PURPOSE: To prevent the expansion of a radioactive contamination area by providing a cooling water recovery device so as to surround the wire part between through-holes and connecting an air suction device to the suction port of the cooling water recovery device to recover the cooling water and powder bonded to the endless wire of a wire saw.

CONSTITUTION: A cooling water recovery device 11 is mounted between a concrete structure 1 and a drive pulley 3 and, when an air suction device is operated, the open air is sucked from the gaps of the through-holes 13, 14 of an enclosure 11a at a high speed by the air suction device and the cooling water and cut powder 5 bonded to a wire 2 are separated from the wire by the sucked air of high flow velocity to be guided to the air suction device 12 from a suction port 15 along with said air to be recovered by a filter 12a. By this constitution, the scattering expansion of the contaminated cooling water and cut powder 5 is prevented by the cooling water recovery device 11 and a scattering preventing plate 7 and the cooling water and cut powder 5 are prevented from circulating along with the wire 2.