Following an earthquake , tsunami , and the failure of cooling systems at the Fukushima I Nuclear Power Plant on March 11 , 2011 , a nuclear emergency was declared . This was the first time a nuclear emergency had been declared in Japan , and 140,000 residents within 20 km of the plant were evacuated . The total amount of radioactive material released is unclear , as the crisis is ongoing
an earthquake , tsunami
2011 Tōhoku earthquake and tsunami
Nuclear energy policy by country