Efforts to Plug Japanese Reactor Leak Are Failing

TOKYO — Workers’ desperate 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 late Sunday as the radiation threat from the crippled plant continued to spread.

Water containing high amounts of radioactive iodine has been spewing directly into the Pacific Ocean from a large crack discovered Saturday in a 6-foot-deep pit at the coastal Fukushima Daiichi Nuclear Power Plant. 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 — by plugging the shaft with a makeshift putty: more than 120 pounds of sawdust, three garbage bags full of shredded newspaper and about 9 pounds of a polymeric powder that officials said absorbs 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.

Experts estimate that about 7 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 at Fukushima Daiichi, contains one million Becquerels per liter of iodine 131, or about 10,000 times levels normally found in water at a nuclear facility.

“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 accumulating in various parts of the plant, endangering workers at the plant and hindering repair efforts. Last week, three workers were injured when they stepped into a pool of radioactive water inside one of the plant’s turbine buildings.

Workers have in recent days tried to clear the contaminated pools, but have struggled to find enough places to store the water. Meanwhile, higher-than-normal levels of radiation have been detected in waters near the plant, raising fears of damage to sea life.

The Tokyo Electric Power Company, the plant’s operator, 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, improvised bid to plug the leak.

“I’ve never heard of anything like it at a nuclear power plant,” said Itsuo 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, triggered by the March 11 quake and tsunami. In recent days, reports surfaced that the company, once the largest utility in the world, 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 Daiichi plant on March 31.

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

The protesters yelled slogans like, “Tokyo Electric, get out of nuclear energy,” and “Compensate the victims.” Others called for the company and government to apologize.

Some carried placards that said, “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 attended with his wife and son.