“The Fukushima Daiichi nuclear disaster (福島第一原子力発電所事故 Fukushima Daiichi (About this sound pronunciation) genshiryoku hatsudensho jiko?) was a nuclear disaster at the Fukushima I Nuclear Power Plant that began on 11 March 2011 and resulted in a nuclear meltdown of three of the plant’s six nuclear reactors.
The failure occurred when the plant was hit by a tsunami that had been triggered by the magnitude 9.0 Tōhoku earthquake.The following day, 12 March, substantial amounts of radioactive material began to be released,creating the largest nuclear incident since the Chernobyl disaster in April 1986 and the only (after Chernobyl) to measure Level 7 on the International Nuclear Event Scale (initially releasing an estimated 10–30% of the earlier incident’s radioactivity). There were several spills of contaminated water at the plant, some into the sea. Plant workers tried to contain the leaks using measures such as building chemical underground walls, but they were ultimately unsuccessful at improving the situation.”