Small modular reactors (SMR) are much smaller than the current nuclear reactors (300MWe or less) and have compact and scalable designs which propose to offer safety, construction, and economic benefits, and offering potential for lower initial capital investment and scalability.

Summary table + Legend

The stated power refers to the capacity of one reactor unless specified otherwise.

+List of small nuclear reactor designs[ view/edit ] Name Plant gross power (MWe) Type Producer Country Status 4S SFR Toshiba Japan Design (Detailed) Aalo Pod 10 (x5) SGR Aalo Atomics United States Experimental reactor under construction at INL. Graphite moderator, water and sodium cooling. ABV-6E PWR OKBM Afrikantov Russia Design (Detailed) ACP100 Linglong One 125 PWR China National Nuclear Corporation China Under constructionACP100S300PWRChina National Nuclear CorporationChinaFeasibility study of demonstration project finished ACR300 300 PWR INVAP Argentina Design (Detailed) Advanced Micro Reactor – AMR3HTGRSTL NuclearSouth AfricaDesign (Pre-conceptual) AP300 300 PWR Westinghouse Electric Company United States Design (Detailed) ARC-100 100 SFR ARC Nuclear Canada Design (Vendor Review) ANGSTREM 6 LFR OKB Gidropress Russia Design (Conceptual) Aurora 75 SFR Oklo Inc. United States First reactor under construction at INL. B&W mPower 195 PWR Babcock & Wilcox United States Cancelled BANDI-60 60 PWR KEPCO South Korea Design (Detailed)BLUE CAPSULE50SGRBlue Capsule TechnologyFrancePreliminary studies BREST-OD-300 300 LFR Atomenergoprom Russia Under construction BWRX-300 300 BWR GE Vernova Hitachi Nuclear Energy United States/Japan Four units are licensed in Ontario as the Darlington New Nuclear Project. At least one unit under construction.CALOGENA30PWRCalogena S.A.FranceDesign (Conceptual) CANDU SMR 300 PHWR Candu Energy Inc. Canada Design (Conceptual) CAP200 PWR SPIC China Design (Completion) CAREM PWR CNEA Argentina Seeking ARC approval for 30 MWe test SMR. Foundational construction now halted.CMSR110MSRSeaborg TechnologiesDenmark Copenhagen Atomics Waste Burner 20 MSR Copenhagen Atomics Denmark Design (Conceptual) DHR400 400 (non-electric) PWR CNCC China Design (Conceptual) EAGL-1 240 LFR First American Nuclear United States Design (Detailed) ELENA 0.068 PWR Kurchatov Institute Russia Design (Conceptual)Energy Multiplier Module (EM2)265 (×4)GFRGeneral AtomicsUnited StatesPre-conceptual design complete Energy Well 8.4 MSR Czechia Design (Conceptual) eVinci 5 HPR Westinghouse Electric Company United States Design (Pre-licensing communications with the US NRC initiated.)Fast Modular Reactor (FMR)44GFRGeneral AtomicsUnited StatesDesign (Conceptual) FLEX Reactor 24 MSR MoltexFLEX, Ltd. United Kingdom Design (Conceptual) Flexblue 160 PWR Areva TA / DCNS group France Design (Conceptual) Fuji MSR 200 MSR International Thorium Molten Salt Forum (ITMSF) Japan Design (Conceptual)GTHTR300100~300HTGRJAEA-ledJapanDesign (Conceptual) GT-MHR 285 HTGR OKBM Afrikantov Russia Design (Completed) G4M 25 LFR Gen4 Energy United States Cancelled (Company ceased trading) GT-MHR 50 HTGR General Atomics, Framatome United States/France Design (Conceptual) HAPPY200 200 MWt PWR SPIC China Design (Conceptual)HEXANA150 (x2)SFRHexanaFrancePreliminary studiesHOLOS-QUAD 10HTGRHolosGenUnited StatesDeveloped detailed step-by-step installation procedureHOLOS-MONO10HTGRHolosGenUnited StatesDeveloped detailed step-by-step installation procedureHTGR-POLA11.5HTGRNational Centre for Nuclear Research (NCBJ)PolandDesign (Conceptual) HTMR-100 35 HTGR Stratek Global South Africa Design (Conceptual)HTR-102.5HTGRTsinghua UniversityChinaRestartHTR-PM210 (2 reactors one turbine)HTGRChina HuanengChinaOperational (Two reactors. Station connected to the grid in December 2021.)HTR5017.2HTGRJAEAJapanMonolithic fuel element specimen irradiation testHTTR -HTGRJAEAJapanSafety demonstration test IMSR400 195 MSR Terrestrial Energy Canada Design (Detailed) for 98 MWe (per mod), 2 module SMR IRIS 335 PWR Westinghouse-led International Design (Conceptual)i-SMR170PWRInnovative Small Modular Reactor Development Agency (KHNP and