Sunday, March 20, 2011

Workers In Japan Seeing Success In Cooling Reactors


After a week of disasters and setbacks, power plant workers and military personnel at the Fukushima Dai-ichi power plant made some progress today in cooling over-heated fuel rods.

On Friday, U.S. officials warned those rods posed the most urgent danger of radiation leakage into the environment because the water that is supposed to cover them – keeping them cool and shielding their radiation – had largely drained away.

Unlike the nuclear fuel inside the plant's reactors, the rods in the storage pools are not walled off by containment vessels, and the buildings they're in have been heavily damaged by explosions and fires. That allows radioactive gases to escape directly into the environment.

But NPR's Christopher Joyce in Tokyo reports that seawater sprayed from water cannons has succeeded in lowering temperatures in the storage pools.

Workers were also able to back away from a planned release of radioactive gases at the facility's troubled No. 3 reactor because pressure within the reactor stabilized after mounting ominously earlier.

NPR's Science Desk Explains ...

A diagram of the Mark I-type boiling water reactor, like the kind at the Fukushima nuclear facility.

What Went Wrong With Japan's Nuclear Reactors

Officials are scrambling to get water into the Japanese reactors to cool the nuclear cores.

This satellite image of Japan showing damage after an Earthquake and Tsunami at the Daiichi nuclear power plant in Fukushima, Japan.

Tracking The Latest At The Fukushima Nuclear Plant

The latest updates on each of the reactors at the stricken Fukushima Daiichi nuclear facility.

They also brought electrical power to the No. 2 reactor from what was essentially a mile-long extension cord, and planned to extend the power to other reactors.

However, it isn't yet clear whether the power will be able to reactivate pumps and other equipment needed to cool the reactors and adjacent storage pools for radioactive fuel rods. Much of that equipment may have been damaged by the 20-foot tsunami that inundated the power plant on March 11.

Hundreds more workers have been brought in to the afflicted plant, bringing the total to 500. For most of the past week, 170 workers have rotated in and out of highly radioactive parts of the plant and a lead-lined bunker, to keep their radiation exposure below levels that would sicken or even kill them.

Two Survivors Found 9 Days After Quake

An 80-year-old woman and her teenage grandson were rescued Sunday in northeastern Japan when the youth was able to pull himself out of their flattened two-story house nine days after the devastating earthquake and tsunami.

Jin Abe, 16, was seen calling out for help from the roof of the collapsed home in the hard-hit city of Ishinomaki, according to the Miyagi Prefectural Police. Like other homes in northeastern Japan, they had lost electricity and telephone service in the March 11 earthquake.

He led them inside to his 80-year-old grandmother, Sumi Abe. Both were conscious but weak, and had survived on the food they had in their refrigerator, said Shizuo Kawamura of the Ishinomaki police department.

The woman could not get out of the house because she has trouble walking, and the teenager, who was suffering from a low body temperature, had been unable until Sunday to pull himself from the wreckage. During the nine-day ordeal, they ate yogurt and other food.

Fuel, Food And Water Remain Scarce

NPR's Richard Harris in Tokyo reports that radioactive iodine levels in these foods exceed Japanese and U.S. safety standards, but aren't high enough to pose an immediate health threat. Authorities are stepping up screening of produce from the regions near the plant.

Map of Japan Earthquake Epicenter

Dr. Harold M. Swartz of Dartmouth College told the New York Times that the Japanese government's reassurances about contaminated food were "probably reasonable," but people would probably avoid milk and spinach anyway because they're so afraid of any radiation.

Another expert on the health effects of low-level radiation, David J. Brenner of Columbia University, told the Times that he would avoid the tainted foods as a precaution.

Government Admits Mistake

Officials have begun distributing protective potassium iodide pills to people from the area around the power plant. But one official in Fukushima, Kazuma Yokota, told reporters that the government now realizes it should have distributed the pills earlier last week.

Potassium iodide protects people against thyroid cancer if they have been exposed to radioactive iodine, but it must be taken promptly.

The pills help reduce chances of thyroid cancer, one of the diseases that may develop from radiation exposure, by preventing the body from absorbing radioactive iodine. The official, Kazuma Yokota, said the explosion that occurred while venting the plant's Unit 3 reactor last Sunday should have triggered the distribution. But the order came only three days later.

"We should have made this decision and announced it sooner," Yokota told reporters at the emergency command center in the city of Fukushima. "It is true that we had not foreseen a disaster of these proportions. We had not practiced or trained for something this bad. We must admit that we were not fully prepared."

Japanese Worry About Food Safety

Most public concern about radiation this weekend has focused on traces of radioactive iodine that Japanese authorities have found in milk and spinach from Fukushima, the prefecture where the power plant is located, and neighboring Ibaraki. Higher-than-normal levels of radioactivity have been found in foods produced up to 90 miles away from the power plant.

Traces of radiation have also been found in fava beans exported from Japan to Taiwan.

NPR's Richard Harris in Tokyo reports that radioactive iodine levels in these foods exceed Japanese and U.S. safety standards, but aren't high enough to pose an immediate health threat. Authorities are stepping up screening of produce from the regions near the plant.

Dr. Harold M. Swartz of Dartmouth College told the New York Times that the Japanese government's reassurances about contaminated food were "probably reasonable," but people would probably avoid milk and spinach anyway because they're so afraid of any radiation.

Another expert on the health effects of low-level radiation, David J. Brenner of Columbia University, told the Times that he would avoid the tainted foods as a precaution.

With reporting from NPR's Russell Lewis, Christopher Joyce and Richard Harris in Tokyo.

Source: NPR : National Public Radio

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