One SMR project in the world is currently pouring safety-related concrete. One was cancelled after its customers walked away over the price. Everything else — and there is a lot of everything else — is a design, a licence application, or a slide deck. That gap between the spruiking and the shovels is the whole story, so let’s agree on the units before we go any further.
Agree on the units first: what “small” and “modular” actually mean #
A small modular reactor is generally anything under about 300 megawatts, built in factory-fabricated sections that get trucked or shipped to site rather than poured and welded on location like a conventional 1,000-plus megawatt plant. The pitch has been consistent for close to twenty years now: standardise the design, build the tenth one as cheaply as the first was expensive, and you dodge the giant cost overruns that have plagued big nuclear builds from Georgia to Flamanville.
It’s a genuinely reasonable engineering argument. The trouble, historically, has been that nobody gets to the tenth unit, because the first one keeps blowing its budget and its timeline, and the customers who were meant to buy units two through ten quietly disappear. I’ve watched this exact cycle happen twice now with different companies and different countries, and I’d be lying if I said this time obviously feels different.
The one that’s actually happening: Darlington #
Ontario Power Generation’s site at Darlington, on Lake Ontario, is the project furthest along anywhere in the world. OPG is building GE Vernova Hitachi’s BWRX-300 design — a 300-megawatt boiling water reactor, the most conventional of the current SMR field, using licensing lineage from GE’s existing large reactors rather than an exotic new coolant. Site works began several years back and OPG has now moved into safety-related construction on the first of a planned four units, with the Canadian Nuclear Safety Commission overseeing licensing at each stage. That’s a genuine first-of-a-kind build, not a rendering, and it’s the project every other SMR developer points to when they want to look credible.
Worth noting: it’s still one unit, in a country with an existing large nuclear fleet, existing regulator familiarity with the technology base, and a utility that’s built and refurbished reactors before. None of those conditions apply in Australia. Readers of our earlier piece on the Coalition’s nuclear plan and its cost and timeline questions will recognise why that gap matters.
The one that wasn’t: NuScale in Utah #
The counter-example is NuScale Power’s Carbon Free Power Project in Idaho, backed by a group of Utah municipal utilities (UAMPS). It was, for years, the flagship American SMR project — first design certified by the US Nuclear Regulatory Commission, real customers signed up. In late 2023 the project was cancelled after the target price per megawatt-hour rose well beyond what the subscribing utilities were willing to underwrite, and not enough of them stayed in to make the economics work. NuScale itself remains listed and is pursuing other customers, including data centre operators chasing firm, carbon-free power. But the Idaho cancellation is the one every sceptic quotes back at every optimist, and fairly so — it’s the clearest real-world data point we have on what happens when an SMR project meets an actual price signal rather than a press release.
Where Australia actually sits #
The short version is: nowhere yet, and not by accident. Commercial nuclear power generation is prohibited under the Australian Radiation Protection and Nuclear Safety Act 1998 and mirrored state legislation, a moratorium that’s been in place since 1998 and that survived the last federal election largely intact. The only reactor currently operating on Australian soil is ANSTO’s OPAL research reactor at Lucas Heights in Sydney’s south, which makes medical isotopes and does materials research — it doesn’t put a single watt on the grid. Our piece on whether Australia actually needs nuclear power goes through the legal and political mechanics in more detail; nothing has moved on that front since.
The Coalition took a nuclear policy, including SMRs at several nominated coal sites, to the last federal election and it wasn’t the winning argument. Whatever you think of the policy’s substance, the electoral verdict means the moratorium isn’t going anywhere in this term of parliament, which makes SMRs, for now, a live technical conversation and a dormant policy one.
The cost question nobody has actually settled #
CSIRO’s GenCost report, produced jointly with AEMO and updated annually, remains the most rigorous public costing exercise available for Australian conditions, and it has consistently found nuclear — SMR or large-scale — sitting well above firmed renewables on levelised cost, even before you price in the fact that Australia has no existing supply chain, workforce, or regulator experienced in commercial nuclear construction. Our earlier explainer on the Coalition’s nuclear plan and the companion piece on whether Australia actually needs nuclear power both go through those figures; I won’t relitigate the whole argument here, except to say that every SMR vendor globally has revised its own cost estimates upward at least once, usually more, and Australia would be building without the benefit of anyone else’s second or third unit to learn from.
That’s the part that gets lost in the domestic debate, which tends to become a referendum on whether nuclear is good or bad in the abstract. It’s really a referendum on sequencing: coal stations are closing on a schedule, as we’ve covered in our piece on whether Australia is closing coal faster than it can replace it, and nothing SMR-shaped could plausibly be licensed, built, and commissioned inside that window. Darlington’s BWRX-300, in a country that already runs reactors, is targeting completion toward the end of this decade for a single unit. Extend that timeline for a jurisdiction starting from a legislative ban and zero domestic capability, and the numbers stop being close.
What would actually have to be true #
None of this means the technology is a dead end everywhere. If Darlington’s first unit comes in close to budget and on schedule, and if a genuine production run gets underway — Ontario has signalled interest in further units, and Poland, the Czech Republic and a scattering of US utilities have signed letters of intent for the same design — then the standardisation argument starts to have real evidence behind it rather than aspiration. TerraPower’s Natrium project in Wyoming, using sodium coolant rather than water, is a different bet again: it’s backed partly by Bill Gates, aimed at pairing with molten salt storage to firm variable output, and it’s worth watching precisely because it’s trying to solve a different problem to the BWRX-300 — flexibility rather than just size.
My own read, for what it’s worth, is that the Australian SMR argument was never really about the reactors. It’s a proxy fight about how fast coal should close and what should replace it, dressed up in reactor vessel specifications. Pretending the fight is really about thermal efficiency and passive safety systems, when it’s actually about the timetable in NSW’s coal exit and REZ rollout or Queensland’s public ownership model, wastes a lot of good expertise on the wrong argument.
A Perth aside, because I can’t resist #
I spent a clear night up at the Perth Observatory in Bickley a few months back, the volunteers running the old telescopes for a school group, and got talking to one of them about isotope decay chains — turns out old-school astronomers know an unreasonable amount about nuclear physics, given how much of it explains what’s happening inside the stars they’re pointing telescopes at. He made the point, half-joking, that humans have been remarkably patient waiting for fusion and remarkably impatient waiting for fission to get cheap. Watching the SMR industry over the past decade, that feels about right. The physics has been settled for seventy years. The economics of building it small, fast and repeatably has not, and no amount of confident marketing changes that.
Where this leaves Australia is roughly where it’s been for a few years now: a live technical debate sitting on top of a dormant legal one, watching Ontario’s concrete pours more closely than most people would admit. Darlington’s next milestone, and whether OPG’s second unit gets ordered on the strength of the first, will tell us more about the real cost curve than any Australian feasibility study could. I’ll be checking the Canadian Nuclear Safety Commission’s public filings when that milestone lands, and I’d suggest anyone seriously arguing the Australian case do the same before quoting a levelised cost figure with more confidence than the industry itself currently has.
— Tom Fitzgerald, Baseload & Fuels Correspondent
Photo by Jason Mavrommatis on Unsplash