| Description |
The electrochemical properties of actinides in molten salt are of importance in the nuclear pyrochemical material processing. Specifically, the ability to perform fast (real-time) concentration monitoring in such environments is of great importance (and currently not developed). This dissertation aims to develop such concentration monitoring tools that could be applied to either Generation IV nuclear reactor systems, or to spent fuel pyroprocessing. The application in Generation IV systems is treated in the first part of the dissertation. Here, fluoride salts containing thorium and uranium have been investigated using an electrochemical technique called cyclic voltammetry. Signal to concentration correlations have been developed for single-analyte and mixed salts, and other electrochemical data were collected (reduction mechanism, reversibility criteria, diffusion coefficient). The application in spent fuel pyroprocessing is treated in the second part of the dissertation. Here, chloride salts containing thorium and uranium have been investigated using a variety of electrodeposition techniques (chronoamperometry, chronopotentiometry, repeating chronoamperometry). A new, hyphenated analytical technique was developed, which combines a separation step (electrochemical deposition) with a detection step (alpha particle spectroscopy). A theoretical framework for this new technique was presented, together with experimental verification. The verification (signal to concentration correlation) was complicated by unexpectedly low deposition rate in the mixed salt. This interference prompted investigation, and produced a hypothesis which attempts to explain the lower rate as being the result of departure from the mass transfer-limited deposition regime. |
