Experts estimate 7 tons of radioactive water is escaping hourly from Fukushima reactor

04/03/2011 22:39

New York Times

TOKYO — Workers’ struggle to plug a gush of highly contaminated water from the Fukushima Daiichi nuclear power station, using sawdust, shredded newspaper and an absorbent powder, appeared to be failing early Monday as the radiation threat from the crippled plant continued to spread.

On Monday, people in Otsuchi, Japan, in Iwate Prefecture, searched for belongings in homes damaged by the March 11 tsunami.

Water with high amounts of radioactive iodine has been spewing directly into the Pacific Ocean from a large crack discovered Saturday in a six-foot-deep pit at the coastal plant north of Tokyo. The pit is next to the seawater intake pipes at the No. 2 reactor.

After an unsuccessful attempt to flood the pit with concrete to stop the leak, workers on Sunday turned to trying to plug the apparent source of the water — an underground shaft thought to lead to the damaged reactor building — with more than 120 pounds of sawdust, three garbage bags full of shredded newspaper and about nine pounds of a polymeric powder that officials said absorbed 50 times its volume of water.

Although the stopgap measure did not appear to be succeeding, workers would keep trying to stem the leak, said Hidehiko Nishiyama, deputy director general of the Nuclear and Industrial Safety Agency.

Early Monday, workers injected a dye into a separate tunnel where contaminated water had been discovered, to determine whether that was the source of the water in the pit, said Tokyo Electric Power Company, the plant’s operator. Workers are also expected to continue efforts Monday to stop the leakage from the pit into the ocean.

Experts estimate that about seven tons an hour of radioactive water is escaping the pit. Safety officials have said that the water, which appears to be coming from the damaged No. 2 reactor, contains one million becquerels per liter of iodine 131, or about 10,000 times the levels normally found in water at a nuclear plant.

“There is still a steady stream of water from the pit,” Mr. Nishiyama said, but workers would continue to “observe and evaluate” the situation overnight.

The leak underscores the dangerous side effects of the strategy to cool the plant’s reactors and spent fuel storage pools by pumping them with hundreds of tons of water. While much of that water evaporates, a significant portion also turns into dangerous runoff that has been discovered in various parts of the plant, endangering workers at the plant and hindering repair efforts. On March 24, three workers were injured when they stepped into a pool of radioactive water in one of the plant’s turbine buildings.

In recent days, workers have tried to clear the contaminated pools, but have struggled to find places to store the water. Meanwhile, levels of iodine 131 that are over 4,000 times normal, as well as levels of cesium 137 that are 527 times normal have been detected in seawater taken 1,080 feet away from the plant, raising fears of damage to sea life.

Tokyo Electric has said it has little choice but to pump more water into the reactors at the moment, since the normal cooling systems at the plant are inoperable and more radioactive material would be released if the reactors were allowed to melt down fully or if the rods caught fire.

Still, some experts expressed bewilderment at what they called an 11th-hour bid to plug the leak.

“I’ve never heard of anything like it at a nuclear power plant,” said Itsuro Kimura, emeritus professor at Kyoto University and director of the Japan-based Institute of Nuclear Technology. What is really needed, he said, is for the cooling systems to come back online at the plant’s six reactors. Those cooling systems work by circulating water around the nuclear fuel, producing little runoff.

“That is the best way to stop the leakage of radioactive water,” Mr. Kimura said. “But for now, they have to stop the water leaking the best they can.”

Tokyo Electric has come under growing scrutiny for its handling of the nuclear crisis set off by the March 11 earthquake and tsunami that hit Japan. In recent days, reports surfaced that the company would be taken over by the government. Tokyo Electric reported that a protesters’ sound truck, presumably sent to heckle the company, was blocked from entering the Fukushima Daiichi plant on Thursday.

There are also frequent protests at the company’s headquarters in the Uchisaiwai-cho neighborhood of central Tokyo. On Sunday, several hundred antinuclear protesters assembled in front of Tokyo Electric’s offices, then marched to Kasumigaseki to protest in front of the offices of Japan’s nuclear regulators.

The protesters shouted such slogans as, “Tokyo Electric, get out of nuclear energy” and “Compensate the victims.” Others called for the company and government to apologize. Some carried placards that read, “Even if we don’t have nuclear power, we’ll still have electricity.”

“The Japanese people don’t protest usually, but this time, we have to show that we can call for change,” said Masanobu Takeshi, 40, who was there with his wife and son.

Makoto Yanagida, 70, who has been protesting since March 12, said that on the first day, only about 10 people showed up. Sunday’s protest, the 10th, drew more than 300 people, he said. Mr. Yanagida said that he would continue protesting until nuclear plants were shut down.

Nuclear officials warned that it could take months to bring the Fukushima Daiichi plant under control. “It would take a few months until we finally get things under control and have a better idea about the future,” said Mr. Nishiyama of the nuclear safety agency. “We’ll face a crucial turning point within the next few months, but that is not the end.”

Earlier Sunday, Tokyo Electric said that two workers at the Fukushima Daiichi plant who were missing since the day of the earthquake and tsunami had been confirmed dead. Five employees of subsidiary companies have died at other Tokyo Electric facilities.

Tokyo Electric said the two workers at Fukushima Daiichi were found in the basement of the turbine building connected to the No. 4 reactor. The company found the bodies on Wednesday but did not release the details until the families had been notified.

The company said that the workers, Kazuhiro Kokubo, 24, and Yoshiki Terashima, 21, died on March 11, around 4 p.m., after the tsunami hit the plant.

“It pains me that these two young workers were trying to protect the power plant,” Tokyo Electric’s chairman, Tsunehisa Katsumata, said in a statement.

Of the other five deaths, one man died when he was struck by a crane that had toppled at the Fukushima Daini nuclear power plant, and four workers died at Tokyo Electric’s Hitachinaka coal-fired power plant when they fell from the chimneys they were working on.



Share |