The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 18, 2014
Filed:
Aug. 03, 2010
Tsuyoshi Ito, Hitachi, JP;
Hideyuki Hosokawa, Hitachinaka, JP;
Yukio Hirama, Mito, JP;
Motoaki Sakashita, Hitachi, JP;
Makoto Nagase, Mito, JP;
Tsuyoshi Ito, Hitachi, JP;
Hideyuki Hosokawa, Hitachinaka, JP;
Yukio Hirama, Mito, JP;
Motoaki Sakashita, Hitachi, JP;
Makoto Nagase, Mito, JP;
Hitachi-GE Nuclear Energy, Ltd., Hitachi-shi, JP;
Abstract
A bath containing nickel ions and formic acid is injected into a film-forming aqueous solution flowing in a circulation pipe connected to feed water pipe made of carbon steel in a BWR plant. This film-forming aqueous solution is supplied into the feed water pipe through the circulation pipe, and then, a nickel metal film is formed on an inner surface of the feed water pipe. After the nickel metal film is formed, a film-forming aqueous solution containing iron (II) ions, formic acid, nickel ions, hydrogen peroxide, and hydrazine is supplied to the feed water pipe. A nickel ferrite film is formed on the surface of the nickel metal film in the feed water pipe. Then, the nickel ferrite film is come into contact with water containing dissolved-oxygen at 150° C. or above to transform the nickel metal film into a nickel ferrite film. A thick nickel ferrite film is formed on the inner surface of the feed water pipe. Corrosion of the carbon steel member composing the plant can further reduce.