The Criticality Timeline

First human-made self-sustaining nuclear chain reaction (k = 1.0006, 3:25 p.m., Dec 2, 1942)

First continuously operated nuclear reactor and pilot plant for plutonium production

World's first heavy-water-moderated reactor

First industrial-scale nuclear reactor; produced plutonium for the Trinity test and the Nagasaki bomb

First reactor to go critical outside the United States; origin of Canada's heavy-water (CANDU) lineage

World's first fast-neutron reactor (full power reached March 1949)

First reactor to go critical in Europe; launched the Soviet nuclear program and ran until 2012

First reactor to go critical in Western Europe

France's first nuclear reactor, built under Frédéric Joliot-Curie

First reactor to generate usable electricity from nuclear energy (four lightbulbs, December 20, 1951) and first breeder

First nuclear power plant to deliver electricity to a civilian grid (June 26, 1954)

France's first reactor to generate electricity, a CEA plutonium-production gas-graphite pile at Marcoule. First went critical on 7 January 1956 and delivered France's first nuclear-generated power later that year. Permanently shut down 15 October 1968.

World's first commercial-scale nuclear power station (opened by Queen Elizabeth II, October 17, 1956)

First reactor in India and in Asia outside the USSR (rebuilt as Apsara-U in 2018)

Second unit at Calder Hall, the world's first commercial-scale nuclear power station. Later operated by BNFL/Magnox Ltd; shut down 2003.

Japan's first nuclear reactor

First full-scale civilian pressurized water reactor in the United States

Third unit at Calder Hall, the world's first commercial-scale nuclear power station. Later operated by BNFL/Magnox Ltd; shut down 2003.

Second gas-graphite reactor at Marcoule, a dual-purpose plutonium-production and power unit and a prototype for the later UNGG power reactors. First went critical on 21 July 1958. Permanently shut down 2 February 1980.

First unit at Chapelcross, Scotland's first nuclear power station and a sister plant to Calder Hall producing plutonium and power. Later operated by BNFL/Magnox Ltd; shut down 2004.

Fourth and final unit at Calder Hall, the world's first commercial-scale nuclear power station. Later operated by BNFL/Magnox Ltd; shut down 2003.

Second unit at Chapelcross, Scotland's first nuclear power station. The last reactor at the site to cease operation, in 2004.

Third gas-graphite reactor at Marcoule, a dual-purpose plutonium-production and power unit alongside G2. First went critical on 8 June 1959. Permanently shut down 20 June 1984.

Third unit at Chapelcross, Scotland's first nuclear power station. Later operated by BNFL/Magnox Ltd; shut down 2004.

First privately financed nuclear power plant in the United States and first commercial BWR

Fourth and final unit at Chapelcross, Scotland's first nuclear power station. Later operated by BNFL/Magnox Ltd; shut down 2004.

One of the first commercial nuclear power plants in the United States; operated about 30 years before closing in 1991

Germany's first nuclear power reactor to generate electricity; research/test plant shut down 1985

One of the early CEGB Magnox commercial stations; Bradwell operated until 2002

One of the first two CEGB Magnox commercial stations; Berkeley was the first UK commercial nuclear power station to close (1989)

Second reactor at Berkeley, one of the first CEGB Magnox commercial stations; shut down October 1988

Second reactor at Bradwell, an early CEGB Magnox commercial station; shut down March 2002

First CANDU prototype and first nuclear-generated electricity delivered to a Canadian grid

Early US commercial PWR; shut down in 1974 as it lacked an emergency core cooling system meeting new standards

France's first industrial power reactor, a natural-uranium gas-graphite (UNGG) unit on the Loire. First went critical on 16 September 1962. Its spherical steel containment, nicknamed "La Boule," is now preserved as a museum. Permanently shut down 16 April 1973.

One of the oldest US BWRs and, for years, the country's smallest commercial reactor; closed in 1997

Italy's first commercial nuclear reactor and, at the time, the largest reactor in Europe. A British Magnox gas-graphite design that reached first criticality on 27 December 1962. Permanently shut down on 1 December 1987 following the post-Chernobyl Italian nuclear referendum; now under SOGIN decommissioning.

An early General Electric dual-cycle boiling water reactor on the Garigliano river near Sessa Aurunca. Reached first criticality on 5 June 1963. Operations ceased in 1978 due to steam generator problems and it was formally shut down permanently on 1 March 1982; now under SOGIN decommissioning.

Sweden's first nuclear reactor to generate power. A heavy-water design built into rock south of Stockholm, it was primarily a combined heat and power plant supplying ~68 MW of district heating to the Farsta suburb plus about 10 MWe of electricity. Permanently shut down on 2 June 1974.

First Magnox station operated by the South of Scotland Electricity Board; shut down 1990

The first reactor to generate electricity in Japan (26 October 1963). A small GE-supplied BWR demonstration unit operated by the Japan Atomic Energy Research Institute at Tokai; after shutdown in 1976 it became Japan's decommissioning technology test bed, fully dismantled by 1996.

Experimental fast breeder reactor that suffered a partial fuel meltdown on October 5, 1966 (the basis for the book "We Almost Lost Detroit"); shut down in 1972

First unit at Beloyarsk; AMB-100 graphite-moderated channel reactor with nuclear superheat; permanently shut down 1983-01-01

First Soviet commercial VVER (prototype VVER-210); permanently shut down 1988-02-16

Second reactor at Hunterston A, operated by the South of Scotland Electricity Board; shut down December 1989

CEGB Magnox commercial station on the Somerset coast; shut down May 2000

The Enrico Fermi Nuclear Power Plant at Trino Vercellese, a Westinghouse pressurized water reactor that reached first criticality on 21 June 1964 — in 1964 the third commercially operated PWR in the world. Permanently shut down on 1 July 1990 after the 1987 Italian nuclear referendum; now under SOGIN decommissioning.

Second UNGG gas-graphite reactor at Chinon on the Loire. First went critical on 17 August 1964. Permanently shut down 14 June 1985.

One of two Magnox reactors at Trawsfynydd, the only inland (non-coastal) nuclear power station in the UK; shut down in 1991

Second reactor at Hinkley Point A, a CEGB Magnox commercial station; shut down May 2000

Second Magnox reactor at Trawsfynydd, the UK's only inland nuclear power station; shut down in 1991

Japan's first commercial nuclear power reactor. A British-designed Magnox gas-cooled reactor imported from the UK (GEC), it launched Japan's commercial nuclear program. Permanently shut down 1998-03-31 and is undergoing Japan's first commercial reactor decommissioning.

One of two Magnox reactors at Sizewell A; shut down in 2006

World's first molten-salt-fueled reactor; later became the first reactor to run on uranium-233

One of two Magnox reactors at Dungeness A; shut down in 2006

Second Magnox reactor at Dungeness A; shut down in 2006

Second Magnox reactor at Sizewell A; shut down in 2006

East Germany's first nuclear power plant, a small Soviet VVER-70 prototype PWR. Permanently shut down on 1 June 1990 around German reunification.

Third and largest UNGG gas-graphite reactor at Chinon on the Loire. First went critical on 1 March 1966. Permanently shut down 15 June 1990.

West Germany's first commercial-scale nuclear power plant (KRB-A), an early GE/AEG dual-cycle boiling water reactor. Permanently shut down in January 1977 after a coolant-loss incident that flooded the reactor building; never restarted.

