IAEA lifts nuclear outlook to 2060 and puts SMRs in the high case

The International Atomic Energy Agency raised its long-range nuclear power outlook for the sixth year running on 14 September and, for the first time, published figures out to 2060 rather than 2050.

Director General Rafael Mariano Grossi presented the 46th edition of Energy, Electricity and Nuclear Power Estimates at the 70th General Conference in Vienna. At the end of 2025 the world had 413 operating reactors and 377.1 gigawatts of nuclear generating capacity.

In the high case, capacity reaches 1,045 gigawatts by 2050, above last year's 992-gigawatt high case, and 1,284 gigawatts by 2060. That 2060 figure is about 3.4 times the 2025 level. In the low case, capacity reaches 696 gigawatts by 2060, nearly double 2025. Small modular reactors are written into the high case as a new source of supply that the previous 2050-only editions treated more cautiously.

The agency said countries are looking at nuclear plant to meet rising electricity demand and to harden energy security, and that new build must also offset reactors that will retire. The high case is not a forecast of what will be built. It is the upper path in a two-path official estimate that has been revised up every year since 2020.

What changed in the method

Extending the horizon by ten years is the formal novelty. A 2050 high case of 1,045 gigawatts already implied a large construction programme. Adding 239 gigawatts between 2050 and 2060 in the high case assumes that programme continues rather than peaks and fades. The low case still nearly doubles today's fleet by 2060, which means even the cautious path is a growth path.

SMRs are the second change. They appear as a significant new source in the agency's own language for this edition. That is a shift from treating them as a footnote. It does not mean the IAEA has counted specific SMR orders. It means the high case no longer assumes that almost all new megawatts will come from large light-water units of the kind already operating.

Retirement is the third number hiding in the text. Many reactors that entered service in the 1970s and 1980s will reach the end of extended licences in the 2030s and 2040s. The net additions in both cases have to replace those units and then add more. Gross new build is therefore larger than the net figures Grossi read out.

The political room in Vienna

The projections landed on the same morning the conference opened without Iran's nuclear chief, whose visa had been revoked, and a day after the Board of Governors asked Grossi to report Iran to the Security Council. The outlook document is about civilian generating capacity. It is being presented in a hall that is also arguing about inspections and snapback.

Those two files should not be collapsed. A country can add reactors and still be in a safeguards dispute. The 413 reactors and 377.1 gigawatts are a count of machines connected to grids, not a scorecard of compliance.

For governments that have announced nuclear programmes since 2022, the sixth consecutive upward revision is useful cover. For governments that have not, the low case still describes a world with twice today's nuclear capacity by 2060. Either path requires fuel, trained staff and a construction industry that has not delivered at that rate in decades.

The document to read is the 46th estimates report, not the speech. The figures that matter are 377.1 now, 1,045 or 992 at 2050 depending on which year's high case one cites, and 1,284 or 696 at 2060. Everything else is commentary on whether shipyards and welders exist to match those lines.