Evaluation of Nitrogen Influence on the Uranium Metal Stability in LiCl-KCl

This study is focused on nitrogen influence on the uranium metal stability in molten eutectic LiCl-KCl (58.2–41.8 mol.%) in the 450 °C–550 °C temperature range. Preliminary study showed that nitrogen is soluble and electroactive in LiCl-KCl. Then, experiments were done by immersing an uranium plate in LiCl-KCl under two different atmospheres: a low nitrogen atmosphere and a saturated nitrogen one. It was found that uranium spontaneously reacts with nitrogen to form U(III) and N 3- . The kinetics of this reaction was determined by monitoring the U(III) formation rate using chronopotentiometry. It appeared that increasing the temperature or the nitrogen partial pressure in the atmosphere leads to a faster uranium oxidation rate.