Editing Chernobyl Nuclear Power Plant (section)

== Known accidents and incidents ==
[[File:IAEA 02790015 (5613115146).jpg|thumb|The Chernobyl #4 reactor was catastrophically destroyed on 26 April 1986. This photo was taken of the ruins of Chernobyl Nuclear Power Plant Reactor #4 during the construction of the Sarcophagus in the late summer of 1986.]]

=== 1982 reactor #1 partial meltdown ===
On 9 September 1982, a partial [[nuclear meltdown|core meltdown]] occurred in reactor No. 1 due to a faulty cooling valve remaining closed following maintenance. Once the reactor came online, the uranium in the channel 13-44 overheated and ruptured. The extent of the damage was comparatively minor, and no one was killed during the accident. However, due to the negligence of the operators, the accident was not noticed until several hours later, resulting in significant release of radiation in the form of fragments of uranium oxide and several other radioactive isotopes escaping with steam from the reactor via the ventilation stack. This accident was somewhat similar to the 1975 Leningrad unit 1 accident. The accident was not made public until several years later, despite cleanups taking place in and around the power station and Pripyat. The reactor was repaired and put back into operation after eight months.<ref>{{Cite book|url=https://books.google.com/books?id=WwPJDwAAQBAJ&q=rbmk+serpentinite&pg=PA61|title=Midnight in Chernobyl: The Untold Story of the World's Greatest Nuclear Disaster|first=Adam|last=Higginbotham|date=February 4, 2020|publisher=Simon and Schuster|isbn=9781501134630|via=Google Books|access-date=May 3, 2021|archive-date=September 1, 2021|archive-url=https://web.archive.org/web/20210901025133/https://books.google.com/books?id=WwPJDwAAQBAJ&q=rbmk+serpentinite&pg=PA61|url-status=live}}</ref>

=== 1984 reactor #3 and #4 incident ===
According to [[KGB]] documents declassified in Ukraine on 26 April 2021,<ref>{{Cite web|last=Головина|first=Светлана|date=2021-04-26|title=СБУ рассекретила новые документы о катастрофе на Чернобыльской АЭС|url=https://tvzvezda.ru/news/20214261358-yMZcQ.html|access-date=2021-05-03|website=Телеканал «Звезда»|language=ru|archive-date=2021-05-03|archive-url=https://web.archive.org/web/20210503132906/https://tvzvezda.ru/news/20214261358-yMZcQ.html|url-status=live}}</ref> serious incidents occurred in the third and fourth reactors in 1984. According to these documents, the central government in Moscow knew as early as 1983 that the powerplant was "one of the most dangerous nuclear powerplants in the USSR". The reasoning behind this had to do with the building's structural integrity. The room which housed the steam separators would reach temperatures as high as 270 degrees Celsius. This excess heat caused the concrete of the building to shift its position, which made the building unsafe and could potentially result in the collapse of the steam separators, which would cause it to collapse onto the reactor hall, causing a meltdown.

=== 1986 reactor #4 catastrophe (Chernobyl disaster) ===
{{Main article|Chernobyl disaster}}
On 26 April 1986, reactor No. 4 suffered catastrophic [[Nuclear meltdown|meltdown]] resulting in a core explosion and open-air fires. This caused large quantities of radioactive materials to be dispersed in the atmosphere and surrounding land. The disaster is regarded as the worst accident in the history of nuclear power.<ref>{{cite journal |last1=Cardis |first1=E. |last2=Hatch |first2=M. |title=The Chernobyl Accident — An Epidemiological Perspective |journal=Clinical Oncology |date=May 2011 |volume=23 |issue=4 |pages=251–260 |doi=10.1016/j.clon.2011.01.510 |url=https://pmc.ncbi.nlm.nih.gov/articles/PMC3107017/ |access-date=21 April 2025|pmc=3107017 }}</ref>

