Metallic Fast Reactor Separate Effect Studies for Fuel Safety

Sodium-cooled Fast Reactors (SFR) are one of the advanced nuclear reactor concepts to be commercially applied for electricity production. The benefits of SFR are well-known and include: the possibility of a closed fuel cycle, proliferation resistance, nuclear waste minimization via actinides burning, and fissile breeding capabilities. Metallic fuel used in SFR has well demonstrated irradiation performance. However, more studies are necessary to optimize and extend operational and safety limits for their commercialization and licensing. This could be achieved through a better understanding of fuel behaviors during transient and of fuel failure thresholds. This paper describes the experimental Research and Development (R&D) program aimed at providing the necessary data to support the development of SFR-optimized safety limits. This program integrates separate effects testing and integral effects testing, combined with advanced Modeling and Simulation (M&S). This R&D program, finally, focuses on delivering the science-based information necessary for supporting the licensing and utilization of SFR based on metallic fuel. In this paper we will describe the three research areas centered on fuel development and focused on separate effect testing, namely: (1) microstructural, chemistry, and material properties; (2) thermo-mechanical behavior; and (3) source term and fission product behavior. Preliminary results from these Separate Effect Tests (SET) studies and the current instruments and experimental plan are also presented.