Application of normal pulse voltammetry to on-line monitoring of actinide concentrations in molten salt electrolyte

The applicability of electroanalytical methods – square wave voltammetry (SWV) and normal pulse voltammetry (NPV) – to on-line monitoring of actinide concentrations in molten chlorides was investigated for use in pyrometallurgical processes. For SWV curves for plutonium, the concentration dependence of the peak current was not linear at high concentration. However, the limiting currents for uranium and plutonium determined by NPV were proportional to their concentrations up to about 1.7 wt%. The fission product elements do not seem to affect the accuracy in determination of actinide concentrations because the limiting currents for uranium and plutonium were not influenced by the addition of gadolinium. It was found to be difficult to determine neptunium concentration in the presence of plutonium due to the overlap of the output current waves. From those results, NPV was considered more promising although the optimization of applied potential waveform is necessary for use at higher concentrations.