Abstract: A centrifugal pump assembly for use in nuclear reactor plants has a vertical motor shaft, a vertical pump shaft which is coaxial with and is located below and spaced apart from the motor shaft, an intermediate shaft which is coaxial with and is located between the pump shaft and motor shaft, a flexible coupling between the lower end of the motor shaft and the upper end of the intermediate shaft, and a rigid coupling between the upper end of the pump shaft and the lower end of the intermediate shaft. The intermediate shaft is rotatable in radial and/or axial bearings which are installed in a stationary housing, and the intermediate shaft is movable axially of the housing between a lower end position in which the rigid coupling is engaged and a raised position in which the rigid coupling is disengaged and the bearings and/or seals for the pump shaft are accessible.