Nuclear subs in Australia will challenge the nonproliferation regime, and China

President Biden and the prime ministers of Australia and the United Kingdom announced on Sept. 15, as the first action in their new AUKUS defense agreement, the sale to Australia of nuclear submarine technology to replace an existing Australian deal with France for conventional submarines. The plan is to build the submarines in Australia with assistance, and perhaps components, from the UK and U.S.

The announcement surprised many, including the French government, whose foreign minister referred to the decision as a “stab in the back.”

The Biden administration has touted the agreement as a counter to growing Chinese naval intimidation of Australia and other countries in the Indo-Pacific region. It appears likely, however, that any beneficial impacts on China will be offset by negative impacts on the nuclear weapons nonproliferation regime. Other non-nuclear-armed states, such as South Korea and Iran, are likely to be incentivized to acquire nuclear-powered attack submarines from the U.S. and UK, or perhaps Russia or China. 

The AUKUS deal is especially problematic because U.S. and UK nuclear-powered submarines use weapon-grade highly-enriched uranium (HEU) as fuel. An obvious presumption therefore is that the Australian submarines too will be fueled with HEU drawn from the U.S. Cold War surplus. 

It is hard to understate what a departure the Australian plan is from prior U.S. policy. In the 1980s, the U.S. pressured France and the UK not to supply nuclear-powered submarines to Canada due to the perceived negative impact on the nonproliferation regime. U.S. nonproliferation policy has also had a bedrock principle of reducing the global availability and use of HEU. It would be folly for the U.S. to now export weapon-grade uranium to non-nuclear-armed states after spending more than a billion dollars since 9/11 to convert research reactors that the U.S. and the Soviet Union had exported to dozens of countries from weapon-grade to low enriched uranium fuel.

Since Australia does not have a commercial nuclear power program (it does have a research reactor) and no military support facilities for nuclear-powered vessels at this point, it will probably have to rely initially on the U.S. or UK for both personnel training and support for nuclear infrastructure development. Given the strong historic relation between the Royal Australian Navy and UK’s Royal Navy, the UK might provide initial training for submarine cadres to man the new Australian nuclear submarine force. 

The ultimate creation of a nuclear submarine force in Australia will take decades. Therefore, Australia might follow India’s model and start by renting a nuclear submarine from either the U.S. or UK. India rented two submarines: The first from the Soviet Union and then a second from Russia, before building its own nuclear submarine, whose design appears to be based to a significant degree on its second leased submarine. Acquiring a U.S. or UK submarine, possibly with a joint crew, could be a big first step forward for an Australian nuclear submarine program.

If the AUKUS plan goes forward, a significant question is whether the proliferation risks associated with HEU could be reduced by developing propulsion reactors fueled with non-weapon-usable low-enriched-uranium (LEU). France and China already use LEU to fuel their naval reactors. Russia and India use HEU fuel, although not weapon-grade.

Despite encouragement from Congress over the past 25 years, the U.S. Navy has vehemently rejected designing its future submarines to be powered by LEU. The principal argument is that the reactor core would have to be larger or would have to be refueled once or twice. The U.S. Navy’s current reactors are designed to be life-of-the-ship, which the Navy considers to be a significant cost and time savings. U.S. refueling cycles have kept U.S. submarines in shipyards for over a year to carry out refuelings, although France has developed robotic refueling arrangements through hatches that have reduced that time to a few weeks.

After the U.S. nuclear weapon stockpile peaked in 1964, the U.S. continued to produce weapon-grade uranium for naval reactor fuel until 1992. For the past two decades, U.S. and UK submarines have been fueled with HEU from more than 10,000 U.S. nuclear warheads that became excess at the end of the Cold War. This source will run out by around 2060. In order to maintain HEU fueled submarines and aircraft carriers, the U.S. will soon need to study and fund a very expensive new facility to produce HEU. Providing HEU fuel for Australia will accelerate the need for a new facility.

The Biden administration could also look at the Australian development program as an additional motivation to shift U.S. submarines and aircraft carriers to LEU fuel. That would avoid the need for the U.S. setting the dangerous example of developing a new HEU production facility after the existing supply is used up. Australia, France, the U.S. and UK could also work with the International Atomic Energy Agency to deal with the safeguard issues that arise from the military use of nuclear reactors in non-nuclear-weapon states. That too would be made much easier if the submarines were fueled with low-enriched uranium.

Should there be interest in the Biden administration to patch things up with France, it might explore bringing France back into the Australian submarine program to provide its expertise on LEU-fueled submarines. 

George M. Moore is a scientist-in-residence at the Middlebury Institute of International Studies at Monterey. He was previously a staff member at Lawrence Livermore National Laboratory and was a senior analyst at the International Atomic Energy Agency. Frank N. von Hippel, a nuclear physicist, is professor of public and international affairs emeritus in Princeton University’s Program on Science and Global Security.