The destroyed reactor was encased in [[Chernobyl Nuclear Power Plant sarcophagus|a concrete and lead sarcophagus]], followed more recently by [[Chernobyl New Safe Confinement|a large steel confinement shelter]] to prevent further escape of radioactivity. The radioactive cloud spread as far away as Norway.<ref name="MedvedevZ">{{Cite book|last=Medvedev|first=Zhores A.|title=The Legacy of Chernobyl|publisher=W. W. Norton & Company|year=1990|isbn=978-0-393-30814-3|edition=Paperback. First American edition published in 1990|author-link=Zhores A. Medvedev}}</ref>

=== 1991 reactor #2 turbine fire ===
[[File:Reactor Hall of Unit 2, Chernobyl Nuclear Power Plant.webm|thumb|right|250px|Unit # 2 (video shot in 2016)]]
Reactor No. 2 was permanently shut down shortly after October 1991 when a fire broke out due to a faulty switch in a turbine.<ref name="nrc">{{cite web | url=https://www.nrc.gov/reading-rm/doc-collections/fact-sheets/chernobyl-bg.html | title=Backgrounder on Chernobyl Nuclear Power Plant Accident | access-date=January 16, 2011 | publisher=US Nuclear Regulatory Commission | archive-date=March 5, 2011 | archive-url=https://web.archive.org/web/20110305132605/http://www.nrc.gov/reading-rm/doc-collections/fact-sheets/chernobyl-bg.html | url-status=live }}</ref>

On 11 October 1991, a fire broke out in the turbine hall of reactor No. 2.<ref>{{cite web|url=https://www.nytimes.com/1991/10/12/world/fire-reported-in-generator-area-at-the-chernobyl-nuclear-plant.html|title=Fire Reported in Generator Area At the Chernobyl Nuclear Plant|date=October 12, 1991|work=The New York Times|access-date=March 10, 2016|archive-date=March 6, 2016|archive-url=https://web.archive.org/web/20160306122906/http://www.nytimes.com/1991/10/12/world/fire-reported-in-generator-area-at-the-chernobyl-nuclear-plant.html|url-status=live}}</ref> The fire began in reactor No. 2's fourth turbine, while the turbine was being idled for repairs. A faulty switch caused a surge of current to the generator, igniting insulating material on some electrical wiring.<ref>[https://www.baltimoresun.com/1991/10/13/roof-fire-at-chernobyl-intensifies-ukrainian-calls-to-close-nuclear-plant/ Roof fire at Chernobyl intensifies Ukrainian calls to close nuclear plant]  Baltimore Sun (October 13, 1991).</ref> This subsequently led to hydrogen, used as a coolant in the synchronous generator, being leaked into the turbine hall "which apparently created the conditions for fire to start in the roof and for one of the trusses supporting the roof to collapse."<ref>{{Cite news |last=Schmemann |first=Serge |date=1991-10-13 |title=Soviets Assure Safety at A-Plant Damaged by Fire |url=https://www.nytimes.com/1991/10/13/world/soviets-assure-safety-at-a-plant-damaged-by-fire.html |access-date=2024-05-22 |work=The New York Times |language=en-US |issn=0362-4331}}</ref> The adjacent reactor hall and reactor were unaffected, but due to the political climate it was decided to shut down this reactor permanently after this incident.

=== 2017 cyberattack ===
The [[2017 Petya cyberattack]] affected the [[radiation monitoring]] system and took down the power plant's official website, which hosts information about the incident and the area.<ref>{{cite web|url=https://www.independent.co.uk/news/world/europe/chernobyl-ukraine-petya-cyber-attack-hack-nuclear-power-plant-danger-latest-a7810941.html|title=Chernobyl's radiation monitoring system has been hit by the worldwide cyber attack|date=June 27, 2017|website=independent.co.uk|access-date=April 1, 2018|archive-date=August 18, 2019|archive-url=https://web.archive.org/web/20190818234657/https://www.independent.co.uk/news/world/europe/chernobyl-ukraine-petya-cyber-attack-hack-nuclear-power-plant-danger-latest-a7810941.html|url-status=live}}</ref>

