Abstract: Provided are a welding apparatus and a method, including a welding torch, a wire nozzle, a support stand that supports the welding torch and the wire nozzle with a predetermined distance therebetween, and a first support mechanism that supports the support stand so that the support stand is rotatable around a first support axis that is along a direction in which the welding torch and the wire nozzle are arranged.

Abstract: A nozzle repair method and a nuclear reactor vessel include: removing a trepanning portion (208) as a connection portion with respect to an in-core instrumentation cylinder (204) in a groove-welding portion (206); removing the in-core instrumentation cylinder (204) from a lower end plate (66); forming a plug attachment opening (211) by removing the groove-welding portion (206); applying a pressing load to the lower end plate (66) by attaching a plug (212) to the plug attachment opening (211); and welding and fixing the plug (212) attached to the plug attachment opening (211). Accordingly, since a repair is easily performed, it is possible to improve the workability and to decrease a repair cost.

Abstract: A nozzle repair method and a nuclear reactor vessel include: removing a trepanning portion (208) as a connection portion with respect to an in-core instrumentation cylinder (204) in a groove-welding portion (206); removing the in-core instrumentation cylinder (204) from a semi-spherical portion (66) as a lower end plate; forming a surface buttered-welding portion (210) by buttered-welding the surface of the groove-welding portion (206); forming a welding groove (212) by grooving the surface buttered-welding portion (210); inserting a new in-core instrumentation cylinder (204A) provided with a circumferential groove portion (204f) outside an instrumentation equipment guide passage (204d) into an attachment hole (203); and fixing the new in-core instrumentation cylinder (204A) by groove-welding the welding groove (212). Accordingly, since the nozzle welding area is suppressed to a predetermined range, the workability of the repair is improved.

Abstract: In a WJP execution method for a reactor vessel lid, WJP is executed on the inner surface of the reactor vessel lid in a state in which an underwater environment is formed on the inner surface of the reactor vessel lid and an aerial environment is formed on the outer surface thereof. In addition, the reactor vessel lid with a waterproof jig attached thereto is arranged in water, the waterproof jig having a cylindrical shape extending to the side of the outer surface of the reactor vessel lid and constituting a vessel with the reactor vessel lid as the bottom portion thereof. Moreover, the reactor vessel lid is arranged on a base installed in the water.

Abstract: It is possible to improve the workability and the stress corrosion resistance by easily performing a repairing operation in a nozzle repairing method and a nuclear reactor vessel. The repairing method includes: removing a first connection portion ((trepanned portion) 208) with respect to an in-core instrument tube (204) in a groove-welding portion (206); removing the in-core instrument tube (204) from a lower mirror (66); leaving and grooving a second connection portion ((existing welding portion) 211) with respect to the lower mirror (66) in the groove-welding portion (206); inserting a new in-core instrument tube (204A) into an attachment hole (203); and groove-welding (so as to form a new groove-welding portion (213)) the inner side of the lower mirror (66) so as to fix the new in-core instrument tube (204A).

Abstract: A nozzle repair method and a nuclear reactor vessel include: removing a trepanning portion (208) as a connection portion with respect to an in-core instrumentation cylinder (204) in a groove-welding portion (206); removing the in-core instrumentation cylinder (204) from a lower end plate (66); forming a plug attachment opening (211) by removing the groove-welding portion (206); applying a pressing load to the lower end plate (66) by attaching a plug (212) to the plug attachment opening (211); and welding and fixing the plug (212) attached to the plug attachment opening (211). Accordingly, since a repair is easily performed, it is possible to improve the workability and to decrease a repair cost.

Abstract: A nozzle repair method and a nuclear reactor vessel include: removing a trepanning portion (208) as a connection portion with respect to an in-core instrumentation cylinder (204) in a groove-welding portion (206); removing the in-core instrumentation cylinder (204) from a semi-spherical portion (66) as a lower end plate; forming a surface buttered-welding portion (210) by buttered-welding the surface of the groove-welding portion (206); forming a welding groove (212) by grooving the surface buttered-welding portion (210); inserting a new in-core instrumentation cylinder (204A) provided with a circumferential groove portion (204f) outside an instrumentation equipment guide passage (204d) into an attachment hole (203); and fixing the new in-core instrumentation cylinder (204A) by groove-welding the welding groove (212). Accordingly, since the nozzle welding area is suppressed to a predetermined range, the workability of the repair is improved.

Abstract: In a WJP execution method for a reactor vessel lid, WJP is executed on the inner surface of the reactor vessel lid in a state in which an underwater environment is formed on the inner surface of the reactor vessel lid and an aerial environment is formed on the outer surface thereof. In addition, the reactor vessel lid with a waterproof jig attached thereto is arranged in water, the waterproof jig having a cylindrical shape extending to the side of the outer surface of the reactor vessel lid and constituting a vessel with the reactor vessel lid as the bottom portion thereof. Moreover, the reactor vessel lid is arranged on a base installed in the water.

Abstract: In a welding system for performing butt welding which comprises butting the end surfaces of steel plates, materials to be welded, placed on the upper surface of a table of a welding stage and welding the end surfaces together, a welding head is a laser/arc combined welding head for simultaneously performing laser light irradiation and arc discharge of the materials 38 to be welded, thereby welding the materials to be welded, and the position of an arc electrode 40 in an up-and-down direction relative to the materials 38 to be welded, the position of the arc electrode in a direction perpendicular to the direction of the optical axis of laser light 32 applied to the materials 38 to be welded, and the inclination angle of the arc electrode relative to the optical axis of the laser light 32 can be adjusted.

Abstract: In a welding system for performing butt welding which comprises butting the end surfaces of steel plates, materials to be welded, placed on the upper surface of a table of a welding stage and welding the end surfaces together,