To acquire data on a motor shaft and the axis of the motor shaft when a reactor coolant recirculation pump is normally operated on the basis of data when operation of the reactor coolant recirculation pump is suspended, and reduce vibration of the shaft by a simple method.

In inspection of the reactor coolant recirculation pump when operation of the pump is suspended, after maintenance service on the pump is completed and a pump shaft 7 and a motor shaft 1 are coupled with each other by a coupling 21, the suction side and the delivery side of the pump are separated from each other by bulkhead valves 16, 17, and purge water is pressurized and injected into a casing from a purge water injection system to apply a thrust load on the pump shaft 7 so that an actual operation state is simulated. In this simulated state, the pump shaft 7 and the motor shaft 1 are turned, and the dislocation of the shafts is measured. If dada indicating that the axes of the motor shaft 1 and the pump shaft 7 are inclined relatively due to the thrust load is obtained, the installation position of the coupling 21 in the turning direction is changed so as to reverse the change direction of the axes of the pump shaft 7 and the motor shaft 1 after measurement.

COPYRIGHT: (C)2008,JPO&INPIT