A Non-Contact Ultrasonic Sensor for Pipe-Wall Thinning Inspection of Nuclear Power Plants

Aiming to reduce inspection time of a pipe-wall thinning measurement in a nuclear power plant, we have been developing a non-contact ultrasonic sensor which was originally proposed by University of Bristol. In this study, sensor durability against temperature cycles and irradiation which needs to be confirmed to introduce the sensor into actual plant inspection has been experimentally investigated. The experiment results have shown that the sensor has sufficient durability against both in the nuclear power plant condition. In addition to this, we have proposed multi-transducer system where multiple transducers are connected to one transducer coil for further reduction in the inspection time. A prototype of this concept has been manufactured and its feasibility has been experimentally confirmed.