Ultrasonic inspection of reactor coolant pump flywheel used in nuclear power plants

The reactor coolant pump flywheel keyway is a vulnerable part.Therefore, it requires an ultrasonic inspection both pre-service and in-service. This paper focuses on the scope of the inspection and the design of a combined probe which can do the inspection and the signal analysis. It is confirmed that the ultrasonic inspection method meets the requirements of the standards. It also provides a new method of ultrasonic inspection with higher sensitivity. (authors)