State of the Art of Clogging Diagnosis

Abstract

The main hurdle to clogging diagnosis lies in the difficulty to access the inside of steam generators and the absence of internal sensors. These issues are addressed in different manners by diagnosis methods that are used for routine monitoring or occasional assessment of a steam generators “health”. Monitoring devices can be inserted through the upper openings of the steam generators and allow to inspect their upper support plate. The vertical repartition of clogging can be estimated using the signals of the eddy current probes used for crack detection. These two methods were recently complemented by the monitoring in steady states of the wide range level, the pressure difference between the top and the bottom of the steam generator, which is impacted by the additional pressure drop induced by clogging. The new diagnosis methodology presented in this book relies on the analysis of the dynamic response of the wide range level during power transients.