1. A nuclear accident occurred after cooling devices inside the plant malfunctioned, sending three reactors into meltdown.
2. Water levels had dropped earlier at No 2 reactor at the Fukushima Daiichi nuclear complex, completely exposing the fuel rods and raising the threat of a meltdown.
3. nuclear meltdown
3. The partial core meltdown at the Three Mile Island Nuclear Generating Station in 1979 brought America's nuclear plant construction to a screeching halt.