PROBE AND TOOL FOR SEPARATING CONTROL-ROD DRIVING PART

PURPOSE: To provide a tool for separating a control rod drive(CRD). CONSTITUTION: The separating tool is designed to have two modules and one module is a driving assembly 100 for performing a displacement for separating, while the other module is constituted with a probe assembly 110 to inspect a separation condition. The probe assembly 110 is mounted at an end 15c provided with a screw thread of a piston pipe 15, and the probe 118 is extended in the pipe. The drive assembly 100 is mounted on a CRD ring flange 17. The probe assembly 110 detects a ring magnet 67 in a drive piston 24 by using an analogue positional sensor 119a-c functioning in a principle of Hall effect and a solid state circuit 147. A sensor 119a located at the uppermost position generates a signal indicating that a control rod is at a position of full drawing, and a sensor 119c at the lowest position generates a signal showing that the control rod is in a condition of separation. A sensor 119b located in the middle position generates a signal, showing that the control rod is at a transitional position between the positions of full drawing and separation.