A novel degradation state indicator for steam generators of nuclear power plants

We develop a degradation indicator for nuclear power plants steam generators, based on the use of signal measurements collected by sensors during plant operational transients between two successive maintenance interventions. Given the unavailability of information about the real degradation state during operation, an unsupervised approach is adopted. It consists in the extraction of several features from raw signals and in the selection of those features which best describe the degradation state evolution within a multi-objective optimization framework. The two considered objectives are the monotonicity and trendability of the features.