Microsoft, Amazon, Google, and Meta have collectively signed more nuclear power capacity in the last eighteen months than the US signed in the previous twenty years — and almost all of it is tied to AI data centers that need clean, firm, always-on electricity at a scale wind and solar alone can't deliver. Here's exactly what an SMR is, who's building them, which hyperscaler has committed to what, and how close any of it actually is to turning on.
A single hyperscale AI campus under construction in 2026 can draw 1–2 gigawatts continuously — enough to power a mid-sized American city. Grid operators in Virginia, Georgia, Texas, and Arizona have already warned that combined AI buildout load will outstrip planned generation additions before the end of the decade. Solar and wind can't fill that gap because AI training and inference need firm, 24/7 power, not intermittent generation. That leaves nuclear — and specifically, a new generation of small modular reactors designed to be built faster, sited closer to the load, and financed more predictably than the traditional gigawatt-scale plants of the last fifty years.
What an SMR actually is
A small modular reactor is a nuclear reactor built well below the roughly 1,000+ megawatt scale of a conventional plant, designed around standardized components that can be manufactured in a factory and shipped to a site rather than custom-built on location over a decade. The "modular" part is the real innovation: instead of one enormous bespoke construction project, an SMR plant can be built by combining multiple identical, factory-fabricated units — the same approach that made submarine reactors and other small nuclear systems dramatically more predictable to build than one-off megaprojects.
How small is "small," exactly
"Small" is relative to a traditional plant, not to what most people picture when they hear "nuclear reactor." Most SMR designs cluster between roughly 50 and 470 megawatts electric, compared to 1,000–1,600+ MWe for a conventional large reactor — and a sub-category called microreactors goes even smaller.
Scale gives a sense of what that output means in practice: roughly 300 SMRs could generate enough electricity to power 68 million homes — about half of all US households — with carbon emissions avoided equivalent to taking 100 million cars off the road, per Oregon Group critical minerals research. A single hyperscale AI campus alone can require 1–2 GW, meaning it would take multiple SMR units, not one, to serve a large data center's full continuous load.
Why data centers specifically need this
Nuclear offers 24/7 carbon-free baseload power with capacity factors above 90%, positioning SMRs as critical infrastructure specifically because hyperscalers are under shareholder pressure to hit net-zero commitments and can't fill a multi-gigawatt gap with natural-gas peaker plants without breaking those pledges. SMRs add a second advantage over both renewables and traditional nuclear: they can be sited closer to transmission lines and, in some proposed configurations, co-located directly with the data center itself — bypassing some of the grid interconnection queue entirely.
Who makes small modular reactors
SMR is an umbrella term covering genuinely different technologies — different coolants, fuels, and use cases. Here are the designs with real orders, real construction, or real hyperscaler customers behind them as of 2026.
GE Vernova Hitachi — BWRX-300
The furthest along of any Western SMR design. Under construction at Ontario Power Generation's Darlington site in Canada — the first SMR construction project in North America — targeting commercial operation around 2030. Also selected by SaskPower for Saskatchewan's first nuclear plant. Uses natural circulation instead of electrical pumps for core cooling, simplifying the design and its economics.
NuScale Power — VOYGR
The first SMR design to receive full NRC design certification. A 12-module VOYGR plant (684 MWe total) is estimated at roughly $3 billion, or about $4,385/kW — useful as a real-world cost anchor against the sector's more optimistic NOAK (nth-of-a-kind) cost projections.
X-energy — Xe-100
Amazon led a $500 million financing round for X-energy and separately invested $700 million for rights to up to 12 Xe-100 units — part of Amazon's broader push into next-generation SMR technology alongside its existing nuclear power-purchase agreements.
Kairos Power — KP-FHR (Hermes)
Google signed the first US corporate SMR fleet deal with Kairos Power, targeting 500 MW total capacity. The Hermes demonstration reactor is under construction at Oak Ridge, and Kairos holds the first advanced-reactor construction permit issued by the NRC (2023).
TerraPower — Natrium
Bill Gates-founded; secured its NRC construction permit for the Kemmerer, Wyoming demonstration plant. Meta's largest single nuclear commitment (2.8 GW) is tied to eight planned Natrium plants, part of Meta's broader up-to-6.6 GW nuclear agreement announced January 2026.