Prototype pebble-bed high-temperature gas-cooled reactor; ran 1966-1988 as a test bed for HTGR technology

France's first pressurized-water reactor, a Franco-Belgian prototype (SENA / Chooz SEM) built in underground caverns in a hillside on the Meuse. First went critical on 18 October 1966. It pioneered the PWR technology that became the backbone of the French fleet. Permanently shut down 30 October 1991.

Canada's first full-scale nuclear power plant and prototype for the commercial CANDU design; operated by Ontario Hydro, permanently shut down 4 May 1984

France's only power-producing heavy-water reactor, an experimental CEA/EDF unit in the Monts d'Arrée, Brittany. First went critical in December 1966. Its ongoing decommissioning is one of the longest and most contested in France. Permanently shut down 31 July 1985.

One of the earliest US commercial PWRs; shut down in 1992

Early US commercial PWR; closed in 1996 for economic reasons

One of two Magnox reactors at Oldbury; shut down in 2012

AMB-200 graphite-moderated channel reactor with nuclear superheat; permanently shut down 1990-01-01

Second Magnox reactor at Oldbury; shut down in 2011

Early German BWR that used a fossil-fired superheater; shut down 1977

The Netherlands' first power reactor, a small General Electric BWR used partly as a demonstration and test unit. Permanently shut down on 26 March 1997.

Spain's first commercial nuclear power reactor, a small single-loop Westinghouse PWR near Almonacid de Zorita, commonly known as Zorita. It went critical in June 1968 and operated for nearly four decades until its permanent shutdown on 30 April 2006. Its decommissioning was one of the first full dismantlements of a Spanish reactor.

One of Germany's earliest commercial PWRs, shut down on 11 May 2005 under the first (2002) nuclear phase-out law

First UNGG gas-graphite reactor at Saint-Laurent-des-Eaux on the Loire. First went critical on 9 January 1969. Site of a partial fuel-melt incident in 1969 (rated INES 4). Permanently shut down 18 April 1990.

One of Asia's first commercial power reactors; General Electric BWR ordered under a US-India agreement

Twin General Electric BWR at India's first commercial nuclear station

One of the first large commercial BWRs and the oldest operating US reactor when it closed in 2018

One of the two units at Beznau, the world's oldest operating nuclear power plant. Beznau-1 reached first criticality on 30 June 1969 and entered commercial operation later that year, making it among the longest-serving commercial reactors still in service. Operated by Axpo on an island in the Aare river.

Oldest operating GE BWR/2 in the United States

Japan's first light-water reactor and one of its earliest commercial units, a GE BWR at the Tsuruga site. Permanently shut down 2015-04-27.

Largest and last Magnox reactor built; Wylfa 1 was the final operating Magnox reactor in the world, shut down on 30 December 2015

One of the oldest operating nuclear power plants in the United States

Second-generation VVER-365; permanently shut down 1990-08-29

Japan's first commercial PWR and Kansai Electric's first reactor; permanently shut down 27 April 2015 as too small to justify post-Fukushima upgrades.

Second reactor at Wylfa, the largest Magnox station ever built; shut down in April 2012

One of the oldest operating PWRs in the United States and the first large commercial PWR in the US Southeast

Oldest Fukushima Daiichi unit and epicenter of the March 2011 triple-meltdown disaster; core melted after the tsunami disabled cooling, and the reactor building was destroyed by a hydrogen explosion on 2011-03-12. Permanently shut down 2011-05-19.

Shut down permanently in 1998

An early General Electric BWR-3 with Mark I containment on the Ebro river in Burgos, a sister design to Fukushima Daiichi Unit 1. It went critical in November 1970. The operator halted the reactor on 6 July 2013 amid a tax and licensing dispute, and although a restart was debated for years, the government declined to renew its license, making the shutdown permanent on 2 August 2017.

Early CANDU prototype using a vertical pressure-tube boiling-light-water design; troubled operation, only ~180 on-power days, permanently shut down 1 June 1977

Sweden's first commercial nuclear power reactor. Permanently shut down on 19 June 2017.

One of the first four CANDU 500A units at Pickering A; permanently shut down 1 October 2024

A General Electric BWR-4 operated by BKW near Bern. Reached first criticality on 8 March 1971 and ran for nearly five decades before being permanently shut down on 20 December 2019, the first Swiss power reactor to be decommissioned. Dismantling began in January 2020.

Second UNGG gas-graphite reactor at Saint-Laurent-des-Eaux on the Loire. First went critical on 4 July 1971. Site of a 1980 partial fuel-melt incident (rated INES 4), one of the most serious in French history. Permanently shut down 27 May 1992.

Pakistan's first nuclear power reactor; Canadian-supplied CANDU-type PHWR, permanently shut down 1 August 2021 after nearly 50 years.

Pickering A unit; laid up in 1997 and permanently shut down / defuelled 28 May 2007

The second unit at the Beznau plant, twin to Beznau-1. Reached first criticality on 16 October 1971 and began commercial operation in March 1972. Together with Beznau-1, it makes Beznau the oldest operating nuclear power station in the world, run by Axpo in canton Aargau.

Germany's first large BWR; shut down 1994 after core-shroud cracking was found

First-series VVER-440 (V-179); permanently shut down 2016-12-25

One of Germany's earliest commercial PWRs; first plant shut down under the German nuclear phase-out, in 2003

A French-designed UNGG gas-graphite reactor, the only one of its kind in Spain, sharing the design lineage of France's early Magnox-style plants. It went critical in February 1972 and operated until a turbine-hall fire on 19 October 1989 (rated INES level 3) led to its permanent shutdown on 31 July 1990. Decommissioning brought it to a long "latency" safe-store state, with radioactive machinery dismantled by 2003.

The last and most powerful UNGG gas-graphite reactor built in the world, on the Rhône in the Ain. First went critical on 21 March 1972. It marked the end of France's natural-uranium graphite-gas line before the switch to PWRs. Permanently shut down 27 May 1994.

Vermont's only commercial nuclear plant; closed for economic reasons at the end of 2014

Early small 2-loop PWR; permanently shut down 27 April 2015 as uneconomic to retrofit for post-Fukushima standards given its small output.

Pickering A unit; permanently shut down / defuelled 31 October 2008

Massachusetts' last operating nuclear plant; closed in 2019

Pioneering sodium-cooled fast-breeder reactor and the world's first to combine power generation with large-scale seawater desalination (up to ~120,000 m3/day of fresh water). Permanently shut down 22 April 1999. Design output ~350 MWt split between electricity, heat, and desalination.

India's first PHWR (Canadian CANDU design); plagued by leaks and cracks, permanently shut down in October 2004

Maine's only commercial nuclear plant; closed in 1997 rather than fund needed repairs

First nuclear power reactor in Czechoslovakia; Czechoslovak-designed gas-cooled heavy-water reactor, permanently shut down 22 February 1977 after a refuelling accident

First-series VVER-440 (V-179); still operating with life extension

First of three Babcock & Wilcox PWRs at Duke's Oconee station

One of three Fukushima Daiichi units (1-3) that suffered core meltdowns in the March 2011 disaster after the tsunami knocked out cooling. Permanently shut down 2011-05-19.

Pickering A unit; refurbished and returned to service in 2003, permanently shut down 31 December 2024

Shut down April 30, 2020 under a settlement with New York State

Chugoku's first reactor and one of Japan's oldest BWRs; permanently shut down 30 April 2015 rather than back-fit to post-Fukushima standards.

