Resilient Coatings for Roller Bearings in Liquid Metal Reactors

The Office of Nuclear Energy seeks to produce durable components for next generation liquid-sodium cooled fast-spectrum nuclear reactors. Specifically, they want low-cost and short lead-time methods to manufacture robust advanced fuel handling system components like roller bearings and gears. The advanced fuel handling system is a critical component of the fast-spectrum nuclear reactor designs that are being fostered by Nuclear Energy’s Advanced Reactor Demonstration Program Office. To enable efficient, safe, and reliable fast-spectrum nuclear reactor operation, the durability and lifetime of components in the advanced fuel handling system must exceed the reactor’s lifetime, which is anticipated to be 30 years. The durability challenges for existing roller bearings and gears are a result of the commercially available materials for their construction. Specifically, the 52100 steel bearing structures have inadequate corrosion and wear resistant properties for liquid sodium fuel handling operations. Therefore, a refractory metal coating, with corrosion and high temperature wear resistance, will be applied to commercially available roller bearings and gears. The coated components will mitigate wear and corrosion during fuel handling operations. Phase I will develop the coating application and diffusion bonding manufacturing methods, and demonstrate the corrosion, wear, and coefficient of friction of the materials through exposure to a liquid sodium environment. These results will validate the ability of the coating to eliminate corrosion and enhance wear resistance. Once a nominal coating composition and thickness is identified, a tool will be designed that can be built in Phase II, such that the coating can be applied directly to commercially available roller bearings. Lastly, the manufacturing cost and lead time associated with apply the coating to commercially available advanced fuel handling systems will be estimated. The results of Phase I will enable coated roller bearings to be installed into the Mechanisms Engineering Test Loop and tested in a liquid sodium operational environment in Phase II. Commercial applications for the coating application processes include commercially available components that suffer from corrosive attack or high temperature wear related failures. Uses in the Department of Energy including fossil and green energy, accelerator development, and quantum information system sectors.