Oklo — Aurora
Publicly traded (NYSE: OKLO), roughly $12.9 billion market cap. Broke ground at Idaho National Laboratory in September 2025. Part of Meta's 6.6 GW commitment via a 1.2 GW Aurora campus deal.
Rolls-Royce SMR
Progressing through UK regulatory assessment (Generic Design Assessment), with first units targeted for the early 2030s — the leading UK-developed design and one of the largest outputs still marketed as "small."
CNNC — Linglong One (ACP100)
Under construction in Hainan, China, and on track to become the world's first land-based commercial SMR, with commercial operation expected in H1 2026 — ahead of every Western competitor.
The hyperscaler deals, tracked
13 named deals, roughly 9.8–10+ GW of committed capacity, and every major hyperscaler pursuing a genuinely different strategy.
Agreed to buy the entire output of the restarted Three Mile Island Unit 1 (renamed the Crane Clean Energy Center) for 20 years — an existing-reactor restart, not a new SMR build. A June 2026 FERC transmission waiver removed the last major grid obstacle, accelerating the timeline to H2 2027, a year ahead of the original 2028 target. Microsoft will be first among the four hyperscalers to actually receive nuclear power, precisely because it chose restart over new construction.
A power-purchase agreement for 1.9 GW through 2042 from Talen Energy's Susquehanna nuclear plant in Pennsylvania, supporting a $20 billion AWS buildout in the state, plus direct SMR investment via X-energy (up to 12 Xe-100 units) and a roughly $650 million data-center campus acquisition adjacent to Susquehanna for direct grid-bypass access.
The first US corporate SMR fleet deal, with Kairos Power (500 MW target). Separately agreed with Elementl Power in May 2025 to prepare three sites for advanced nuclear projects at 600 MW each — likely twin 300 MW SMRs per site — targeting first deployment around 2030.
The biggest single hyperscaler nuclear commitment tracked, combining TerraPower (8 Natrium plants, 2.8 GW), Oklo (1.2 GW Aurora campus), and separate utility power-purchase agreements. Also carries the longest timeline of the four — 2032 to 2035.
| Company | Committed capacity | Primary approach | Earliest delivery |
|---|---|---|---|
| Microsoft | 835 MW | Existing reactor restart | H2 2027 |
| Amazon | 1.9 GW + SMR stakes | PPA + direct SMR investment | Spring 2026 (PPA); SMRs later |
| 1.8+ GW | Next-gen SMR fleet deals | ~2030 | |
| Meta | Up to 6.6 GW | New-build SMR + utility PPAs | 2032–2035 |
The real benefits, and the honest caveats
| Claimed benefit | The honest caveat |
|---|---|
| Lower cost via factory production | Only materializes after 6–10 units of the same design are built; first-of-a-kind projects remain expensive ($4,000–12,000+/kW) |
| Faster construction (3–5 years vs. 6–10) | Not yet demonstrated at scale in the West — the Darlington BWRX-300 is the actual test case, completion targeted 2030 |
| Enhanced passive safety | Genuine design improvement (natural circulation, gravity-driven cooling), but still subject to full regulatory review per design |
| Siting flexibility, closer to load | Still requires NRC/CNSC/ONR licensing and community approval — not a shortcut around all regulatory process |
| 24/7 carbon-free baseload | The genuinely uncontested benefit — 90%+ capacity factor vs. 25–35% typical for solar/wind |
How close is any of this to actually turning on
Despite the scale of capital committed, SMRs remain, by the industry's own admission, still years from widespread commercial operation in the West.
The bottleneck nobody's solved yet
Per the 2026 State of Small Modular Reactors intelligence report, the HALEU (high-assay low-enriched uranium) fuel supply chain remains the single biggest bottleneck facing the entire industry, with domestic US production lagging far behind reactor demand. Several of the most advanced designs — TerraPower's Natrium, X-energy's Xe-100, Oklo's Aurora — specifically require HALEU rather than the conventional low-enriched uranium used in existing US reactor fleets. Until that supply chain scales, fuel availability, not reactor design or construction, may end up being the actual limiting factor on how fast any of these projects can move from construction permit to commercial operation.
