TOKYO – The Japanese government acknowledged Friday that it was overwhelmed by the scale of last week's twin natural disasters, slowing the response to the nuclear crisis that was triggered by the earthquake and tsunami that left at least 10,000 people dead.
The admission came as Japan welcomed U.S. help in stabilizing its overheated, radiation-leaking nuclear complex, and reclassified the rating of the nuclear accident from Level 4 to Level 5 on a seven-level international scale, putting it on a par with the 1979 Three Mile Island accident.
[Related: What is radioactive iodine poisoning?]
Nuclear experts have been saying for days that Japan was underplaying the severity of the nuclear crisis, which later Friday the prime minister called "very grave."
The International Nuclear Event Scale defines a Level 4 incident as having local consequences and a Level 5 as having wider consequences.
Hidehiko Nishiyama of Japan's nuclear safety agency said the rating was raised when officials realized that at least 3 percent of the fuel in three of the reactors at the Fukushima Dai-ichi plant had been severely damaged, suggesting those reactor cores have partially melted down and thrown radioactivity into the environment.
"The unprecedented scale of the earthquake and tsunami that struck Japan, frankly speaking, were among many things that happened that had not been anticipated under our disaster management contingency plans," said Chief Cabinet Secretary Yukio Edano, admitting that information had not been shared quickly enough.
"In hindsight, we could have moved a little quicker in assessing the situation and coordinating all that information and provided it faster," he said.
