Seiichiro Nishimoto, CEO of Shelter Co., poses wearing a gas mask at a model room for the company's nuclear shelters in the basement of his house in Osaka, Japan on April 26, 2017. With nearby North Korea increasing its show of power day by day with missile launches and nuclear tests, people in Japan are preparing for the worst by building private nuclear shelters, Reuters reports. (Photo by Kim Kyung-Hoon/Reuters)

Tree trunks lie on the railtracks that will be used to transport nuclear waste on November 25, 2011 in Leitstade, near Metzingen, Germany. A train carrying the Castor containers of processed, spent nuclear fuel started from La Hague in France Wednesday for its journey to the Gorleben temporary nuclear waste storage facility in Germany, and thousands of protesters are expected to attempt to blockade the route. (Photo by Carsten Koall/Getty Images)

South Korean environmentalists participates in a rally held to commemorate the Fukushima nuclear disaster on the eve of the one year anniversary of Japan's earthquake and tsunami on March 10, 2012 in Seoul, South Korea. Currently four nuclear power plants are in operation in South Korea while the government plans to increase the number of reactors to 32 by the year 2021. (Photo by Chung Sung-Jun/Getty Images)

A woman walk by South Korean police during a anti-terror exercise on March 9, 2012 in Seoul, South Korea. The drill is part of South Korea's preparation for the upcoming 2012 Seoul Nuclear Security Summit, scheduled for March 26 and 27. Some 50 world leaders, including U.S. President Barack Obama, are expected to attend the summit to discuss how to make the world safe without nuclear weapons. (Photo by Chung Sung-Jun/Getty Images)

Soviet Army soldiers sit on their tanks in front of the Czechoslovak Radio station building in central Prague during the first day of Soviet-led invasion to then Czechoslovakia on August 21, 1968. (Photo by Libor Hajsky/Reuters)

A man and a woman both wounded by what locals say was recent shelling by Ukrainian forces, react as they sit in an ambulance in Donetsk August 23, 2014. (Photo by Maxim Shemetov/Reuters)

A marine aims an RPG-7, a portable rocket- propelled grenade launcher, during military exercises conducted by the Russian Pacific Fleet' s naval infantry unit at the Bamburovo firing range on February 2, 2017. The drills are a part of preparations for the Suvorov Attack and Sniper Line army competitions. (Photo by Yuri Smityuk/TASS)

An Iraqi Kurdish Peshmerga takes part in a graduation ceremony at the Zakho military academy in the Iraqi Kurdish town of Zakho, some 500 kilometres north of Baghdad, on January 30, 2018. (Photo by Safin Hamed/AFP Photo)