Fission
This is the vocabulary term. For an overview of the sector, see Fission.
Energy released by splitting heavy nuclei. Every operating nuclear power station works this way; every fusion device in this dataset does not.
In the record: 70 companies, 10 laboratories and programmes, 161 reactors and 62 reactor designs. These counts include Water-cooled, Salt-based, Gas-cooled, Liquid-metal cooled and Heat-pipe microreactor.
Related approaches
Narrower:
- Water-cooled Reactors cooled by ordinary or heavy water, which in most designs is also the neutron moderator.
- Salt-based Reactors using molten salt as fuel carrier, coolant, or both.
- Gas-cooled Reactors cooled by gas, usually helium or carbon dioxide, allowing higher outlet temperatures than water.
- Liquid-metal cooled Reactors cooled by molten metal at near-atmospheric pressure. Most designs use no moderator, so the neutrons stay fast. A few do slow their neutrons: Aalo Atomics describes its sodium-cooled Aalo-1 as a thermal reactor, and the IAEA lists Idaho National Laboratory's MARVEL microreactor as liquid-metal-cooled with a thermal spectrum.
- Heat-pipe microreactor Heat moved by sealed heat pipes rather than pumped coolant or forced convection. No primary pumps and no coolant loop, which suits very small transportable reactors. Heat-pipe describes how heat is moved, not the neutron spectrum. Moderator and fuel vary by design: some designs are fast and unmoderated, others use a graphite or beryllium oxide moderator, with TRISO or metal fuel, usually HALEU.
Companies 70
Includes companies recorded under a narrower approach, named beside each.
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Aalo Atomics · Liquid-metal cooled - Akkuyu Nuclear · Pressurised water reactor
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Antares Nuclear · Heat-pipe microreactor -
ARC Clean Technology · Sodium fast reactor - AtkinsRéalis · Pressurised heavy-water reactor
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Blykalla · Lead fast reactor -
Bruce Power · Pressurised heavy-water reactor -
BWX Technologies · High-temperature gas-cooled reactor -
Calogena · Water-cooled -
CGN · Pressurised water reactor - China Huaneng Group · High-temperature gas-cooled reactor
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CNNC · Pressurised water reactor -
Copenhagen Atomics · Molten salt reactor -
Deep Fission · Pressurised water reactor -
Dual Fluid Energy · Liquid-metal cooled - EDF · Pressurised water reactor
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Eletronuclear · Pressurised water reactor - Emirates Nuclear Energy Company · Pressurised water reactor
- Energoatom · Pressurised water reactor
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Flibe Energy · Molten salt reactor -
Framatome · Pressurised water reactor -
GE Vernova Hitachi Nuclear Energy · Boiling water reactor, Sodium fast reactor -
Hadron Energy · Pressurised water reactor -
HEXANA · Sodium fast reactor -
Hitachi GE Vernova Nuclear Energy · Boiling water reactor -
Holtec International · Pressurised water reactor -
Jimmy · High-temperature gas-cooled reactor -
Kairos Power · Fluoride salt-cooled high-temperature reactor - KEPCO Engineering & Construction · Pressurised water reactor
- Korea Hydro & Nuclear Power · Pressurised water reactor
- Kozloduy NPP · Pressurised water reactor
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Last Energy · Pressurised water reactor -
Moltex Energy · Molten salt reactor -
MVM Group · Pressurised water reactor - NAAREA · Molten salt reactor
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NANO Nuclear Energy · Heat-pipe microreactor, High-temperature gas-cooled reactor - Natura Resources · Molten salt reactor
- NB Power · Pressurised heavy-water reactor
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newcleo · Lead fast reactor -
NPCIL · Pressurised heavy-water reactor -
Nuclearelectrica · Pressurised heavy-water reactor - Nucleoeléctrica Argentina · Pressurised heavy-water reactor
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NuScale Power · Pressurised water reactor - NUWARD · Pressurised water reactor
- OKBM Afrikantov · Pressurised water reactor, High-temperature gas-cooled reactor
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Oklo · Sodium fast reactor - Ontario Power Generation · Pressurised heavy-water reactor
