The Fukushima nuclear disaster began on 11 March 2011 when a tsunami knocked out power and cooling at Fukushima Daiichi, melting three reactor cores. The tsuna…
The 25th release of treated, diluted water began on 26 October 2026. The IAEA found tritium far below Japan's limit of 1,500 becquerels per litre.
Police count 15,901 dead and 2,519 missing from the earthquake and tsunami. Japan also counts 3,810 disaster-related deaths. Neither is a radiation toll.
About 880 tonnes of fuel debris remain. Two small samples were taken from Unit 2 in 2024-25; full-scale removal will not start before 2037.
The Supreme Court finalised two former TEPCO executives' acquittal in March 2025. In June the Tokyo High Court overturned a 13.32 trillion yen damages order.
Treated water filled about 1,000 tanks. ALPS removes most radionuclides but not tritium, so the water is diluted before release. The IAEA judged the impact negligible.
UNSCEAR found no documented health effects among residents directly attributable to radiation, and none expected to be discernible. Evacuation itself caused serious harm.
Parliament's commission called the accident profoundly man-made: tsunami risk was underestimated and regulation was weak. A new regulator followed in 2012.
No. Hydrogen from overheated fuel exploded in Units 1, 3 and 4. Unit 2's containment was damaged. The accident was later rated INES Level 7.
A magnitude 9.0 earthquake shut the reactors down. A tsunami about 15 metres high, against a 5.7-metre design basis, knocked out power and cooling.
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