Ultrasonic Flow Monitoring of SDS/ECI Feeder Channels

Abstract

The indicated flows of some of the instrumented-channels of the CANDU Shutdown System (SDS) and Emergency Cooling Injection (ECI) system can become degraded over time, which will result in reduction of operating margin, nuisance alarms and workarounds. As one mitigation strategy, using Ultrasonic Cross-Correlation Flow Meter (USCCFM) to monitor flow rate of SDS and ECI feeder channels has been implemented in Ontario Power Generation (OPG) Darlington Nuclear Generation Station (DNGS) for years. This paper introduces the methods in data analysis for USCCFM monitoring and the detection of abnormal measurement drift in the feeders’ orifice flow meter. Results represented in the paper reveal that the long-term, reliable and stable flow measurement by USCCFM can be used as benchmark when the orifice based Flow Instrument Degradation (FID) occurs.