Advanced Processing and Cladding of High Density U-Mo Dispersion Fuels

Low enriched uranium fuels are desirable for reduced nuclear proliferation concerns. In the leading program for advanced fuel development, Reduced Enrichment for Research and Test Reactors (RERTR), U-Mo fuels are being developed to substitute low enriched for current highly enriched uranium fuels used in research and test reactors. At higher burnup and higher U loading, swelling and interdiffusion with the Al matrix and cladding limit the use of high density metallic fuels. Under this SBIR, Powdermet will develop fluidized bed coating processes for applying metal and ceramic claddings onto U-Mo fuel particles. Fuel particle simulants will be developed using nonradioactive materials, and process conditions for depositing various metal and ceramic claddings, including silicon, titanium nitride, and niobium, to the metallic fuels will be developed. A dedicated reactor will be designed and built, and silicon and niobium coatings will be applied to depleted uranium (or DU-Mo) powders to investigate differences in nucleation and growth of the metal coatings on uranium materials. Dispersion fuels will be fabricated using Powdermets developed direct powder forging of clad particles approach to metal matrix composite fabrication. Commercial Applications and Other benefits This program will develop a national capability to produce coatings and produce non-enriched fuel materials at low cost, for study of interfacial reactions and irradiation effects of high density, high burn-up fuels. The development of high burn-up and high conductivity metallic fuels will enable the use of low enriched fuels in small high power reactors, and reduce the production of spent fuel, while potentially eliminating the need for reprocessing and greatly reducing the threat of proliferation from commercial reactors using these fuels.