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Orlen Synthos Green Energy · Boiling water reactor -
Otrera · Sodium fast reactor - Polskie Elektrownie Jądrowe · Pressurised water reactor
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Radiant · High-temperature gas-cooled reactor -
Rolls-Royce SMR · Pressurised water reactor - Rosatom · High-temperature gas-cooled reactor, Lead fast reactor, Pressurised water reactor
- Rosenergoatom · Pressurised water reactor
- Saltfoss Energy · Molten salt reactor
- State Power Investment Corporation · Pressurised water reactor
- Steady Energy · Water-cooled
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Stellaria · Molten salt reactor -
Teollisuuden Voima · Boiling water reactor, Pressurised water reactor - Terra Innovatum · Gas-cooled
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TerraPower · Sodium fast reactor -
Terrestrial Energy · Molten salt reactor -
ThorCon International · Molten salt reactor -
Thorizon · Molten salt reactor -
Toshiba · Heat-pipe microreactor, Sodium fast reactor -
TRISO-X · High-temperature gas-cooled reactor - Valar Atomics · High-temperature gas-cooled reactor
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Westinghouse Electric Company · Heat-pipe microreactor, Pressurised water reactor -
X-energy · High-temperature gas-cooled reactor -
Zap Energy · Sodium fast reactor
Laboratories and programmes 10
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Abilene Christian University · Molten salt reactor - China Institute of Atomic Energy · Sodium fast reactor
- CNEA · Pressurised water reactor
- Indira Gandhi Centre for Atomic Research · Sodium fast reactor
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Institute of Nuclear and New Energy Technology, Tsinghua University · High-temperature gas-cooled reactor -
JAEA · High-temperature gas-cooled reactor - KAERI · Pressurised water reactor
- King Abdullah City for Atomic and Renewable Energy · Pressurised water reactor
- NIKIET · Lead fast reactor
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Shanghai Institute of Applied Physics, Chinese Academy of Sciences · Molten salt reactor
Reactors 161
Operating reactors first, then those being built or planned, then those shut down, suspended or cancelled.
- Advanced Test Reactor Operating Idaho National Laboratory · US · Water-cooled · 1 measurement
- Advanced Test Reactor Critical Operating Idaho National Laboratory · US · Water-cooled · 1 measurement
- AGN-201, Idaho State University Operating Idaho State University · US · 1 measurement
- AGN-201K Operating Kyung Hee University · KR · 1 measurement
- AGN-201M, Texas A&M Operating Texas A&M Nuclear Engineering and Science Center · US · 1 measurement
- Akademik Lomonosov Operating RU · Pressurised water reactor · 1 measurement
- Annular Core Research Reactor Operating Sandia National Laboratories · US · Water-cooled · 1 measurement
- Argonauta Operating Instituto de Engenharia Nuclear · BR · Water-cooled · 1 measurement
- BAEC TRIGA Research Reactor Operating Bangladesh Atomic Energy Commission · BD · Water-cooled · 1 measurement
- BME Training Reactor Operating BME Institute of Nuclear Techniques · HU · Water-cooled · 1 measurement
- BOR-60 Operating Research Institute of Atomic Reactors · RU · Sodium fast reactor · 1 measurement
- BR1 Operating SCK CEN · BE · 1 measurement
- BR2 Operating SCK CEN · BE · Water-cooled · 1 measurement
- Breazeale Nuclear Reactor Operating Penn State Radiation Science & Engineering Center · US · Water-cooled · 1 measurement
- Budapest Research Reactor Operating HUN-REN Energiatudományi Kutatóközpont · HU · Water-cooled · 1 measurement
- China Advanced Research Reactor Operating China Institute of Atomic Energy · CN · Water-cooled · 1 measurement
- China Experimental Fast Reactor Operating China Institute of Atomic Energy · CN · Sodium fast reactor · 1 measurement
- Dalat Nuclear Research Reactor Operating Vietnam Atomic Energy Institute · VN · Water-cooled · 1 measurement
- Dhruva Operating BARC · IN · Water-cooled · 1 measurement
- ETRR-2 Operating Egyptian Atomic Energy Authority · EG · Water-cooled · 1 measurement
- Fast Breeder Test Reactor Operating Indira Gandhi Centre for Atomic Research · IN · Sodium fast reactor · 1 measurement
