(TOKYO) -- Japan's Nuclear and Industrial Safety Agency Tuesday raised the level of severity at the Fukushima Daiichi nuclear power plant from 5 to level 7 -- the highest level on the international scale and equal to the Chernobyl accident.
The agency says the level 7 ranking was made because the damaged reactors have been releasing large amounts of radioactive substances, posing a threat to humans and the environment in a much wider area.
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. He added that the Fukushima event is different from Chernobyl, where a nuclear reactor in Ukraine exploded and sent massive amounts of radiation into the 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 last month.
The Nuclear and Industrial Safety Agency ranked the severity of the Fukushima situation at level 5 on March 18.
At a news conference Tuesday, Nishiyama said after reviewing the radiation amounts released since the initial assessment of radioactive iodine-131 and cesium-137 levels, officials decided that the incident should be categorized as a level 7.
The new categorization comes after TEPCO workers at the reactor complex on Tuesday morning extinguished a small fire at a switchbox that contained batteries, according to a news release.
It was unclear whether the blaze was sparked by a 6.3 aftershock that hit about 48 miles offshore from Tokyo Tuesday.
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