Additive Manufacturing of BWR Lower Tie Plates and other Fuel Assembly Components

Metallic 3D printing of nuclear fuel assembly components has the potential to remove unwanted cost, waste, and time from the fabrication process.In addition to the direct manufacturing benefits, design engineers can create fuel assembly components that increase the performance of nuclear fuel assemblies with features that were not manufacturable a few years ago.Because of the reduced build time, each new design can be quickly iterated, producing rapid transitions between prototypes and final designs.For these reasons, the Department of Energy is highly interested in advancing methods of manufacturing for nuclear energy technologies that allow for easier engineering and commercial production of nuclear fuel assembly components.Overall, Phase I and II are focusing on optimizing the lower portion of the fuel assembly by adding beneficial 3D printed features and combining components.Phase I successfully built two BWR lower tie plates with an integrated filter design and channel seal.These components were tested for pressure drop and debris filtering to determine which design had the best performance.Specifically addressing the lower tie plate of a BWR fuel assembly, 3D printing with Inconel-718 can enhance the debris filtering performance by constructing torturous flow passages that can be optimized for debris filtering efficiency and pressure drop.With the lower tie plate being 3D printed, channel seals can be added to the design, allowing for a reduction in part count and easier assembly.3D printing additional lower tie plates, analyzing specific features in different reactor environments, and performing full scale flow loop testing are the main goals of Phase II.The commercial benefits for 3D printing in the nuclear industry are innumerable.A 3D printed lower tie plate with channel seals and debris filtering features as one component can directly reduce cost by minimizing fuel assembly component failures and decreasing the number of components.In general, the benefits to commercial nuclear reactor operators and the public are the countless areas where this technology can be applied to make nuclear components more efficient and thereby reducing the cost of electricity generated by nuclear power.