REPAIR METHOD OF SAFE END AND THERMAL SLEEVE OF REACTOR PRESSURE VESSEL

摘要

PROBLEM TO BE SOLVED: To provide a repair method which allows access from outside a reactor and allows replacement of a safe end and a thermal sleeve and processing of improving residual stress on inner surfaces of a weld between a nozzle and the safe end.SOLUTION: A new safe end 2 on which a welding bevel 4a having an inner diameter larger than an outer diameter of a welding bevel 5a of a thermal sleeve 5 is projectingly formed on the inner peripheral portion is prepared, and an existing safe end 2 is separated from a nozzle 1 and the thermal sleeve 5, and butt welding bevels are formed on the nozzle 1 and the new safe end 2 respectively, and the nozzle 1 and the new safe end 2 are butt-welded, and the thermal sleeve 5 is inserted into the new safe end 2 from outside the reactor to butt-weld the bevel of the new safe end 2 and the bevel of the thermal sleeve 5.