The meltdown at reactor No. 1 in Fukushima happened more quickly than feared, Tokyo Electric Power Co. said Sunday in a new analysis.
The core of the heavily damaged reactor at the Fukushima No. 1 power plant is believed to have melted 16 hours after the March 11 mega-quake and tsunami rocked the complex in northeastern Japan.
Preliminary analysis shows that No. 1 had already entered a critical state by 6:50 a.m. on March 12, with most of its fuel having melted and fallen to the bottom of the pressure vessel, the plant operator said. Tepco released data Thursday showing some of the fuel rods had melted.