Shut down in 1998 for economic reasons

The Netherlands' only operating nuclear power reactor. A German KWU PWR that has been repeatedly life-extended and is central to Dutch plans for new nuclear build.

First nuclear unit above the Arctic Circle; early VVER-440 (V-230)

Smallest commercial PWR in the US at the time of its 2016 closure

First unit at Browns Ferry, the largest nuclear plant when completed; restarted in 2007 after a 22-year shutdown

The only boiling water reactor at the otherwise PWR-based Ringhals station. Permanently shut down on 31 December 2020, the first of the two Ringhals units retired in Sweden's early-2020s fleet reduction.

France's prototype fast breeder; first commercial-pilot-scale breeder connected to a national grid

First RBMK-1000 reactor ever built; first-generation unit permanently shut down 21 December 2018 after 45 years

First of four tiny EGP-6 graphite-moderated cogeneration reactors at the remote Arctic Bilibino plant, supplying heat and power to Chukotka. Permanently shut down 23 March 2018.

Lead unit of East Germany's largest nuclear station (KKW Bruno Leuschner). Shut down on 18 December 1990 when the entire Greifswald VVER-440/230 fleet was closed on safety grounds after German reunification.

Shut down in 1998 for economic reasons

First nuclear power reactor in Latin America; unique Siemens/KWU heavy-water pressure-vessel design

Largest single-unit electrical generator in Nebraska

Second unit at Oskarshamn. Permanently shut down on 22 December 2016.

Closed in 2013 for economic reasons despite holding a renewed 20-year license

One of Japan's oldest operating reactors; approved for 60-year life extension and resumed operation 2 August 2023 after a long post-Fukushima suspension.

Undamaged unit that kept running after the 1979 TMI-2 accident; shut down for economic reasons in 2019 and now slated to restart as the Crane Clean Energy Center (see crane-tmi-1)

Sweden's first Westinghouse PWR to enter service. Permanently shut down on 31 December 2019.

First Hamaoka unit; permanently shut down on 2009-01-30 and under decommissioning rather than seismic retrofit.

First nuclear power reactor in Bulgaria; shut down 31 December 2002 as an EU accession condition

Taken offline in the March 2011 post-Fukushima moratorium and permanently shut down that August during Germany's nuclear phase-out

One of Belgium's first commercial reactors. Permanently shut down on 14 February 2025 after 50 years of operation.

Suffered a core meltdown in the March 2011 disaster; its reactor building was destroyed by a hydrogen explosion on 2011-03-14. Permanently shut down 2011-05-19.

Closed in 1989 after a public ballot referendum — the first US reactor shut down by voter initiative

Early VVER-440 (V-230); operating in the Arctic Kola region

Second VVER-440/230 unit at East Germany's Greifswald station; shut down on 14 February 1990 as the fleet was retired on safety grounds around reunification.

Second EGP-6 cogeneration reactor at the remote Arctic Bilibino plant. Permanently shut down 1 December 2025 as the plant is retired ahead of floating and modular replacement capacity.

Granted a 60-year operating extension; resumed operation 20 September 2023 after post-Fukushima suspension.

Located near Malmö and across the sound from Copenhagen, its proximity to Denmark made it politically contentious. Permanently shut down on 30 November 1999 under Sweden's nuclear phase-out policy, the first Swedish power reactor closed for political rather than technical reasons.

Kyushu Electric's first reactor; permanently shut down 27 April 2015 rather than fund post-Fukushima upgrades on an aging small unit.

First unit at Tihange, jointly owned with EDF of France. Permanently shut down on 30 September 2025 after 50 years of service.

First-generation RBMK-1000; permanently shut down 10 November 2020

Twin unit to Doel-1. Permanently shut down on 30 November 2025 under Belgium's nuclear phase-out schedule.

Shut down 31 December 2002 as an EU accession condition

Third EGP-6 cogeneration reactor at the remote Arctic Bilibino plant. Permanently shut down 19 December 2025.

Oregon's only commercial nuclear plant; closed in 1992 well before its license expired

Site of a fatal 2004 steam-pipe rupture; later the first Japanese reactor to operate beyond 40 years, restarting in 2021 with a life extension to 2036.

Taken offline in the March 2011 post-Fukushima moratorium and permanently shut down that August during Germany's nuclear phase-out

Last Indian Point unit to close, shut down April 30, 2021

Taken offline in the March 2011 post-Fukushima moratorium and permanently shut down that August during Germany's nuclear phase-out

BWR with a troubled operating history; offline from 2007 and formally shut down in 2011

Bruce A unit; laid up in 1995 and refurbished, returning to service in 2012

First-generation RBMK-1000; permanently shut down 19 December 2021

Last of the four EGP-6 cogeneration reactors at the remote Arctic Bilibino plant and the final unit in operation. Permanently shut down 30 December 2025, ending the plant's 50+ years of Arctic operation.

First unit of Armenia's only nuclear plant; permanently shut down 25 February 1989 following the 1988 Spitak earthquake, and never restarted.

Bruce A unit; laid up in 1997 and refurbished, returning to service in 2012

Retired in 2013 after containment concrete cracked during a steam generator replacement project

Finland's first nuclear power reactor. A Soviet VVER-440 fitted with a Westinghouse-derived containment and Western instrumentation, a hybrid East-West design often cited as one of the safest VVER installations.

Shikoku Electric's first reactor; permanently shut down 10 May 2016 rather than back-fit to post-Fukushima safety standards.

One of the first two units of France's standardized 900 MWe CP0 PWR series, on the Rhine in Alsace. First went critical on 7 February 1977. France's oldest operating reactor at the time of its politically driven closure. Permanently shut down 22 February 2020.

Second Barsebäck unit. Permanently shut down on 31 May 2005 under Sweden's nuclear phase-out policy, closing the station entirely.

South Korea's first commercial nuclear reactor; permanently shut down 18 June 2017 after 40 years of operation.

Second CP0-series 900 MWe PWR at Fessenheim on the Rhine in Alsace. First went critical on 27 June 1977. Permanently shut down 30 June 2020, closing France's oldest nuclear station.

First unit of the Chernobyl NPP; permanently shut down 30 November 1996.

Site of the 2002 reactor pressure vessel head corrosion incident, one of the most serious US nuclear safety events

Survived the March 2011 disaster without a meltdown (units 5 and 6 shared a working generator to keep cooling) but never restarted. Permanently shut down 2013-12-17.

Third VVER-440/230 unit at East Germany's Greifswald station; shut down on 28 February 1990 during the post-reunification closure of the fleet.

Taiwan's first commercial nuclear reactor. Permanently shut down 6 December 2018 at end of its operating licence.

Boiling water reactor at the Isar/Ohu site alongside the later Isar 2 PWR. Taken offline in the March 2011 post-Fukushima moratorium and permanently shut down that August.

Bruce A unit

First unit at Kansai Electric's Ohi plant; permanently shut down 1 March 2018 after not operating since 2011, deemed uneconomic to upgrade post-Fukushima.

Italy's largest nuclear reactor, a General Electric BWR-4 with Mark II containment. Reached first criticality on 31 December 1977. Operations were suspended after the 1987 Italian nuclear referendum and it was permanently shut down on 1 July 1990; now under SOGIN decommissioning.

JAPC's boiling water reactor adjacent to the original Tokai-1 site. Shut down for the March 2011 earthquake and idle since; it received Nuclear Regulation Authority approval to restart but remains offline pending safety upgrades and local consent.

