ULTRASONIC FLAW DETECTION DEVICE

摘要

PURPOSE:To perform a test without human approaching the lower portion of the inside of a nuclear reactor by installing a flaw detection device under water from above the nuclear reactor to perform flaw detection in order to inspect an access hole cover, and achieving processes up to removal of the device through remote control. CONSTITUTION:To make sure the sanity of an access hole cover 1 mounted to a ring-shaped buffle plate 6 a welding portion 3, a flaw detection device 13 is passed through the hole of a guide block 7 and mounted on the cover 1. Remote control is performed from a fuel exchange truck 10 and the device 13 is set in a predetermined position from the truck 10 using a winch 11 and the device 13 is controlled by a controller 14. Rotary scanning by a probe 26 is done by a motor 15 for rotation and radial scanning is done by a piston 22 and ultrasonic signals of scanning are transmitted to a flaw detector on the truck 10 through a flaw detection cable 27. The motor 15 is controlled by the controller 14 via a control cable 32. The piston 22 is remote controlled by a water hose 23. Thus flaw detection can be performed wholly by remote control.