Recovery of actinides from actinide–aluminium alloys by chlorination: Part I

• Published in: Journal of nuclear materials Vol. 414; no. 1; pp. 12 - 18
• Main Authors: Cassayre, L., Souček, P., Mendes, E., Malmbeck, R., Nourry, C., Eloirdi, R., Glatz, J.-P.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.07.2011; Elsevier
• Subjects: Actinides; Alloys; Aluminum; Anodic dissolution; Applied sciences; Chlorination; Controled nuclear fusion plants; Dissolution; Electrodes; Energy; Energy. Thermal use of fuels; Exact sciences and technology; Fission nuclear power plants; Fuels; Installations for energy generation and conversion: thermal and electrical energy; Nuclear Experiment; Nuclear fuels; Physics; Preparation and processing of nuclear fuels; Recovery; Distillation; Actinide; Thermodynamics; Cathode; Sublimation; Aluminium; Nuclear fuel; High temperature; Irradiated nuclear fuel; Nuclear reactor; Molten salt; Chlorination; Actinides
• ISSN: 0022-3115; 1873-4820
• DOI: 10.1016/j.jnucmat.2011.04.023

Pyrochemical processes in molten LiCl–KCl are being developed in ITU for recovery of actinides from spent nuclear fuel. The fuel is anodically dissolved to the molten salt electrolyte and actinides are electrochemically reduced on solid aluminium cathodes forming solid actinide–aluminium alloys. A chlorination route is being investigated for recovery of actinides from the alloys. This route consists in three steps: Vacuum distillation for removal of the salt adhered on the electrode, chlorination of the actinide–aluminium alloys by chlorine gas and sublimation of the formed AlCl 3. A thermochemical study showed thermodynamic feasibility of all three steps. On the basis of the conditions identified by the calculations, experiments using pure UAl 3 alloy were carried out to evaluate and optimise the chlorination step. The work was focused on determination of the optimal temperature and Cl 2/UAl 3 molar ratio, providing complete chlorination of the alloy without formation of volatile UCl 5 and UCl 6. The results showed high efficient chlorination at a temperature of 150 °C.