Mass transfer of iron impurities in LBE loops under non-isothermal flow conditions

Lead–bismuth eutectic (LBE) regained interest as a target and a nuclear coolant in nuclear applications. However, the corrosion of the structural materials such as ferritic/martensitic and austenitic stainless steels remains a major issue. Usually, their corrosion behavior measured as the mass transfer by dissolution/precipitation of metal solutes in non-isothermal flowing LBE is tested in loop systems. The exposures usually last for several thousand hours but, to date, almost no reliable long-term experience is reported. A mass transfer model based on species conversion and experimentally verified flow parameters is proposed and applied to predict the corrosion rate of iron solute at dissolved oxygen levels typical for active oxygen control in LBE. The sensitivity of the model indicates that iron diffusion seems to play a decisive role.