- GHARR-1 Operating Ghana Atomic Energy Commission · GH · Water-cooled · 1 measurement
- Groves Isotope Test Reactor Operating Oklo · US
- HANARO Operating KAERI · KR · Water-cooled · 1 measurement
- High Flux Isotope Reactor Operating Oak Ridge National Laboratory · US · Water-cooled · 1 measurement
- High Flux Reactor, Petten Operating NRG PALLAS · NL · Water-cooled · 1 measurement
- HOR Operating Reactor Institute Delft · NL · Water-cooled · 1 measurement
- HTR-10 Operating Tsinghua University · CN · High-temperature gas-cooled reactor · 1 measurement
- HTR-PM demonstration plant, Shidao Bay Operating CN · High-temperature gas-cooled reactor · 1 measurement
- HTTR Operating JAEA · JP · High-temperature gas-cooled reactor · 1 measurement
- IAN-R1 Operating Colombian Geological Survey · CO · Water-cooled · 1 measurement
- IBR-2 Operating Joint Institute for Nuclear Research · RU · 1 measurement
- IEA-R1 Operating Instituto de Pesquisas Energéticas e Nucleares · BR · Water-cooled · 1 measurement
- IGR Operating National Nuclear Center of the Republic of Kazakhstan · KZ
- ILL High-Flux Reactor Operating Institut Laue-Langevin · FR · Water-cooled · 1 measurement
- IPEN/MB-01 Operating Instituto de Pesquisas Energéticas e Nucleares · BR · Water-cooled · 1 measurement
- IPR-R1 Operating Centro de Desenvolvimento da Tecnologia Nuclear · BR · Water-cooled · 1 measurement
- IRR-1 Operating Soreq Nuclear Research Center · IL · Water-cooled · 1 measurement
- IRT-MEPhI Operating National Research Nuclear University MEPhI · RU · Water-cooled · 1 measurement
- IRT-T Operating Tomsk Polytechnic University · RU · Water-cooled · 1 measurement
- IVG.1M Operating National Nuclear Center of the Republic of Kazakhstan · KZ · Water-cooled · 1 measurement
- JRR-3 Operating JAEA · JP · Water-cooled · 1 measurement
- KAMINI Operating Indira Gandhi Centre for Atomic Research · IN · Water-cooled · 1 measurement
- Kansas State University TRIGA Mark II Operating Kansas State University · US · Water-cooled · 1 measurement
- Kyoto University Critical Assembly Operating Kyoto University · JP · 1 measurement
- Kyoto University Research Reactor Operating Kyoto University · JP · Water-cooled · 1 measurement
- LR-0 Operating Research Centre Řež · CZ · Water-cooled · 1 measurement
- LVR-15 Operating Research Centre Řež · CZ · Water-cooled · 1 measurement
- MARIA Operating National Centre for Nuclear Research · PL · Water-cooled · 1 measurement
- Maryland University Training Reactor Operating University of Maryland, College Park · US · Water-cooled · 1 measurement
- McClellan TRIGA reactor Operating McClellan Nuclear Research Center · US · Water-cooled · 1 measurement
- McMaster Nuclear Reactor Operating McMaster University · CA · Water-cooled · 1 measurement
- MIR.M1 Operating Research Institute of Atomic Reactors · RU · Water-cooled · 1 measurement
- Missouri S&T Reactor Operating Missouri University of Science and Technology · US · Water-cooled · 1 measurement
- MIT Research Reactor Operating MIT Nuclear Reactor Laboratory · US · Water-cooled · 1 measurement
- NBSR Operating NIST Center for Neutron Research · US · Water-cooled · 1 measurement
- NRAD Operating Idaho National Laboratory · US · Water-cooled · 1 measurement
- NSRR Operating JAEA · JP · Water-cooled · 1 measurement
- Ohio State University Research Reactor Operating Ohio State University · US · Water-cooled · 1 measurement
- OPAL Operating Australian Nuclear Science and Technology Organisation · AU · Water-cooled · 1 measurement
- Oregon State TRIGA Reactor Operating Oregon State University Radiation Center · US · Water-cooled · 1 measurement
- PARR-1 Operating Pakistan Institute of Nuclear Science and Technology · PK · Water-cooled · 1 measurement
- PARR-2 Operating Pakistan Institute of Nuclear Science and Technology · PK · Water-cooled · 1 measurement
- PIK Operating National Research Centre Kurchatov Institute · RU · Water-cooled · 1 measurement
- PRR-1 Operating Philippine Nuclear Research Institute · PH
- PULSTAR Operating NC State Nuclear Reactor Program · US · Water-cooled · 1 measurement
- PUR-1 Operating Purdue University School of Nuclear Engineering · US · Water-cooled · 1 measurement
- RA-1 Enrico Fermi Operating CNEA · AR · Water-cooled · 1 measurement
- RA-3 Operating CNEA · AR · Water-cooled · 1 measurement
