A closer look at the enrichment process

URENCO’s part in the enrichment process starts with the arrival of UF6 at our facilities. UF6 is the most suitable form of uranium for enrichment because it is easily turned into a gas when heated.

Heating UF6 to turn it into a gas

UF6 is delivered to our facilities in internationally approved transport containers, which we connect to our plant feed system. The UF6 is then vaporised and turned into gas at sub-atmospheric pressure.

Spinning UF6 at high speed 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, U238, is forced closer to the rotor wall than the lighter U235. As a result, the UF6 gas closer to the wall is depleted of U235, and the UF6 gas nearer the rotor axis is slightly enriched in U235. We repeat the process until we achieve the levels of U235 enrichment that our customers require.

Compressing and cooling the enriched uranium

Next, we feed the enriched uranium (UF6 containing up to 5% of U235) from the centrifuge cascades into a compressor, then into a cooling box. As it cools, the UF6 vapour solidifies in cylinders. We homogenise the cylinders and check a sample for quality. We weigh and analyse all cylinders to comply with the accounting and tracking requirements of the European Atomic Energy Community (EURATOM), United States Nuclear Regulatory Commission (USNRC) and the International Atomic Energy Agency (IAEA).

Storing and converting depleted uranium

The UF6 gas closer to the wall of the centrifuge is partially depleted of U235. This by-product is known as ‘tails’ (depleted UF6). We collect and cool tails in a cooling box containing a cylinder, which is weighed to ensure we can account for all material. Still containing a low concentration of U235, tails 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 safe, intermediate storage on our sites ahead of long-term disposal.

We are constructing our Tails Management Facility so we can carry out the process of chemically transforming depleted UF6 into U3O8. The deconversion process also creates hydrofluoric acid, a valuable chemical used globally by a number of industries.

Do you consent to this website placing cookies on your device?
You can find out more by reading our cookies policy here.