Teased and speculated for more than two years, Peter Dutton has finally revealed his nuclear power policy.
There is still a lot we don't know — the Coalition still hasn't said how much it will cost, how much of the bill taxpayers will foot, or when all the nuclear plants would be built.
But we do now have seven sites scattered across five states, all of them home to former or soon-to-be-former coal plants.
That is no coincidence: it will be key to Peter Dutton's pitch to voters that nuclear, not renewable energy, is the smoothest way to replace coal.
It might sound like a clean switch, but standing in the way are thorny questions of politics, economics, engineering and timing.
Why has the Coalition opened the floodgates to a nuclear conversation, and what lies ahead?
The problem
Australia is undergoing an energy transition.
The main reason is to reduce emissions — both major parties are committed to zero net emissions by 2050, and Labor has legislated a 2030 target consistent with global climate agreements.
But a secondary reason is that Australia's coal plants are fading fast. Several plants have closed in recent years. Eleven of the 18 coal plants we have left are set to close over the next decade.
And those that remain are creaky and increasingly unreliable. Unexpected coal plant closures have been a significant contributor to recent high power prices.
So far, the main alternatives have been renewable — solar, wind and hydro power — and gas, which Labor says will be needed throughout the transition.
But the pace of the renewable rollout has been slow, something the Labor government has blamed on its predecessor's lack of firm national targets and supporting policies.
That is something Labor hopes it is changing with its Capacity Investment Scheme, which underwrites renewable projects to improve their commercial viability and provide investors with certainty. Labor points to figures showing that renewables are now rolling out at a record pace.
But there is still a mountain of work to be done, including new transmission lines and storage capability needed to make renewables work year-round. Labor is just shy of being on track for its 2030 emissions target and local community objections are threatening to obstruct the process.
The proposal
It is in that context that the Coalition now proposes nuclear power.
Peter Dutton and Nationals leader David Littleproud say nuclear would be an alternative to renewables, delivering zero-emissions energy on ready-made sites using existing transmission lines, and therefore avoiding the need for the geographical footprint of renewable projects.
They propose to build on seven sites:
They are undecided between two types of nuclear power: large-scale reactors, like the ones that have long been operational in Europe, or small 'modular' reactors, an emerging but as-yet unproven technology.
The distinction is an important one. Large-scale plants are a 'base load' power source, hard to turn on and off so best deployed as primary, constant generators.
Conversely, small modular reactors could be more easily switched on and off and so could play a supplementary 'firming' role alongside base load renewables, coal or gas.
The Coalition says five of the sites could host either large or small, but the sites in WA and SA could only host small.
The practical difficulties
This poses the first challenge: even if it's assumed that five large plants and two small plants are built, that would add up to just over 6 gigawatts (GW) of generation capacity. That's compared to 22 GW of coal used currently, and well over 50 GW of generation capacity currently needed for the National Electricity Market (excluding WA).
That casts doubt over whether nuclear power would alone be a sufficient replacement for coal. The Coalition has sent mixed signals on that front — for example, David Littleproud said today he believed renewables had a role to play, but also said nuclear was "visionary" because it would mean a country "not covered in solar panels and wind turbines".
There would also need to be extensive studies to confirm that the nominated areas are actually suitable. Mr Dutton has pointed out that coal sites have some of the necessary attributes for nuclear, such a proximity to water for cooling.
But other attributes remain to be seen — for example, the likelihood of earthquakes in the proposed areas and how this might affect safety.
The next question: who pays?
Closer examination of the sites would also shed light on another unknown: the cost.
All available evidence suggests it will be expensive. According to CSIRO and the Australian Energy Market Operator's cost study ('GenCost'), large-scale nuclear is more expensive than renewables and small-scale nuclear is dramatically more expensive than anything else.
Coalition politicians have quibbled with the assumptions of that study, but it includes the cost of construction, generation and transmission and is the most detailed study available in the Australian context.
A Coalition business case would need either to come up with a convincing lower number or else argue that the hefty bill is worthwhile.
And that bill looks likely to be paid by taxpayers. Despite Shadow Treasurer Angus Taylor's insistence last month that the Coalition would only pursue nuclear if it was "commercially viable" and needed "no subsidies", the proposal is for the government to own the plants.
The Coalition has not said who would pay for the construction, but government ownership would generally require partial or full public subsidy — though the taxpayer could recoup the benefits in future if it retained ownership when the plants turn a profit.
When could the plants be built?
Next there is the question of timing. The Coalition says it could have the first two plants operational between 2035 and 2037 – the former date if it opts for small reactors and the latter date if it opts for large reactors.
That is more than a decade away, but it still falls short of the timeline suggested in GenCost, which puts the earliest possible date in the 2040s.
Either way, this would represent a very different trajectory for emissions reduction compared to Labor's plans, especially if it is accompanied by a scaling back of renewable energy ambition.
While Peter Dutton says he remains committed to net zero by 2050, he has discarded Labor's 2030 target and with it Australia's global climate commitments, dismissing the Paris climate accords as "Anthony Albanese wanting to be a Parisian."
Parliamentary barriers
Peter Dutton believes voters will not be troubled by this shift on climate targets. But the move has angered Labor, the Greens and teal independents, which points to difficulties ahead for a future Coalition government to legislate its plan.
New laws would be needed to remove the current ban on nuclear energy, enact safety regulations and waste disposal arrangements, and establish the financial arrangements for government ownership.
Those would be complicated pieces of legislation likely requiring years of consultation. But they also may struggle to get through the parliament. Even if the Coalition were to win a majority in the House of Representatives, it would need to defy two decades of history to win control of the Senate.
With the current Senate make-up, it is four shy of a majority even if it could count on right-wing crossbenchers, with Labor and the Greens implacably opposed.
Then there is the question of state laws — Queensland, NSW and Victoria all have state bans on nuclear power which would also need to be overturned, and so far no major party leader in any state has given Mr Dutton's plan public support.
Political debate lies ahead
Finally and most significantly, there is the political question: will voters be happy with nuclear, especially those in seats tapped to host nuclear plants, given six of the seven were won by the Coalition at the last election?
Labor is confident it can tap into community discontent, but the Coalition is confident it can get communities onside by emphasising the jobs associated with nuclear plants and has flagged extensive community consultation.
Whether it will have to offer communities other financial incentives to get them over the line remains to be seen.