metal which is carried out in nuclear power plant

The present disclosure provides a method for relieving a corrosive environment of a boiling water reactor, the method including a step of injecting hydrogen and a noble metal compound into water to be replenished into the reactor pressure vessel during a period of a generating operation of a boiling water nuclear power plant including the reactor pressure vessel. In the method, the hydrogen is injected into water to be supplied into the reactor pressure vessel, and the noble metal compound is injected into water in a line of the boiling water nuclear power plant in which a concentration of oxygen or hydrogen peroxide is stoichiometrically higher than the concentration of hydrogen at which hydrogen undergoes a chemical reaction to turn to water. Thus, when a noble metal is injected into a boiling water reactor, the noble metal can be restrained from adhering onto a pipe for an injection and other pipes, and thereby can increase the amount of the noble metal to be injected into a cooling water in a reactor pressure vessel.