Japan has upgraded the Fukushima nuclear crisis to a level five, of seven, calling it an "accident with wider consequences." Emergency workers were racing to stabilize reactors and minimize further threats.
Four of six reactors at the plant were damaged
Japan's nuclear safety agency on Friday upgraded the Fukushima emergency from a level four to a level five accident rating on the International Nuclear Event Scale.
The increase indicates that the disaster has gone from "an incident with local consequences" to an "incident with wider consequences."
The agency's decision has put the crisis two steps below the 1986 Chernobyl disaster, which reached level seven, the highest rating on the scale, and at the same level as the Three Mile Island accident in the United States in 1979.
Efforts have continued to prevent the catastrophe from escalating, as emergency technicians raced to cool a set of overheated reactors to avert a nuclear meltdown.
The Tokyo Electric Power Company (TEPCO), which operates the plant, said it hoped to finish work on a new power line to reactors No. 1 and 2 by Saturday. Engineers worked to lay the kilometer-long (0.6 mile) cable from the main electricity grid, which would help restore the cooling systems.
The reactors' cooling systems were knocked out following last Friday's magnitude 9 earthquake off the coast of Japan and the subsequent tsunami that battered coastal cities. The twin disasters sparked a series of fires and explosions at the Fukushima plant.
'Fighting a fire we cannot see'
Fire trucks converged to spray water at Fukushima plant
At reactors three and four, workers were carrying on with efforts to douse the reactors with water. Japan's Nuclear and Industrial Safety Agency said that the priority was to dump water into reactor three which contains plutonium and is the most critical.
Japan's nuclear safety agency reported Friday that smoke or steam could be seen rising from reactor two, possibly from the spent fuel pool or from an explosion in the suppression chamber.
Military helicopters and a fleet of fire trucks were on standby to aid in the effort. But Japanese engineers said they cannot say if the crisis is under control.
"With the water-spraying operations, we are fighting a fire we cannot see," said Hideohiko Nishiyama, deputy director general of the Japan's nuclear agency.
"That fire is not spreading, but we cannot say yet that it is under control," he added.
Throughout the week, workers have had to be temporarily evacuated from the plant after radiation levels spiked as high as 1,000 millisieverts per hour. Experts say such a dose can cause radiation sickness.
The official death toll stood at around 7,000 on Saturday, with over 15,000 missing or dead. In positive news, rescue workers said Saturday they had pulled a young man from a crushed house eight days after the devastating tsunami.
Japan mourned the victims in a moment of silence on Friday
Silence for victims
Victims were remembered at 2:46 p.m. local time (05:46 GMT) exactly one week after a massive earthquake struck the country.
Live television showed elderly survivors in evacuation centers with their heads bowed in respect for the dead.
Meanwhile, foreign nationals continued to look for ways to leave Japan amid the ongoing fears of a nuclear meltdown at the Fukushima plant, which lies only 250 kilometers from the capital, Tokyo.
Foreign governments were advising their citizens to leave Tokyo and shun the northeast region. Many embassies, including the German embassy, have temporarily moved to Osaka, in Japan's south.
In a statement on its website, the World Health Organization cautioned against those in Japan self-medicating with potassium iodide or products containing iodine, which can be used in anti-radiation treatment.
Author: Darren Mara, Charlotte Chelsom-Pill (AFP, AP, Reuters)
Editor: Nancy Isenson