The management of uranium refining wastes

Eldorado Nuclear Limited operates Canada's only uranium refinery at Port Hope, Ontario, and is conducting design and environmental studies towards the establishment of two additional refineries in Ontario and Saskatchewan. The Port Hope refinery receives uranium mine concentrates (yellowcake), refines the uranium by a solvent extraction process and converts it to ceramic grade uranium dioxide for CANDU reactor fuel and uranium hexafluoride for use in the light water reactor fuel cycle. Production is approximately 6000 tonnes U per year, of which about 20% is used in the CANDU system. The principal wastes are raffinate from the solvent extraction process, a mixture of fluoride compounds from the UF6 process and ammonium nitrate from the UO2 process, all in aqueous solution. After recovery of some processing chemicals and uranium, the practice has been to precipitate the remaining material with lime and filter off a wet cake for shallow land burial. About a tonne of waste has been produced per tonne of uranium processed. New programs under development to eliminate or reduce waste quantities include additional chemical recovery and recycle, the recycle of raffinate to uranium mills, the production of dry neutral waste for storage. Final disposal options under examination include intermediate depth burial and associated waste immobilization techniques. Other waste types generated at the refinery are contaminated garbage and metallic scrap. An incinerator is being commissioned to handle combustible waste and several methods of handling scrap metal are being investigated. (auth)