It is unprecedented for a non-nuclear armed nation to acquire nuclear-powered submarines.

Proliferation Risk

The acquisition of naval nuclear power via the AUKUS arrangement exploits a loophole in the Nuclear Non-Proliferation Treaty (NPT) safeguards agreements, and undermines the treaty.

The proposed naval nuclear reactors will require weapons-grade Highly Enriched Uranium (HEU).

States without nuclear weapons, like Australia, can remove HEU from safeguards for a temporary period for use in military applications short of nuclear weapons. No nation has yet done this in relation to naval nuclear reactors. 

Nuclear Waste

Naval nuclear reactors have lifecyles of 33-40 years and must be decommissioned and replaced.

The British Navy has failed to dismantle 20 submarines retired since 1980, meaning that the British Navy stores twice as many submarines as it operates.

Australia will be required to manage and store spent nuclear fuel, and radioactive parts from decommissioned submarines.  No nation anywhere in the world has developed a viable solution for the permanent disposal of high level nuclear waste.

Safety

Naval nuclear reactors – like all nuclear reactors – pose potentially serious risks for people and the environment. Communities in proposed and existing port sites strongly oppose naval nuclear reactors.

But unlike other reactors, most information about naval reactors is kept classified. Safety regulations that apply to civilian ports and commercial nuclear reactors do not apply to military vessels. There is strong precedent for withholding naval nuclear safety information from the public, even when there are safety breaches and risks.