REPAIR WELDING METHOD AT INSIDE OF REACTOR PRESSURE VESSEL AND REPAIR WELDING APPARATUS USED FOR IT

摘要

PROBLEM TO BE SOLVED: To provide a repair welding method, inside a reactor pressure vessel, in which there is no fear of radiation exposure to an operator, in which an approach can be made easily to a narrow part or a part in a complicated shape so as to perform a welding operation while reactor water is filled and in which the operation can be performed in a short construction period and to provide a repair welding apparatus used for it. SOLUTION: A welding-operation mechanism part 10 to which a YAG laser beam is transmitted via an optical fiber cable 41 from a YAG laser oscillator 32 arranged and installed at the outside of a reactor pressure vessel 1, to which a shield gas and a filler wire are supplied from the outside of the reactor pressure vessel 1 and which is provided with a YAG laser torch is sunk inside the reactor pressure vessel 1 filled with reactor water so as to be fixed to a prescribed position, the water is cut off by the shield gas by a remote control operation from the outside of the reactor pressure vessel 1, and a repair welding operation is performed inside the reactor water.