Uranium Processing

Milling

Ore is crushed and processed in mills, generally located at or near the mines, to isolate uranium by using chemical processes that remove impurities. A fine powder, called "yellowcake", is the resulting product and is packed in 55 U.S. gallon ring-sealed drums containing approximately one-half tonne of yellowcake. All waste and water from the mine and mill tailings area is treated prior to release.

Refining

The yellowcake produced at the mills is about 70% uranium. At a refinery, in Canada at Blind River, Ontario, it is further processed to remove impurities, then chemically converted to uranium trioxide, a form suitable for further processing.

Conversion

Additional processing at a "conversion" facility, in Canada at Port Hope, Ontario, is required to chemically transform the product to either uranium dioxide, for CANDU reactor fuel, or uranium hexafluoride, the feedstock for enriched light water reactor fuel. Most reactors outside Canada are light water reactors that use enriched uranium fuel.

Fuel Fabrication

In Canada, natural uranium dioxide powder, packaged in drums at the conversion plant, is shipped to one of the two fuel fabricators. Currently, both fuel fabricators manufacture only uranium fuel assemblies comprised of natural uranium. The uranium dioxide powder is first pressed into cylindrical shapes and "fired" to produce fuel pellets. The pellets, about 2 cm long and 1 cm in diameter, are then trucked to a plant where they are placed in 50 cm-long zirconium alloy tubes, and fastened together into 10 cm-diameter fuel bundles for CANDU-type reactors in Canada and abroad.

All natural uranium hexafluoride produced in Canada is transported in specially designed steel shipping containers to enrichment plants in France, the U.K., Germany, Japan or the Netherlands.