- RA-6 Operating CNEA · AR · Water-cooled · 1 measurement
- RBT-10/2 Operating Research Institute of Atomic Reactors · RU · Water-cooled · 1 measurement
- RBT-6 Operating Research Institute of Atomic Reactors · RU · Water-cooled · 1 measurement
- RECH-1 Operating Chilean Nuclear Energy Commission · CL · Water-cooled · 1 measurement
- Reed Research Reactor Operating Reed College · US · Water-cooled · 1 measurement
- RP-10 Operating Peruvian Institute of Nuclear Energy · PE · Water-cooled · 1 measurement
- RSG-GAS Operating National Research and Innovation Agency · ID · Water-cooled · 1 measurement
- SAFARI-1 Operating South African Nuclear Energy Corporation · ZA · Water-cooled · 1 measurement
- SLOWPOKE-2, Polytechnique Montréal Operating Polytechnique Montréal · CA · Water-cooled · 1 measurement
- SLOWPOKE-2, Royal Military College of Canada Operating Royal Military College of Canada · CA · Water-cooled · 1 measurement
- SLOWPOKE-2, University of the West Indies Operating International Centre for Environmental and Nuclear Sciences · JM · Water-cooled · 1 measurement
- SM-3 Operating Research Institute of Atomic Reactors · RU · Water-cooled · 1 measurement
- STACY Operating JAEA · JP · 1 measurement
- SUR Stuttgart Operating University of Stuttgart · DE
- Texas A&M NSC TRIGA reactor Operating Texas A&M Nuclear Engineering and Science Center · US · Water-cooled · 1 measurement
- THOR Operating National Tsing Hua University · TW · Water-cooled · 1 measurement
- TMSR-LF1 Operating Shanghai Institute of Applied Physics, Chinese Academy of Sciences · CN · Molten salt reactor · 1 measurement
- TREAT Operating Idaho National Laboratory · US · 1 measurement
- TRIGA Mark II reactor, Vienna Operating Atominstitut, TU Wien · AT · Water-cooled · 1 measurement
- TRIGA Mark II, Ljubljana Operating Jožef Stefan Institute · SI · Water-cooled · 1 measurement
- TRIGA Mark III, Salazar Operating National Institute for Nuclear Research (Mexico) · MX · Water-cooled · 1 measurement
- TRIGA PUSPATI Operating Malaysian Nuclear Agency · MY · Water-cooled · 1 measurement
- TRIGA reactor, Pitești Operating Institute for Nuclear Research Pitești · RO · Water-cooled · 1 measurement
- TRR-1/M1 Operating Thailand Institute of Nuclear Technology · TH · Water-cooled · 1 measurement
- UC Irvine TRIGA reactor Operating University of California, Irvine · US · Water-cooled · 1 measurement
- UMass Lowell Research Reactor Operating University of Massachusetts Lowell · US · Water-cooled · 1 measurement
- University of Florida Training Reactor Operating University of Florida · US · Water-cooled · 1 measurement
- University of Missouri Research Reactor Operating University of Missouri Research Reactor · US · Water-cooled · 1 measurement
- University of Utah TRIGA reactor Operating University of Utah Nuclear Engineering Program · US · Water-cooled · 1 measurement
- University of Wisconsin Nuclear Reactor Operating University of Wisconsin-Madison · US · Water-cooled · 1 measurement
- UT Austin TRIGA Mark II Operating University of Texas at Austin · US · Water-cooled · 1 measurement
- UTR-KINKI Operating Kindai University · JP · Water-cooled · 1 measurement
- VENUS-F Operating SCK CEN · BE · 1 measurement
- VK-50 Operating Research Institute of Atomic Reactors · RU · Boiling water reactor · 1 measurement
- VR-1 Operating Czech Technical University · CZ · Water-cooled · 1 measurement
- VR-2 Operating Czech Technical University · CZ
- Washington State University Reactor Operating Washington State University Nuclear Science Center · US · Water-cooled · 1 measurement
- WWR-K Operating Institute of Nuclear Physics (Kazakhstan) · KZ · Water-cooled · 1 measurement
- ZED-2 Operating Canadian Nuclear Laboratories · CA · Water-cooled · 1 measurement
- Palisades Nuclear Plant Commissioning Holtec International · US
- Prototype Fast Breeder Reactor Commissioning IN · Sodium fast reactor
- BREST-OD-300 Under construction RU · Lead fast reactor · 1 measurement
- Darlington New Nuclear Project Unit 1 Under construction Ontario Power Generation · CA · Boiling water reactor
- Hermes test reactor Under construction Kairos Power · US · Fluoride salt-cooled high-temperature reactor · 1 measurement
- Jules Horowitz Reactor Under construction FR · Water-cooled · 1 measurement
