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)

Pine trees are seen after a forest fire near Sao Pedro do Sul, Portugal August 14, 2016. Deadly wildfires raging for two weeks in Portugal have destroyed a wooded area the size of 100,000 soccer fields, and the small Iberian nation alone accounts for half of all forests burned in the European Union this year. (Photo by Rafael Marchante/Reuters)

Decorated veterans take part in the Veterans Day parade in honor of the victory over the Nazi Germany, on May 11, 2011 in Jerusalem, Israel. Hundreds of Jewish World War II veterans from the Allied armies, mostly the former Soviet Union, and Israelis took part in the parade. (Photo by Avi Ohayon/GPO via Getty Images)

An officer is on fire as demonstrators clash with police during a protest against plans for new austerity measures on June 28, 2011 in Athens, Greece. Greece's largest labor unions have called for a 48-hour strike, while the Socialist government is beginning to push through legislation for cost cutting reforms. (Photo by Milos Bicanski/Getty Images)

Participants gather in the Union Square subway station during the annual No Pants Subway Ride on January 8, 2012 in New York City. The annual event is staged by the group Improv Everywhere which encourages people in dozens of cities worldwide to discard their pants while riding the subway. (Photo by Mario Tama/Getty Images)

Demonstrators confront riot police during clashes in central Brussels November 6, 2014. Tens of thousands of public and private sector workers, employees and trade union members demonstrated over austerity measures to be taken by the new Belgian government. (Photo by Francois Lenoir/Reuters)

Chinese artist Kong Ning walks in her costume made of hundreds of orange plastic blowing horns during her art performance raising awareness of the hazardous smog in front of the Drum tower in a historical part of Beijing on a very polluted day December 7, 2015. Kong, whose works include themes related to China's air pollution problem, named her new performance “The Orange Horns Bride Marries the Blue Sky” and presented it dressed in orange, the colour of the second highest pollution alert level issued again in Beijing as hazardous smog blankets the capital. (Photo by Damir Sagolj/Reuters)

Two Hindu holy men of the Juna Akhara sect are being take on a motorcycle by their teacher as they got delayed for a rituals that are believed to rid them of all ties in this life and dedicate themselves to serving God as a “Naga” or naked holy men, at Sangam, the confluence of the Ganges and Yamuna River during the Maha Kumbh festival in Allahabad, India, Wednesday, February 6, 2013. The significance of nakedness is that they will not have any worldly ties to material belongings, even something as simple as clothes. This ritual that transforms selected holy men to Naga can only be done at the Kumbh festival. (Photo by Rajesh Kumar Singh/AP Photo)