Japan ups nuclear crisis rating to top level

Japan has raised the severity ratingfor its tsunami-stricken nuclear reactor from Level 5 to Level 7, the highest grade,equal to the 1986 disaster at Chornobyl in the former Soviet Union.

The country'sNuclear and Industrial Safety Agency made the decision Monday, sayingthat while the radiationemission rate at theFukushima Daiichi plantisabout10 per cent of thatat Chornobyl,the crippled Japanesefacility has emitted a huge amount of radioactive substances that pose a risk over alarge area.

"We have upgraded the severity level to 7 as the impact of radiation leaks has been widespread from the air, vegetables, tap water and the ocean,"agency spokesmanMinoru Oogoda said Tuesday.

Agency officials said one of the factors behind the decision was that the total amount of radioactive particles released into the atmosphere since the incident had reached levels that apply to a Level 7 disaster.

The Chornobyl disaster is the only previous time that an event has been rated Level 7 or "major accident" on the international and radiological events scale, which starts at zero and is designed to express the severity of nuclear mishaps.

TheFukushima crisis was previously ratedLevel 5,equalling the 1979 Three Mile Island incident inPennsylvania. Each level higher is considered to be roughly 10 times more severe.

A small fire broke out at the Fukushima nuclear facilityon Tuesday in a box that holds batteries, but it was quicklyextinguished. Plant operator Tokyo Electric Power Co. said the flames had no effect on radiation levels or any critical systems, and the fire had nothing to do with the decision to hike the incident rating at the plant.

2 more aftershocks

The news came as twonew earthquakes rattled Japan's east and northeast, and as the government urged more people living neartheFukushima Daiichi generating stationto leave, citing concerns about long-term health risks from radiation.

A magnitude 6.3 aftershock struck an area neighbouring Tokyo just after 8 a.m. local time Tuesday, the country's meteorological agency reported, though there were no initial reports of injuries or damage. No tsunami warning was issued.

An earliermagnitude 7.0 aftershockonMondaytrapped some people in collapsed homes, and came just hours after residents bowed their heads and wept in ceremonies to mark a month sincethe massive earthquake and tsunami killed up to 25,000 people and set off radiation leaks at the nuclear plant by knocking out its cooling systems.

"Even after a month, I still cry when I watch the news," said Marina Seito, 19, a student at a junior college who recalled being in a basement restaurant in Sendai when the original 9.0 magnitude earthquake hit on March 11. Plates fell and parts of the ceiling crashed down around her.

The epicentre ofMonday's aftershockwas just inland and about 160 kilometres north of Tokyo. A warning was issued for a one-metre tsunami, but it was subsequently lifted.

In Iwaki, a city close to the epicentre of Monday's tremor, a landslide brought down three houses, trapping up to seven people. Four were rescued alive, but one of those a 16-year-old girl died at the hospital, a police official said. He would not give his name, citing policy.

The 9.0 magnitude earthquake and the tsunami it generated on March 11are believed to havecaused as much as $310 billion in damage. The nuclear power plant they disabled has been spewing radiation since, and even a month on, officials say they don't know how long it will take to cool reactors there.

In a move unrelated to Monday's aftershock, the Japanese government is expanding the evacuation zone around the plant to 30 kilometres from 20, citing the risks of cumulative radiation exposure.

"This isn't animmediate evacuation," CBC's Craig Dale reported from Tokyo. "Over a month's period they're hoping that people living 30 kilometres away from Fukushima Daiichi will leave those areas, or at least stay indoors."

The latest calculations from Japan's Nuclear Safety Commission found that an area stretching 60 kilometres north of the nuclear plant and 40 kilometres south have, in the month since the earthquake,already been exposed toradiationequivalenttothe annual dosage limit. Within theold 20-kilometre evacuation zone, radiation exposure has reached up to 100 times the annual limit.

At-riskgroups prioritized

People being targeted in the evacuation are children, pregnant women and patients in hospitals. Dale said the evacuation zone is not a perfect circle and stretches up to 40 kilometres from the plant in at least one place.

A nuclear safety official said the repeated strong aftershocks were slowing work at the plant, and said that if one of them were to spawn a tsunami, the complex would be just as vulnerable as on March 11.

"At the moment, no tsunami resistance has been added to the plant. At the moment, there is nothing we can do about it," the Nuclear and Industrial Safety Agency's Hidehiko Nishiyama said.

Monday's aftershock briefly forced Tokyo's main international airport to close both of its runways. There were no new reports of damage.

'My chest has been ripped open by the suffering and pain that this disaster has caused.' Yuhei Sato, governor of Fukushima

Aftershocks have repeatedly rattled the disaster-weary region, but there is little left in the northeast to ruin. Last Thursday's 7.1 magnitude aftershock, which had been the strongest tremor since the day the original quake hit, did sink hundreds of thousands more households into darkness, however. Electricity has been restored to most of those homes.

With workers still far from bringing the nuclear plant under control, the bodies of thousands of tsunami victims yet to be found and more than 150,000 people living in shelters, there was little time for reflection on Japan's worst disaster since the Second World War.

People in hard-hit towns gathered for ceremonies at 2:46 p.m., the exact moment of the massive quake a month earlier.

"My chest has been ripped open by the suffering and pain that this disaster has caused the people of our prefecture," said Yuhei Sato, the governor of Fukushima, which saw its coastal areas devastated by the tsunami and is home to the damaged plant at the centre of the nuclear crisis. "I have no words to express my sorrow."

Japan's government marked the one-month period by putting an ad in newspapers in China, South Korea, Russia, France, the United Kingdom and the United States a letter from Prime Minister Naoto Kan thanking people for the outpouring of support that followed the tsunami. The Red Cross alone said it has collected $102 millionCdn from overseas.

Kan described the outpouring as "kizuna," the bond of friendship.

"We deeply appreciate the kizuna our friends from around the world have shown and I want to thank every nation, entity, and you personally, from the bottom of my heart."