Acoustic-based detection and precise localization of seal failure points in nuclear power plant containment

Containment structures are paramount as the ultimate physical defense in nuclear power plants, tasked with hindering the release of radioactive materials. Seal failures, typically referring to leakage events, on the containment are deemed unacceptable defects. Additionally, capturing the initial moment of leakage event in practical applications often presents a significant challenge to conventional localization methods. This paper reports an experimental investigation on the location of the real continuous leakage caused by air vibration through an acoustical location method under the platform of a simulated containment leak location system. We propose a cross-correlation time difference estimation strategy based on minimum variance cutoff optimization. This method addresses the challenge of determining the arrival time of continuous signals by optimizing the cross-correlation time difference estimation. It overcomes the limitations of traditional TDOA algorithms in continuous signal scenarios and enables the localization of continuous leakage signals. The results indicate that this method achieves a localization error margin of less than 3 cm for actual gas leakages within the simulated containment environment. Furthermore, this method addresses the issue faced by traditional localization techniques, which struggle to ascertain the arrival time of continuous gas leakage signals, thus complicating precise positioning. Demonstrating significant utility, this method is notably suited for detecting continuous leakage signals within large storage tanks, suggesting broad applicability in ensuring containment integrity in nuclear facilities.