In Situ Structural Repair and Protection of LWR Components Using Cold Spray

The U.S. depends on its fleet of light water nuclear facilities for the clean and reliable generation of electricity. With much of the facilities reaching the end of their initial 40-year license, and with electricity demand expected to grow, the U.S. needs methods to extend the lifetime of these facilities for up to 60 years. Stress corrosion crack-susceptible nickel alloys are used in approximately 70% of wetted non-fuel areas in a typical facility, which makes the stress corrosion cracking problem particularly widespread, and especially prevalent with extended service life. Repair of damaged components in situ stands as a superior option for sustaining the existing reactor fleet and can result in significant cost savings vs. replacement. VRC Metal Systems, in collaboration with our academic and research partner, the South Dakota School of Mines and Technology propose to develop cold spray processes to mitigate and repair stress corrosion cracked metal components in light water reactor facilities. The repair will arrest crack growth, protect from further corrosion damage, and fully restore load carrying capacity of the component. VRC will also improve the form-factor of the cold spray equipment to allow for transport of the machine throughout the LWR facility and perform repairs in situ, thereby avoiding the cost and time required to disassemble and remove the component. The repair of stress corrosion cracking in power generation facilities, especially primary water circuits, will not only benefit nuclear power generation facilities, but all generation facilities with water loops, which includes fossil fueled facilities. Therefore, the repair approach being developed in this effort will impact a much larger market than just LWR reactors. Additionally, the development of cold spray processing of corrosion resistant material could find applications in other electric generation sectors, such as cavitation repair on hydroelectric turbine blades. The proposed method of sustainment of LWR stress corrosion cracking issues will allow extended operation of the U.S. LWR fleet to drastically reduce the greenhouse gas emissions of the nation for another 20 years. This repair approach also improves the safety of LWR facilities, which provides both a benefit to the plant owner / operator, as well as the general public. VRC Metal Systems has a proven track record of success transitioning advanced technologies to DOD customers and prime contractors. We will use our quality program management system to coordinate the multidisciplinary team and ensure a successful phase I and transition to phase II and beyond.