Enrichment Process

1. Heating uranium hexafluoride (UF₆) to turn it into a gas

Approved suppliers deliver UF₆ to our enrichment facilities in international, standardised transport containers.

UF₆ is solid at ambient temperature. At our enrichment facilities, we connect the transport container holding UF₆ to the plant feed system. We then heat the container to vaporise the UF₆ and turn it into gas at sub atmospheric pressure.

2. Spinning UF₆ in high speed centrifuges to enrich it

We feed the UF₆ gas into a centrifuge casing containing a cylindrical rotor which spins at high speed, separating uranium’s two isotopes. The heavier isotope uranium₂₃₈ (U₂₃₈) is forced closer to the cylinder wall than the lighter uranium₂₃₅ (U₂₃₅). As a result, the UF₆ gas closer to the wall is depleted in U₂₃₅ and the UF₆ gas nearer the rotor axis is slightly enriched in U₂₃₅. We repeat the process many times in a series of centrifuges, known as cascades, until we achieve the desired levels of U₂₃₅ enrichment to meet our customers’ specifications, typically between 3% and 5%.

3. Compressing and cooling the enriched uranium

We feed the enriched uranium from the centrifuge cascades into a compressor and then into a cooling box containing a cylinder. As it cools, the UF₆ vapour solidifies within cylinders. We homogenise the UF₆ in the cylinders and check the quality of a sample before delivering it to customers. We weigh all cylinders to comply with the accounting and tracking requirements of the European Atomic Energy Community, United States Nuclear Regulatory Commission and the International Atomic Energy Agency.

4. Storing and converting depleted uranium

The UF₆ gas closer to the centrifuge wall is partially depleted in U₂₃₅. This by-product is known as tails. We collect and cool tails in a cooling box containing a cylinder, weighing it to ensure all material can be accounted for. Tails still contain a low concentration of U₂₃₅ and can be re-enriched if economically viable.

We store tails at our enrichment facilities in internationally approved containers pending deconversion to a chemically stable form, uranium oxide (U₃O₈), for long term storage for future enrichment or final disposal. Our Tails Management Facility is responsible for deconversion and converts UF₆ to U₃O₈. This process also creates hydrofluoric acid, a valuable chemical used globally by industry.

Find out more about our Tails Management Facility here.