=== 2022 Russian invasion of Ukraine ===
{{main|Capture of Chernobyl|l1 = Battle of Chernobyl}}

The Chernobyl Exclusion Zone was the site of fighting between Russian and Ukrainian forces during the [[Capture of Chernobyl|Battle of Chernobyl]] as part of the [[2022 Russian invasion of Ukraine|Russian invasion of Ukraine]]. On 24 February 2022, Russian forces captured the plant.<ref name="AAUfZWmChernobyl">{{cite web |title=Chernobyl nuclear power plant under control of Russian troops, says Ukrainian President |url=https://www.msn.com/en-gb/news/newslondon/chernobyl-nuclear-power-plant-under-control-of-russian-troops-says-ukrainian-president/ar-AAUfZWm |website=MSN |access-date=24 February 2022 |archive-date=25 February 2022 |archive-url=https://web.archive.org/web/20220225025927/https://www.msn.com/en-gb/news/newslondon/chernobyl-nuclear-power-plant-under-control-of-russian-troops-says-ukrainian-president/ar-AAUfZWm |url-status=live }}</ref><ref>{{Cite web |last=Zelenskyy |first=Volodymyr |date=February 24, 2022 |title=Ukraine President on Twitter |url=https://twitter.com/zelenskyyua/status/1496862540957114370 |url-status=live |archive-url=https://web.archive.org/web/20220224151756/https://twitter.com/zelenskyyua/status/1496862540957114370 |archive-date=2022-02-24 |access-date=2022-02-24 |website=Twitter |language=en}}<br />{{cite news |title=Russian forces trying to seize control of Chernobyl Nuclear Plant in Ukraine, says President Zelensky |url=https://www.aninews.in/news/world/asia/russian-forces-trying-to-seize-control-of-chernobyl-nuclear-plant-in-ukraine-says-president-zelensky20220224212625/ |url-status=live |archive-url=https://web.archive.org/web/20220224172356/https://www.aninews.in/news/world/asia/russian-forces-trying-to-seize-control-of-chernobyl-nuclear-plant-in-ukraine-says-president-zelensky20220224212625/ |archive-date=24 February 2022 |access-date=24 February 2022 |work=ANI News |language=en}}<br />{{cite news |title=Chernobyl power plant captured by Russian forces – Ukrainian official |url=https://www.reuters.com/world/europe/chernobyl-power-plant-captured-by-russian-forces-ukrainian-official-2022-02-24/ |url-status=live |archive-url=https://web.archive.org/web/20220224174356/https://www.reuters.com/world/europe/chernobyl-power-plant-captured-by-russian-forces-ukrainian-official-2022-02-24/ |archive-date=2022-02-24 |access-date=24 February 2022 |website=Reuters |language=en}}<br />{{Cite web |author=Sangal |first1=Aditi |last2=Wagner |first2=Meg |last3=Vogt |first3=Adrienne |last4=Macaya |first4=Melissa |last5=Picheta |first5=Rob |last6=Said-Moorhouse |first6=Lauren |last7=Upright |first7=Ed |last8=Chowdhury |first8=Maureen |date=2022-02-24 |title=Russian troops seize Chernobyl nuclear power plant, Ukrainian official says |url=https://www.cnn.com/europe/live-news/ukraine-russia-news-02-24-22-intl/h_438d63764e04c5907533d2c095e73cfd |url-status=live |archive-url=https://web.archive.org/web/20220224182927/https://www.cnn.com/europe/live-news/ukraine-russia-news-02-24-22-intl/h_438d63764e04c5907533d2c095e73cfd |archive-date=2022-02-24 |access-date=2022-02-24 |website=CNN |language=en-us}}</ref> The resulting activity reportedly led to a 20-fold increase of detected radiation levels in the area due to disturbance of contaminated soil.<ref>{{Cite web |last=Gill |first=Victoria |date=2022-02-25 |title=Chernobyl: Radiation spike at nuclear plant seized by Russian forces |url=https://www.bbc.com/news/science-environment-60528828 |website=BBC |language=en |access-date=2022-02-25 |archive-date=2022-02-25 |archive-url=https://web.archive.org/web/20220225165134/https://www.bbc.com/news/science-environment-60528828 |url-status=live }}</ref>

