Model calculation of Cr dissolution behavior of ODS ferritic steel in high-temperature flowing sodium environment

Abstract

 A calculation model was constructed to systematically study the Cr dissolution behavior of fuel cladding tube.  Chromium dissolution was significantly influenced by small changes in Cr concentration (i.e. chemical potential of Cr) in liquid sodium in the model calculation.  Both the experimental measurement and the model calculation indicated that the cladding surface Cr concentrations in 9Cr-and 12Cr-ODS steels converged approximately to a unique value.

Further insights into the mechanisms involved in the corrosion of 316L(N) austenitic steel in oxygenated liquid sodium at 550 °C

“…To conclude this short review, stainless steels and ferritic-martensitic steels are dissolved in liquid [38].…”

“…If this high value of Cr solubility in sodium is confirmed, its effects on corrosion modelling is of primary importance. Indeed, the solubility is involved in the driving force of corrosion and only a small variation of this parameter could lead to large changes in the corrosion modelling of steels [38] in liquid sodium heat exchangers that could be used in future nuclear power plants. This new data shows the importance of taking Cr selective oxidation into account when modelling corrosion.…”