Defueled and offline for maintenance when the March 2011 disaster struck, yet its reactor building was still wrecked by a hydrogen explosion on 2011-03-15, with the spent-fuel pool a major crisis focus. Permanently shut down 2011-05-19.

Prototype Advanced Thermal Reactor (ATR), a uniquely Japanese heavy-water-moderated, boiling-light-water-cooled design that could burn plutonium-uranium MOX fuel. Operated by the Power Reactor and Nuclear Fuel Development Corp (later JNC/JAEA). Permanently shut down 2003-03-29.

Site of the worst commercial nuclear accident in US history — a partial core meltdown on March 28, 1979; permanently shut down the same day

Permanently shut down on 2009-01-30 alongside Unit 1; under decommissioning.

First of four CP0 units at Bugey, among the earliest standardized French 900 MWe PWRs

First unit at Olkiluoto, a Swedish ASEA-Atom BWR that has been substantially uprated over its life.

Second CP0 unit at Bugey on the Rhône, east of Lyon

Second Ohi unit; permanently shut down 1 March 2018 alongside Ohi-1, retired rather than upgraded to post-Fukushima standards after years offline.

Taken offline in the March 2011 post-Fukushima moratorium and permanently shut down that August during Germany's nuclear phase-out

Second unit of Taiwan's first nuclear plant. Permanently shut down 16 July 2019 at end of its operating licence.

Second unit of the Chernobyl NPP; permanently shut down 11 October 1991 after a turbine-hall fire.

First VVER-440/230 unit built outside the Soviet Union; shut down 31 December 2006 as an EU accession condition

Bruce A unit

First-generation RBMK-1000; permanently shut down 31 January 2024

A Siemens/KWU three-loop pressurized water reactor on the Aare river at Däniken, operated by KKG. Reached first criticality on 20 January 1979 and entered commercial operation in November 1979. One of Switzerland's four operating reactors and the country's largest by a single-unit design of its era.

Third CP0 unit at Bugey, rated 880 MWe net

Boiling water reactor at the Philippsburg site, paired with the later Philippsburg 2 PWR. Taken offline in the March 2011 post-Fukushima moratorium and permanently shut down that August.

Largest and newest Fukushima Daiichi unit; its air-cooled backup diesel generator survived the March 2011 tsunami and powered cooling for both units 5 and 6, sparing them from meltdown. Permanently shut down 2013-12-17.

Fourth and final CP0 unit at Bugey, completing the operating four-reactor station (the earlier Bugey-1 UNGG reactor is permanently shut down)

Fourth VVER-440/230 unit at East Germany's Greifswald station; shut down on 2 June 1990 as the fleet was retired on safety grounds after reunification.

Second-generation RBMK-1000; operating, planned shutdown around 2030

Second ASEA-Atom BWR at Olkiluoto, sister unit to Olkiluoto-1.

Armenia's sole operating reactor; shut down in 1989 after the 1988 Spitak earthquake and restarted 5 November 1995. Life extended to 2036. First criticality recorded as early January 1980 by WNA/PRIS.

First of four CP1 units at Tricastin in the Rhône valley, which historically supplied power to the adjacent Georges Besse uranium enrichment plant

First of six CP1 900 MWe PWRs at Gravelines, the largest nuclear power station in Western Europe by installed capacity

BN-600 sodium-cooled fast breeder reactor; long-running demonstration fast reactor

First of four CP1-series 900 MWe pressurized water reactors at the Dampierre plant on the Loire, and among the earliest units of France's standardized CP1 fleet built by Framatome for EDF. Part of the rapid nuclear buildout that made France one of the most nuclearized grids in the world.

Second V1 unit; shut down 31 December 2008 as an EU accession condition

First of three operating BWR units at Forsmark, Sweden's most modern nuclear station.

Prototype VVER-1000 (V-187), lead unit of the VVER-1000 series

Small 2-loop PWR permanently shut down 9 April 2019 ahead of schedule, judged uneconomic to upgrade for continued operation.

First new US nuclear plant licensed after the Three Mile Island accident

Second CP1 unit at Tricastin, one of the earliest French 900 MWe series reactors

One of two operating PWR units at Ringhals, Sweden's largest power station by output.

Second CP1 unit at Gravelines, connected to the grid in 1980 alongside Gravelines-1

Second Canadian CANDU-derived PHWR at Rawatbhata; completed by India after Canada withdrew support post-1974

Second VVER-440 unit at Loviisa, operated by Fortum with Western safety upgrades.

Second BWR unit at Forsmark, still operating.

Third CP1 unit at the Tricastin nuclear site in the Drôme

Third CP1 unit at the Gravelines station on the North Sea coast near Dunkirk

Shut down 31 December 2006 as an EU accession condition

Second CP1-series 900 MWe PWR at the Dampierre plant, one of four identical Framatome units on the Loire river serving EDF's standardized 900 MWe fleet.

First unit of the Rivne (Rovno) NPP; one of Ukraine's two older VVER-440 units.

Second-generation RBMK-1000; operating, planned shutdown around 2031

First of two CP2-series 900 MWe PWRs (the "B" units) at Saint-Laurent-des-Eaux on the Loire. It replaced the earlier gas-graphite A1/A2 reactors on the same site, marking the transition to standardized PWR technology.

Third CP1-series 900 MWe PWR at the Dampierre plant, part of EDF's standardized Framatome-built fleet on the Loire.

Taiwan's second nuclear plant (Second Nuclear Power Plant). Permanently shut down 28 December 2021 at end of its 40-year operating licence.

Second-generation VVER-440 (V-213) with improved safety systems

One of two Westinghouse 3-loop PWR units at the Almaraz plant on the Tagus river in Extremadura, western Spain. Almaraz-1 first went critical in April 1981 and remains one of Spain's largest baseload power sources. Owned by a consortium (Iberdrola, Endesa, Naturgy) and operated by CNAT.

Second of two CP2-series 900 MWe PWRs (the "B" units) at Saint-Laurent-des-Eaux on the Loire, completing the site's PWR pair for EDF.

First of four CP1-series 900 MWe PWRs at the Blayais plant on the Gironde estuary. The Blayais site is notable for the December 1999 storm-surge flood that partially inundated the plant, a formative event in nuclear flood-safety regulation worldwide.

Fourth and final CP1 unit at Tricastin, completing the four-reactor station in 1981

Fourth CP1 unit at Gravelines, completing the plant's first construction phase in 1981

Third unit of the Chernobyl NPP; the last operating unit, permanently shut down 15 December 2000, closing the plant.

Sister plant ~12 km south of Fukushima Daiichi; the four Daini units narrowly avoided meltdown in March 2011 by restoring cooling before fuel damage. Never restarted; TEPCO decided in 2019 to decommission the site (permanent shutdown 2019-09-30).

Permanently shut down 23 May 2018 after ~36 years; decommissioning approved by Japan's NRA.

Fourth and final CP1-series 900 MWe PWR at the Dampierre plant, completing the four-unit Framatome station on the Loire for EDF.

Slovenia's only nuclear reactor; jointly owned by Slovenia and Croatia, built in the former Yugoslavia

Shut down on 27 June 2015, the first German reactor retired after the 2011 phase-out decision took effect

Second unit of the Rivne (Rovno) NPP; VVER-440 design.

Brazil's first nuclear power reactor

Second unit of the Kuosheng plant. Permanently shut down 15 March 2023 at end of its 40-year operating licence.

