March 26, 2011
By WILLIAM J. BROAD and DAVID JOLLY
The world’s chief nuclear inspector said Saturday that Japan was “still far from the end of the accident” that struck its Fukushima nuclear complex and continues to spew radiation into the atmosphere and the sea, and acknowledged that the authorities were still unsure about whether the reactor cores and spent fuel were covered with the water needed to cool them and end the crisis.
The inspector, Yukiya Amano, the director general of the International Atomic Energy Agency, taking care to say that he was not criticizing Japan’s response under extraordinary circumstances, said, “More efforts should be done to put an end to the accident.”
More than two weeks after a devastating earthquake and tsunami, he cautioned that the nuclear emergency could still go on for weeks, if not months, given the enormous damage to the plant.
His concerns were underscored on Sunday when officials in Japan announced higher levels of radiation in pools of water at the facility’s stricken reactors. The Nuclear and Industrial Safety Agency said that water seeping out of the crippled No. 2 reactor into the adjacent turbine building contained levels of radioactive iodine 134 that were about 10 million times the level normally found in water used inside nuclear power plants. The higher levels further suggested there was a leak from the reactor’s fuel rods — either from damage to the piping or suppression chamber under the rods — or a breach in the pressure vessel that houses the rods, the agency said.
Tests also found increased levels of radioactive cesium, a substance with a longer half-life, it said.
“Because these substances originate from nuclear fission, there is a high possibility they originate from the reactor,” said Hidehiko Nishiyama, the agency’s deputy director-general, at a news conference. He said that it was likely that radiation was leaking from the pipes or the suppression chamber, and not directly from the pressure vessel, because water levels and pressure in the vessel were relatively stable.
He also said that radioactive iodine in seawater just outside the plant had risen to 1,850 times the usual level on Sunday, up from 1,250 on Saturday.
“Radiation levels are increasing and measures need to be taken,” he said, but added that he did not think there was need to worry about high levels of radiation immediately escaping the plant.
Yukio Edano, the chief cabinet secretary, said he did not think the pressure vessel, which cases the fuel rods, was broken at the No. 2 reactor. He said pressure levels inside the reactor remained higher than atmospheric pressure, suggesting that there was no breach.
“I don’t think the container is breached, but there is a possibility the water is coming from somewhere inside the reactor,” he said. “We want to find out as quickly as possible where the highly radioactive water is leaking from, and take measures to deal with it,” Mr. Edano said on a live interview on the public broadcaster, NHK, early Sunday.
On Saturday, the Japanese government said that it could not predict when the nuclear complex would be brought under control. Mr. Edano insisted that the situation at the damaged plant was not getting worse, but said that “this is not the stage for predictions” about when the crisis would be over.
Mr. Amano, a former Japanese diplomat who took over the United Nations nuclear agency in late 2009, said in a telephone interview from Vienna that his biggest concern now centered on spent fuel rods sitting in open cooling pools atop the reactor buildings.
He said he was still uncertain that the efforts to spray seawater into the pools — to keep the rods from bursting into flames and releasing large amounts of radioactive material — had been successful. If workers fill the pools with water but leave the cooling systems unrepaired, he said, “The temperature will go up,” raising the threat of new radioactive releases.
He said he was particularly concerned about the pool at Reactor No. 4, which contains the entire core of a reactor that was removed shortly before the disaster struck, and is particularly radioactive. “But the need exists for all of them” to be cooled, he said.
He also said he was concerned about radioactivity in the environment.
The Japanese authorities have played down the news of the elevated levels of iodine in the seawater. Mr. Nishiyama said Saturday that he expected the iodine to dilute rapidly, minimizing the effect on wildlife, and pointed out that fishing had been suspended in the area after the earthquake and tsunami.
“There is unlikely to be any immediate effect on nearby residents,” he said.
Mr. Amano said that he believed that the Japanese authorities were not withholding information, but that his recent trip back to Japan had been intended to secure from Prime Minister Naoto Kan a commitment to what he called “full transparency.”
In recent days, American and international officials have said that the statements from Japan asserting that the nuclear cores and fuel ponds were covered with water were essentially inferences, based on how much seawater had been poured in and analysis of the radioactive steam emerging from the plant. But they expressed little confidence that many details were known about what was taking place inside the buildings, with instruments still knocked out.
“There are areas where we don’t have information,” Mr. Amano said. “We don’t, and the Japanese don’t, too.”
Workers at the plant began pumping in fresh water to reactors No. 1, 2 and 3 on Saturday, after days of spraying them with corrosive saltwater. The United States military was aiding the effort, sending two barges carrying a total of 500,000 gallons of fresh water from the Yokosuka naval base.
The workers also restored lighting to the central control room of the No. 2 unit, Tokyo Electric Power said, an incremental step in efforts to restart the cooling system there that shut down after the disaster. That leaves only the No. 4 unit without lighting.
The National Police Agency said Saturday that the official death toll from the earthquake and tsunami had reached 10,418, with 17,072 listed as missing. The authorities have said that the final death toll will surpass 18,000. There are 244,339 people in refugee centers around Japan, the police said.
Damage to oil refineries across the country, as well as to ports and roads, has created a fuel shortage in the disaster zone, hampering relief efforts.
Joy Portella, an aid worker with Mercy Corps, a United States-based group, said that fuel shortages remained acute in the hardest-hit areas. The group distributed about 500 gallons of kerosene in the town of Kesennuma on Saturday, she said.
The amount of radiation in Tokyo’s water supply continued to diminish for a third day after a big scare on Wednesday. The city’s waterworks bureau said samples showed no radiation in the water at one plant, and lower levels at two plants.
Until now, Mr. Amano, the United Nations nuclear chief, has tended to be more reassuring in his public comments.
On Saturday, his tone seemed to darken. He stressed the emergency steps taken so far were only stopgaps, not solutions. “This is a very serious accident by all standards,” he said, “and it is not yet over.”
William J. Broad reported from New York, and David Jolly from Tokyo. Reporting was contributed by David E. Sanger from Palo Alto, Calif., Hiroko Tabuchi and Chika Ohshima from Tokyo, and Kevin Drew from Hong Kong.
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