On 9 March 2022, there was a power cut at the plant itself. No radiation leaks were reported at the time. However, Ukrainian authorities reported that there was a risk of a radiation leak due to spent fuel coolant being unable to circulate properly.<ref>{{Cite web |date=2022-03-09 |title=Chernobyl 'cut off from grid', sparking fears over cooling of spent nuclear fuel |url=https://www.independent.co.uk/news/world/europe/ukraine-chernobyl-nuclear-power-plant-outage-b2031874.html |access-date=2022-03-09 |website=The Independent |language=en}}</ref>

On 31 March 2022, Russian forces formally handed control of the plant back to its employees, and most occupying forces withdrew. [[Ukrainian National Guard]] personnel were moved to [[Belarus]] as [[prisoners of war]].<ref>{{Cite web |date=2022-03-31 |title=Ukraine: Second UN convoy reaches Sumy, Mariupol access thwarted |url=https://news.un.org/en/story/2022/03/1115252 |website=UN News |language=en |access-date=2022-04-01}}</ref><ref name="11648764981Chernobyl">{{Cite news |last1=Tashkevych |first1=Yana |last2=Marson |first2=James |last3=Hinshaw |first3=Drew |title=Russia Hands Control of Chernobyl Back to Ukraine, Officials Say |url=https://www.wsj.com/articles/russia-hands-control-of-chernobyl-back-to-ukraine-officials-say-11648764981 |access-date=2024-05-22 |work=WSJ |language=en-US}}</ref> On 2 April 2022, Ukrainian media reported that the [[flag of Ukraine]] was raised at the plant.<ref>{{Cite web |title=Ukrainian flag was raised at the Chornobyl nuclear power plant |url=https://www.pravda.com.ua/eng/news/2022/04/2/7336590/ |access-date=2024-05-22 |website=Ukrainska Pravda |language=en}}</ref>

Russian troops dug trenches and other fighting positions on the outskirts of the highly contaminated [[Red Forest]], which attracted considerable media attention due to unconfirmed reports that soldiers were being treated for radiation sickness in [[Belarus]].<ref name="Chernoby60945666"/> The IAEA later clarified that only modest radiation doses (6.5 mSv/year) could have resulted from such activities, and a tour guide in the Zone later acknowledged to the Washington Post that he had helped start these rumors in a "huge exaggeration." 

On 14 February 2025, Ukrainian president [[Volodymyr Zelenskyy]] said that a [[Chernobyl Nuclear Power Plant drone strike|Russian drone attack]] significantly damaged the Chernobyl [[New Safe Confinement]], which covers the sarcophagus and Unit No. 4.<ref>{{Cite web |title=Russian drone attack damages Chernobyl nuclear plant’s shelter, Zelensky says|url=https://www.theage.com.au/world/europe/russian-drone-attack-damages-chernobyl-nuclear-plant-s-shelter-zelensky-says-20250214-p5lcbh.html |access-date=2025-02-14 |via=The Age|language=en|agency=[[Reuters]]}}</ref> The [[IAEA]] said that radiation levels at the site remained normal.<ref>{{Cite web |title=A drone pierced the outer shell of Ukraine’s Chernobyl nuclear plant. Radiation levels are normal |url=https://apnews.com/article/russia-ukraine-war-chernobyl-zelenskyy-71d781dbd66754d0a548edd388f3447a |access-date=2025-02-15 |work=[[AP News]]|author1=Illia Novikov |author2=Efrem Lukatsky |language=en}}</ref>