Japan's government foresaw the possibility of a meltdown at the Fukushima nuclear power plant hours after a huge tsunami smashed into it, according to cabinet minutes released on Friday, although it took officials more than a month to acknowledge it.
The earthquake and tsunami on March 11 knocked out cooling systems at Tokyo Electric Power Co's (Tepco) Fukushima Daiichi plant, triggering the world's worst nuclear accident since Chernobyl in Ukraine in 1986.
Cooling functions still in service are those run by batteries. They will last eight hours, a summary of the first emergency cabinet meeting, four hours after the quake, quoted an unidentified participant as saying.
If core temperatures in the reactors remain on the rise for more than eight hours, there is a possibility that meltdown may occur.
A Trade Ministry official who acted as a government spokesman after the disaster struck was replaced after he mentioned the possibility of meltdown on March 12.
It was not until May that Tepco acknowledged that a meltdown of fuel rods appeared to have occurred, sparking criticism that the operator and officials were playing down the severity of the accident.
Tepco now believes that three of the six reactors at the plant, 240 km (150 miles) northeast of Tokyo, suffered fuel meltdown.
The minutes were released two days before the first anniversary of the disaster that left 19,000 dead or missing.
Other entries in minutes of emergency cabinet meetings show confusion and disagreement among top leaders as Japan faced its deepest crisis since World War Two.
Who is the leader of the actual operation? Yoshihiro Katayama, internal affairs minister at the time, told a March 15 meeting of the Nuclear Emergency Response headquarters.
I've got too many unintelligible demands and requests. No one is holding the reins.
On March 14, then-Prime Minister Naoto Kan spoke of a consensus among specialists that a 20-km evacuation zone around the plant was sufficient. He was challenged by Koichiro Gemba, national strategy minister at the time, who pointed out contradicting views.
Gemba, whose constituency is in Fukushima, told a different meeting: This is war. We only win or lose. We are already losing in some battles. But the important thing is how we manage to limit our loss.
(Reporting by Kiyoshi Takenaka; Editing by; Ron Popeski)