American Nuclear Society

Home / Publications / Journals / Nuclear Technology / Volume 181 / Number 3

Development of Treatment Process for Anode Residue from Molten Salt Electrorefining of Spent Metallic Fast Reactor Fuel

Masatoshi Iizuka, Masaaki Akagi, Takashi Omori

Nuclear Technology / Volume 181 / Number 3 / March 2013 / Pages 507-525

Technical Papers / Reprocessing /

A new treatment process was proposed for the anode residue from a molten salt electrorefining step in the pyrometallurgical reprocessing of spent metallic fast reactor fuel. This treatment process consists of two steps: (a) oxidation of the remaining actinides in the anode residue by the addition of CdCl2 and (b) removal of the accompanying chloride by high-temperature distillation. The oxidation of the remaining uranium by CdCl2 was studied using anode residue from previous electrorefining experiments using U-Zr alloys. The reaction between uranium and CdCl2 was completed in [approximately]2 days with a satisfactory chlorine balance among the species in the molten chlorides solvent. A high uranium oxidation rate was attained by appropriately controlling the rate of CdCl2 addition. The high-temperature distillation tests were carried out at 1473 K with pressure of [approximately]300 Pa to remove the solvent accompanying the anode residue. The chloride content in the anode residue was lowered to 1% to 2.5% by the distillation operation. Although the anode residue was heated to 1673 to 1773 K at a pressure of [approximately]50 kPa after the distillation, it was not melted completely. The remaining ratio of uranium after the electrorefining and the above treatment process was evaluated to be 0.04% to 0.20%. Material flow calculations were performed for a pyrometallurgical reprocessing facility equipped with the anode residue treatment process. It showed that (a) the chlorine and uranium supply/demand balance is maintained unless the remaining ratio of uranium after electrorefining exceeds a certain value and (b) the addition of the anode residue treatment process does not have an adverse effect on either the performance of the overall process or the facility design.

Questions or comments about the site? Contact the ANS Webmaster.