State of emergency at second plant

A child evacuated from areas surrounding the Fukushima nuclear facilities is checked for radiation exposure (AP)

Japan has declared a state of emergency at another earthquake-affected nuclear plant where higher-than-permitted levels of radioactivity were measured, the UN's nuclear agency has said.
The International Atomic Energy Agency said Japan informed it that the source of the radioactivity at the Onagawa power plant is being investigated. It said all three reactors at the plant are under control.
Japan also said authorities at another plant have resorted to using sea water to cool a second reactor in an attempt to prevent a meltdown.
Japan said earlier attempts to cool the No. 3 reactor at the Fukushima Dai-ichi plant had failed. Sea water is also being used to cool the plant's No. 1 reactor, but as it is corrosive it is being used as a last resort.
More than 180,000 people had been evacuated near the Fukushima plant as a precaution, though Chief Cabinet Secretary Yukio Edano said the radioactivity released into the environment so far was so small it did not pose any health threats.
"First I was worried about the quake," said Kenji Koshiba, a construction worker who lives near the plant. "Now I'm worried about radiation."
Mr Edano said neither Fukushima Dai-ichi reactor was near the point of complete meltdown, and he was confident of escaping the worst scenarios.
A complete meltdown - the collapse of a power plant's systems and its ability to keep temperatures under control - could release uranium and dangerous contaminants into the environment and pose major, widespread health risks.
Up to 160 people, including 60 elderly patients and medical staff who had been waiting for evacuation in the nearby town of Futabe, and 100 others evacuating by bus, might have been exposed to radiation, said Ryo Miyake, a spokesman from Japan's nuclear agency. The severity of their exposure, or if it had reached dangerous levels, was not clear. They were being taken to hospitals.