Behavior of control rods during core degradation: pressurization of silver-indium-cadmium control rods

Activity data for the liquid binary systems Ag-Cd, Ag-In, and In-Cd are correlated in terms of the Wilson equation. These correlations are used to construct a model of the ternary system Ag-In-Cd. Spectroscopic data for the vapor species Ag(g), Ag2(g), Ag3(g), Ag+(g), In(g), In2(g), In+(g), Cd(g), Cd2(g), Cd+(g), AgIn(g), and CdIn(g) are reviewed and are used to define thermodynamic functions for these species for temperatures between 298 and 35000K. Vapor pressures for the liquid phase pure elements, liquid binary alloys, and the liquid ternary alloy are calculated using the Wilson equation model and using the assumption that the condensed phase is an ideal mixture. An azeotrope is predicted for the Ag-In system. Predictions are made of the vaporization of alloys of 80% Ag, 15% In, and 5% Cd used as control materials in some pressurized water reactors. 92 refs., 58 figs., 45 tabs