With regard to on-site modification and periodic inspection of power plants, there is a strong demand for reducing the required work period from the viewpoint of securing a stable power supply. The work generally involves welding of piping. As their post-weld quality inspection, radiographic testing (RT) is usually employed. However, RT needs to follow radiation safety management, which sometimes serves as a bottleneck in achieving a shorter work period. Mitsubishi Heavy Industries, Ltd. developed the process and technology so that ultrasonic testing (UT) can be performed in lieu of the conventionally applied RT for quality inspection. The application of UT has enabled other necessary work and inspections to be conducted simultaneously, making it possible to shorten the work period substantially.
