The Chernobyl disaster was a catastrophic nuclear accident that occurred on 26 April 1986 at the Chernobyl Nuclear Power Plant in Ukraine, which was under the direct jurisdiction of the central authorities of the Soviet Union. The Chernobyl disaster is the worst nuclear power plant accident in history in terms of cost and resulting deaths, and is one of only two classified as a level 7 event (the maximum classification) on the International Nuclear Event Scale (the other being the Fukushima Daiichi nuclear disaster in 2011). Photo: Graffiti of a crying baby on a wall, Chernobyl Power Plant, Chernobyl, Ukraine. (Photo by Hans Neleman/Getty Images)

A containment shelter for the damaged fourth reactor (L) and the New Safe Confinement (NSC) structure (R) at the Chernobyl Nuclear Power Plant are seen from Ukraine's abandoned town of Pripyat, Ukraine, April 22, 2016. (Photo by Gleb Garanich/Reuters)

A woman wearing in face mask to curb the spread of COVID-19 passes street's cafe in Kyiv, Ukraine, Friday, October 22, 2021. Coronavirus infections and deaths in Ukraine have surged to all-time highs amid a laggard pace of vaccination, which is one of the lowest in Europe. (Photo by Efrem Lukatsky/AP Photo)

A Ukrainian service member shoots from a machine gun at a position on the front line, amid Russia's attack on Ukraine, near the town of New York, Donetsk region, Ukraine on June 9, 2022. (Photo by Gleb Garanich/Reuters)

Soldiers of Ukraine's National Guard 1st brigade Bureviy (Hurricane) fire a recoilless cannon during combat training at a military training ground in the north of Ukraine Friday, November 3, 2023. (Photo by Efrem Lukatsky/AP Photo)

A Ukrainian serviceman of 80th Separate Galician Air Assault Brigade makes a snow angel in a bomb crater, amid Russia's attack on Ukraine, at a position near Bakhmut in Donetsk region, Ukraine on January 25, 2024. (Photo by Inna Varenytsia/Reuters)

A Ukrainian serviceman of the 47th “Magura” Separate Mechanized Brigade plays with a cat, which his unit evacuated from a frontline, amid Russia's attack on Ukraine, at undisclosed location in Donetsk region, Ukraine on February 8, 2024. (Photo by Alina Smutko/Reuters)

A new volunteer for the Ukrainian interior ministry's “Azov” battalion takes part in tests before heading to frontlines in eastern Ukraine, at the battalion's training centre in Kiev, Ukraine, August 14, 2015. (Photo by Gleb Garanich/Reuters)