Japan’s nuclear safety agency on Tuesday raised the crisis level at the nation’s disaster-stricken Fukushima Daiichi nuclear power plant to the worst on the global scale of atomic accidents, the same level as the 1986 Chernobyl catastrophe.
The government’s Nuclear and Industrial Safety Agency said it has upgraded the severity level of the accident at the Fukushima plant from the current 5 to the highest level of 7 on the International Nuclear Event Scale.
The previous evaluation of 5 was the same level as the 1979 partial reactor meltdown at Three Mile Island in the US. The decision was made based on the condition of the No. 1, No. 2 and No. 3 reactors at the Fukushima plant, which was hit by a magnitude 9.0 quake and 15-meter tsunami on March 11, the agency said.
The level 7 defined as a “major release of radioactive material with widespread health and environmental effects requiring implementation of planned and extended countermeasures,” according the International Nuclear Event Scale.
But the agency stressed that Fukushima was less serious than Chernobyl, pointing out that the amount of radiation leaking from the Fukushima plant is estimated to be about 10 percent of the Chernobyl accident.
In Chernobyl, 29 people died of acute radiation exposure, but there are no fatal radiation casualties in the Fukushima case,” senior agency official Hidehiko Nishiyama told a press conference.
“At Chernobyl, a nuclear reactor itself exploded. But at Fukushima, only buildings housing reactors were damaged by explosions, and the reactors themselves retain their shape,” Nishiyama also said.
However, plant operator Tokyo Electric Power Co. (TEPCO) said at a separate news conference that radiation leakage at the plant could eventually exceed that of the 1986 Chernobyl disaster. “The radiation leak has not stopped completely. If the leaks continue, the total radiation from the reactors may eventually exceed that of Chernobyl,” a TEPCO spokesman said.
The utility is still struggling to restore the reactors’ cooling functions at the plant located 230 km north of Tokyo, which are crucial to put the ongoing radiation crisis under the control. It discovered a small fire near a reactor building Tuesday morning. The fire was extinguished seven minutes later.