Patent Number: 
Section: abstract

A control rod grasped by a hook of a grasping equipment is moved down and is positioned at an upper end of a hollow piston of a control rod drive mechanism (CRD) in a state that the control rod is fully withdrawn from a core. Furthermore, the hook is inserted into an opening of a handle of the control rod. The hook is lifted up so as to make contact with the handle. The control rod grasped by the grasping equipment is rotated by a grasping equipment rotation apparatus. A state that gaps formed between joint convexities in a coupling socket of the control rod are positioned right above coupling spud convexities of the hollow piston occurs. At this time, the control rod falls by its own weight and the coupling spud convexities pass through the gaps. A grasping equipment movement apparatus suppresses the falling speed of the control rod. The control rod is rotated at 90° and the control rod and CRD are connected. The time required for connecting the control rod and the hollow piston of the control rod drive mechanism can be shortened even further.