An Approach to Addressing Vibrations in Vertical Water Pumps in NPP

Abstract

Vertical water pumps are widely used to supply cooling water to various plants including the nuclear power plants (NPPs). Reliable operation and maintenance of these components are vital to sustain plant operation and availability. The ability to accurately diagnose and troubleshoot pump problems is often very challenging for the plant maintenance engineering and operating staffs of these power plants.

This paper outlines a systematic approach to addressing water pump vibration and resulting damage. As a first step, the approach suggests review of history of pump performance, its maintenance, and repairs along with operational experience (OPEX) from other plants. Next step is to understand pump’s structural dynamic behavior. It is preferable if the vibro-dynamic measurements can be taken so a detailed simulation model can be created and tuned with the measurement data. The various simulation models can then study structural dynamics of the pump assembly, pump assembly behavior under fluid structure interaction and other sources of excitation. Once the source of excessive vibrations is identified, the focus then shifts to generate modification options that can be validated by analytical simulations before implementing in the pump assembly in the plant.