Floor noise based bubble detection method in sodium using EVFM

Abstract

The steam generator is a heat exchange device between sodium coolant and water in the sodium-cooled fast reactors. Its transfer tubes are prone to leakage to result in sodium-water reaction, which will affect the operational safety of the entire nuclear reactor. To this end, a signal processing method is studied to detect the steam generator leakage using electromagnetic vortex flowmeter (EVFM). An EVFM is designed for measuring water flow to perform hydraulic experiments to collect the output signals of EVFM sensor under different gas injection volumes. The characteristics of the collected signals are analyzed in the frequency domain, and the floor noise based signal processing method is proposed and realized with a DSP-based hardware system in real time. The gas injection experiments in sodium are conducted to verify the effectiveness of the proposed signal processing method and developed system. The experimental results show that the EVFM with the floor noise based signal processing method can detect the minimum water leak rate in the steam generator as low as 0.1 g/s.