Japan nuke accident emergency assessment:

Severity rises to maximum level

Powerful quake strikes northeast Japan

Japan: A powerful earthquake struck northeast Japan yesterday, shaking buildings in Tokyo. No tsunami warning was issued, NHK reported.

The broadcaster, citing the meteorological agency, said the quake in Fukushima prefecture, the latest in a series of powerful tremors, had a magnitude of 6.3.

Workers from the stricken Fukushima Daiichi nuclear plant were ordered to evacuate, an official from operator Tokyo Electric Power said. Tokyo, Tuesday, AFP

Japan: Japan Tuesday upgraded its assessment of the severity of the Fukushima nuclear emergency to a maximum seven on an international scale, the country’s nuclear watchdog said. The regrading to a “major accident” puts Fukushima on a par with the 1986 Chernobyl disaster, the world’s worst ever peacetime nuclear event.

Officials said it was difficult to estimate exactly how much radioactive material had been released but available estimates “show levels equivalent to level seven,” a nuclear safety agency official said.

“We have issued a provisional assessment of level seven. This is the same as Chernobyl.”

The agency estimated the level of radioactive materials released by Fukushima Daiichi as equal to 10 percent of that emitted in the former Soviet Union but said the two events were markedly different. “In Chernobyl, there was acute exposure to a high level of radiation, and 29 people died from it. This is not the case in Fukushima,” safety agency official Hidehiko Nishiyama said.

“In Chernobyl, reactors themselves exploded.

“In Fukushima, hydrogen that had built up inside buildings exploded and blew buildings apart, but the reactors themselves have stayed intact, although we are seeing some leakage. “It is different from Chernobyl. We do not have the huge and sustained source of fire like that.

“In Chernobyl, because of the high level of contaminants spreading in the area, they had no choice but to leave it for a while. But in Fukushima, crews are working day and night. We have secured the environment to allow their work.” The safety agency, a government body, estimates the amount of radiation released to be 370,000 terabecquerels. One terabecquerel is a trillion becquerels, the standard measure of radiation.

Japan’s safety commission, an quasi-independent panel of experts advising the government, estimates the total amount emitted is much higher, at 630,000 terabecquerels. Both figures are arrived at retrospectively, using calculations based on readings in the atmosphere at a given time.

It was not immediately apparent why the two numbers were so different.

Tokyo, Tuesday, AFP