Shut down 31 December 2006 as an EU accession condition

The youngest reactor at Ringhals and one of two units still operating at the station.

A larger three-loop PWR at Doel. The reactor pressure vessel drew international scrutiny after hydrogen flaking was found in 2012. Permanently shut down on 23 September 2022.

Second CP1-series 900 MWe PWR at the Blayais plant on the Gironde estuary, one of four identical Framatome units serving EDF's standardized fleet.

First CANDU 6 unit; refurbished 2008-2012 and returned to full service November 2012

Closed permanently in 2013 after premature wear in replacement steam generators

One of the largest single-unit boiling water reactors in the United States

Second-generation RBMK-1000; operating

Quebec's only commercial CANDU 6 unit; permanently shut down 28 December 2012

Its reactor vessel, like Doel-3, showed hydrogen flaking flaws that prompted extended safety reviews. Permanently shut down on 1 February 2023.

First of the four Pickering B units; slated for refurbishment under OPG's Pickering B life-extension program

First of four CP2-series 900 MWe PWRs (the "B" units) at the Chinon plant on the Loire. The B units succeeded Chinon's pioneering A1/A2/A3 gas-graphite reactors, France's earliest power reactors, on the same historic site.

South Korea's first heavy-water (CANDU-6 PHWR) reactor; permanently shut down 24 December 2019.

First unit of the South Ukraine NPP; earliest VVER-1000 (small-series V-302 design) to enter service in Ukraine.

First nuclear power reactor in Hungary

Argentina's CANDU 6 unit; refurbished and life-extended 2016-2019

First of four CP2-series 900 MWe PWRs at the Cruas-Meysse plant on the Rhône. The Cruas station is known for the large fresco of a child holding the Earth painted on its cooling towers.

Operation suspended in April 2023 when its 40-year license expired; KHNP is pursuing a continued-operation (license renewal) approval rather than permanent decommissioning.

One of four Fukushima Daini units that avoided meltdown in March 2011. Permanently shut down 2019-09-30 under TEPCO's decision to decommission the site.

Fourth and final CP1-series 900 MWe PWR at the Blayais plant on the Gironde estuary, completing the four-unit Framatome station for EDF. It reached criticality and grid before unit 3 despite its higher number.

The first of two Westinghouse 3-loop PWR units at the Ascó plant on the Ebro river in Tarragona, Catalonia. Ascó-1 went critical in June 1983 and is operated by ANAV, the joint operating company of Endesa and Iberdrola that also runs Vandellòs-2.

First reactor of the Madras Atomic Power Station (MAPS); early indigenous PHWR

Third CP1-series 900 MWe PWR at the Blayais plant on the Gironde estuary, part of EDF's standardized Framatome-built fleet.

Second-generation RBMK-1000; operating

First reactor in Japan to restart under post-Fukushima safety standards, in August 2015.

Closed permanently in 2013 after premature wear in replacement steam generators

Full-scale thorium-fueled pebble-bed HTGR; ran only ~1 year commercially before shutdown in 1988

One of the world's largest BWRs by output; shut down 2011 under Germany's post-Fukushima nuclear exit

The second Westinghouse 3-loop PWR unit at the Almaraz plant in Cáceres, western Spain. Almaraz-2 reached first criticality in September 1983, two years after its sister unit. Together the two Almaraz reactors form one of Spain's most important baseload generating sites.

Second CP2-series 900 MWe PWR at the Chinon plant on the Loire, one of four "B" units serving EDF's standardized fleet.

One of two RBMK-1500 units at Ignalina, the largest reactor design of the RBMK line (1500 MWe design, derated in operation). Permanently shut down 31 December 2004 as a condition of Lithuania's EU accession.

Pickering B unit

First Onagawa unit; permanently shut down on 2018-12-21, with Tohoku opting to decommission rather than retrofit.

Site of the 26 April 1986 Chernobyl disaster, history's worst nuclear accident; the reactor was destroyed and later entombed in a sarcophagus and the New Safe Confinement.

Only commercial nuclear power plant in Washington State; formerly known as WNP-2 (Washington Nuclear Project 2)

Switzerland's largest and newest nuclear reactor, a General Electric BWR-6 with a Mark III containment on the Rhine near the German border. Reached first criticality on 9 March 1984 and entered commercial operation in December 1984. Operated by KKL.

One of the two large KRB II boiling water reactors that replaced the earlier KRB-A unit. Permanently shut down on 31 December 2017 under Germany's nuclear phase-out.

First and only nuclear power reactor on the African continent (with Koeberg-2)

Taiwan's only PWR plant (Third Nuclear Power Plant). Permanently shut down 28 July 2024 at end of its 40-year operating licence.

Third CP2-series 900 MWe PWR at the Cruas-Meysse plant on the Rhône, part of EDF's standardized Framatome-built fleet. It reached criticality and grid before unit 2 despite its higher number.

First unit at Kalinin NPP, an early VVER-1000/338 model

Mitsubishi 3-loop PWR; among the first Japanese reactors cleared to run on MOX fuel and to restart under post-Fukushima rules.

First of four 1300 MWe P4-series PWRs at Paluel, among the highest-output nuclear sites in France.

Bruce B unit; first Bruce B unit to complete a major component refurbishment (2020-2023)

Second CP2-series 900 MWe PWR at the Cruas-Meysse plant on the Rhône, one of four identical Framatome units serving EDF's standardized fleet.

Fifth Gravelines unit, part of the second construction phase that brought the site to six reactors

First of two operating V2 units at Bohunice

Second 1300 MWe P4 PWR at Paluel, reaching first criticality within months of unit 1.

Spain's only General Electric BWR-6 boiling water reactor, located on the Júcar river in Valencia. Cofrentes went critical in August 1984 and is wholly owned and operated by Iberdrola. Uprates have raised its output over its lifetime to about 1,064 MWe net.

Second unit at Paks

Shut down on 31 December 2021 in the penultimate wave of Germany's nuclear phase-out

Fourth and final CP2-series 900 MWe PWR at the Cruas-Meysse plant on the Rhône, completing the four-unit Framatome station for EDF.

Second-generation VVER-440 (V-213); youngest of the four Kola units

Mitsubishi 3-loop PWR at Takahama; licensed for MOX fuel use and returned to service under post-Fukushima safety standards.

One of four Fukushima Daini units that avoided meltdown in March 2011. Permanently shut down 2019-09-30 under TEPCO's decision to decommission the site.

Pickering B unit

The last operating boiling water reactor in Germany; permanently shut down on 31 December 2021 under the nuclear phase-out.

Largest and newest unit at Forsmark, a BWR-3000 design still in operation.

Bruce B unit

First unit of Zaporizhzhia NPP, the largest nuclear plant in Europe (six VVER-1000 units, ~5,700 MWe). Under Russian military occupation since March 2022; units held in shutdown.

First unit at the Kashiwazaki-Kariwa complex, the world's largest nuclear station by capacity; idle since the post-Fukushima nationwide shutdown, not permanently closed.

Shut down on 31 December 2019 as part of Germany's staged nuclear phase-out

The only operating unit remaining at Oskarshamn and one of the largest BWRs in the world by net output.

Second unit of the South Ukraine NPP; small-series VVER-1000 V-338 design.

Westinghouse 3-loop PWR, operating. First criticality reported as early January 1985 (source lists 1 January, likely a month-level placeholder); grid connection 22 January 1985.

Taiwan's last operating nuclear reactor; its permanent shutdown on 18 May 2025 made Taiwan nuclear-free.

