Nuclear emergency declared in northeastern Japan

Almost 3,000 residents near the Fukushima I nuclear power plant 170 miles northeast of Tokyo are evacuating the area after the 8.9-magnitude earthquake triggered a power outage that left a cooling system unable to supply water to cool the reactor. Radiation levels in the control room rose to 1,000 times above normal levels, Marketwatch reports.

Some radiation has now leaked outside the plant, Public Broadcaster NHK quoted nuclear safety officials as saying, with levels just outside the main gate measured eight times the normal level.

Chief Cabinet Secretary Yukio Edano told reporters that residents have been instructed to stay at least 1.5 to 2 miles from the plant and those within a few miles should stay indoors.

"The IAEA [International Atomic Energy Agency] continues to stand ready to provide technical assistance of any kind, should Japan request this," IAEA Director General Yukiya Amano announced on the IAEA Web site, which is posting regular updates on the emergency.

Cham Dallas, a toxicology expert and professor of disaster management at the University of Georgia, tells CNN the reactors might get "both thermally hot and radioactively hot" after being shut down: "When they shut down reactors, it takes a long time for them to go down. It does not necessarily mean radioactive material got out of the reactor."

A nuclear safety agency official speaking anonymously to CNN adds that the worst-case scenario is if the cooling system continues to fail, radiation could leak out and even possibly lead to a reactor meltdown.

Meanwhile, Reuters is reporting that the U.S. is transporting a cargo of liquid coolant to the plant in further efforts to cool the reactor. "We just had our Air Force assets in Japan transport some really important coolant to one of the nuclear plants," Secretary of State Hillary Clinton said at a meeting of the President's Export Council Friday.

The IAEA is reporting that a fire broke out at one Onagawa plant, but crews were able to put that out. There is also a water leak at another plant at Onagawa.

The earthquake off the coast of Honshu, Japan, ranks fifth on the list of biggest earthquakes in the past century. (The largest earthquake on record was a 9.5 in Chile in 1960, which killed 1,655, left 2 million people homeless, and resulted in a tsunami that killed 61.)

The death toll from the Japan quake and its aftermath is expected to pass 1,000, most due to drownings, and the BBC reports that hundreds remain missing, including on a passenger ship and as many as four trains. Google has launched a Japanese Quake Person Finder to create records for missing persons. There are currently more than 7,000 records.

Updated at 3:25 p.m. PT with information on the response to the nuclear emergency and radiation levels outside the plant.