KAERI)South KoreaDesign (Conceptual)JIMMYHTGRJIMMY ENERGYFranceDesign (Basic) Kaleidos 1 HTGR Radiant Nuclear United States Design (Detailed), test reactor under construction. KLT-40S Akademik Lomonosov 70 PWR OKBM Afrikantov Russia Operational May 2020 (floating plant) KP-FHR 140 FHR Kairos Power United States Design (Detailed), two test reactors under construction.LFR-AS-200200LFRNewCleoItaly/FranceDesign (Conceptual)Lithium Fluoride Thorium Reactor250MSRFlibe EnergyUnited StatesDesign (Conceptual)MARVEL Research MicroreactorLMRIdaho National LaboratoryUnited StatesDemonstration test bed MMR 5–15 HTGR purchased by NANO Nuclear Energy United States/Canada Company filed for Chapter 11 bankruptcy. Had been seeking licensing. Design acquired by Nano Nuclear Energy, who renamed the design KRONOS MMR. Applied for an NRC construction permit to build one unit at the University of Illinois Urbana-Champaign. MHR-100 HTGR OKBM Afrikantov Russia Design (Conceptual) MHR-T 205.5 (x4) HTGR OKBM Afrikantov Russia Design (Conceptual)MoveluX3~4HPRToshiba Energy Systems & SolutionsJapan MRX PWR JAERI Japan Design (Conceptual) NOVA Core HTGR Valar Atomics United States Design (Working prototype). Design achieved cold criticality state at LANL on 18 November 2025. NP-300 PWR Areva TA France Design (Conceptual)NuScale Power Module77PWRNuScale PowerUnited StatesReceived NRC Standard Design Certification in 2025. 50 MW version certified in 2023. Nuward unknown PWR consortium France Design (Conceptual). In July 2024, existing design discontinued for a simpler redesign. OPEN100 100 PWR Energy Impact Center United States Design (Conceptual) PBMR 165 HTGR Eskom South Africa Cancelled – demonstration plant postponed indefinitelyPeLUIt-4010HTGRBRIN, ITBIndonesiaDesign (Conceptual) PWR-2020 PWRLast EnergyUnited StatesDesign (Conceptual)Pylon D1HTGRUltra Safe Nuclear CorporationUnited StatesDesign (Pre-conceptual)RITM-200N55PWROKBM AfrikantovRussiaUnder constructionRITM-200S106PWROKBM AfrikantovRussiaUnder construction Rolls-Royce SMR 470 PWR Rolls-Royce United Kingdom Seeking UK GDA licensing in April 2022 In final stage 3 of assessmentStable Salt Reactor Wasteburner300~900MSR (Static Fuelled)Moltex EnergyCanada, United Kingdom SEALER 55 LFR Sweden DesignSHELF-M10PWRNIKIETRussiaDesign SMART100 110 PWR KAERI South Korea Licensed in Korea (standard design approval) SMR-160 160 PWR Holtec International United States US NRC pre-application suspended in favor of SMR-300 design SMR-300 300 PWR Holtec International United States Applied for an NRC construction permit for two units at Palisades. Seeking UK Generic Design Assessment. 100 LFR OKB Gidropress Russia Design (Detailed) SSR-W MSR Moltex Energy Canada Design (Phase 1, vendor design review). STAR10PWRSTAR ENERGY SASwitzerlandDesign (Detailed)Stellarium110MSRStellariaFrancePre-conceptual design S-PRISM 311 SFR GE Vernova Hitachi Nuclear Energy United States/Japan Design (Detailed) TEPLATOR 50 (non-electric) PHWR University of West Bohemia Czech Republic Design (Conceptual)Natrium345SFRTerraPowerUnited StatesUnder construction as Kemmerer Unit 1. Thorcon TMSR-500 500 MSR ThorCon Indonesia Design (Conceptual)THORIZON100Modular core fast-spectrum reactor with chloride saltTHORIZONNetherlandsPre-conceptual designUNITHERM10PWRNIKIETRussiaDesign U-Battery 4 HTGR U-Battery consortium United Kingdom Cancelled. Design archived. VBER-300 325 PWR OKBM Afrikantov Russia Design 250 BWR Atomstroyexport Russia Design (Detailed) VVER-300 300 BWR OKB Gidropress Russia Design (Conceptual) Westinghouse SMR 225 PWR Westinghouse Electric Company United States Cancelled. Preliminary design completed.XAMR40MSRNAAREAFranceDesign (Conceptual) Xe-100 80 HTGR X-energy United States Applied for an NRC construction permit to build a four-module plant with Dow Chemical Company.Updated . Some reactors are not included in IAEA Report. Not all IAEA reactors are listed in this table. Some were added (anno 2023) that were not yet listed in the now dated IAEA report. However, new manufacturers are being added as news reports and NRC information becomes available.