First of four VVER-440/213 units at Dukovany, the Czech Republic's first nuclear power station

Restarted October 2015, the second Japanese reactor back online after the post-Fukushima shutdown of the fleet.

Newest unit at Doel and one of the Belgian reactors granted a 10-year life extension to 2035.

Second-generation RBMK-1000; operating

Part of the largest nuclear generating station in the United States

Newest unit at Tihange and one of the Belgian reactors granted a 10-year life extension to 2035.

Second unit of Zaporizhzhia NPP, Europe's largest nuclear plant. Under Russian military occupation since March 2022.

Second unit of Africa's only nuclear power station

Sixth and final reactor at Gravelines, giving the station a total installed capacity of roughly 5.5 GWe

Second of two operating V2 units at Bohunice

First of two 1300 MWe P4 PWRs on the Rhône at Saint-Alban.

Third 1300 MWe P4 PWR at Paluel, brought online in 1985.

Second unit of the Madras Atomic Power Station (MAPS)

The world's first full-scale commercial sodium-cooled fast breeder reactor, on the Rhône near Creys-Malville. First went critical on 7 September 1985. Plagued by sodium leaks, legal challenges, and low availability, it operated only intermittently. Permanently shut down by government decree on 30 December 1998 (having last operated in December 1996).

The second Westinghouse 3-loop PWR unit at the Ascó plant in Tarragona, Catalonia. Ascó-2 reached first criticality in September 1985. Operated by ANAV alongside Ascó-1, the two units are a major source of electricity for northeastern Spain.

First 1300 MWe P4 PWR at Flamanville, the Normandy site that later hosted the Flamanville-3 EPR.

Westinghouse 3-loop PWR, operating; last of the original four Kori units.

Second-generation RBMK-1000; operating

First of four VVER-1000/320 units at Balakovo, one of Russia's largest nuclear stations

Last of the four Pickering B units to enter service

Bruce B unit

Second VVER-440/213 unit at the Dukovany nuclear power station

Westinghouse 3-loop PWR; plant renamed from Yeonggwang (Yonggwang) to Hanbit in 2013. Operating.

Operated barely over a year before a court voided its construction license; permanently shut down 1988

Fourth and last 1300 MWe P4 PWR at Paluel, completing the four-unit station.

JAPC pressurized water reactor idle since the 2011 shutdown. In 2024 Japan's Nuclear Regulation Authority rejected its restart bid over an active fault line running beneath the reactor building, the first such rejection under the post-Fukushima safety rules.

Second 1300 MWe P4 PWR at Saint-Alban, reaching criticality in mid-1986.

Second 1300 MWe P4 PWR at Flamanville, on the same Normandy site as the later EPR.

Third unit at Paks

Third CP2-series 900 MWe PWR at the Chinon plant on the Loire, part of EDF's standardized Framatome-built "B" fleet.

Shut down on 31 December 2021 in the penultimate wave of Germany's nuclear phase-out

Westinghouse 3-loop PWR; plant renamed from Yeonggwang (Yonggwang) to Hanbit in 2013. Operating.

Newest Fukushima Daini unit; avoided meltdown in March 2011. Permanently shut down 2019-09-30 under TEPCO's decision to decommission the site.

First of four 1300 MWe P'4-series PWRs at Cattenom in Lorraine, cooled by the Moselle.

Third VVER-440/213 unit at the Dukovany nuclear power station

Third unit of the Rivne (Rovno) NPP; first VVER-1000 unit at the site.

Idle since the government-requested Hamaoka shutdown of 2011; seeking restart approval, not permanently closed.

Second VVER-1000/338 unit at Kalinin NPP

Second RBMK-1500 unit at Ignalina; commissioning delayed after the 1986 Chernobyl disaster. Permanently shut down 31 December 2009 as a condition of Lithuania's EU accession, ending nuclear power in the country.

Third unit of Zaporizhzhia NPP, Europe's largest nuclear plant. Under Russian military occupation since March 2022.

Last of the eight Bruce units to enter commercial service

Single-unit BWR/6; proposed site of a future SMR expansion

Fourth and final VVER-440/213 unit at Dukovany; all four units connected to the grid within about 28 months

Second 1300 MWe P'4 PWR at Cattenom, online in 1987.

Fourth unit at Paks

First of two 1300 MWe P'4 PWRs at Belleville-sur-Loire on the Loire river.

First of two 1300 MWe P'4 PWRs at Nogent-sur-Seine, the nuclear station closest to Paris.

Second VVER-1000/320 unit at Balakovo NPP

Fourth and final CP2-series 900 MWe PWR at the Chinon plant on the Loire, completing the four-unit "B" station for EDF.

First VVER-1000 unit in Bulgaria; one of two operating reactors at Kozloduy

A Westinghouse 3-loop PWR on the Costa Daurada in Tarragona, Catalonia, built adjacent to the earlier gas-graphite Vandellòs-1. Unlike its predecessor, Vandellòs-2 is a modern PWR that went critical in November 1987 and remains in operation, run by ANAV (Endesa and Iberdrola).

First unit of the Khmelnitski NPP; series VVER-1000 V-320 design.

Fourth unit of Zaporizhzhia NPP, Europe's largest nuclear plant. Under Russian military occupation since March 2022.

One of the last three German reactors, shut down on 15 April 2023 completing the nuclear phase-out

One of the last three German reactors, shut down on 15 April 2023 completing the nuclear phase-out

Spain's only German-designed reactor, a Siemens/KWU 3-loop PWR on the Tagus river in Guadalajara. Trillo-1 was the last Spanish nuclear plant to enter service, going critical in May 1988. It is operated by CNAT with Iberdrola as the largest owner.

Idle after the 2011 fleet shutdown; restarted in December 2024 as the first BWR to return to operation under post-Fukushima standards.

Second 1300 MWe P'4 PWR at Belleville-sur-Loire, online in 1988.

Second 1300 MWe P'4 PWR at Nogent-sur-Seine, online in 1988.

Mexico's first nuclear power reactor

Hokkaido's first reactor; idle since April 2011 and seeking NRA clearance to restart (not permanently retired).

Third VVER-1000/320 unit at Balakovo NPP

One of the last three German reactors, shut down on 15 April 2023 completing the nuclear phase-out

First unit of the Narora Atomic Power Station (NAPS)

The one newer-design VVER-440/213 unit at Greifswald. It ran only a few weeks of trial operation before being shut down on 24 November 1989, and was never restarted as the East German fleet was closed around reunification.

One of the newest US reactors; long-delayed by regulatory and financing disputes

Fifth unit of Zaporizhzhia NPP, Europe's largest nuclear plant. Under Russian military occupation since March 2022.

Idle (suspended operation) since January 2012 amid the post-Fukushima shutdown; awaiting restart, not permanently closed.

Third unit of the South Ukraine NPP; series VVER-1000 V-320 design.

First Darlington CANDU unit into service; first unit refurbished under OPG's program (returned to service 2020)

Last RBMK-1000 unit brought online in Russia; operating

Idle (suspended operation) since the 2007 Niigata-Chuetsu offshore earthquake; not restarted and not permanently closed.

Third 1300 MWe P'4 PWR at Cattenom, reaching criticality in 1990.

First of two 1300 MWe P'4 PWRs at Penly on the English Channel coast of Normandy.

First of two 1300 MWe P'4 PWRs at Golfech on the Garonne in southwest France.

