| 摘要 |
PROBLEM TO BE SOLVED: To remotely operate under an air environment for reducing the load on workers and radiation exposure dose in washing the inside of the riser pipe of a jet pump. SOLUTION: In the riser pipe 12 of a jet pump 10 placed in a reactor pressure vessel 1, a flexible shaft 70 attaching a wiping pad 83 at the tip end is inserted. The flexible shaft 70 is easily inserted and withdrawn with a roller guide mechanism 41 placed nearby a recirculation inlet nozzle 13. The back end of the flexible shaft 70 connects to a shaft rotation drive device 59. The flexible shaft 70 is moved up and down by a position support device 42 and the center is positioned in the riser pipe 12. The center of the flexible shaft 70 is set to position around a thermal sleeve 22 in the center with the position support device 42, and by rotating the sweeping pad 83, the inside of the riser pipe 12 is wiped and washed.
|
