The government's initial responses to contain the crisis at the Fukushima No. 1 nuclear power station after the March 11 quake were delayed by Prime Minister Naoto Kan's effort to inspect the plant by helicopter the next morning, government sources revealed Sunday.
By the evening of March 11, hours after the massive quake hit northern Japan and the ensuing tsunami wiped out towns on the Pacific coast of Tohoku, the Nuclear and Industrial Safety Agency had drawn up the worst-case scenario for the troubled No. 2 reactor: Its failed cooling system could cause the fuel rods in the core to start burning up and release radioactive material outside it.
The government's nuclear watchdog conveyed its assessment of the reactor's state to Kan's team at 10:30 p.m., the sources said. By the early hours of March 12, high levels of radioactive iodine had been detected at the plant, which is operated by Tokyo Electric Power Co.