Idle since August 2011; awaiting NRA clearance to restart under post-Fukushima standards (not permanently retired).

Darlington CANDU unit (distinct from the co-sited BWRX-300 new build); refurbished 2021-2024

Fourth and final 1300 MWe P'4 PWR at Cattenom, completing the four-unit station.

Large Mitsubishi 4-loop PWR; restarted 14 March 2018 as one of the first Japanese reactors to resume operation under post-Fukushima safety standards.

Second VVER-1000 unit at Kozloduy; one of two operating reactors

Second unit of the Narora Atomic Power Station (NAPS)

First indigenously designed and built nuclear power plant in China

Second 1300 MWe P'4 PWR at Penly, online in 1992; the site is planned to host future EPR2 units.

Mitsubishi 4-loop PWR; restarted 9 May 2018 after post-Fukushima shutdown and remains in operation.

First unit of the Kakrapar Atomic Power Station (KAPS)

Idle (suspended operation) since 2007 following the Niigata-Chuetsu offshore earthquake; awaiting restart, not permanently closed.

Darlington CANDU unit; refurbished 2022-2023

Hokuriku's first reactor; idle since a 2011 shutdown and not yet cleared to restart under post-Fukushima rules (not permanently retired).

Idle since the government-requested Hamaoka shutdown of 2011; seeking restart approval, not permanently closed.

Last Darlington CANDU unit into service; final unit refurbished under OPG's program (completed 2025-2026)

Fourth VVER-1000/320 unit at Balakovo NPP; completed after the Soviet Union's dissolution

Second 1300 MWe P'4 PWR at Golfech; among the last of the P'4 series to enter service.

Large Mitsubishi 4-loop PWR; restarted 23 March 2018 after a seven-year post-Fukushima shutdown.

First large commercial PWR in China, French Framatome M310 design

Idle since the post-Fukushima nationwide shutdown; awaiting restart, not permanently closed.

Only operating unit at Ikata; runs on MOX fuel and was among the first Japanese reactors to restart under post-Fukushima rules (2016).

Japan's prototype sodium-cooled fast breeder reactor and centerpiece of its plutonium fuel-cycle ambitions. Reached first criticality in 1994 but a serious sodium coolant leak and fire in December 1995 kept it idle for most of its life; it generated power for only a few months total. The government decided to decommission it in December 2016, and it was formally permanently shut down in 2017.

Second unit at Mexico's only nuclear power station

Korean-designed PWR (CE System 80-based, OPR-1000 lineage); one of the first Korean Standard Nuclear Power Plant units. Operating.

Restarted in October 2024, the first BWR to resume operation in Japan after Fukushima and closest operating plant to that 2011 disaster's epicenter.

Second unit of the Kakrapar Atomic Power Station (KAPS)

Korean-designed PWR (CE System 80-based, OPR-1000 lineage). Operating.

Sixth and final unit of Zaporizhzhia NPP, Europe's largest nuclear plant (~5,700 MWe total). Under Russian military occupation since March 2022.

One of the world's first two ABWRs (with Unit 7); restarted in January 2026, the first Kashiwazaki-Kariwa unit to resume operation after the post-Fukushima shutdown.

Last US reactor to enter commercial operation in the 20th century

First nuclear power reactor in Romania; first CANDU unit at Cernavoda

First of France's four N4-design PWRs (the last, most powerful French-designed reactor series before the EPR). Chooz B1 first went critical on 25 July 1996 and shares the Chooz site in the Ardennes with the earlier, now-shut-down Chooz-A prototype. Reference power later uprated toward 1500 MWe.

Mitsubishi 4-loop PWR; restarted in June 2018 and remains one of Kyushu Electric's operating units.

Among the world's first-generation ABWRs; idle (suspended operation) since 2011, cleared by regulators and awaiting restart, not permanently closed.

CANDU-6 heavy-water reactor. Operating.

Second N4-design PWR at the Chooz site in the Ardennes, near the Belgian border. Chooz B2 first went critical on 10 March 1997. The N4 units at Chooz and Civaux were the last French-designed reactors before the EPR.

Third of France's four N4 reactors, on the Vienne river. Civaux-1 first went critical on 29 November 1997. Commercial operation was delayed until 2002 after a 1998 primary-circuit crack in the residual heat removal system prompted fleet-wide inspections of the N4 units.

CANDU-6 heavy-water reactor. Operating.

First unit at Mochovce, completed after a decade-long construction interruption

CANDU-6 heavy-water reactor; last of the four original Wolsong units. Operating.

Second unit of the Kaiga Generating Station (KGS)

Last of France's four N4 reactors and the final French-designed unit before the EPR. Civaux-2 first went critical on 27 November 1999. Like its sister unit, commercial operation was delayed to 2002 following the N4 residual heat removal circuit crack found at Civaux-1 in 1998.

Second unit at Mochovce

Indigenous 220 MWe PHWR

First Chinese-supplied CNP-300 PWR in Pakistan and first unit of the Chashma complex.

Brazil's largest reactor; built under the 1975 Brazil-West Germany nuclear agreement

First unit of the Kaiga Generating Station (KGS)

First VVER-1000 unit at Temelín; Soviet-designed reactor completed with Westinghouse instrumentation and fuel upgrades after the Velvet Revolution

Indigenous 220 MWe PHWR

First unit at the Rostov (Volgodonsk) NPP; construction halted after Chernobyl and completed in 2001

Newest Onagawa unit; idle since the post-Fukushima shutdown with restart pending, not permanently closed.

First unit of Qinshan Phase II, an indigenous CNP-600 PWR design

OPR-1000 (Korean Standard Nuclear Power Plant) PWR. Operating.

First unit of Ling Ao Phase I, French M310 PWR adjacent to Daya Bay

Second VVER-1000 unit at Temelín, the Czech Republic's largest power plant

OPR-1000 (Korean Standard Nuclear Power Plant) PWR; last of the six Hanbit units. Operating.

One of two CANDU-6 heavy-water reactors, China's only PHWR units

Newest and largest Hamaoka unit, an ABWR; idle since the government-requested Hamaoka shutdown of 2011, seeking restart approval.

Second unit of the Khmelnitski NPP; construction stalled after the 1990-93 Ukrainian nuclear moratorium and was completed in 2004.

Fourth unit of the Rivne (Rovno) NPP; construction stalled after the 1990-93 Ukrainian nuclear moratorium and was completed in 2004.

Third Kalinin unit, a VVER-1000/320 completed decades after construction began

First of India's indigenous 540 MWe PHWRs to go critical, completed ahead of schedule

One of Japan's advanced boiling water reactors; idle since the March 2011 fleet shutdown and awaiting NRA clearance to restart (not permanently retired).

First Russian-designed VVER-1000 unit in China, built under the Sino-Russian AES-91 agreement

Part of India's indigenous 540 MWe PHWR pair, the largest reactors built domestically before the 700 MWe fleet

Australia's only nuclear reactor — reached criticality at 11:25 p.m. on 12 August 2006, full 20 MW power in November 2006, and was officially opened 20 April 2007; replaced HIFAR and supplies roughly 8% of the world's Mo-99 for nuclear medicine

Third unit of the Kaiga Generating Station (KGS)

Second VVER-1000/V-428 unit of the Sino-Russian AES-91 phase one at Tianwan

Second CANDU unit at Cernavoda, completed more than a decade after Unit 1

Newest Tomari unit; idle since May 2012 and progressing through NRA safety screening toward restart (not permanently retired).

