Nuclear Power Plants Issues in IAEA Technical Guidelines on Fluid-Structure Interactions

This paper introduces nuclear power plant issues described in International Atomic Energy Agency (IAEA) technical guidelines on fluid-structure interactions (FSIs). The occurrence of FSIs has been recognized for a long time in industry. It is sometimes difficult to predict the FSI phenomena accurately, however, and FSI vibration and water hammer are concerns for structural design or trouble shooting. There have been many problems caused by FSIs in nuclear power plants. In order to avoid FSI problems for newly designed components, it is important to learn from past FSI events that have occurred at actual plants. Four major types of FSI events that have been publicly disclosed are introduced here and the importance of evaluating reactor internals with respect to flow-induced vibration is noted, if the designs of the reactor internals are for prototypes or the operating conditions are changed. The especially significant internals that are susceptible to flow-induced vibration based on past experience are introduced.