The electrochemical behavior of MgCl 2 in molten LiCl-KCl eutectic was investigated to evaluate its suitability as a surrogate for PuCl 3 in studies related to the eletrorefining of used nuclear fuel. The reduction of Mg 2+ was found to be electrochemically reversible up to 300 mV s-1 at 773 K. The diffusion coefficient for Mg 2+ was calculated to be 1.74 and 2.17 × 10-5 cm 2 s-1 with and without U 3+ present, respectively, at 773 K using cyclic voltammetry (CV). Upon comparison to literature data, the diffusion coefficient of Mg 2+ differs by only 8.8% (with U 3+ present) from that of Pu 3+ and the difference in peak potentials was only 79 mV. Binary-analyte mixtures of UCl 3 and MgCl 2 in eutectic LiCl-KCl were further investigated using CV, normal pulse voltammetry (NPV), chronoamperometry (CA) and open-circuit potential (OCP) measurements for the purpose of comparing each technique's accuracy in measuring U 3+ and Mg 2+ concentrations. Of all the techniques tested, NPV resulted in the lowest error which was, on average, 11.4% and 9.81% for U 3+ and Mg 2+ , respectively.
One problematic issue with molten salt reactors (MSRs) is the tendency for the salt’s redox potential to increase with irradiation, causing greater corrosivity. U and Zr were identified as redox buffer candidates in a NaCl-CaCl2-UCl3 salt. Uranium and zirconium are attractive redox buffers since they should not reduce the redox potential below sustainable operating conditions for MSRs. Redox potentials—represented by open circuit potential (OCP)—were measured at a tungsten working electrode vs. a Ag/AgCl reference electrode housed in a mullite tube. Continuous OCP measurements were taken at 600°C, while NiCl2 was added to the molten salt to replicate irradiation effects on redox potential. OCP rose by 0.23 V with the addition of 0.1 wt% NiCl2. A zirconium rod was then submerged in the salt, causing an OCP drop of -0.63 V over a 100 min period. The potential drop for a U rod was -0.5 V over 160 min.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.