TOKYO — Japanese Prime Minister Naoto Kan said Friday he would convene a national council on rebuilding within 10 days as U.S. and Japanese forces launched a massive effort to locate the bodies of more than 16,000 people still listed as missing three weeks after the giant March 11 tsunami and earthquake.
Kan said resolving the crisis at the stricken Fukushima Daiichi nuclear plant would take a while, but he pledged to do "whatever it takes to win the battle" there and brushed off talk that Tokyo Electric Power Co., which runs the facility, would be nationalized. Tepco, he said, must do what it can to clean up radioactive leaks at the plant and compensate those affected by the accident.
Meanwhile, the International Atomic Energy Agency once again questioned very high radioactivity readings at the plant, and U.S. Energy Secretary Steven Chu said that at least one of the reactor fuel cores may have suffered a 70 percent meltdown.
Tepco, had said early Friday that radiation levels in water accumulating in reactor No. 1 had reached 10,000 times permissible levels and were particularly high in radioactive iodine.
But a spokesman for the IAEA said Friday that the agency "suspected" Tepco's readings and was looking forward to new results.
Engineers have observed bursts of heat and radiation and even flashes of light at the core, which suggests what is known as a "localized criticality," in which the nuclear chain reaction that normally powers the plant proceeds more rapidly. Such events might occur if fuel melted and accumulated in pools that were not covered by water and thus not cooled.
In a speech Friday morning in Washington, Chu said as much as 70 percent of the fuel in the reactor may be damaged, but did not provide details.
Prime minister Kan was scheduled to visit the devastated city of Rikuzentakata on Saturday as well as the site serving as the emergency staging headquarters for the Fukushima crisis.
Asked at a news conference how long people who have been evacuated from their homes because of the nuclear crisis can expect to remain displaced, Chief Cabinet Secretary Yukio Edano said, "It's not a situation where we can say we can lift the instructions for evacuation in a matter of weeks."
Edano wore a business suit to the news conference, instead of the blue workman's jacket that he and many other government officials have worn since the early days of the disaster. Asked about this, he indicated this was an effort to "take one step forward" toward reconstruction.
Tepco released data showing how much force the Fukushima facility was subjected to in the magnitude-9 earthquake. Reactors 2, 3 and 5 sustained forces in excess of what they were designed to withstand, the utility said. Spraying of water continued at reactors 1, 3 and 4 to keep the temperature down.
Tepco also said Friday that it may begin injecting nitrogen gas into the reactors in an effort to prevent hydrogen explosions. Three of the reactors suffered such explosions in the first four days following the earthquake and tsunami that shut down the plant and disabled the backup cooling systems.
Hydrogen accumulates when the zirconium cladding on the fuel rods heats up, then comes into contact with water. The water oxidizes the zirconium, releasing explosive hydrogen. The nitrogen would dilute the hydrogen and the oxygen necessary to support an explosion.
Meanwhile, the government said that beef from a cow in Fukushima prefecture that had originally been found to contain elevated levels of cesium was cleared in a second test.
Some 18,000 Japanese troops and 7,000 Americans were being mobilized, along with Japanese police, firefighters and coast guard in the search by air and sea for corpses along hundreds of miles off Japan's northeast coast that was devastated by the tsunami.
Tomoko Osawa, a clinical psychologist with the Hyogo Institute for Traumatic Stress, said locating the bodies and bringing them home for funeral services was important to helping the hundreds of thousands of people affected by the disaster to move forward with rebuilding their lives.
Still, she said the condition of any bodies that are found was certain to be difficult for survivors to deal with.
Some 11,700 people have been confirmed dead in the disaster.
In a bit of good news, Tepco said that it would not need to implement rolling blackouts planned for Saturday, Sunday and Monday because of the weather forecast and the trend of power demand.
Friday marked the start of Japan's fiscal year, and many companies and government agencies held the customary welcoming ceremonies for new employees.
(Makinen reported from Tokyo and Maugh from Los Angeles.)