A reliability assessment method for pipe wall thinning management using electromagnetic acoustic transducer (EMAT) is discussed. In the series of laboratory experiments, we collect the measurement data for carbon steel test pipes fabricated to simulate flow-accelerated corrosion (FAC). Those data are used for the reliability assessment of EMAT based NDE system. The reliability of the system can be derived from the so-called probability of detection (POD). The POD evaluation is carried out and evaluated using a signal response model. The final part of this paper is devoted to the applicability and the validity of the POD based assessment method considered here.