Japan’s Nuclear Safety Commission on Tuesday raised their rating of the severity of the Fukushima Daiichi nuclear crisis from Level 5 to Level 7 on a seven-point international scale. The only nuclear disaster to be rated at Level 7 until now was the 1986 Chernobyl disaster.
Radiation leaking from Fukushima Daiichi so far amounts to only about 10 percent of that from Chernobyl, a nuclear agency official said. However, the leaks are ongoing.
The Financial Times quoted Junichi Matsumoto, an official at Tokyo Electric Power, as saying: “We have not stopped the release of radioactive material from Fukushima Daiichi station, so there is a concern that [the eventual contamination] could be equal to or greater than Chernobyl. If 100 per cent of the radioactive material escaped from the reactors, it is possible that the accident would exceed Chernobyl.”
Level 5 is defined as an “accident with off-site risk,” while Level 7 is a “major accident.” According to the International Nuclear and Radiological Event Scale, a Level 7 accident is typified by a “major release of radioactive material with widespread health and environmental effects.”
“There are still major differences from Chernobyl,” said Hidehiko Nishiyama, an official at the Nuclear and Industrial Safety Agency.
The nuclear reactor at Chernobyl had exploded, spreading radiation over a wide area. This has not happened at Fukushima, he said. Nor have there been any deaths from contamination, unlike Chernobyl.
Japan widened its evacuation zone Monday, however, which was previously set at 12 miles from the plant. Residents of several towns 19 miles away from the plant were also ordered evacuated.