The formation of the carbonate system of circulating cooling water of the Rivne NPP and its influence on changes in the surface waters pH levels of the Styr river

Abstract

Abstract The data on pH changes and corresponding equilibrium shifts of the carbonate system of process and return waters of the circulating cooling system (RCS) of the Rivne NPP during water treatment were analysed. In the additional cooling water previously clarified by liming, there is no dissolved carbon dioxide and no residual free alkalinity. The effects that occur during heating, cooling, and aeration in the RCS cause a shift in the equilibrium of the carbonate cooling water system with a decrease or increase in the content of carbon dioxide, bicarbonate, and carbonate ions, and pH level. The influence of the shift of the carbonate system and the changes in pH level during the discharge of return water from the Rivne NPP into a natural water body (Styr River) was analysed.