Japanese officials have admitted that the meltdown at Fukushima released almost twice as much radiation as they had initially allowed. ("Did we say 370,000 terabecquerels? Oops, that should have been 770,000.") They also said that the meltdown at the plant began five hours after the quake/tsunami double-punch. The plant's operator had said earlier the meltdown began 10 hours later than that.
The radiation release is still only a fraction as bad as Chernobyl, releasing about 15 percent as much radiation. At least, as far as we know now. Wait a couple months, and who knows. (“Oops, did we say 770,000 terabecquerels?“)
The lesson here: Don't trust government officials or corporate officials, especially during a disaster. If a nuclear plants starts failing anywhere in your vicinity, even if you're outside the evacuation zone, get far, far away.
Japan 'unprepared' for Fukushima nuclear disaster, BBC News.