Assessment of 3# primary pump vibration of unit 1 in Qinshan NPP3

The vibration of 3# primary pump of unit l in Qinshan NPP3 is serious during the start-up and operation. In order to find out the reasons for the vibration, the main parameters in four fields were measured rotating machinery vibration test, mode test, the vibration test and the heat displacement test of the primary pump. Based on the analysis of the measurement data, the root cause for the vibration of the primary pump is diagnosed, and the modification scheme is put forward. After the implementation of the modification scheme, the vibration is reduced greatly, and the alarm defect of the primary pump vibration has been eliminated. (authors)