Uranium is the fuel used in nuclear power plants to generate electricity. Before it can be used in a nuclear reactor, however, uranium has to undergo several industrial processes to make it fit for purpose.
Producing a raw product
Uranium is mined as uranium ore, then milled, purified and concentrated at the mine site. This produces a solid known in the industry as yellowcake.
Preparing for enrichment
Yellowcake is then transported to specialist converters, which convert the uranium into uranium hexafluoride (UF6). This substance is a solid at normal temperatures, but is easily converted into a gas. The uranium is converted because, as gaseous UF6, it becomes possible to enrich it in the manner required for nuclear power plants to use it successfully.
Enrichment – the key step
Uranium contains two isotopes, U-238 and the slightly lighter U-235. The yellowcake which is produced at the mine site contains only around 0.7% U-235, whereas today’s nuclear reactors usually require a concentration of between 3% and 5% of this isotope for effective nuclear operation. Uranium enrichment is the key step in the nuclear fuel supply chain. ETC has developed very efficient and reliable centrifuge technology, which has proven its effectiveness over many years of operation.
Fuel production
Enrichment produces both a stream of UF6 enriched in U-235, and a stream of that is depleted in U-235. The enriched UF6 is converted into pellets, which are then loaded into fuel rods. Depleted UF6 can often be fed back into the enrichment process for further processing.
Creating nuclear energy
The fuel rods are delivered to nuclear power plants where they are inserted into the core of the reactor. Heat generated by nuclear fission within the core is used to heat water to produce high pressure steam. This steam drives turbines which in turn generate electricity.
Electricity on demand
The electricity produced is fed into the national grid, and distributed at high voltage. After the voltage is reduced, it is supplied to homes and businesses. Because electricity cannot be stored, it must be supplied on demand. As global reliance on electricity increases it becomes ever more important that our electricity needs are met via a sustainable route.