Proliferation warnings over enriched nuclear fuel for advanced reactors

Governments and oth­ers promoting the use of high-assay low-enriched uranium (HALEU) for nuclear power have not considered the po­tential terrorism risk that wide adoption of this fuel creates, nuclear scientists have warned.

HALEU is a nuclear reactor fuel enriched with uranium-235 to between 5% and 20%. At 20% uranium-235 and above, the mix­ture is called highly-en­riched uranium (HEU) and it is internationally recognised that it can be employed in nuclear weapons.

Historically, HALEU use has been limited to research reactors, where it is used in small quantities, while commercial reactors typically used fuels with low enrichments, in the range of 3 to 5% uranium-235, which cannot sustain an explosive chain reaction.