Objective  The safety of nuclear power is a key concern of the international community. As an important system of transmission medium and heat exchange, nuclear power pipelines have many safety problems. Corrosion of pipeline walls will lead to leakage or rupture, which will cause accidents and threaten personnel lives and public safety. Therefore, nuclear power pipeline corrosion detection is of great significance for the safe operation of nuclear power.

  Method  The corrosion detection of pipeline wall is usually done by piezoelectric ultrasound, which requires couplant, and cannot be applied in the high temperature and unattended environment of nuclear power plants. Electromagnetic acoustic transducer (EMAT) excites and receives ultrasonic waves with the way of electromagnetic coupling, which doesn’t need couplant, and it is applicable for high temperature and unattended scenarios. In this paper, a thickness measurement method with shear waves by EMAT is proposed, and applied to the corrosion detection of the inner wall of nuclear power pipelines. The shear wave probe of EMAT is optimized to obtain signals with higher signal-to-noise ratio, which are filtered and denoised by wavelet to get the actual thickness of the measured pipeline.

  Result  The result shows that this method achieves measurement errors within 1%, indicating high detection accuracy suitable for corrosion detection on the inner walls of nuclear power plant pipelines.

  Conclusion  By conducting corrosion detection on pipeline walls, problems can be identified early, and preventive maintenance measures can be taken to extend the equipment's lifespan, reduce maintenance costs, and enhance the safety of nuclear power operation.