The UK government has announced that it is to invest £300-million in the creation of a commercial-scale production plant for high-assay low-enriched uranium (HALEU) fuel for nuclear reactors. It will be located in the north-west of England. HALEU is defined as uranium that is enriched to more than 5%, but less than 20%, with the uranium-235 (U-235) isotope. Currently, HALEU is largely used in research reactors and for the production of medical radioisotopes. Current conventional nuclear power plant reactors use low-enriched uranium (enriched to 5%, or less, of U-235). But HALEU will be required to power advanced reactor designs, including more than half of the small modular reactors (SMRs), currently under development.