Japan’s nuclear safety agency and officials from Tokyo Electric Power Company have denied a claim by a top U.S. nuclear official that all the water has evaporated from one of the spent fuel pools at Japan's crippled Fukushima nuclear plant.
Gregory Jaczko, who heads the U.S. Nuclear Regulatory Commission, made the statement today at a hearing in Congress without saying where he had learned it from. But 11 experts from the NRC and U.S. Department of Energy are on site at the plant.
If correct, it would mean there is nothing to stop the fuel rods from getting hotter and ultimately melting down. The outer shell of the rods could also ignite with enough force to propel the radioactive fuel inside over a wide area.
Jaczko said the spent fuel pool in reactor No. 4 may be dry or nearly dry, that there might be a crack in the pool in reactor No.3, and that the water level in reactor No. 2 “is decreasing."
He added, "We believe that radiation levels are extremely high, which could possibly impact the ability to take corrective measures.”
But a spokesman for the Tokyo utility, Hajime Motojuku, said the "condition is stable" in pool No. 4.
The new fears came after a day in which Japanese officials again worked desperately to cool down the earthquake- and tsunami-stricken nuclear power plant, attempting at one stage to drop sea water on the facility without success.
Military helicopters carried giant buckets of sea water to drop on the number three reactor of the Fukushima Daiichi plant. It is the only reactor there that is powered with plutonium, which is far more hazardous to health than the uranium powering the other five reactors.
Earlier, plant workers were briefly ordered out of the facility when radiation surged to high levels. The evacuation order was lifted an hour later when the level of radiation escaping from the reactor fell, allowing a skeleton crew of workers to return and try to prevent a meltdown.
The evacuation order came as Japan's chief cabinet secretary, Yukio Edano, warned that the inner containment shell of reactor number three may be damaged.
"This radiation level at the entrance gate, or main gate, since 10 o'clock this morning has suddenly dramatically increased and now has reached 1,000 millisieverts, and that is the report I have heard so far," he said, adding, "Following this, we have now requested the workers to evacuate temporarily to safe areas."
The inner shell is one of three containment structures designed to prevent leakage of radioactive materials from the reactor. Edano said he had no definitive information about the inner shell. But he said radioactive steam may have leaked through cracks in the structure today.
The developments have further raised fears that the nuclear crisis at the complex -- about 240 kilometers north of Tokyo -- is spiraling out of control.
The United States took the unusual step today of advising its own citizens to move 80 kilometers away from the plant.
The advice from the U.S. Embassy in Tokyo is much more aggressive than that of Japanese authorities, who have called for an evacuation of residents within 20 kilometers of the plant and told residents within 30 kilometers to stay indoors.
White House spokesman Jay Carney said Japanese "standards are different" from U.S. standards and said the decision was based on American analysis of the data and what action would be taken if the meltdown threat was occurring in the United States.
Meanwhile, days after the March 11 twin disasters, millions of people were struggling along Japan's coast with little food, water, or heat. Freezing temperatures and heavy snow added to the misery of nearly half a million homeless who are staying in temporary shelters, often sleeping on the floor of school gymnasiums.
More than 11,000 people are officially listed as dead or missing as a result of the deadly quake and tsunami. Most Japanese officials think the final death toll will be well over 10,000 people.
In a rare address to the nation, Japan's Emperor Akihito expressed condolences for victims of the quake and tsunami, and he urged the country not to give up hope. He called all on Japanese citizens to share the difficulties they will face in the days ahead, saying that he is praying people will all take care of each other and overcome the tragedy.
Akihito also expressed his worries about the nuclear crisis, saying: "With the help of those involved, I hope things will not get worse."
Nuclear specialists say the solutions being proposed to quell the radiation leaks at Fukushima were last-ditch efforts to prevent what could become one of the world's worst-ever industrial disasters.
In the first hint of international frustration about information being released by the Japanese government, the International Atomic Energy Agency's (IAEA) director-general, Yukiya Amano, said he wants Tokyo to provide more timely and detailed reports about what is happening.
Amano announced that he will travel to Tokyo on March 17 to meet with officials and find ways for the IAEA to assist.
Japanese media also have become more critical of the government's handling of the crisis, criticizing the cabinet and the plant operator for failing to provide enough information about what is happening.
Nuclear specialists also say Japanese authorities appear to be underplaying the severity of the crisis -- particularly on a scale called INES that is used to rank nuclear crises. So far, Japan has rated the accident a four on the one-to-seven scale. But that rating was issued on March 12; since then, the situation has worsened dramatically.
France's nuclear safety authority, the ASN, said before the March 16 release of radioactive material that the accident should be classed as level six out of seven.
Meanwhile, the head of Russia's state nuclear corporation said today that Japan's nuclear crisis is developing along the lines of a worst-case scenario. Sergei Kiriyenko told Reuters the crisis was likely to have a negative impact on Russia's overseas nuclear power construction business.
Russian President Dmitry Medvedev said in Turkey today after talks with Prime Minister Recep Tayyip Erdogan that their countries would continue to work on plans for Russia to build Turkey's first nuclear power plant despite the Japanese nuclear accident.
Medvedev said the project in Turkey is different from the stations in Japan in terms of age and the level of protection.
"It can be safe, and it is safe," he said. "But what is necessary is the right choice of the location for the nuclear-power plant, of the project that is going to be implemented, and of its operator. With these conditions met, nuclear power is safe and more and more beneficial for mankind."
Foreign governments today have been advising citizens not to travel to Japan and telling their nationals still in the country to either leave Japan or travel further south.
compiled from agency reports