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)

Members of the Oath Keepers and general public return fire during a simulated attack as they take part in a tactical training session in northern Idaho, U.S. October 1, 2016. In April 2015 Reuters photographer Jim Urquhart was assigned to cover the Oath Keepers during a tour of the Sugar Pine gold mine in Oregon after the group of former cops, military, firefighters and other first responders had risen to prominence during a standoff in Nevada over land rights. (Photo by Jim Urquhart/Reuters)

Forensic investigators look at the body of a man infected with the new coronavirus who collapsed on the street and died, according to Police Captain Diego Lopez, in Quito, Ecuador, Tuesday, May 5, 2020. (Photo by Dolores Ochoa/AP Photo)

Barrier tape is tied around 15-month-old Shivani's ankle to prevent her from running away, while her mother Sarta Kalara works at a construction site nearby, in Ahmedabad, India, April 19, 2016. Kalara says she has no option but to tether her daughter Shivani to a stone despite her crying, while she and her husband work for 250 rupees ($3.8) each a shift digging holes for electricity cables in the city of Ahmedabad. There are about 40 million construction workers in India, at least one in five of them women, and the majority poor migrants who shift from site to site, building infrastructure for India's booming cities. Across the country it is not uncommon to see young children rolling in the sand and mud as their parents carry bricks or dig for new roads or luxury houses. (Photo by Amit Dave/Reuters)

A woman argues with police officer during a protest in support of jailed opposition leader Alexei Navalny in Ulan-Ude, the regional capital of Buryatia, a region near the Russia-Mongolia border, Russia, Wednesday, April 21, 2021. Navalny's team has called for nationwide protests on Wednesday following reports that the politician's health was deteriorating in prison, where he has been on hunger strike since March 31. Russian authorities have stressed that the demonstrations were not authorized and warned against participating in them. (Photo by Anna Ogorodnik/AP Photo)

All the drugery of dishwashing in this three-times -a day task, which comes to the house wife who does her own house work, has been eliminated by the new dish washer shown in the photograph on April 25, 1921. It is the invention of a Cincinnati school teacher, who sought to make things a bit more pleasant for his wife. Incedently, his idea was worth 12,00 to him, for a manufacturing concern thought so much of the “dish-washer” they purchased the rights and will seek to add a little joy to thousands of other housewives. With the aid of only hot water, dishes placed in a wire rack and set into the drum are made clean and spotless in two minutes. (Photo by Bettmann Archive/Getty Images)

Pooh, a one-year-old cat, who lost his hind legs in an accident and has been given bionic paws, walks in a vet clinic in Sofia on January 31, 2017. Pooh, who is thought to have lost his legs in a car or train accident last April, is back on the prowl thanks to Bulgarian veterinary surgeon Vladislav Zlatinov. He is the first vet in Europe to successfully apply the pioneering method of Irish neuro-orthopaedic surgeon Noel Fitzpatrick, who shot to fame in 2009 when making Oscar the first bionic cat by fitting him with new hind legs in Britain. (Photo by Nikolay Doychinov/AFP Photo)

In this April 14, 2014 file photo, Hamamatou Harouna, 10, who lost the use of her legs to polio, crawls to the restroom on the grounds of the Catholic Church where she and hundreds of others found refuge after fleeing violence in her village, in Carnot, Central African Republic. Health authorities on Tuesday, August 25, 2020 are expected to declare the African continent free of the wild poliovirus after decades of effort, though cases of vaccine-derived polio are still sparking outbreaks of the paralyzing disease in more than a dozen countries. (Photo by Jerome Delay/AP Photo/File)