- Kemmerer Power Station Unit 1 Under construction TerraPower · US · Sodium fast reactor
- KJRR Under construction KAERI · KR · Water-cooled · 1 measurement
- Linglong One demonstration unit, Changjiang Under construction CNNC · CN · Pressurised water reactor · 1 measurement
- MBIR Under construction Research Institute of Atomic Reactors · RU · 1 measurement
- PALLAS Under construction NRG PALLAS · NL · Water-cooled · 1 measurement
- RA-10 Under construction CNEA · AR · Water-cooled · 1 measurement
- RMB (Brazilian Multipurpose Reactor) Under construction National Nuclear Energy Commission (Brazil) · BR · Water-cooled · 1 measurement
- Aurora-INL Planned Oklo · US · Sodium fast reactor
- Clinch River Nuclear Site Unit 1 Planned Tennessee Valley Authority · US · Boiling water reactor · 1 measurement
- Hermes 2 test reactor facility Planned Kairos Power · US · Fluoride salt-cooled high-temperature reactor
- Long Mott Generating Station Planned US · High-temperature gas-cooled reactor · 1 measurement
- Molten Salt Research Reactor (Abilene Christian University) Planned Abilene Christian University · US · Molten salt reactor
- MYRRHA Planned SCK CEN · BE · Lead fast reactor · 1 measurement
- Pioneer Unit 1 (Palisades SMR-300) Planned Holtec International · US · Pressurised water reactor
- Pioneer Unit 2 (Palisades SMR-300) Planned Holtec International · US · Pressurised water reactor
- F-1 Shut down National Research Centre Kurchatov Institute · RU · 1 measurement
- Halden Reactor Shut down Institute for Energy Technology · NO · Water-cooled · 1 measurement
- HIFAR Shut down Australian Nuclear Science and Technology Organisation · AU · Water-cooled · 1 measurement
- JEEP II Shut down Institute for Energy Technology · NO · Water-cooled · 1 measurement
- JMTR Shut down JAEA · JP · Water-cooled · 1 measurement
- NRU Shut down Canadian Nuclear Laboratories · CA · Water-cooled · 1 measurement
- TRICO I Shut down CREN-K · CD · Water-cooled · 1 measurement
- CIRUS Decommissioned BARC · IN · Water-cooled · 1 measurement
- CP-5 Decommissioned Argonne National Laboratory · US · Water-cooled · 1 measurement
- DIORIT Decommissioned Paul Scherrer Institute · CH · Water-cooled · 1 measurement
- FiR 1 Decommissioned VTT Technical Research Centre of Finland · FI · Water-cooled · 1 measurement
- Ford Nuclear Reactor Decommissioned University of Michigan Nuclear Engineering and Radiological Sciences · US · Water-cooled · 1 measurement
- KRR-1 Decommissioned KAERI · KR · Water-cooled · 1 measurement
- KRR-2 Decommissioned KAERI · KR · Water-cooled · 1 measurement
- Omega West Reactor Decommissioned Los Alamos National Laboratory · US · Water-cooled · 1 measurement
- PROTEUS Decommissioned Paul Scherrer Institute · CH · 1 measurement
- R1 Decommissioned KTH Royal Institute of Technology · SE · Water-cooled
- RA (Vinča) Decommissioned Vinča Institute of Nuclear Sciences · RS · Water-cooled · 1 measurement
- SAPHIR Decommissioned Paul Scherrer Institute · CH · Water-cooled · 1 measurement
- University of Illinois Advanced TRIGA Decommissioned University of Illinois · US · Water-cooled · 1 measurement
- CAREM-25 Status not recorded CNEA · AR · Pressurised water reactor
- ETRR-1 Suspended Egyptian Atomic Energy Authority · EG · Water-cooled · 1 measurement
- FRM II Suspended Heinz Maier-Leibnitz Research Neutron Source (FRM II) · DE · Water-cooled · 1 measurement
- GRR-1 (Demokritos) Suspended National Centre for Scientific Research Demokritos · GR · Water-cooled · 1 measurement
- IRT-1 (Tajoura) Suspended Tajoura Nuclear Research Centre · LY · Water-cooled · 1 measurement
- Jōyō Suspended JAEA · JP · Sodium fast reactor · 1 measurement
- RA-8 Suspended CNEA · AR · 1 measurement
- RB (Vinča) Suspended Vinča Institute of Nuclear Sciences · RS · Water-cooled
- RECH-2 Suspended Chilean Nuclear Energy Commission · CL · Water-cooled · 1 measurement
- TR-2 Suspended Turkish Energy, Nuclear and Mineral Research Agency · TR · Water-cooled · 1 measurement
- TRICO II Suspended CREN-K · CD · Water-cooled · 1 measurement
- WWR-M (Gatchina) Suspended National Research Centre Kurchatov Institute · RU · Water-cooled · 1 measurement
Reactor designs 62
Size class is worked out from the electrical output of one unit: up to 10 MWe is a microreactor, up to 300 MWe a small modular reactor. A design with no stated output is not classed.
