Patent ID: 11862355
Assignee: KOREA ATOMIC ENERGY RESEARCH INSTITUTE
Field: Engines, pumps, turbines (Mechanical engineering)
Classification: CPC G  Y | IPC G

Claim 0:
1. A method of removing a radioactive structure within a wall in a nuclear power plant, comprising:
flattening at least a portion of an uneven outer surface at a drilling portion of the wall, the uneven outer surface at the drilling portion of the wall extending in a vertical direction of the wall, wherein the radioactive structure is buried in the wall and the drilling portion is adjacent to the radioactive structure;
installing at least two drilling devices in the flattened drilling portion and performing a drilling operation in a horizontal direction of the wall, the at least two drilling devices including a first drilling device and a second drilling device;
extracting the radioactive structure from the wall; and
cutting the extracted radioactive structure and storing pieces of the cut radioactive structure in a shielding container,
wherein the performing the drilling operation includes,
performing a first drilling operation including a dry drilling operation using the first drilling device having a first core bit, and
performing a second drilling operation including a wet drilling operation using the second drilling device having a second core bit,

wherein the performing the second drilling operation includes,
collecting a cooling medium used in the wet drilling operation using a cooling medium collection unit,
transferring the cooling medium collected by the cooling medium collection unit from the cooling medium collection unit to a first water collection tank,
depositing dust or sludge contained in the cooling medium in a lower portion of the first water collection tank to separate at least a portion of the dust or the sludge contained in the cooling medium,
purifying the cooling medium from which the dust or the sludge is separated, and
resupplying the purified cooling medium to reuse the purified cooling medium as the cooling medium of the second drilling device, and

wherein at least one portion of the radioactive structure absorbs neutrons during an operation of a nuclear reactor included in the nuclear power plant so that the radioactive structure has radioactivity after the operation of the nuclear reactor, and
wherein in the flattening, the at least the portion of the uneven outer surface is filled with mortar so that the at least two drilling devices are stably installed on the wall.