Development of automatic ultrasonic inspection system for turbine shrunk-on disks

The turbine shrunk-on disk is examined during the periodic inspection in nuclear power plants. However, the present examination method is incapable of making a complete inspection, or to execute a speedy and accurate inspection within a limited period, as the procedure requires the preparation and consecutive replacements of many special probes. To solve these problems, we have conducted research, along with increasing the flaw detectability, to develop a method with higher inspection efficiency, as well as equipment that implements this method. This report describes these developments and their results. (author)