A dramatic deterioration in Asian security could push Australia to acquire nuclear weapons, a strategy that it abandoned four decades ago, a new study says.

But Australian Strategic Policy Institute (ASPI) analyst Dr Rod Lyons says such a decision certainly isn't close nor is it inevitable.

He said the 2006 Switkowski report on nuclear power suggested it would take Australia at least 10 years and probably 15 to bring the first civil reactor into service.

"It's true that Australia might be able to conduct an emergency nuclear weapon construction effort in rather less time, especially if it were to focus on uranium enrichment to provide a uranium 235 bomb," he said.

"In that case, we wouldn't need to build a reactor. But enrichment is still a highly challenging exercise."

Australia flirted with the nuclear weapon option up until the late 1960s, with a 1968 cabinet paper costing a bomb program at what now seems a modest $150 million. Signing the non-proliferation treaty in 1970 closed off that option.

Dr Lyons said for Australia to swing back to a course it abandoned in the late 1960s would mean a huge - and reluctant - change in strategic policy.

"That course would be taken only with extreme reluctance and it's certainly not one that Australian governments have done much to prepare for over recent decades," he said.

Dr Lyons said Australian policies now aimed to achieve regional nuclear order as much as possible by establishing a benign strategic environment and by stressing non-proliferation, arms control and peaceful exploitation of nuclear technologies.

But should the regional approach change, with a rising prevalence of the technologies that could lead to nuclear weapons, Australia might need a different approach.

Dr Lyons said a number of scenarios could lead to a more worrying Asian nuclear order.

One is a weakening of US nuclear capabilities and loss of confidence in US nuclear deterrence. In such an environment, nations such as Japan, Korea or even Burma could develop nuclear weapons.

A revisionist great power could also arise. Much of the momentum towards an Australian nuclear weapon arose in the 1950s in response to communist China.

And the existing non-proliferation regime could collapse.

Dr Lyons said none of these scenarios were likely, but any would heighten the sense of regional nuclear disorder.

In such a climate, Australia might opt for what's termed "nuclear hedging" - maintaining, or appearing to maintain, capabilities to acquire nuclear weapons in a relatively short time, ranging from a few weeks to a few years.

On that basis Australia now has no semblance of a hedging strategy, lacking any enrichment, weapon design or missile capability. However Australia does produce a large amount of the world's uranium.

"Nuclear hedging is a strategy with remarkably long legs: it can be pursued at a modest tempo over decades," he said.

"It typically involves no hasty, expensive strategic programs, but the gradual accretion of expertise and systems."

On that basis, both Sweden and Japan could develop nuclear weapons within a few years.

Dr Lyons said Australia would have good advance warning of changing strategic circumstances, although developing the necessary capabilities could still take 20 years or more.