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Smoke spews from 2 reactors at stricken Japanese nuclear plant

Published: 2011-03-22    Views:257 reads

Smoke spewed Monday from two adjacent reactors in Japanese nuclear power plant, a nuclear safety official said, setbacks that came despite fervent efforts to prevent the further release of radioactive materials at the stricken facility.

After 6 p.m., white smoke was seen emanating from the facility's No. 2 reactor, according to Hidehiko Nishiyama, an official with Japan's Nuclear and Industrial Safety Agency. About two hours earlier, workers were evacuated from the area around the No. 3 reactor after gray smoke began to rise from the wreckage of its steel-and-concrete housing, which was blown apart by a hydrogen explosion last week.

The No. 3 reactor has been the top priority for authorities trying to contain damage to the plant and stave off a possible meltdown. Its fuel includes a small percentage of plutonium mixed with the uranium in its fuel rods, which experts say could cause more harm than regular uranium fuels in the event of a meltdown.

Nishiyama said there was no evident explosion, spike in radiation or injuries at the No. 3 reactor. The smoke was coming from the building's southeastern side, where the reactor's spent nuclear fuel pool is located, but the origin of the smoke at either reactor was unknown.

The coolant pools contain spent fuel rods that still generate high amounts of heat. Authorities have been working to keep them full to prevent the rods from being exposed. The nuclear agency estimated that, between roughly 9 p.m. Sunday to 4 a.m. Monday, 1,170 tons of water were sprayed on the reactor and its fuel pool.

In Geneva, Switzerland, the head of the International Atomic Energy Agency warned that while signs of improvement at the site are evident, the plant "has been seriously damaged by flood water and is littered with debris."

"The crisis has still not been resolved, and the situation at the Fukushima Daiichi nuclear power plant remains very serious," Yukiya Amano, the director-general of the U.N. nuclear watchdog agency, told its board of governors Monday after a visit to the site.

"Buildings have been damaged by explosions," he said. "There has, for the most part, been no electric power. Radiation levels are elevated. It is no exaggeration to describe the work of the emergency teams as heroic."

On the other hand, Amano told reporters, rising pressure inside the containment unit at reactor No. 3, a concern from the weekend, was down and power had been restored to some of the reactors.

The plant's owner, the Tokyo Electric Power Company, has been working to restore electricity to the damaged plant after it was hit by the massive earthquake and tsunami the struck northern Japan on March 11. The electric company told CNN on Monday that electrical cables had been laid to connect the No. 3 reactor and the neighboring No. 4 reactor with an outside power source.

That meant that power could now be funneled to all six of the plant's reactors for its cooling systems. But electricity was still not moving to units No. 1 through No. 4 because the quake and tsunami had damaged numerous pumps and other gear.

A Tokyo Electric official said spare parts were being brought in so that everything could work again.

The disaster has killed more than 8,800 people and left close to 13,000 missing, many of them killed as a wall of water rushed in following the quake. Ever since, authorities have been working to avert further crisis -- and prevent more deaths -- at the Fukushima Daiichi plant, some 240 kilometers (150 miles) north of Tokyo.

Those efforts include the possibility of encasing one or more of the reactors in concrete, a last-ditch effort similar to what was done after the 1986 meltdown at the Chernobyl nuclear plant in the former Soviet Union -- considered the worst nuclear disaster at a Japanese nuclear power plant.

Japan's nuclear agency said Monday that it expected to conduct tests on what it called a "concrete pump engine," which the agency initially said would pump a mix of mortar and water into the No. 4 reactor's spent nuclear fuel pool and containment vessel, the agency said.

But Tokyo Electric said later that the device would be used only to pour water, not the mortar mixture.

In just over two hours on Monday morning alone, 13 fire engines sprayed about 90 tons of water toward that reactor in an attempt to cool it down.

A Tokyo electric official told  that six workers trying to restore electricity to that reactor have been exposed to more than 100 millisieverts of radiation. For reference, an individual in a developed country naturally is exposed to 3 millisieverts of radiation a year -- though Japan's Ministry of Health, Labor, and Welfare has reset the exposure level upward to 250 millisieverts for those trying to combat the crisis Japanese nuclear power plant. That is 2.5 times the previous limit, according to the ministry.