PURPOSE: To attain repair from a remote position distant from a leak position by providing a reciprocation table which is put in a housing in a free reciprocation state, a tool attachment, a moving means for the reciprocation table and tool attachment, etc.

CONSTITUTION: A canopy seal cleaning process and cutting tool 34 is fixed at the fixation position of a curl cell. After this fitting process, the tool 34 becomes rotatable on the center axis of a control rod driving mechanism and the tool 34 is arranged at a desired position in the outer periphery of the canopy seal. Then a master screw 36 is rotated so that the reciprocation table 46 is displaced vertically by a driven body 44. Then a driving motor 64 is driven so as to position an air motor 84 in level with the reciprocation table 46. A master screw 38 is also rotated by the rotation of the motor 64 to move the outside part 68 of the reciprocation table 46 vertically. A cam groove 80 is moved about the motor 84 by the movement of the part 68. Through this operation, a bearing stud 88 is pushed horizontally along the cam groove 82 to properly arrange the attachment.