https://goingcritical.org Every nuclear reactor first criticality, as it happens. https://goingcritical.org/reactor/aalo-x https://goingcritical.org/reactor/aalo-x Sat, 04 Jul 2026 00:00:00 GMT Aalo-X (United States) achieved first criticality on July 4, 2026. 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 https://goingcritical.org/reactor/deployable-unity https://goingcritical.org/reactor/deployable-unity Wed, 01 Jul 2026 00:00:00 GMT Deployable Energy Unity (United States) achieved first criticality on July 1, 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) https://goingcritical.org/reactor/taipingling-2 https://goingcritical.org/reactor/taipingling-2 Thu, 25 Jun 2026 00:00:00 GMT Taipingling-2 (China) achieved first criticality on June 25, 2026. https://goingcritical.org/reactor/valar-ward-250 https://goingcritical.org/reactor/valar-ward-250 Thu, 18 Jun 2026 00:00:00 GMT Valar Atomics Ward 250 (United States) achieved first criticality on June 18, 2026. 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 https://goingcritical.org/reactor/antares-mark-0 https://goingcritical.org/reactor/antares-mark-0 Thu, 04 Jun 2026 00:00:00 GMT Antares Mark-0 (United States) achieved first criticality on June 4, 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 https://goingcritical.org/reactor/saeul-3 https://goingcritical.org/reactor/saeul-3 Sun, 12 Apr 2026 00:00:00 GMT Saeul-3 (South Korea) achieved first criticality on April 12, 2026. 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. https://goingcritical.org/reactor/pfbr https://goingcritical.org/reactor/pfbr Mon, 06 Apr 2026 00:00:00 GMT PFBR (Prototype Fast Breeder Reactor) (India) achieved first criticality on April 6, 2026. 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 https://goingcritical.org/reactor/sanao-1 https://goingcritical.org/reactor/sanao-1 Sat, 14 Feb 2026 00:00:00 GMT San'ao-1 (China) achieved first criticality on February 14, 2026. First of six planned Hualong One units at San'ao and the first Hualong One in operation in the Yangtze River Delta https://goingcritical.org/reactor/taipingling-1 https://goingcritical.org/reactor/taipingling-1 Tue, 03 Feb 2026 00:00:00 GMT Taipingling-1 (China) achieved first criticality on February 3, 2026. First of six planned Hualong One units at Taipingling and the first Hualong One to enter operation in the Greater Bay Area https://goingcritical.org/reactor/zhangzhou-2 https://goingcritical.org/reactor/zhangzhou-2 Mon, 03 Nov 2025 00:00:00 GMT Zhangzhou-2 (China) achieved first criticality on November 3, 2025. https://goingcritical.org/reactor/flamanville-3 https://goingcritical.org/reactor/flamanville-3 Tue, 03 Sep 2024 00:00:00 GMT Flamanville-3 (France) achieved first criticality on September 3, 2024. France's first EPR and its first new reactor startup since Civaux-2 in 1999 https://goingcritical.org/reactor/vogtle-3 https://goingcritical.org/reactor/vogtle-3 Mon, 06 Mar 2023 00:00:00 GMT Vogtle-3 (United States) achieved first criticality on March 6, 2023. First AP1000 in the United States and first US reactor built from scratch in over three decades https://goingcritical.org/reactor/olkiluoto-3 https://goingcritical.org/reactor/olkiluoto-3 Tue, 21 Dec 2021 00:00:00 GMT Olkiluoto-3 (Finland) achieved first criticality on December 21, 2021. First EPR in Europe and Western Europe's first new reactor in over 15 years https://goingcritical.org/reactor/shidaowan-htr-pm-1 https://goingcritical.org/reactor/shidaowan-htr-pm-1 Sun, 12 Sep 2021 00:00:00 GMT Shidaowan HTR-PM (Reactor No. 1) (China) achieved first criticality on September 12, 2021. World's first modular pebble-bed high-temperature gas-cooled power reactor https://goingcritical.org/reactor/barakah-1 https://goingcritical.org/reactor/barakah-1 Fri, 31 Jul 2020 00:00:00 GMT Barakah-1 (United Arab Emirates) achieved first criticality on July 31, 2020. First nuclear power reactor in the Arab world https://goingcritical.org/reactor/kakrapar-3 https://goingcritical.org/reactor/kakrapar-3 Wed, 22 Jul 2020 00:00:00 GMT Kakrapar-3 (India) achieved first criticality on July 22, 2020. First of India's indigenous 700 MWe PHWR fleet to go critical https://goingcritical.org/reactor/sanmen-1 https://goingcritical.org/reactor/sanmen-1 Thu, 21 Jun 2018 00:00:00 GMT Sanmen-1 (China) achieved first criticality on June 21, 2018. World's first Westinghouse AP1000 to achieve criticality https://goingcritical.org/reactor/taishan-1 https://goingcritical.org/reactor/taishan-1 Wed, 06 Jun 2018 00:00:00 GMT Taishan-1 (China) achieved first criticality on June 6, 2018. World's first EPR to achieve criticality and grid connection https://goingcritical.org/reactor/phenix https://goingcritical.org/reactor/phenix Fri, 31 Aug 1973 00:00:00 GMT Phénix (France) achieved first criticality on August 31, 1973. France's prototype fast breeder; first commercial-pilot-scale breeder connected to a national grid https://goingcritical.org/reactor/msre https://goingcritical.org/reactor/msre Tue, 01 Jun 1965 00:00:00 GMT MSRE (Molten Salt Reactor Experiment) (United States) achieved first criticality on June 1, 1965. World's first molten-salt-fueled reactor; later became the first reactor to run on uranium-233 https://goingcritical.org/reactor/npd https://goingcritical.org/reactor/npd Wed, 11 Apr 1962 00:00:00 GMT NPD (Nuclear Power Demonstration) (Canada) achieved first criticality on April 11, 1962. First CANDU prototype and first nuclear-generated electricity delivered to a Canadian grid https://goingcritical.org/reactor/dresden-1 https://goingcritical.org/reactor/dresden-1 Thu, 15 Oct 1959 00:00:00 GMT Dresden-1 (United States) achieved first criticality on October 15, 1959. First privately financed nuclear power plant in the United States and first commercial BWR https://goingcritical.org/reactor/shippingport https://goingcritical.org/reactor/shippingport Mon, 02 Dec 1957 00:00:00 GMT Shippingport (United States) achieved first criticality on December 2, 1957. First full-scale civilian pressurized water reactor in the United States https://goingcritical.org/reactor/jrr-1 https://goingcritical.org/reactor/jrr-1 Tue, 27 Aug 1957 00:00:00 GMT JRR-1 (Japan) achieved first criticality on August 27, 1957. Japan's first nuclear reactor https://goingcritical.org/reactor/apsara https://goingcritical.org/reactor/apsara Sat, 04 Aug 1956 00:00:00 GMT Apsara (India) achieved first criticality on August 4, 1956. First reactor in India and in Asia outside the USSR (rebuilt as Apsara-U in 2018)