Junhyuk Jang

A study on chlorination of uranium metal using ammonium chloride

In this study, the chlorination of uranium metal using ammonium chloride (NH4Cl) was conducted to derive an easy and simple uranium chloride production method without impurities. In thermodynamic equilibrium calculations, it was predicted that only uranium chlorides can be produced by the reactions between uranium metal and NH4Cl. Experimental conditions for the chlorination of uranium metal were determined using a chlorination test of cerium metal using NH4Cl. It was confirmed that UCl3 and UCl4 in the form of particles as uranium chlorination products can be obtained from the chlorination method using NH4Cl.

Numerical analysis and experimental validation of planar electrorefiner for spent nuclear fuel treatment using a tertiary model

ABSTRACT To improve the uranium recovery rate in pyroprocessing, it is crucial to develop a planar-type electrorefiner. This can be achieved prior to actual experiments by using computer simulations to analyze the shape, arrangement, and size of the cathode. In this paper, tertiary-model-based computational analysis was performed on a planar-type electrorefiner. Flat-plate and rod-type cathodes were analyzed under constant-current condition; calculations were performed on high-efficiency-type electrodes with convection effects under the same conditions by comparing the dependence of the generated overpotential on the applied current. Analytic and experimental results were analyzed by comparing the electric potential of the plate-type device with that of a uranium electrorefiner while varying the arrangement of the electrodes.

Reusability Test for Ceramic Crucibles as Liquid Cadmium Cathode Containers inPyroprocessing

The compatibility of various ceramic crucibles (AlN, BeO, and SiC) for repeated use in pyroprocessing was investigated. Each ceramic crucible loaded with liquid cadmium was immersed in molten chloride salt containing uranium and rare earth elements (Nd, Ce, and La) at 500 °C to perform an electrodeposition, followed by heating to 920°C to separate the metal deposits from Cd during distillation. Repeated process runs showed that the ceramic crucibles could be recycled and reused, more specifically, 7 times for AlN, >13 times for BeO, and 4 times for the SiC crucible. Considering the reactivity of ceramic materials with metal deposits as well as their durability at high temperature, the crucible composed of BeO was concluded to be suitable for use in electrorefining and distillation.