Diffusivity of oxygen in molten lead - Bismuth eutectic alloy (44.5% Pb - 55.5% Bi)

Lead - bismuth eutectic alloy, LBE. (44.5% Pb - 55.5% Bi) is one of the proposed alloys to be used as a coolant for Accelerator Driven System reactors. LBE is highly corrosive for structural steels. In order to avoid this corrosion, a passivation layer of magnetite on the structural material should be formed and maintained stable. In this direction, many studies about physicochemical properties of oxygen in molten LBE have been performed. In this work, a method to determine the oxygen diffusivity in LBE has been developed. It is based in the following electrochemical cell: O₂ (reference mixture), Pt // YSZ // O₂ (LBE) Oxygen diffusion coefficient at 460, 500 and 540°C has been obtained. They show a good agreement with other bibliographic experimental data, so the method presented in this work is a good way to determine oxygen diffusion in LBE.