Recent news worth knowing
- June 2026: FERC approved a transmission waiver transferring 760 MW of grid-connection rights to Microsoft's Crane Clean Energy Center site, removing the last major grid obstacle and accelerating full power delivery to H2 2027.
- May 2026: Terrestrial Energy and Riot Platforms announced a collaboration targeting up to 4,000 MW of data center capacity powered by multiple 390 MW Integral Molten Salt Reactor plants.
- February 2026: Oklo filed for an IPO-adjacent public listing move targeting a $10 billion+ valuation, reflecting investor appetite for pure-play SMR exposure.
- December 2025: X-energy filed its NRC construction permit application for the SMR-300, alongside a $400 million DOE award supporting the project.
Frequently asked questions
The leading developers with real orders or construction underway include GE Vernova Hitachi (BWRX-300), NuScale Power (VOYGR), X-energy (Xe-100), Kairos Power (KP-FHR), TerraPower (Natrium), Oklo (Aurora), Rolls-Royce SMR, Westinghouse (AP300, eVinci), and China's CNNC (Linglong One) — each pursuing a different reactor technology and fuel type.
Most SMR designs range from about 50 to 470 megawatts electric, versus 1,000–1,600+ MWe for a conventional large reactor. Microreactors go even smaller, under 20 MWe, small enough in some designs to be transportable.
Microsoft, via the restarted Crane Clean Energy Center (formerly Three Mile Island Unit 1), targeting H2 2027 — ahead of Google, Amazon, and Meta's new-build SMR projects, which mostly target 2030 or later, because Microsoft chose an existing reactor restart rather than new construction.
The economics are still unproven at scale in the West. SMRs target $4,000–7,000/kW at nth-of-a-kind production versus $8,000–12,000/kW for recent large reactor builds, but that cost reduction depends on building at least 6–10 units of an identical design — a milestone no Western SMR developer has yet reached.
Our methodology
Every reactor specification, deal figure, and timeline in this article is sourced from a named developer, government agency (DOE, NRC), or specialist industry intelligence publisher tracking the sector directly. We did not include unconfirmed rumors or unnamed-source reporting, and we flagged the sector's real setbacks (the 2023 US SMR cancellation, the unresolved HALEU bottleneck) alongside the positive momentum rather than presenting only the promotional narrative.
- Reactor specifications (MWe output, coolant type, design status) are sourced to each developer's own published data and cross-checked against DOE and NRC public filings where available.
- Hyperscaler deal figures reflect publicly announced capacity commitments as of August 2026; several deals name target dates that remain subject to construction and licensing risk.
- Where sources gave differing capacity totals for the same company (for example, Meta's commitment cited as both 5.2 GW and 6.6 GW across different reports), we used the more recent, more specific figure and noted the range.
- This article is reviewed periodically as new hyperscaler deals, construction milestones, and NRC/CNSC licensing decisions are announced.
Sources
Data compiled from the following primary and named sources (accessed August 2026):
- U.S. Department of Energy, Office of Nuclear Energy — "First U.S. Small Modular Boiling Water Reactor Under Development"
- GE Vernova Hitachi Nuclear — BWRX-300 Small Modular Reactor program pages
- SMR Intelligence — "State of Small Modular Reactors 2026 — Annual Intelligence Report" and "Every Nuclear-Powered Data Center Deal: Google, Amazon, Meta & Microsoft (2026)"
- IEEE Spectrum — "Big Tech Embraces Nuclear Power to Fuel AI and Data Centers"
- IDTechEx — "Data Centers Go Nuclear: Why AI Giants are Investing in SMRs"
- Trellis — "Amazon, Google, Meta and Microsoft go nuclear"
- EnkiAI — "Google Nuclear 2026, 1,800 MW Elementl Power Deal"
- Internet Pros — "Small Modular Reactors (SMRs) 2026 - How Micro Nuclear Is Powering AI Data Centers"
- Discovery Alert — "Small Modular Reactors: Clean Energy Revolution Explained"
- How To Store Electricity — "SMR Types and Designs 2026: BWRX-300, NuScale, Natrium, Xe-100 Compared"
- Energy Solutions Intelligence — "Small Modular Reactors (SMR) 2026: AI Data Centers, LCOE & Global Deployment Intelligence"
- The Oregon Group — "Small reactors, big stakes: how the global SMR race is reshaping uranium demand"
