As of April 2026, at least 12 countries are actively building, licensing, or operating small modular reactors. China and Russia lead with operational units — China's HTR-PM at Shidao Bay has been grid-connected since 2023, and Russia's Akademik Lomonosov floating plant has operated since 2020. The United States, Canada, and Argentina have SMR units under construction. The UK, South Korea, France, Poland, Romania, Japan, and India are at various stages from design certification to site selection. Over 80 SMR designs are tracked by the IAEA globally, with projections of 50–80 units operational or under construction by 2035.
| COUNTRY | SMR DESIGNS | LEAD PROGRAM | STATUS | TARGET ONLINE | REGULATOR |
|---|---|---|---|---|---|
| 🇺🇸United States | NuScale VOYGR, TerraPower Natrium, Kairos Hermes, X-energy Xe-100, GE-Hitachi BWRX-300 | NuScale CFPP (Idaho) | Under construction | 2029–2030 | NRC |
| 🇨🇦Canada | GE-Hitachi BWRX-300, ARC-100, Moltex SSR-W | BWRX-300 at Darlington (OPG) | Under construction | 2029 | CNSC |
| 🇬🇧United Kingdom | Rolls-Royce SMR, GE-Hitachi BWRX-300, Holtec SMR-300 | Rolls-Royce SMR (Wylfa) | GDA Stage 2 | 2030s | ONR |
| 🇨🇳China | HTR-PM, Linglong One (ACP100) | HTR-PM (Shidao Bay) | Operational | 2023 (operational) | NNSA |
| 🇷🇺Russia | RITM-200, SHELF-M | Akademik Lomonosov FNPP | Operational | 2020 (operational) | Rostechnadzor |
| 🇦🇷Argentina | CAREM-25 | CAREM-25 (Lima) | Under construction | 2027–2028 | ARN |
| 🇰🇷South Korea | i-SMR, SMART | i-SMR | Design certification | 2030s | NSSC |
| 🇫🇷France | Nuward SMR | Nuward (EDF) | Design phase | 2030s | ASN |
| 🇯🇵Japan | BWRX-300 (GE-Hitachi) | Various | Considering | 2030s | NRA |
| 🇵🇱Poland | BWRX-300, NuScale | BWRX-300 (ORLEN) | Site selected | 2030s | PAA |
| 🇷🇴Romania | NuScale VOYGR | Doicești | Under development | 2030s | CNCAN |
| 🇮🇳India | PHWR-220 (indigenous), AHWR | PHWR fleet | Operational (PHWR) | Ongoing | AERB |
Only three countries have SMR-class reactors in commercial operation as of 2026. China's HTR-PM represents the most advanced commercial deployment — a 210 MWe high-temperature gas-cooled reactor at Shidao Bay. Russia operates the Akademik Lomonosov, a floating nuclear power plant with two 35 MWe RITM-200-class reactors serving the remote port of Pevek. India operates a fleet of small PHWR-220 pressurized heavy water reactors, which predate the modern SMR category but fall within the IAEA's sub-300 MWe definition.
HTR-PM, Linglong One (ACP100)
RITM-200, SHELF-M
PHWR-220 (indigenous), AHWR
Three countries currently have SMR units actively under construction. The United States is progressing multiple projects including the NuScale CFPP in Idaho and TerraPower Natrium in Wyoming. Canada's Ontario Power Generation is building the BWRX-300 at the Darlington site, targeting 2029 grid connection. Argentina's CAREM-25, a domestically designed 32 MWe integral PWR, has been under construction at Lima, Buenos Aires Province, with a 2027–2028 target.
NuScale VOYGR, TerraPower Natrium, Kairos Hermes, X-energy Xe-100, GE-Hitachi BWRX-300
GE-Hitachi BWRX-300, ARC-100, Moltex SSR-W
CAREM-25
| REGION | COUNTRIES ACTIVE | DESIGNS UNDER REVIEW | FURTHEST ALONG | EST. CAPACITY BY 2035 |
|---|---|---|---|---|
| North America | US, Canada | 8+ | BWRX-300 (Canada, 2029) | 5–8 GWe |
| Asia-Pacific | China, S. Korea, Japan, India | 5+ | HTR-PM (China, operational) | 3–5 GWe |
| Europe | UK, France, Poland, Romania | 4+ | Rolls-Royce SMR (UK, 2030s) | 2–4 GWe |
| Russia / CIS | Russia | 2+ | FNPP (operational) | 1–2 GWe |
| Latin America | Argentina | 1 | CAREM-25 (2027–2028) | 0.1 GWe |
The global SMR landscape is no longer theoretical. China and Russia have proven that small reactors can reach commercial operation, while the US, Canada, and Argentina are now in active construction phases. The next wave of deployments — expected between 2029 and 2035 — will determine whether SMRs can scale beyond first-of-a-kind projects into serial production. North America leads on design diversity with 8+ reactor concepts in various review stages. Asia-Pacific has the operational advantage. Europe is moving more cautiously but has committed significant policy backing, particularly in the UK and Poland. The key bottleneck across all regions remains the same: regulatory timelines and construction cost control will determine which countries move from plans to operating reactors.