Determination of Thorium on the Mixed of (Th,U)O2 by Potentiometric Titration Method

Thorium analysis on the mixed oxide (Th,U)O2 using potentiometric method was done. The aim of the research was to study thorium analysis in the mixed oxide fuel of (Th,U)O2. Range of the mixed oxide fuel of (Th,U)O2 were 80 % - 95 % Th O2 and 20 % - 5 % UO2. Thorium and Uranium in the mixed oxide fuel of (Th,U)O2 firstly was changed to Th(NO3)4 and UO2(NO3)2 by solve in the mixed HNO3 14,4 M and HF in boiling point of solution, than was diluted by HNO3 1 M. The solution was titrated by EDTA 0,05 M at pH 2.8 in mixture medium of 5 ml of alcohol, 5 ml of mixtures alcohol and nitric acid 1 M, 2:1 (V/V), 5 ml of mixtures of alcohol and water 2:1 (V/V), 10 ml of mixtures of CH2CICOOH 1 M and CH3COONa 1M and 25 ml of water by potentiometer Metrohm at potential 250 mV and derivatif potential 500 mV. The result showed that no effect of the uranyl ion to the thorium determination of (Th,U)O2. The method could be used to thorium determination of (Th,U)O2 in the range 80 % - 95 % ThO2 and 20 % - 5 % UO2 the error found was, 0,045 % - 2,836 %. (author)