| Design | Developer | Approach | Electrical output per unit | Size class | Licensing stage |
|---|---|---|---|---|---|
| 4S Super-Safe, Small and Simple | Toshiba | Sodium fast reactor | 10 MWe planned | Microreactor | No milestone recorded |
| Aalo-1 Aalo-1 Reactor | Aalo Atomics | Liquid-metal cooled | 10 MWe planned | Microreactor | No milestone recorded |
| ABV-6E | OKBM Afrikantov with Rosatom | Pressurised water reactor | 6 to 9 MWe planned | Microreactor | No milestone recorded |
| ACP100 Linglong One | CNNC | Pressurised water reactor | 125 MWe planned | Small modular reactor | No milestone recorded |
| ACP100S | CNNC | Pressurised water reactor | 125 MWe planned | Small modular reactor | No milestone recorded |
| Advanced Boiling Water Reactor (ABWR) ABWR | GE Vernova Hitachi Nuclear Energy | Boiling water reactor | 1,350 to 1,460 MWe claimed | Large reactor | No milestone recorded |
| AP1000 | Westinghouse Electric Company | Pressurised water reactor | 1,110 MWe claimed | Large reactor | No milestone recorded |
| AP300 | Westinghouse Electric Company | Pressurised water reactor | 330 MWe planned | Large reactor | No milestone recorded |
| Aurora powerhouse Aurora | Oklo | Sodium fast reactor | 15 to 75 MWe planned | Small modular reactor | Application denied for one plant: NRC denies Aurora combined licence application · US Nuclear Regulatory Commission · 2022-01-06 |
| BWRX-300 | GE Vernova Hitachi Nuclear Energy | Boiling water reactor | 300 MWe planned | Small modular reactor | Construction permit issued for one plant: CNSC licence to construct one BWRX-300 at the Darlington New Nuclear Project · Canadian Nuclear Safety Commission · 2025-04-04 |
| BWXT Advanced Nuclear Reactor (BANR) BANR | BWX Technologies | High-temperature gas-cooled reactor | Output not stated | Not classed | No milestone recorded |
| CAREM CAREM25 | CNEA | Pressurised water reactor | 30 MWe planned | Small modular reactor | No milestone recorded |
| Compact Molten Salt Reactor (CMSR) CMSR | Saltfoss Energy | Molten salt reactor | 110 MWe planned | Small modular reactor | No milestone recorded |
| Copenhagen Atomics Waste Burner CA Waste Burner, Onion Core | Copenhagen Atomics | Molten salt reactor | Output not stated | Not classed | No milestone recorded |
| DF-1500 | Dual Fluid Energy | Liquid-metal cooled | Output not stated | Not classed | No milestone recorded |
| DF-300 | Dual Fluid Energy | Liquid-metal cooled | Output not stated | Not classed | No milestone recorded |
| Economic Simplified Boiling Water Reactor (ESBWR) ESBWR | GE Vernova Hitachi Nuclear Energy | Boiling water reactor | 1,520 MWe planned | Large reactor | No milestone recorded |
| Energy Multiplier Module (EM2) EM2 | General Atomics | Gas-cooled | 265 MWe planned | Small modular reactor | No milestone recorded |
| EPR European Pressurised Reactor, Evolutionary Power Reactor | Framatome | Pressurised water reactor | Output not stated | Not classed | No milestone recorded |
| eVinci | Westinghouse Electric Company | Heat-pipe microreactor | 5 MWe planned | Microreactor | No milestone recorded |
| Fast Modular Reactor (FMR) FMR | General Atomics | Gas-cooled | 44 MWe planned | Small modular reactor | No milestone recorded |
| Gravity Nuclear Reactor Gravity reactor, Deep Fission Borehole Reactor | Deep Fission | Pressurised water reactor | 15 MWe planned | Small modular reactor | No milestone recorded |
| GT-MHR Gas Turbine Modular Helium Reactor | OKBM Afrikantov with Rosatom | High-temperature gas-cooled reactor | 288 MWe planned | Small modular reactor | No milestone recorded |
| GTHTR300 Gas Turbine High Temperature Reactor 300 | JAEA | High-temperature gas-cooled reactor | 100 to 300 MWe planned | Small modular reactor | No milestone recorded |
