DECONTAMINATION DEVICE AND DECONTAMINATION METHOD

摘要

PROBLEM TO BE SOLVED: To provide a decontamination device and decontamination method capable of highly efficiently performing decontamination in a short period of time without causing uneven cleaning even while reducing the use amount of a decontamination agent about decontamination of a pressure vessel inner surface in a nuclear reactor and a structure in a furnace.SOLUTION: A structure 60 for contamination liquid volume reduction constituting a decontamination device includes a cylindrical bottomed metal body 60a for further enhancing volume reduction of decontamination liquid in a pressure vessel 20, and a flange 60b provided on the body 60a to come into contact with the top of a flange 20a of the pressure vessel 20. The flange 60b is provided with a bolt insertion hole 60c through which a basic design bolt 63 on the pressure vessel 20 side is inserted. Further, a decontamination liquid injection device 61 comprising an annular shell 61a for receiving heated decontamination liquid and a plurality of liquid sprinkling nozzles 61b provided toward an inner surface of the pressure vessel 20 having an interval in a circumferential direction on an outer circumferential side of the shell 61a is provided at a lower surface side of the flange 60b of the structure 60.