Thousands Flee as Japan's Crisis Grows.

Thousands Flee as Japan's Crisis Grows.

Japan races to prevent nuclear reactor meltdowns

Officials have declared states of emergency at six plants in quake-affected area

Japan's nuclear crisis intensified Sunday as authorities raced to combat the threat of multiple reactor meltdowns and more than 170,000 people evacuated the quake- and tsunami-savaged northeastern coast where fears spread over possible radioactive contamination.

Nuclear plant operators were frantically trying to keep temperatures down in a series of nuclear reactors — including one where officials feared a partial meltdown could be happening Sunday —  to prevent the disaster from growing worse.

But hours after officials announced the latest dangers to face he troubled Fukushima Daiichi nuclear complex, including the possibility of a second explosion in two days, there were few details about what was being done to bring the situation under control.

Chief Cabinet Secretary Yukio Edano said Sunday that a hydrogen explosion could occur at the complex's Unit 3, the latest reactor to face a possible meltdown. That would follow a hydrogen blast Saturday in the plant's Unit 1, where operators attempted to prevent a meltdown by injecting sea water into it.

A meltdown at the No. 3 reactor could be more serious than at the other reactors because it is fuelled by both plutonium and uranium, BBC News reported. The others have only uranium fuel.

"At the risk of raising further public concern, we cannot rule out the possibility of an explosion," Dean said. "If there is an explosion, however, there would be no significant impact on human health."

Such statements, though, did little to ease public worries. "First I was worried about the quake," said Kenji Koshiba, a construction worker who lives near the plant. "Now I'm worried about radiation." He spoke at an emergency center in Koriyama, about 40 miles (60 kilometers) from the troubled reactors and 125 miles (190 kilometers) north of Tokyo.

At the makeshift center set up in a gym, a steady flow of people — mostly the elderly, schoolchildren and families with babies — were met by officials wearing helmets, surgical masks and goggles.

About 1,500 people had been scanned for radiation exposure, officials said.

 Thousands Flee as Japan's Crisis Grows.