Chemical regime analysis for the WWER-type nuclear power plant secondary circuit with regard to salt concentration in steam generator feedwater

The secondary circuit water chemistry was examined at unit 1 of the Dukovany nuclear power plant. Two regimes were investigated, viz. the conventional operating regime at pH 8.4 and a regime with the pH value increased to approximately pH 9.0. The trace amounts of anions were determined by ion chromatography whereas the total salt concentration was determined by electrolytic conductivity measurement of the effluent passed through a cation exchanger column in the H cycle. Moreover, the electrolytic conductivity without treatment in the column, the concentrations of ammonia, hydrazine, oxygen and of iron ions, the feedwater pH value, and the chloride concentration distribution within the secondary circuit were also measured. (E.J.). 1 tab., 2 refs