Abstract
Nuclear power plants use high-temperature, high-pressure steam and cooling water for power generation, which generates high-speed fluid flow in the piping, resulting in erosion and corrosion of the piping during operation. Therefore, regular inspections for pipe-wall thinning are essential. On the other hand, since there is a large amount of piping to be inspected, it is desirable to introduce more efficient inspection methods to improve the economic efficiency of nuclear power plants. This paper introduces the standards related to the wall-thinning inspection in nuclear power plant piping, as well as technologies that are close to practical application in the inspection of the pipe-wall thinning: a wireless ultrasonic sensor, a high-temperature thin-film ultra-sonic sensor, a pulsed eddy current testing method, an electromagnetic acoustic transducer, and a dry-coupled ultrasonic sensor. The main features of each technology are outlined with appropriate citations.
https://ror.org/02exqgm79 
