Emergency workers in Japan scrambled to connect a new power line to the damaged Fukushima Dai-ichi nuclear complex Saturday even as officials said the facility's tsunami-shattered equipment may be unable restart critical cooling systems.
Plant operator Tokyo Electric Power Co. hoped to have power reconnected to four of the six reactor units, starting with reactor No. 2, on Saturday and another on Sunday.
It's an especially complex operation because workers must methodically sort through Fukushima's badly damaged and deeply complex electrical systems and make the final link without setting off a spark and potentially an explosion. Once they get power into the plant, workers will be able to see if pumps and other vital machinery are still functioning after the plant was hit by the massive March 11 earthquake and tsunami.
"Most of the motors and switchboards were submerged by the tsunami and they cannot be used," said Hidehiko Nishiyama of Japan's Nuclear and Industrial Safety Agency.
In a sign of progress Saturday, TEPCO officials said temperatures had begun to fall at one of the pools holding spent fuel rods at the complex after crews were able to restart a diesel generator to pump in cooling water, NPR's Russell Harris reported.
Official Says Backup Power Systems Were Vulnerable
The failure of Fukushima's backup power systems — which were supposed to keep cooling systems going in the aftermath of the magnitude 9.0 quake and resultant tsunami — let uranium fuel overheat and were a "main cause" of the crisis, Nishiyama said.
He said the backup power systems had been improperly protected, leaving them vulnerable to the twin natural disasters that set off the nuclear emergency.
"I cannot say whether it was a human error, but we should examine the case closely," Nishiyamatold reporters.
TEPCO spokesman Motoyasu Tamaki said that while the generators themselves were not directly exposed to the waves, some of the electrical support equipment was outside. He said the complex was designed to protect against tsunamis of up to 16 feet. Media reports say the tsunami was at least 20 feet high when it struck Fukushima.
Tamaki also acknowledged that the complex was old, and might not have been as well-equipped as newer facilities.
Meanwhile, emergency workers at Fukushima Dai-ichi were preparing to use water cannons for a third day to hose down overheating spent fuel rods.
NPR's Chris Joyce said powerful water cannons have succeeded in getting at least some water into a spent fuel pool into reactor No. 3, where a hydrogen explosion Monday blew the roof off the building.
Workers have set up a big tanker truck they're calling "super pumper" next to one of the damaged reactors. The truck is connected to a hose that extends a quarter mile to draw sea-water in.
The water is needed to keep the fuel from breaking down and releasing radioactive material into the air. It also serves as a radiation shield.
"They can't see the pools, so they can't be sure the water's actually getting there. But spraying does produce a big cloud of steam, so Japanese officials say they're confident that the water is hitting something hot," NPR's Richard Harris reported.
Four of the troubled plant's six reactor units have had fires, explosions or partial meltdowns. The unfolding crises have led to power shortages in Japan, forced factories to close, sent shockwaves through global manufacturing and triggered a plunge in Japanese stock prices.
Most of Japan's auto industry is shut down. Factories from Louisiana to Thailand are low on Japanese-made parts. Idled plants are costing companies hundreds of millions of dollars. And U.S. car dealers may not get the cars they order this spring.
But Prime Minister Naoto Kan vowed that the disasters would not defeat Japan.
"We will rebuild Japan from scratch," he said in a nationally televised address, comparing the work with the country's emergence as a global power from the wreckage of World War II.
Government Admits Slow Response To Nuclear Crisis
The earthquake and tsunami have killed more than 7,200 people and obliterated entire villages along the northeast coast. Thousands more people were missing.
Japan acknowledged Friday that the enormity of the natural disasters overwhelmed the government and slowed its response to the nuclear crisis.
Chief Cabinet Secretary Yukio Edano said the "unprecedented scale" was beyond the scope of Japan's disaster contingency plans. "In hindsight, we could have moved a little quicker in assessing the situation and coordinating all that information and provided it faster," he said.
The Japanese government has been slow in releasing information on the crisis, even as the troubles have multiplied. In a country where the nuclear industry has a long history of hiding its safety problems, this has left many people in Japan and among governments overseas confused and anxious.
Edano's admission came as Japan's nuclear safety agency raised the severity rating of the disaster at the Fukushima Dai-ichi plant from Level 4 to Level 5 on the seven-level International Nuclear Event Scale, said agency spokesman Ryohei Shiomi. That puts it on a par with the Three Mile Island accident in Pennsylvania in 1979.
The scale defines a Level 4 incident as having local consequences and a Level 5 incident as having wider consequences. The 1986 Chernobyl accident, which killed at least 31 people with radiation sickness, raised long-term cancer rates, and spewed radiation for hundreds of miles, was ranked a Level 7.
While it's up to Japan to set the rating, other nations have suggested the Fukushima accident should be ranked a Level 6, which denotes a serious accident.
"We see it as an extremely serious accident," Yukiya Amano, the head of the U.N.'s International Atomic Energy Agency, told reporters Friday just after arriving in Tokyo. "This is not something that just Japan should deal with, and people of the entire world should cooperate with Japan and the people in the disaster areas."
"I think they are racing against the clock," he said of the efforts to cool the Fukushima complex.
Edano, the Cabinet secretary, said Friday that Tokyo has asked Washington for help and that the two allies were discussing the specifics.
"We are coordinating with the U.S. government as to what the U.S. can provide and what people really need," he said.
Experts from the U.S. Department of Energy and the Nuclear Regulatory Commission are currently in Japan. The U.S. also is sending specialized aircraft to help determine the scope of the nuclear contamination. The converted Boeing C-135 plane, called Constant Phoenix or "the Sniffer," will fly over Japan's nuclear plants and take samples from the atmosphere. Another Air Force plane, a drone called Global Hawk, is already circling above the plants. Its infrared sensors can detect heat and help determine the effectiveness of attempts to cool the reactors.
Low levels of radiation have been detected well beyond Tokyo, which is 140 miles south of the plant, but hazardous levels have been limited to the plant itself. Still, the crisis has forced thousands to evacuate their homes and drained Tokyo's normally vibrant streets of life, its residents either leaving town or holing up indoors.
The U.S. military, which has 50,000 troops based in Japan, was working to ramp up its relief effort. But snow has limited helicopter flights and American aircraft are under orders to skirt the area around the nuclear plant to reduce the risk of radiation exposure.
In a statement Friday, the U.S. 7th Fleet said 12,750 of its personnel were involved in the relief effort, dubbed Operation Tomodachi, along with 20 ships led by the aircraft carrier USS Ronald Reagan and 140 aircraft.
With reporting from NPR's Russell Lewis, Christopher Joyce and Richard Harris in Tokyo and Tom Bowman in Washington, D.C. Material from The Associated Press was used in this story. Copyright 2011 National Public Radio. To see more, visit http://www.npr.org/.