PREVENTIVE MAINTENANCE METHOD FOR REACTOR INTERNAL PUMP AND DEVICE FOR IT

摘要

PROBLEM TO BE SOLVED: To suppress the occurrence of stress corrosion cracking of riser brace and bracket welded on a riser pipe of a jet pump placed in a reactor pressure vessel by facilitating the transmission of laser light. SOLUTION: Laser light emitted from a laser oscillator 11 and transmitted with fibers 13 is cast on and nearby the welded part of the riser brace 16 and bracket 17 attached to the riser pipe 15 of the jet pump 5 in the reactor pressure vessel 2. By using fibers 13 for transmitting laser light, laser light transmission is facilitated, the surface of the welding part and nearby is reformed and remaining tension stress can be reduced.