Thermodynamic Modeling of Phase-Chemical Transformations and Equilibrium in Multicomponent Natural and Industrial Waters

Abstract

The behavior of the water carrier used in nuclear energy plants has been studied using the method of thermodynamic modeling. The problem of chemical deactivation of the equipment from corrosive deposits in the form of iron oxides and hydroxides has been solved. The proposed method for the calculation of activity coefficients and the extrapolation of thermodynamic properties of the solution components into the high-temperature region provides correctness and effectiveness of our computations and modeling. As a result, basic chemical and phase transformations occurring in the wide composition and temperature (298-623 K) range have been defined. In addition, all chemical forms in the solution and the solubility of corrosion products have been obtained. These results were useful for finding the optimal conditions for chemical equipment deactivation and improvement of the ecology and radiation situation.