The largest nuclear power plant disaster since chernobyl in the ukraine occurred in 2011 at:

The Fu ku shi ma Daiichi nuclear disaster was an energy misfortune at the Fu ku shi ma Daiichi Nuclear Power Plant in Fu ku shi ma, started mainly by the tsunami following the Tōhoku earthquake on 11 March 2011. Nearly after the earthquake, the active reactors automatically shut down their continued fission reactions. Though, the tsunami deactivated the emergency generators that would have provided power to control and operate the pumps essential to cool the reactors. The inadequate cooling directed to three nuclear breakdowns, hydrogen-air blasts, and the release of radioactive material in Units 1, 2, and 3 from 12 March to 15 March. Loss of cooling also produced the pool for storage of spent fuel from Reactor 4 to overheat on 15 March due to the decay heat from the fuel rods. This is the largest nuclear disaster since the Chernobyl disaster of 1986. a