Hitachi, Ltd.

Babcock-Hitachi Kabushiki Kaisha

Toshio Kawakami

Katsumi Ohsumi

Akira Minato

Takashi Honda

Osamu Asai

Masakiyo Izumiya

Katsumi Suzuki

A nuclear power plant using a structural material consisting of metal which comes into contact with a liquid in which radioactive substances are dissolved has a function to suppress the deposition of the radioactive substances. In this function, metal elements constituting the surface layer of the structural material which comes into contact with the liquid are oxidized by injecting oxidizing agents from outside, thereby preliminarily producing an oxide film. The oxidizing agents comprise at least one kind selected from the group consisting of oxygen, hydrogen peroxide, chromate, nitrite, molybdate, tungstate and ferrate. Particularly, by suppressing the deposition of radioactive substances on a stainless steel, the dose rate of exposure of workers is effectively reduced.

Nuclear power plant providing a function of suppressing the deposition

A boiler tube and a method for manufacturing the same are disclosed in which an inner surface of the boiler tube used in the center of a high-temperature, high-pressure boiler is formed with a spinel layer consisting of an oxide of iron, chromium and nickel, which is exposed. The specific method of the manufacture is that after the boiler tube is brought into contact with high temperature steam, a magnetic iron (Fe.sub.3 O.sub.4) layer produced on the inner surface is removed.

Method of manufacturing a stainless steel boiler tube with anticorrosive

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Mito, Japan

Toshio Kawakami