Tokyo Electric Power Co. started to inject seawater into the No. 1 reactor at the Fukushima No. 1 nuclear plant a day after the March 11 earthquake and tsunami but suspended the operation for 55 minutes at the direction of Prime Minister Naoto Kan, according to government sources.
With criticism growing that a delay in the seawater injection may have caused a meltdown in the reactor and aggravated the disaster, analysts have said Tepco should have continued pumping the water into the reactor vessel to cool it down.
The government had previously said Tepco started to inject seawater into the No. 1 reactor at 8:20 p.m. March 12, but a document released by the utility Monday revealed it began the work at 7:04 p.m. that day, stopped it at 7:25 p.m. and resumed it at 8:20 p.m.