Fukushima reactor has explosion

Saturday, March 12, 2011

Four injured; meltdown feared as nuclear plant spews radiation

Compiled from Kyodo, AP

SENDAI — Officials scrambled to prevent a meltdown Saturday after an explosion at a nuclear power station blew apart the building housing its reactor, injuring four workers.

The blast followed the failure of the power plant's cooling system, which was compromised by Friday's 8.8-magnitude temblor.

Tokyo Electric Power Co., the utility that runs the Fukushima No. 1 plant, said the four workers injured in the blast — two of its own staff and two from another company, do not have life-threatening injuries and all remained conscious.

At the time of the 3:36 p.m. blast, the four were tending to problems caused by the massive quake, which devastated northeastern Japan and generated giant tsunami.

The explosion about 250 km northeast of Tokyo destroyed the walls and roof of the aging facility, which housed the reactor, Chief Cabinet Secretary Yukio Edano told reporters at a hastily convened news conference Saturday evening.

TV footage showed that the power plant's roof and walls had disappeared. Tepco said the roof of the building collapsed after a large tremor.

Edano urged local residents to stay calm and said radiation levels were being carefully monitored. He also urged all residents living within 20 km of its Fukushima No. 1 and No. 2. plants to evacuate.

"We are now trying to analyze what is behind the explosion," Edano said. "We ask everyone to take action to secure safety."

The nuclear power plant lost cooling ability after being jolted by Friday's devastating quake, and radioactive cesium and iodine were detected nearby Saturday.

Detection of the materials, which are created in the atomic fission process, prompted the nuclear safety agency to admit the reactor has been melting, a first for Japan.

According to the Fukushima Prefectural Government, hourly radiation emissions from the Fukushima plant reached 1,015 microsieverts on the premises — an amount equivalent to the dose an ordinary person would receive in one year.

The Nuclear and Industrial Safety Agency said serious damage to the stricken reactor's containment facility was unlikely despite the explosion.

Wind in the region is weak and headed northeast — toward the sea — for the time being, the Meteorological Agency said.

The company scrambled earlier Saturday to release pressure in the containers housing the reactors to prevent a nuclear meltdown from occurring, the Nuclear and Industrial Safety Agency said.

Even before Tepco succeeded in reducing the pressure, which involved releasing steam that would likely include radioactive materials, radiation had risen to an unusually high level in and near the No. 1 nuclear plant.

Work to depressurize the containers, aimed at preventing the plants from sustaining damage and losing their critical containment function, was conducted under an unprecedented government order.

At the No. 1 plant, the amount of radiation reached around 1,000 times normal inside the control room of the reactor, and 70 times normal near its main gate.

It was the first time an external radioactive leak had been confirmed since the disaster.

Earlier reports said the U.S. Air Force was helping to deliver coolant to the damaged plant, which Secretary of State Hillary Clinton was believed to have confirmed Friday in the U.S.

The plant was using a battery to run systems that keep the reactor's fuel from overheating, officials of the nuclear safety agency had said Friday.