| HTR50S | JAEA | High-temperature gas-cooled reactor | 17.2 MWe planned | Small modular reactor | No milestone recorded |
| Hualong One HPR1000 | CNNC with CGN | Pressurised water reactor | Output not stated | Not classed | No milestone recorded |
| i-SMR innovative SMR | Korea Hydro & Nuclear Power with KAERI | Pressurised water reactor | 170 MWe planned | Small modular reactor | No milestone recorded |
| Integral Molten Salt Reactor (IMSR) IMSR, IMSR400 | Terrestrial Energy | Molten salt reactor | 195 MWe planned | Small modular reactor | No milestone recorded |
| IPHWR-700 700 MWe PHWR, Indian PHWR-700 | NPCIL | Pressurised heavy-water reactor | 700 MWe claimed | Large reactor | No milestone recorded |
| Jimmy | Jimmy | High-temperature gas-cooled reactor | Output not stated | Not classed | No milestone recorded |
| Kaleidos | Radiant | High-temperature gas-cooled reactor | Output not stated | Not classed | No milestone recorded |
| KLT-40S | OKBM Afrikantov with Rosatom | Pressurised water reactor | 35 MWe claimed | Small modular reactor | No milestone recorded |
| KP-FHR Kairos Power Fluoride Salt-Cooled High-Temperature Reactor, KP-X | Kairos Power | Fluoride salt-cooled high-temperature reactor | 75 MWe planned | Small modular reactor | No milestone recorded |
| KRONOS MMR KRONOS, KRONOS MMR Energy System | NANO Nuclear Energy | High-temperature gas-cooled reactor | 3.5 to 15 MWe planned | Stated range spans two size classes | No milestone recorded |
| LDR-50 | Steady Energy | Water-cooled | Output not stated | Not classed | No milestone recorded |
| LFR-AS-200 | newcleo | Lead fast reactor | 200 MWe planned | Small modular reactor | No milestone recorded |
| LOKI MMR LOKI | NANO Nuclear Energy | High-temperature gas-cooled reactor | 0.01 to 3 MWe planned | Microreactor | No milestone recorded |
| MHR-100 | OKBM Afrikantov with Rosatom | High-temperature gas-cooled reactor | 25 to 87 MWe planned | Small modular reactor | No milestone recorded |
| MHR-T | OKBM Afrikantov with Rosatom | High-temperature gas-cooled reactor | 205.5 MWe planned | Small modular reactor | No milestone recorded |
| MoveluX | Toshiba | Heat-pipe microreactor | 3 to 4 MWe planned | Microreactor | No milestone recorded |
| MSR-100 | Natura Resources | Molten salt reactor | Output not stated | Not classed | No milestone recorded |
| Natrium | TerraPower with GE Vernova Hitachi Nuclear Energy | Sodium fast reactor | 345 MWe planned | Large reactor | Construction permit issued for one plant: NRC construction permit CPAR-1 issued for Kemmerer Power Station Unit 1 (Natrium) · US Nuclear Regulatory Commission · 2026-03-09 |
| NuScale Power Module (US460) US460, NPM, VOYGR | NuScale Power | Pressurised water reactor | 77 MWe planned | Small modular reactor | Design approval or certification for the design · US Nuclear Regulatory Commission · 2025-05-29 |
| PWR-20 | Last Energy | Pressurised water reactor | 20 MWe planned | Small modular reactor | No milestone recorded |
| R1 Microreactor Antares R1 | Antares Nuclear | Heat-pipe microreactor | 0.1 to 1 MWe planned | Microreactor | No milestone recorded |
| RITM-200M | OKBM Afrikantov with Rosatom | Pressurised water reactor | 50 MWe planned | Small modular reactor | No milestone recorded |
| RITM-200N | OKBM Afrikantov with Rosatom | Pressurised water reactor | 55 MWe planned | Small modular reactor | No milestone recorded |
| Rolls-Royce SMR | Rolls-Royce SMR | Pressurised water reactor | 470 MWe planned | Large reactor | Accepted for review for the design · Office for Nuclear Regulation · 2022-04 |
