A global threat for millennia: experts warn Australia’s nuclear submarine legacy will be weapons-usable uranium cache

A Virginia-class submarine off the coast of Western Australia last year. The uranium left behind by Australia’s Aukus nuclear submarines at the end of their working lives will likely still be enriched to about 80%: the same level as the atomic bomb dropped on Hiroshima. Photograph: Colin Murty/AFP via Getty Images

Australia’s proposed nuclear submarine fleet will leave behind tonnes of weapons-usable uranium-235: radioactive for hundreds of millions of years, and capable of being processed into scores of warheads, nuclear experts have told a public inquiry into Aukus.

And a former White House national security adviser has told the Guardian that Australia’s Aukus deal – involving the transfer of highly enriched uranium to a non-nuclear weapons nation – sets a dangerous proliferation precedent that other countries such as Iran could try to exploit, weakening global control of the spread of weapons-usable nuclear material.