PREDICTION OF METAL OXIDE STABILITY IN SUPERCRITICAL WATER REACTORSPOURBAIX VERSUS ELLINGHAM

摘要

Knowledge of the thermodynamic stabilities of metals and their oxides is important for understandingmaterial degradation and corrosion product transport in a supercritical water-cooled reactor (SCWR).The thermodynamic stability under various conditions can be illustrated using graphical representationssuch as Pourbaix and Ellingham diagrams. This paper will show how a combination of Pourbaix andEllingham diagrams is necessary to characterize the thermodynamic stability of alloys and oxide filmsunder proposed SCWR coolant conditions. Results predicted using both Pourbaix and Ellinghamdiagrams will be compared with literature data. The advantages and disadvantages of these methodsunder SCWR conditions will also be discussed.