Indigenous 220 MWe PHWR; later operated on imported fuel under IAEA safeguards

Second VVER-1000/320 unit at the Rostov (Volgodonsk) NPP

Indigenous 220 MWe PHWR

First unit of Ling Ao Phase II, an early domestic CPR-1000 PWR

First of the OPR-1000 units at the Shin-Kori site, adjacent to the original Kori plant.

Fourth unit of the Kaiga Generating Station (KGS)

Second CNP-300 unit at Chashma, completed under Sino-Pakistani nuclear cooperation.

Iran's first nuclear power reactor; construction begun by Siemens/KWU in the 1970s and completed by Russia's Atomstroyexport as a VVER-1000

Fourth VVER-1000/320 unit at Kalinin NPP

Second OPR-1000 unit at the Shin-Kori site, adjacent to the original Kori plant.

First OPR-1000 pressurized water reactor at the Wolsong site, which otherwise hosts CANDU heavy-water units.

Lead CPR-1000 unit at Ningde, the first nuclear plant in Fujian province

First nuclear unit in northeast China (Liaoning) and lead CPR-1000 unit at Hongyanhe

First unit of Kudankulam (KKNPP); India's first VVER, built with Russian cooperation

First unit of CGN's six-reactor Yangjiang plant in Guangdong.

Construction begun in 1981 and completed decades later; among the longest reactor build timelines in history

BN-800 sodium-cooled fast reactor; world's largest operating fast reactor, used to develop MOX and closed fuel cycle

First unit of CNNC's Fuqing plant in Fujian.

Third unit at the Rostov (Volgodonsk) NPP, an upgraded VVER-1000/320 subtype

Second OPR-1000 pressurized water reactor at the Wolsong site.

First nuclear unit in the Guangxi region.

Completed Hongyanhe phase one, China's largest nuclear project in the northeast at the time

Completed Ningde phase one, four CPR-1000 units totaling about 4,072 MW

World's first Generation III+ VVER-1200 (AES-2006) to enter commercial operation; PRIS lists it as Novovoronezh 2-1

First new US reactor to enter commercial operation in the 21st century

Second VVER-1000 unit at Kudankulam (KKNPP)

Third CNP-300 unit at Chashma, uprated to 315 MWe net.

Fourth and final CNP-300 unit at Chashma before the larger Hualong One Chashma-5.

First of the VVER-1000/V-428M phase two units at Tianwan

Fourth Rostov unit and the last VVER-1000/V-320 reactor ever built

First VVER-1200/491 (AES-2006) unit at Leningrad, replacing the first-generation RBMK units

First of the two Generation-III ACPR-1000 units at Yangjiang.

World's first EPR to achieve criticality and grid connection

World's first Westinghouse AP1000 to achieve criticality

Second VVER-1000/V-428M unit of Tianwan phase two

One of two KLT-40S reactors aboard the barge Akademik Lomonosov, the world's first operational floating nuclear power plant, moored at Pevek; the world's northernmost nuclear facility.

Second KLT-40S reactor aboard the barge Akademik Lomonosov, the world's first operational floating nuclear power plant, supplying power and heat to Pevek, Chukotka.

Second VVER-1200 (AES-2006) unit at Novovoronezh; PRIS lists it as Novovoronezh 2-2

First of India's indigenous 700 MWe PHWR fleet to go critical

First indigenous ACPR-1000 unit at Tianwan, replacing the Russian VVER design in phase three

First nuclear power reactor in the Arab world

Second VVER-1200/491 unit at Leningrad, replacing the first-generation RBMK units

First unit of Belarus's first nuclear plant and the first VVER-1200 to operate outside Russia.

First Hualong One (HPR-1000) reactor in the world to reach criticality (Oct 2020).

First Hualong One (HPR-1000) reactor built outside China, and Pakistan's first Generation III PWR.

Second ACPR-1000 unit of Tianwan phase three

First ACPR-1000 unit of Hongyanhe phase two

Second unit of the Arab world's first nuclear power station

World's first modular pebble-bed high-temperature gas-cooled power reactor

Second domestic Hualong One (HPR-1000) unit at Fuqing.

First EPR in Europe and Western Europe's first new reactor in over 15 years

Second Hualong One (HPR-1000) export unit in Pakistan, twin of K-2.

Final unit completing Hongyanhe's six-reactor, 6,710 MW station

Second VVER-1200 unit at the Belarusian NPP, bringing the plant to full two-unit capacity.

First APR-1400 unit at the Shin-Hanul site; entered commercial operation in December 2022 after delays tied to Korea's earlier phase-out policy.

Third unit of the Arab world's first nuclear power station

Completed after a construction suspension from 1990 to 2015; among the last VVER-440/213 units built

First Hualong One (HPR-1000) unit at Fangchenggang.

First AP1000 in the United States and first US reactor built from scratch in over three decades

Second APR-1400 unit at the Shin-Hanul site; reached commercial operation in April 2024.

Fourth AP1000 in the United States and the most recent new US reactor to enter commercial operation

Fourth and final unit of the Arab world's first nuclear power station, completing the plant

France's first EPR and its first new reactor startup since Civaux-2 in 1999

Part of India's indigenous 700 MWe PHWR fleet; reached first criticality in September 2024

First VVER-TOI reactor in the world; reached first criticality May 2025, grid-connected 31 December 2025, replacing the Kursk RBMK units

First of six planned Hualong One units at Taipingling and the first Hualong One to enter operation in the Greater Bay Area

First of six planned Hualong One units at San'ao and the first Hualong One in operation in the Yangtze River Delta

India's first commercial-scale fast breeder reactor and the key step in stage two of its three-stage nuclear programme; criticality came roughly 15 years behind original schedule

Formerly Shin-Kori 5; operating licence issued December 2025, NSSC cleared initial criticality 10 April 2026 and it was achieved two days later. Commercial operation expected around August 2026.

First heat-pipe, zirconium-hydride-moderated LEU microreactor to reach criticality — a high-temperature (>800°C) zero-power physics validation run over four weeks in April–May 2026 on the Deimos testbed at NCERC in Nevada; a Los Alamos National Laboratory design, announced 30 July 2026

First reactor to reach criticality under the DOE Reactor Pilot Program (EO 14301); zero-power fueled criticality — no power conversion or heat removal systems

First DOE-authorized reactor built outside a national laboratory; DOE-authorized zero-power fueled criticality June 18 (company reported an earlier non-DOE zero-power criticality in Nov 2025); power ascension to 10 kWt on June 22, 2026

Third DOE-authorized criticality under EO 14301; selected under the Nuclear Energy Launch Pad (successor/expansion of the Reactor Pilot Program), not among the original 11 pilot projects; ~150 days from project kick-off to zero-power fueled criticality (DOE announcement implies late June 30)

Fourth DOE-authorized reactor to reach criticality (zero-power fueled criticality at 12:20 a.m. MT, July 4, 2026), meeting the EO 14301 Independence Day goal

First criticality achieved at 18:00 local time on 10 July 2026 (CNNC, via WNN) — the second HPR-1000 unit of Changjiang Phase II; both Phase II units are expected to be fully operational in early 2027

First advanced reactor project on private land with fully commercially sourced fuel and systems to receive DOE DSA approval; the test platform preceding Atomic Alchemy's planned ~15 MWt VIPR production units, not one of them (Oklo acquired Atomic Alchemy in 2025)

Final unit of a project begun in 1987; sister unit Mochovce 3 started up in 2023