Teams at Japan reactor hold back crisis

Emergency workers shuttled into and out of Japan's Fukushima Dai-ichi nuclear plant today as they scrambled to contain melting nuclear cores and even wider releases of dangerous radiation.

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  By Paula Bronstein, Getty Images
  Yukie Ito, left, tries to comfort daughter Hana, 8, center, with grandmother Tamiyo, right, at a refugee center in Kesennuma, Japan.

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By Paula Bronstein, Getty Images

Yukie Ito, left, tries to comfort daughter Hana, 8, center, with grandmother Tamiyo, right, at a refugee center in Kesennuma, Japan.

After temporarily evacuating the plant for five hours in the face of high radiation, the 180 workers, in shifts of 50 at a time, resumed pumping seawater into the plant's three damaged reactors.

The workers were hailed as heroes in Japan.

"I don't know any other way to say it, but this is like suicide fighters in a war," said Keiichi Nakagawa, associate professor of the Department of Radiology at University of Tokyo Hospital.

Meanwhile, concerns shifted to the spent nuclear fuel rods in pools above the reactors, which remain radioactive for years.

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"Essentially they are open to the air," said physicist Edwin Lyman of the Union of Concerned Scientists.

If water in the pools drains off or is boiled away, exposing the rods, they will heat, crack and release radioactive elements.

"We could have significant releases of radioactive products," Lyman said.

That's a worry, because in the past two days, fires at two of those fuel rod pools have led to spikes in radiation that exceeded worker safety limits and triggered evacuations.

High radiation makes it too dangerous for workers to manually use hoses. Instead, Tokyo Electric Power Co. spokesman Naoki Tsunoda said that high-pressure firetruck hoses will spray water into the pools from a safe distance.

Government officials said they asked special police units to bring in water cannons — normally used to quell rioters — to spray water onto one of the fuel storage pools.

The cannons are thought to be strong enough to allow emergency workers to remain a safe distance from the complex, said Minoru Ogoda of Japan's nuclear safety agency.

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Warning of the danger to workers within the reactor areas, U.S. Nuclear Regulatory Commission Chairman Gregory Jaczko told a House panel that one pool has likely been depleted of water, though the power company denied the report.

Tsunoda also reported that a new outside power line would be connected to the plant. The electrical cooling systems were knocked out by Friday's magnitude-9.0 earthquake and tsunami, at the coast-hugging facility.

The reactors at the plant have numerous problems:

•Three reactors have partly-melted fuel rods. Two may have radiation leaks.

•Pumped seawater has not fully covered the damaged rods, keeping temperatures high and increasing hydrogen levels.

•Venting of the hydrogen has led to explosions that have so far, damaged two of the reactors.

Unlike the reactor fuel rods, the spent ones in the pools should contain very little radioactive iodine, the element linked to most of the cancers caused by the 1986 Chernobyl disaster, said radiation safety expert Henry Royal of Washington University School of Medicine in St. Louis and co-leader of a Chernobyl health study.

"The workers face a real exposure risk," Royal said. "But I don't think the general population really faces a significant one."