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:
May. 29, 2001
Filed:
Aug. 04, 1999
Koichi Kurosawa, Hitachi, JP;
Eisaku Hayashi, Hitachi, JP;
Sadato Shimizu, Hitachinaka, JP;
Minoru Ootaka, Takahagi, JP;
Fujio Yoshikubo, Mito, JP;
Ren Morinaka, Hitachi, JP;
Masayuki Nishino, Hitachinaka, JP;
Noboru Chiba, Tokai-mura, JP;
Kunio Enomoto, Tokai-mura, JP;
Kazunori Sato, Kure, JP;
Other;
Abstract
A method of performing maintenance on a structural member inside a reactor pressure vessel includes lowering an annular guide rail having a second lug until the guide rail rests on an upper flange of a core shroud provided inside the reactor pressure vessel, detachably mounting the second lug of the guide rail to a first lug mounted on the core shroud, positioning a discharging nozzle at a position at which compressive remaining stress is added to a surface of the core shroud by moving the discharging nozzle in a radial direction and an axial direction of the core shroud by a discharging nozzle moving apparatus mounted on a turnable revolving on the guide rail and discharging water to add compressive remaining stress to a surface of the core shroud from the discharging nozzle.