Patent ID: 9728285
Date: 2017-08-08
CPC Classifications: B24C,G21C,Y02E

Claim:
1. A water jet peening (WJP) method for a nuclear reactor vessel comprising: disposing a clamping cylinder at the outer peripheral side of an instrumentation nozzle with a predetermined gap therebetween; fixing a positioning member provided in the clamping cylinder to the instrumentation nozzle at a position adjacent to the upper end of the instrumentation nozzle; moving an inner surface WJP nozzle downward to the instrumentation nozzle through the clamping cylinder; jetting high-pressure water to an inner surface of the instrumentation nozzle by moving the inner surface WJP nozzle downward in a rotation state while the high-pressure water including cavitation air bubbles is jetted from the inner surface WJP nozzle; and discharging the high-pressure water jetted from the inner surface WJP nozzle to an outside of the instrumentation nozzle through a drainage hole provided in the positioning member.