IAEA Chief Yukiya Amano is flying to Tokyo to talk with authorities today and will return for the meeting as soon as possible, he told reporters in Vienna yesterday. It will be the first extraordinary meeting of the agency’s 35-member board since his election to succeed Mohamed ElBaradei two years ago.
The containment vessel of Dai-Ichi’s No. 2 reactor may have been breached yesterday, and pressure in the chamber fell “substantially,” said Masahisa Otsuku, a Tokyo Electric Power Co. nuclear maintenance official.
The company suspected damage following an explosion in the reactor building March 15. About 70 percent of the fuel rods at the plant’s No. 1 reactor and a third of the No. 2 reactor’s fuel may have been damaged, and temperatures at spent-fuel-rod- cooling pools were rising, Tepco said.
Clouds of steam rose from the reactor buildings following a fire at Dai-Ichi’s No. 4 reactor yesterday morning. Radiation levels at the No. 4 reactor hampered efforts to confirm whether the fire had been extinguished, a day after a similar blaze at the same structure.
“If you get enough cold water inside you may stop the generation of steam and then life will get easier,” said Robert Kelley, a nuclear engineer based in Vienna. “As long as there is steam coming out it will carry radioactive particles and gases with it.”
Spent Fuel Rods
Temperatures in the spent-fuel-rod cooling pools of the shuttered No. 5 and No. 6 reactors were rising to as high as 63 degrees Celsius (145 degrees Fahrenheit) at 2 p.m. yesterday from 60 degrees Celsius at 7 a.m., said Tsuyoshi Makigami, head of nuclear maintenance at Tepco. Water levels at spent fuel pools at the three inactive reactors, Nos. 4, 5 and 6, dropped by about two meters, exposing the fuel rods, Amano said.
Exposed to air, the fuel bundles could chemically react with moisture, catch fire and spread radiation into the atmosphere, said Edwin Lyman, a physicist with the Union of Concerned Scientists, based in Cambridge, Massachusetts.
“Spent fuel is pretty hot and so it is stored under water to keep it cool,” said Kelley, who worked for 30 years at the U.S. Energy Department. “If the water leaks or boils away, then the fuel is exposed,” then after burning, the uranium corrodes and releases cesium, contaminating the area, he said.
A core group of 50 workers remain at the plant to manage the reactors, Tepco said. Those engineers were temporarily evacuated yesterday when dangerous radiation levels were detected, but have now returned, chief government spokesman Yukio Edano said.
Tepco is building a power cable to supply electricity to the plant’s cooling systems, spokesman Daisuke Hirose said. The systems were knocked out by the March 11 earthquake and tsunami. The Yomiuri newspaper reported yesterday that if the plan succeeds, the company may be able to stabilize its reactors. Hirose said there is no timetable for completion.
The latest incidents follow a blast at the No. 3 reactor March 14 after a buildup of hydrogen gas, and a similar explosion at the No. 1 reactor on March 12.
About 140,000 people within a radius of 20 to 30 kilometers from the plant were ordered to stay indoors. The magnitude-9 temblor and tsunami have led to what Prime Minister Naoto Kan has called Japan’s worst crisis since World War II. More than 450 aftershocks have followed. The death toll reached 3,771 with 7,843 missing as of 2 p.m. yesterday, the National Police Agency said. The number of dead and missing exceeds the more than 6,400 who died in the 1995 Kobe earthquake.
In a national address yesterday, Emperor Akihito expressed his condolences to victims of the earthquake and tsunami, and told the people of Japan not to give up.