from the conferences organized by TANGER Ltd.
Small Modular Reactors (SMRs) based on Lead-cooled Fast Reactor (LFR) technology represent a promising option for future nuclear energy systems due to their enhanced safety features and efficient fuel utilization. A critical challenge for SMR‑LFR deployment is the long-term compatibility of structural materials with liquid lead coolant under high-temperature and varying oxygen conditions. This work presents a comparative investigation of the corrosion behavior of two candidate structural materials, the ferritic-martensitic steel T91 and the austenitic stainless steel 316L. Both materials were studied in as ¬ received state to assess the corrosion performance/behavior of the reference material. To enhance corrosion resistance, material samples coated with a protective layer based on AlTi with tungsten (W) were investigated. Exposure experiments were conducted in liquid lead at a temperature of 520 °C under controlled low-oxygen and high-oxygen concentrations in the melt, simulating/ to simulate relevant operating regimes of SMR‑LFR systems. The material degradation was evaluated with respect to corrosion mechanisms, formation and stability of protective oxide layers, dissolution phenomena, and coating integrity as a function of oxygen concentration in liquid lead. The results provide deeper insight into the relative performance of T91 and 316L steels, as well as the effectiveness of AlTi+W coating under different oxygen conditions at elevated temperature. The findings contribute to the optimization of material selection and surface protection strategies for structural components operating in liquid lead-cooled SMR systems.
Keywords: Small Modular Reactors, ferritic–martensitic steel T91, austenitic steel 316L, liquid lead, corrosion, coating© This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.