| SEALER-55 SEALER | Blykalla | Lead fast reactor | 55 MWe planned | Small modular reactor | No milestone recorded |
| SHELF-M | NIKIET with Rosatom | Pressurised water reactor | 10 MWe planned | Microreactor | No milestone recorded |
| SMART System-integrated Modular Advanced Reactor, SMART100 | KAERI | Pressurised water reactor | 107 MWe planned | Small modular reactor | No milestone recorded |
| SMR-300 | Holtec International | Pressurised water reactor | 320 MWe planned | Large reactor | Accepted for review for one plant: Pioneer Units 1 and 2: Part 1 of phased construction permit application accepted for docketing · US Nuclear Regulatory Commission · 2026-02-13 |
| SOLO SOLO Micro-Modular Reactor | Terra Innovatum | Gas-cooled | 1 MWe planned | Microreactor | No milestone recorded |
| Stable Salt Reactor - Wasteburner (SSR-W) SSR-W, SSR-W300 | Moltex Energy | Molten salt reactor | 300 MWe planned | Small modular reactor | No milestone recorded |
| Stellarium | Stellaria | Molten salt reactor | 110 MWe planned | Small modular reactor | No milestone recorded |
| SVBR-100 | Rosatom | Lead fast reactor | 100 MWe planned | Small modular reactor | No milestone recorded |
| ThorCon ThorCon 500, TMSR-500 | ThorCon International | Molten salt reactor | 250 MWe planned | Small modular reactor | No milestone recorded |
| Thorizon One Thorizon | Thorizon | Molten salt reactor | 100 MWe planned | Small modular reactor | No milestone recorded |
| UNITHERM | NIKIET with Rosatom | Pressurised water reactor | 6.6 MWe planned | Microreactor | No milestone recorded |
| VBER-300 | OKBM Afrikantov with Rosatom | Pressurised water reactor | 325 MWe planned | Large reactor | No milestone recorded |
| Xe-100 | X-energy | High-temperature gas-cooled reactor | 80 MWe planned | Small modular reactor | Accepted for review for one plant: Long Mott construction permit application accepted for docketing · US Nuclear Regulatory Commission · 2025-05-12 |
| ZEUS | NANO Nuclear Energy | Fission | Output not stated | Not classed | No milestone recorded |
Measurements
144 reactors using this approach carry 144 measurements: 132 claimed, 12 planned. The values, each with its status and source, are on the benchmark and on each device's page. Most measured: Advanced Test Reactor (1), Advanced Test Reactor Critical (1), AGN-201, Idaho State University (1), AGN-201K (1), AGN-201M, Texas A&M (1).
Guides
Includes guides about the narrower approaches.
- Find companies by reactor type How to list the companies working on one kind of fusion machine or fission reactor, using the companies directory, the technology pages and the device table.
- How fission reactors work How a fission reactor sustains a chain reaction, what the moderator, coolant and control rods do, why delayed neutrons make control possible, where decay heat comes from, and what passive safety does and does not mean.
- Small modular reactors What makes a reactor a small modular reactor, where the IAEA draws the size lines, why size is judged per unit rather than per plant, which ones actually operate, and why their cost claims are not yet proven.
- Microreactors What microreactors are, how heat-pipe, gas-cooled and sodium-cooled designs work, what they are meant for, why most need HALEU or TRISO fuel, and where the leading projects actually stand.
- Reactor types explained The three questions that classify any fission reactor, and how pressurised water, boiling water, heavy water, gas-cooled, salt-cooled, molten-salt, sodium, lead and heat-pipe reactors each answer them.
- Fusion and fission compared How fusion and fission differ in the physics, the fuels, the neutrons, the waste, the safety case and how far each has come, set side by side with the numbers.