Applications of Underwater Laser Peening in Nuclear Power Plant Maintenance

Stress corrosion cracking is the major threat to the safe and stable operation of nuclear power plants, and the residual tensile stress is one of its major causes. For in-service nuclear power plants, the most effective means to prevent stress corrosion cracking is change the stress status of material surface by peening technology. Compared with traditional shot peening, laser peening has advantages of good directionality, good accessibility,easy to control,no residue,deeper compressed layer,and more suited to use in the maintenance of in-service nuclear power plants. In this paper, research and application of underwater laser peening technology in nuclear power plant maintenance are summarized.