Numerical analysis of oxygen transport in liquid lead bismuth eutectic systems

Active oxygen control technique is a recently developed effective method for mitigating structural corrosions in liquid lead bismuth eutectic (LBE) systems. By carefully increasing the concentration of oxygen in liquid LBE, an iron and chrome based oxide film can be formed on the surfaces of the structural steels and thus successfully prevent the direct dissolution of the steel elements into the liquid alloy; The proper formation of oxide layers critically depends on the control of the oxygen concentration, so it is necessary to monitor the on-line concentration in LBE systems. The Yttria-Stabilized Zirconia (YSZ) oxygen sensor has been designed by Los Alamos National Laboratory (LANL) for measuring the oxygen level in LBE. The measurement range of this type sensor is a few hundreds of ppm to a few tens of ppb using molten bismuth saturated with oxygen as the reference. However, the characteristics of this sensor have not been well examined at present. (Abstract shortened by UMI.)