Alloy 690 TT 전열관의 결함 검출능 향상을 위한 MRPC Noise 신호기준에 대한 연구

To investigate the influence of MRPC background noise on crack inspectability, the artificial cracks with different depth were produced on three Alloy 690 TT steam generator tube with different background noise using laser. MRPC noise and crack signal were analyzed using +point probe. As a result, it is possible to detect the cracks with the depth larger than 40% for high background noise, while to detect the cracks less than 30% for low background noise. Therefore, it is recommended that MRPC noise value would be at least 0.05 V to improve the crack detectability.