April 12, 2011— -- Japan's Nuclear and Industrial Safety Agency Tuesday raised the level of severity at the Fukushima Daiichi nuclear power plant from 5 to 7 – the highest level on the international scale and equal to the Chernobyl accident.
The agency says the level 7 ranking was made after the damaged reactors have been releasing large amounts of radioactive substances that pose a threat to humans and the environment in a much wider area.
"Level 5 is Three Mile Island. Level 7 is Chernobyl. This doesn't mean it's as bad as Chernobyl. But that's the last time I think 7 was used. It's the highest set by the IAEA (International Atomic Energy Agency)," said physicist Michio Kaku.
Hidehiko Nishiyama with the Nuclear and Industrial Safety Agency (NISA) said the radiation from Fukushima equals about 10 percent of what was released after the Chernobyl accident in 1986.
Nishyama said that the Fukushima event is different from Chernobyl, where a nuclear reactor in Ukraine exploded and sent massive amounts of radiation into atmosphere.
"In the case of Chernobyl, there were many acute radiation injuries reported, 29 people died and in Fukushima's case we have not seen such a situation arise yet," he said.
Operator Tokyo Electric Power Company (TEPCO) has tried to stabilize the nuclear reactor since the magnitude 9.0 quake and tsunami damaged the plant March 11.
Earlier, the Nuclear and Industrial Safety Agency ranked the severity of the Fukushima situation to level 5 on March 18.
At a news conference Tuesday, Nishiyama said after reviewing the radiation amount released since the initial assessment of radioactive iodine-131 and cesium-137, officials decided that the incident should be categorized as a level 7.
"The announcement is being made now because it became possible to look at and check the accumulated data assessed in two different ways," Nishiyama said, in reference to measurements from NISA and the Nuclear Security Council, the Associated Press reported.