Improving monitoring of PWR electrical power plants `in core´ instrumentation with time-frequency signal analysis

The purpose of this study is to demonstrate what can be gained from a time-frequency analysis in the fields of machine diagnosis and monitoring. The problem consists of detecting a possible abnormal state of the in-core instrumentation thimbles in PWR power plants, due to vibration phenomena, and the objective is to increase the automatization of the monitoring. It is shown that a Wigner-Ville time-frequency analysis is well-suited not only to confirm the diagnosis, but also to provide a better understanding of the involved physical phenomena