Buoyancy-enhanced oxygen transport in the experimental liquid lead bismuth eutectic container

The active oxygen control technique is a recently developed effective method for mitigating structural corrosions by forming a protective oxide film along the structural materials in corrosive lead bismuth eutectic (LBE) systems. The mechanisms of LBE corrosion and the oxidation of stainless steel in LBE environment have been analyzed. The active oxygen control technique is introduced and the oxidation experiment results with oxygen control are summarized. The buoyancy-enhanced oxygen transport, both laminar and turbulent, in the experimental LBE container has been numerically investigated using the finite volume method. The flux of oxygen at the gas-liquid and solid-liquid interfaces, the oxygen concentration in the bulk flow, and the rate of oxide layer formation are calculated. The time needed for the momentum and energy to reach the steady sate and the time for the bulk concentration of oxygen to reach equilibrium are estimated. The rate of oxide layer formation on the steel surface under different thermal boundary conditions and diffusivities is also calculated. The numerical analysis provides a guideline for the design and setup of the apparatus in testing and calibrating low-concentration oxygen sensors and to study the oxidation of stainless steel containers for LBE. (author)