4 P.M. UPDATE: 3 NUCLEAR REACTORS IN TROUBLE AFTER JAPAN QUAKE
Radiation surged to around 1,000 times the normal level in the control room of the No. 1 reactor of the Fukushima Daichi plant, Japan's Nuclear and Industrial Safety Agency said. Radiation — it was not clear how much — had also seeped outside, prompting widening of an evacuation area to a six-mile radius from a two-mile radius around the plant. Earlier, 3,000 people had been urged to leave their homes.
Tokyo Electric Power Co. said Saturday that the temperatures of its No.1 and No.2 reactors at its Fukushima Daini nuclear power station were rising, and it had lost control over pressure in the reactors.
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Fukushima Daini station is the second nuclear power plant the company has in Fukushima prefecture in northeastern Japan, where the troubled Fukushima Daiichi plant is located.
Tepco said at about 2:46 p.m. local time three of its six reactors shut following the earthquake. All are boiling water reactors.
Tepco said the reactors shut due to the loss of offsite power due to the malfunction of one of two off-site power systems. That triggered emergency diesel generators to startup and provide backup power for plant systems.
About an hour after the plant shut down, however, the emergency diesel generators stopped, leaving the units with no power for important cooling functions.
Nuclear plants need power to operate motors, valves and instruments that control the systems that provide cooling water to the radioactive core.
Earlier, Chief Cabinet Secretary Yukio Edano said, "Residents are safe after those within a 3-kilometer (1.8-mile) radius were evacuated and those within a 10-kilometer (6.2-mile) radius are staying indoors, so we want people to be calm."
The country's nuclear safety agency said pressure inside one of six boiling water reactors at the Fukushima Daiichi plant near Onahama, some 170 miles northeast of Tokyo, had risen to 1.5 times the level considered normal.
Hours after the evacuation order, the government announced that the plant will release slightly radioactive vapor from the unit to lower the pressure in an effort to protect it from a possible meltdown.
Edano said the amount of radioactive element in the vapor would be "very small" and would not affect the environment or human health. "With evacuation in place and the ocean-bound wind, we can ensure the safety," he said at a televised news conference.
U.S. President Barack Obama said he spoke with Japanese Prime Minister Naoto Kan earlier Friday, and that the Japanese leader told him there were no radiation leaks from Japan's nuclear power plants.
"Right now our Department of Energy folks are in direct contact with their counterparts in Japan and are closely monitoring the situation," a senior administration official who handles nuclear issues told NBC News. "So far the government of Japan has not asked for any specific assistance with regard to the nuclear plant, but DOE and other U.S. government agencies are assessing the role they could play in any response and stand by to assist if asked."
Japan has a "tremendous amount of technical capability and resources" to respond to the issue themselves for now, sources told NBC News.
Meanwhile, new power supply cars to provide emergency electricity for systems that failed at the Fukushima-Daiichi plant have arrived there, the World Nuclear Association said.
"The World Nuclear Association understands that three to four power supply cars have arrived and that additional power modules are being prepared for connection to provide power for the energy cooling system," said Jeremy Gordon, analyst at the London-based WNA.
The cables were being set up to supply emergency power. Other power modules were in transit by air, WNA added on its website.
'Stages away from Three Mile Island'
The cooling problems at the Japanese plant raised fears of a repeat of 1979's Three Mile Island accident, the most serious in the history of the U.S. nuclear power industry. Experts, however, said the situation was, so far, less serious.
Equipment malfunctions, design problems and human error led to a partial meltdown of the reactor core at the Three Mile Island plant, but only minute amounts of dangerous radioactive gases were released.
"The situation is still several stages away from Three Mile Island when the reactor container ceased to function as it should," said Tomoko Murakami, leader of the nuclear energy group at Japan's Institute of Energy Economics.
Toshiaki Sakai, director of the Japan Atomic Industrial Forum International Cooperation Center, said nuclear power companies around the globe have since implemented over 53 safety improvements to avert a repeat.
The International Atomic Energy Agency estimates that around 20 percent of nuclear reactors around the world are currently operating in areas of significant seismic activity.
The IAEA said the sector began putting more emphasis on external hazards after an earthquake hit TEPCO's Kashiwazaki-Kariwa plant in July 2007, until then the largest to ever affect a nuclear facility.
When the earthquake hit the Kashiwazaki-Kariwa nuclear power plant, four reactors shut down automatically. Water containing radioactive material was released into the sea, but without an adverse effect on human health or the environment, it said.
Backup generator failed
Pressure is rising inside the Fukushima-Daiichi nuclear reactor, Japanese officials said, after a backup generator also failed and the cooling system was unable to supply water to cool the reactor, though at least one backup cooling system is being used. The reactor core remains hot even after a shutdown.
Underscoring grave concerns about the Fukushima plant, U.S. Secretary of State Hillary Clinton said the U.S. Air Force had delivered coolant to try to lower the temperature of the facility's nuclear rods. However, Japan said it did not need assistance from the United States but Clinton did not appear to have been updated before she made her public remarks.
Experts said there could be leakage if water levels in the Fukushima reactor fell and the temperature of the nuclear rods rose, though this might not happen immediately.
"Even if fuel rods are exposed, it does not mean they would start melting right away," said Murakami, and "even if fuel rods melt and the pressure inside the reactor builds up, radiation would not leak as long as the reactor container functions well."
Continuing to supply water is crucial. "If you don't, the fuel will start to overheat and could melt," said Edwin Lyman, a senior staff scientist in the Global Security program at the Union of Concerned Scientists in Washington, D.C., told ABC News.
Tepco confirmed that water levels were falling, but said it was working to avert any exposure of the nuclear fuel rods.
"There is a falling trend (in water levels) but we have not confirmed an exposure of nuclear fuel rods," a TEPCO spokesman said.
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Reactors shut down due to the earthquake account for 18 percent of Japan's nuclear power generating capacity.
Tepco had been operating three out of six reactors at the Fukushima Daiichi nuclear plant at the time of the quake, all of which shut down.
The spokesman added that there were no concerns of a water leak for the remaining three reactors at the plant, which had been shut for planned maintenance.
Japan's nuclear power sector produces about 30 percent of the country's electricity and has been rocked periodically over the past decade by safety concerns. Many reactors are located in earthquake-prone zones such as northeastern Fukushima prefecture and Fukui prefecture on the Japanese coast.