Ultrasonic inspection of baffle bolts of nuclear power reactor internals

According to the operating experience of foreign nuclear power plants, with the accumulation of reactor operating time and the influence of high irradiation, the irradiation assisted stress corrosion crack will be generated inside the baffle bolts, which will lead to fracture. Therefore, the bolt should be examined by volume inspection. This paper analyzes the structure of baffle bolts in the nuclear power plant, and designs an ultrasonic inspection scheme for the areas where defects may occur. The effectiveness of this scheme is verified by experiments, and the ultrasonic inspection of baffle bolts is implemented in field.