Reactor designs

ACP100: China In 2021, construction of the ACP100 was started at the Changjiang Nuclear Power Plant site in Hainan province. Previously, in July 2019 CNNC announced it would start building a demonstration ACP100 SMR by the end of the year. Design of the ACP100 started in 2010 and it became the first SMR project of its kind to be approved by the International Atomic Energy Agency in 2016. It is a fully integrated reactor module with an internal coolant system, with a two-year refuelling interval, producing 385MWt and about 125MWe. The 125MWe pressurised water reactor (PWR) is also referred to as the Linglong One and is designed for multiple purposes including electricity production, heating, steam production or seawater desalination.

ARC-100: US/Japan The ARC-100 is a 100MWe sodium cooled, fast-flux, pool-type reactor with metallic fuel based on the 30-year successful operation of the Experimental Breeder Reactor II in Idaho. ARC Nuclear is developing this reactor in Canada, in partnership with GE Vernova Hitachi Nuclear Energy, with the intent of complementing existing CANDU facilities.

Bharat Small Reactor: India

India announced in 2024 their intention to develop an SMR design called the Bharat Small Modular Reactor.

CAREM: Argentina

Developed by the Argentine National Atomic Energy Commission (CNEA) & INVAP, CAREM is a simplified pressurized water reactor (PWR) designed to have electrical output of 100MW or 25MW. It is an integral reactor – the primary system coolant circuit is fully contained within the reactor vessel.

The fuel is uranium oxide with an enrichment of 3.4%. The primary coolant system uses natural circulation, so there are no pumps required, which provides inherent safety against core meltdown, even in accident situations. The integral design also minimizes the risk of loss-of-coolant accidents (LOCA). Annual refueling is required. Currently, the first reactor of the type is being built near the city of Zárate, in the northern part of Buenos Aires province.

Copenhagen Atomics: Denmark The Copenhagen Atomics Waste Burner is designed by Copenhagen Atomics, a Danish molten salt technology company. The Copenhagen Atomics Waste Burner would be a single-fluid, heavy water moderated, fluoride-based, thermal spectrum and autonomously controlled molten salt reactor. This is designed to fit inside of a leak-tight, 40-foot, stainless steel shipping container. The heavy water moderator is thermally insulated from the salt and continuously drained and cooled to below 50 °C. A molten lithium-7 deuteroxide (7LiOD) moderator version is also being researched. The reactor would utilize the thorium fuel cycle, using separated plutonium from spent nuclear fuel as the initial fissile load for the first generation of reactors, eventually transitioning to a thorium breeder. (9 MB)

Encapsulated Nuclear Heat Source (ENHS): United States ENHS is a liquid metal reactor (LMR) that uses lead (Pb) or lead–bismuth (Pb–Bi) coolant. Pb has a higher boiling point than the other commonly used coolant metal, sodium, and is chemically inert with air and water. The difficulty is finding structural materials that will be compatible with the Pb or Pb–Bi coolant, especially at high temperatures. The ENHS uses natural circulation for the coolant and the turbine steam, eliminating the need for pumps. It is also designed with autonomous control, with a load-following power generation design, and a thermal-to-electrical efficiency of more than 42%. The fuel is either U–Zr or U–Pu–Zr, and can keep the reactor at full power for 15 years before needing to be refueled, with either at 11% or at 13%