US Congressional report argues that Australia’s acquisition of nuclear submarines would actually undercut deterrence of China by depleting the US submarine fleet. With the promise of nuclear submarines becoming ever distant, it may be time to reconsider other options. 

Recent surprising disclosures have revealed that nuclear-powered submarines, which Australia plans to acquire under the trilateral AUKUS partnership, cannot achieve three of the government’s main stated objectives for the program. The Australian purchase would degrade, not enhance, deterrence against China. It could provide only a miniscule and inconsistent presence at sea even after two decades. And it would undermine rather than sustain the global non-proliferation regime. Thankfully, only a tiny fraction of the program’s total estimated cost of up to AUD $368bn has been spent to date, so it is not too late for Australians to consider better ways to ensure national security.

On the first objective, Australia’s former prime minister, Scott Morrison, who negotiated the AUKUS submarine deal, claimed it was necessary to achieve a “credible deterrent” against China, and his successor Anthony Albanese soon agreed. Last month, however, the US Congressional Budget Office (CBO) belied that assertion. It reported that, because the United States would sell Australia three to five existing nuclear attack submarines (SSNs) from the US fleet before the US industrial base could expand to replace them, “the sale of SSNs to Australia would reduce the number of attack submarines available to the [US] Navy.”

The CBO then posed a crucial question: “Would China be less deterred if the United States reduced the number of its attack submarines to help Australia develop its submarine force?” The answer appeared obvious because “Australia would control its own submarines, and their participation in any particular conflict would not be guaranteed. In fact, in March 2020, the Australian defence minister stated that his country did not promise to support the United States in the event of a conflict involving Taiwan and the People’s Republic of China.” Thus, the report indicated that Australia’s acquisition of nuclear submarines would undercut deterrence of China – exactly opposite to the claims of Australia’s leaders.

Second, Morrison declared in 2021 that AUKUS’s “first major initiative” would be to provide Australia a nuclear-powered submarine fleet. This year, however, Albanese conceded that the still-under-design SSN-AUKUS would not begin delivery to Australia until the 2040s at least. In the meantime, according to RAN Vice Admiral Jonathan Mead’s Senate Estimates testimony in May, Australia expects to receive from the United States by the late 2030s two partially used nuclear submarines and one new one. That may sound like three submarines, but it is illusory. Recent reports reveal that only 63 percent of the US Navy’s submarines are operable in any year, and those that can operate spend only 39 percent of the year at sea. Thus, on average, each US attack submarine is on duty for just 25 percent of the year, or three months. This means that even if Australia received its promised three US vessels by the late 2030s, on average the RAN would be able to deploy less than one nuclear submarine at a time. Is that really the “fleet” that Aussies expect for their billions of tax dollars?

Third, Albanese promised at the 2023 AUKUS summit that “Australia’s proud record of leadership in the international nuclear non-proliferation regime will of course continue.”  However, the SSN-AUKUS would violate a fundamental tenet of that regime by needlessly using weapons-grade, highly enriched uranium (HEU) fuel – sufficient for hundreds of nuclear bombs.

Since the 1970s, the non-proliferation regime has banned HEU fuel in the new reactors of countries like Australia that have pledged under the Nuclear Non-Proliferation Treaty to eschew nuclear weapons. The regime went so far as to convert 71 old reactors from HEU fuel to low-enriched uranium (LEU) fuel, to eliminate the proliferation risk. Indeed, HEU minimisation is deemed so vital for non-proliferation that it has been applied even to tiny reactors containing only one kilogram of weapons-grade uranium. Now Australia intends to eviscerate that non-proliferation norm by fuelling each SSN-AUKUS with hundreds of kilos of such bomb-grade uranium.

Fortunately, nuclear submarines do not require HEU fuel and can function perfectly well with LEU fuel, as the navies of France and China use. Despite this, Australia and its partners insist on HEU fuel for SSN-AUKUS, to enable smaller reactors without refuelling, thereby sending a message globally that HEU is required for the best submarines. As a result, we can expect other countries to declare – as Iran did immediately following the AUKUS announcement – that their navies too will use HEU, which they will enrich themselves, opening a huge back door to nuclear weapons. By contrast, LEU fuel is infinitely more proliferation resistant than HEU fuel, notwithstanding musings by uninformed AUKUS cheerleaders.

Australia’s defence minister, Richard Marles, has dismissed proliferation concerns by saying the HEU fuel would be imported in “sealed” reactors and thus inaccessible. In reality, however, Australia announced this year that it would extract the HEU fuel from all retired submarines and retain it in perpetuity, thereby savaging the non-proliferation regime even further. The supposedly “spent” fuel from each retired submarine would in fact contain an estimated 200 kilograms of still very highly enriched uranium, sufficient for a dozen or more nuclear weapons.

So, what can Australia do now? At the least, it should ask its partners to switch to LEU fuel for Australia’s SSN-AUKUS, to comport with non-proliferation norms. Fortunately, the US Congress has funded development of LEU naval fuel for the last eight years, providing a head-start to incorporate such proliferation-resistant fuel in the ongoing design of the SSN-AUKUS. If Albanese means what he says about “leadership in the international nuclear non-proliferation regime,” this step is a no-brainer.

The bigger question is whether Australia should abandon pursuit of nuclear submarines entirely. The Congressional report suggests that doing so would actually strengthen deterrence over the next few decades by not depleting the US fleet. Australia instead could reprogram the hundreds of billions earmarked for its nuclear submarines to buy defence systems that would complement rather than undermine US deterrence. That certainly sounds like a win-win.

Alan J. Kuperman is associate professor and coordinator of the Nuclear Proliferation Prevention Project at the LBJ School of Public Affairs, University of Texas at Austin.

This article is published under a Creative Commons License and may be republished with attribution.