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.
Around the same time, pressure in the No. 1 reactor had begun to rise. That was the most critical point in the emergency because it was necessary to lower the pressure in the reactors and prevent an explosion, the unnamed sources said. But Kan flew in to view the power plant in the early morning of March 12.
“How could Tepco irradiate the prime minister flying up above by ventilating the reactors?” asked a government official familiar with the development. “His inspection delayed the ventilating steps.”
It was not clear whether Tepco emphatically warned Kan to stay away. Tepco started the process to ventilate the reactors at 9:04 a.m. only after the chopper Kan was aboard left the area, the sources said. But workers could not open valves that were necessary to release the air until 2:30 p.m., the sources said. Despite ventilation, a hydrogen explosion occurred at the No. 1 reactor hours later.
A nuclear expert close to the government’s nuclear policy speculated that the loss of time at the initial stage probably narrowed the scope of options available to contain the crisis.