Chlorination of HALEU regulus casting dross

A scoping study was performed for chlorinating dross formed during uranium casting operations. The purpose is to minimize the losses of uranium to dross wastes. The dross is primarily a mixture of uranium metal and uranium oxide with a minor fraction of crucible and crucible coating materials. The reaction chemistries were performed in a carrier salt of LiCl-KCl eutectic at 500 °C. The addition of FeCl₂ chlorinated the uranium metal to UCl₃, by reducing the FeCl₂ to iron metal. After the uranium metal was chlorinated, zirconium metal was added to the salt. The residual FeCl₂ chlorinated the zirconium metal to ZrCl₄, by reducing the FeCl₂ to iron metal. In turn, the ZrCl₄ chlorinated the uranium oxide to UCl₃, by converting the ZrCl₄ to zirconium oxide. The effectiveness of the chlorination reactions was qualitatively verified by cyclic voltammograms that indicated the presence or absence of FeCl₂ and UCl₃ in the salt.