Tainted Groundwater Found At Japan Nuclear Plant Workers have discovered contaminated groundwater beneath a leaking nuclear reactor at Japan's troubled Fukushima Dai-ichi complex, plant operators say. The radiation levels were 10,000 times the government health standard. Other readings find radiation levels rose in seawater near the plant.

Tainted Groundwater Found At Japan Nuclear Plant

The facilities at the Fukushima Dai-ichi nuclear power plant were designed to withstand strong earthquakes and tsunamis, but not to the strength and size experienced on March 11. Air Photo Service/AP hide caption

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Air Photo Service/AP

Officials with the company that operates the leaking Japanese nuclear plant say radioactive contamination in groundwater just discovered underneath a reactor has been measured at 10,000 times the government health standard.

It was the first confirmation of groundwater contamination since the March 11 quake and tsunami hit the Fukushima Dai-ichi nuclear power plant in northeastern Japan. A Tokyo Electric Power Co. official said, "We're aware this is an extremely high figure," Kyodo News reported.

The water apparently came from around the turbine building near the plant's Unit 1. But the implication of the finding remains unclear — the spokesman for TEPCO says the company doesn't believe any drinking water supply is affected so it's not yet a health concern.

New readings on Thursday also showed radiation levels rising in the ocean near the plant. Officials were also debating whether to broaden the evacuation zone around the tsunami-damaged facility because of a report showing elevated radiation levels in a village outside the current evacuation zone.

High Radiation Readings Outside Evacuation Zone

Japan's government nuclear safety agency said it was looking into a report from the International Atomic Energy Agency about high levels of radiation in the ground of the village of Iitate, 25 miles from the plant in Fukushima prefecture. The IAEA, the U.N.'s nuclear watchdog, said the level tested in Iitate was twice its suggested threshold for evacuation.

Japanese safety spokesman Hidehiko Nishiyama said most residents in Iitate have left, but about 100 have chosen to stay.

But the independent Nuclear Safety Commission said it sees no reason to expand the evacuation zone. Commission member Seiji Shiroya said evacuation criteria in Japan are decided according to how much radiation people would be exposed to, not radiation levels in the ground.

Meanwhile, preparations continued Thursday to cool down the dangerously overheated the plant, which has leaked radiation after being damaged in the March 11 earthquake and tsunami.

The mission to stabilize the plant, 140 miles northeast of Tokyo, has become more complicated since the discovery a week ago that radioactive water is pooling in different places around the plant, restricting the areas in which crews can work. Workers have also struggled to find places to store the leaking water, as some temporary storage facilities are already full.

On Thursday, workers began emptying storage tanks so that contaminated water from tunnels and trenches could be transferred there. The hope is that moving the water will prevent it from harming workers or flowing out to sea.

TEPCO is also planning to spray the grounds of the plant with a material that's supposed to trap the radioactive dust that's settled on the site.

Assessing Seawater Contamination

Contamination from the plant has been seeping into the sea, and seawater some 360 yards from the shore south of the plant measured 4,385 times the legal limit Thursday, up from 3,355 times the allowed amount the previous day, TEPCO officials said.

But the contaminated seawater poses no threat to human health because fishing and swimming aren't allowed in the vicinity.

Radioactive iodine is short-lived, with a half-life of just eight days, and in any case was expected to dissipate quickly in the vast Pacific Ocean. Experts also do not expect it to affect the food chain.

"We have repeatedly told consumers that it is perfectly safe to eat fish," said Shoichi Takayama, an official with Japan's fishery agency.

Citing dilution in the ocean, the U.S. Food and Drug Administration has played down the risks of seafood contamination.

Fear Vs. Science

But, as with other reports of radiation levels in food and tap water, fear has begun to override science. Several countries, including China, India and South Korea, have ordered special inspections for or outright bans on fish from areas near the plant.

In Iitate, radiation in the village's tap water spiked about 10 days ago, although it remained well below levels that would pose an immediate health risk, the IAEA said. The latest reading came between March 18 and March 26, when a series of samples were taken from a wide area, according to a report on the agency's website. Both iodine-131 and cesium-137 were found in the samples.

The agency's evacuation limits are "intended to be extremely conservative," and even the highest levels fell well below the radiation contained in a heart scan, said Richard Morin, a medical physicist with the American College of Radiology.

TEPCO, which owns the Fukushima plant, has come under growing criticism for its handling of the nuclear crisis. The nuclear safety agency ordered plant operators nationwide on Wednesday to review their emergency procedures. The agency told utilities they must have on hand mobile backup generators and fire engines, which have been used at Fukushima to cool the reactors.

The tsunami has also created another disaster overshadowed by the nuclear crisis: Hundreds of thousands of people were forced from their homes after the wave surged miles inland, decimating whole towns. The official death toll stood at 11,417 on Thursday, with the final toll likely to surpass 18,000.

With reporting by NPR's Jon Hamilton in Tokyo and Richard Harris in Washington. Material from The Associated Press was used in this report.