SMR tracker: small modular reactor companies and projects, 2026
Small modular reactor news moves quickly, and much of it is announcements rather than steel in the ground. This tracker separates the two. Each row is a company or project with a public milestone, and each milestone links to the regulator, government agency or company that published it.
How to read the tracker
- Size is electrical output (MWe) unless marked thermal (MWt). The U.S. EIA defines SMRs as about 300 MW per unit or less, and microreactors, a subset of SMRs, as generally 20 MW or less.
- Stage uses five plain steps: Concept or agreement, Licensing, Under construction, Test reactor critical, Operating.
Operating and under construction
| Project | Company | Size | Location | Stage | Milestone | Source |
|---|---|---|---|---|---|---|
| HTR-PM | China Huaneng; Tsinghua University; CNNC | 2 x 250 MWt; 210 MWe turbine | Shidao Bay, Shandong, China | Operating | Entered commercial operation | 2023-12-06 |
| Darlington New Nuclear Project BWRX-300 | Ontario Power Generation; GE Vernova Hitachi | 300 MWe | Clarington, Ontario, Canada | Under construction | Licence to construct Apr 2025; RHP-1 removed 30 Mar 2026; operating licence applied Mar 2026 | 2026 |
Test reactors that reached criticality in 2026
DOE's Reactor Pilot Program set a goal of criticality for at least three advanced test reactors outside the national laboratories by 4 July 2026. DOE reported four.
| Project | Company | Location | Stage | Milestone | Source |
|---|---|---|---|---|---|
| Mark-0 | Antares Nuclear | US | Test reactor critical | Criticality June 2026 | 2026-07-06 |
| Ward 250 | Valar Atomics | US | Test reactor critical | Criticality June 2026 | 2026-07-06 |
| Unity | Deployable Energy | US | Test reactor critical | Criticality June 2026 | 2026-07-06 |
| Aalo-X | Aalo Atomics | Idaho National Laboratory, US | Test reactor critical | Zero-power fueled criticality early July 2026 | 2026-07-06 |
Licensing, planned projects and other milestones
| Project | Company | Type | Size | Location | Stage | Milestone | Source |
|---|---|---|---|---|---|---|---|
| Clinch River BWRX-300 | Tennessee Valley Authority; GE Vernova Hitachi | BWR | 300 MWe | Oak Ridge, Tennessee, US | Licensing | Construction permit application submitted to NRC | 2026 |
| BWRX-300 fleet Poland | ORLEN Synthos Green Energy | BWR | About 24 units, six locations | Poland | Concept or agreement | Fleet plan | 2026 |
| ReFirm BWRX-300 | Studsvik; GE Vernova Hitachi; Samsung C&T; DS Investment Partners | BWR | Four units, about 1.2 GW | Sweden | Concept or agreement | Agreement 3 Sep 2026; first unit mid-2030s | 2026-09-03 |
| NuScale US460 | NuScale Power | PWR | 77 MWe per module | US | Licensing (design approved) | NRC standard design approval May 2025 | 2025-05 |
| Carbon Free Power Project | UAMPS; NuScale | PWR | n/a | Idaho, US | Cancelled | Project terminated | 2023-11-08 |
| Energy Northwest Xe-100 | X-energy; Energy Northwest; Amazon | HTGR, TRISO-X fuel | 4 x 80 MWe, option 12 units / 960 MWe | Central Washington, US | Concept or agreement | Amazon-backed initial project; 5 GW by 2039 target | 2024-10-16 |
| Kairos Power fleet | Kairos Power; Google | Advanced | Up to 500 MW | US | Concept or agreement | First SMR targeted by 2030; more through 2035 | 2024-10-14 |
| KRONOS MMR | NANO Nuclear Energy | HTGR microreactor | Up to 45 MWth per unit | US; Canada | Licensing | NRC licensing process; CNSC formal review (company claim) | 2026 |
| DOE Reactor Pilot Program (1 project) | Atomic Alchemy | Test reactor | n/a | US | Selected | Selected 12 Aug 2025 | 2025-08-12 |
| DOE Reactor Pilot Program (1 project) | Deep Fission | Test reactor | n/a | US | Selected | Selected 12 Aug 2025 | 2025-08-12 |
| DOE Reactor Pilot Program (1 project) | Last Energy | Test reactor | n/a | US | Selected | Selected 12 Aug 2025 | 2025-08-12 |
| DOE Reactor Pilot Program (1 project) | Natura Resources | Test reactor | n/a | US | Selected | Selected 12 Aug 2025 | 2025-08-12 |
| DOE Reactor Pilot Program (2 projects) | Oklo | Test reactor | n/a | US | Selected | Selected 12 Aug 2025 | 2025-08-12 |
| DOE Reactor Pilot Program (1 project) | Radiant Industries | Test reactor | n/a | US | Selected | Selected 12 Aug 2025 | 2025-08-12 |
| DOE Reactor Pilot Program (1 project) | Terrestrial Energy | Test reactor | n/a | US | Selected | Selected 12 Aug 2025 | 2025-08-12 |
What the tracker shows
- One commercial SMR plant is operating, and it is a pebble bed: HTR-PM. See the pebble bed reactor explained.
- The BWRX-300 has the deepest pipeline of any light-water SMR.
- Hyperscalers are now anchor customers. See nuclear power for data centers.
- Test reactors moved fastest in 2026, through DOE authorisation rather than NRC licensing.
For comparisons between reactor classes, see SMR vs microreactor and CANDU reactor.
Methodology
Sources: regulators (CNSC, NRC), government (U.S. DOE, EIA), the trade press of record (World Nuclear News) and company announcements. We do not publish costs, price estimates or our own forecasts. For definitions, see small modular reactors and SMR vs microreactor.
About BridgePower Nuclear
BridgePower Nuclear, a joint venture of USP&E and BAM Energy, maintains this tracker. USP&E brings 24+ years in power, 150+ power projects in 45+ countries, and 2,000+ MW in stock.
Corrections: send them through our contact page with a source.
Frequently asked questions
Are there any small modular reactors in operation?
Yes, a few. China's HTR-PM pebble-bed plant entered commercial operation in December 2023. In the US, several small test reactors reached criticality in June and July 2026 under DOE's Reactor Pilot Program. The first BWRX-300 in Canada is under construction.
Which companies are building small modular reactors?
Companies with public projects include GE Vernova Hitachi (BWRX-300), X-energy (Xe-100), Kairos Power, NuScale, NANO Nuclear, Oklo, Radiant, Last Energy, Aalo Atomics, Antares Nuclear and Valar Atomics, among others.
Where is the first SMR in the Western world being built?
At the Darlington New Nuclear Project in Ontario, Canada. OPG holds a licence to construct one GE Vernova Hitachi BWRX-300, and GE Vernova says construction began in May 2025.
How is this tracker compiled?
Only from public regulator, government and company sources, each linked in the row. Status reflects the source as of the date shown. We do not publish costs or estimates of our own.