| 摘要 |
PROBLEM TO BE SOLVED: To remove substances on a water surface without scattering them by holding the insides of an intermediate cylinder and an external cylinder under negative pressure, sucking the water surface to be decontaminated to their tips, and generating an air flow from the inside of the intermediate cylinder to the inside of the external cylinder. SOLUTION: The tip of the external cylinder 24 is made to abut against the wall surface 21 of a nuclear reactor container 2 filled with water and a suction device 33 is placed in operation to reduce the pressure in the external cylinder 24, and air is sent from an air sending device 30 to the inside of the intermediate cylinder 22. At this time, the quantity of suction is made larger than the quantity of air sending to hold the insides of the intermediate cylinder 22 and external cylinder 24 under negative pressure, thereby bringing the tips of the intermediate cylinder 22 and external cylinder 24 into contact with the wall surface 21. After the water in the external cylinder 24 is discharged, air flows are generated from an air sending pipe 29 to a suction pipe 31 through the inside of the intermediate cylinder 22 and the space at the outer periphery of the external cylinder 24. The substances sticking on the wall surface 21 are broken and peeled, but the tips of the intermediate cylinder 22 and external cylinder 24 are in contact with the wall surface 21, so they are never scattered into the pressure container 2. Further, the peeled substances are carried to a filter 32 with the air flowing in the suction pipe 31. |
