Acoustic Leak Detection System for Sodium-Cooled Reactor Steam Generators Using Delay-and-Sum Beamformer

Abstract

A new acoustic leak detection system for sodium-cooled reactor steam generators using a delay-andsum beamformer is proposed. The major advantage of the delay-and-sum beamformer is that it could provide information on the acoustic source direction. An acoustic source of a sodium-water reaction is supposed to be localized, while the background noise of the steam generator operation is uniformly distributed in the steam generator tube region. Therefore, the delay-and-sum beamformer could distinguish the acoustic source of the sodium-water reaction from the steam generator background noise. In this paper, results of numerical analyses are provided to show the fundamental feasibility of the new method.

Water experiment on phased array acoustic leak detection system for sodium-heated steam generator

“…And the tube bundle does not seem to affect array analysis performance. Combining those experimental results and the previous numerical analysis (Chikazawa, 2010), performance of the proposed acoustic leak detection system has been confirmed fundamentally. …”

“…The steam generator shell is separated into several sections and an array set in each horizontal section is sufficient to provide leak detection. Performance of the phased array system was confirmed by numerical analysis in the previous study (Chikazawa, 2010). However, in the numerical analysis, acoustic transportation through the SG tube bundle was not modeled.…”

“…Performance of the new method was confirmed by numerical analyses in the previous study (Chikazawa, 2010). In the analysis, the array system was composed of 5 accelerometers and the pitch of the accelerometers is selected to be 120 mm focusing the acoustic band around 10 kHz.…”

“…Though acoustic detection has advantage from the view point of rapid detection, separation of target leak source and operation noise is an issue. In the previous study, past developments were reviewed briefly and an acoustic leak detector with phased array system was proposed (Chikazawa, 2010). Basically, the past acoustic detection systems have been succeeded in fundamental experiments in laboratory scale.…”

Spatial coherence of pipe vibrations induced by an internal turbulent flow

“…Given the practical importance of the above problem in the complex framework of leak noise detection and propagation [23], it is worthwhile to explain it in some more detail. In recent years, a beamforming approach based on vibration measurements on the external hull of the SGU rather than on acoustic measurements [24][25][26][27] was studied in a collaboration between the French Alternative Energies and Atomic Energy Commission (CEA), and the Institut National des Sciences Appliquées (INSA) Lyon. The basis of the approach was developed in the framework of the PhD thesis of Moriot (2013).…”