Firefighters also began pumping tons of water directly from the ocean into one of the most troubled areas of the Fukushima Dai-ichi nuclear complex, the cooling pool for used fuel rods at the plant’s Unit 3, which is at risk of burning up and sending a broad release of radioactive material into the environment.
Just outside the bustling disaster response center in the city of Fukushima, 40 miles (60 kilometers) northwest of the plant, government nuclear specialist Kazuya Konno took a three-minute break from nearly nonstop work and met with his wife Junko and their children for the first time since a March 11 earthquake and massive tsunami spawned the nuclear crisis.
“It’s very nerve-wracking. We really don’t know what is going to become of our city,” said Junko Konno, 35. “Like most other people we have been staying indoors unless we have to go out.” She brought her husband a small backpack with a change of clothes and snacks. The girls — aged 4 and 6 and wearing pink surgical masks decorated with Mickey Mouse — gave their father hugs.
At the plant, a fire truck with a high-pressure cannon parked outside Unit 3, about 300 meters from the Pacific coast, and began shooting an arc of water nonstop into the pool for seven straight hours, said Kenji Kawasaki, a spokesman for the nuclear safety agency.
A separate pumping vehicle will keep the firetruck’s water tank refilled. Because of high radiation levels, firefighters will only go to the truck every three hours when it needs to be refueled. They expect to pump about 1,400 tons of water, nearly the capacity of the pool.
Meanwhile, Hidehiko Nishiyama of Japan’s Nuclear and Industrial Safety Agency said backup power systems at the Fukushima Dai-ichi plant had been improperly protected, leaving them vulnerable to the tsunami that savaged the northeastern coast after the quake and killed more than 7,200 people.
The failure of Fukushima’s backup power systems, which were supposed to keep cooling systems going in the aftermath of the massive 9.0-magnitude earthquake, let uranium fuel overheat and were a “main cause” of the crisis, Nishiyama said.
“I cannot say whether it was a human error, but we should examine the case closely,” he told reporters.
A spokesman for Tokyo Electric Power Co., which owns and runs the plants, said that while the generators themselves were not directly exposed to the waves, some of the electrical support equipment was outside. The complex was designed to protect against tsunamis of up to 5 meters (16 feet), he said. Media reports say the tsunami was at least 6 meters (20 feet) high when it struck Fukushima.
Motoyasu Tamaki also acknowledged that the complex was old, and might not have been as well-equipped as newer facilities.
Plant operators also said they would reconnect four of the plant’s six reactor units to a power grid Saturday.
Although a replacement power line reached the complex Friday, workers had to methodically work through badly damaged and deeply complex electrical systems to make the final linkups without setting off a spark and potentially an explosion.
“Most of the motors and switchboards were submerged by the tsunami and they cannot be used,” Nishiyama said.
Even once the power is reconnected, it is not clear if the cooling systems will still work.
The storage pools need a constant source of cooling water.
Even when removed from reactors, uranium rods are still extremely hot and must be cooled for months, possibly longer, to prevent them from heating up again and emitting radioactivity.
As Japan crossed the one-week mark since the cascade of disasters began, the government conceded Friday it was slow to respond and welcomed ever-growing help from the United States in hopes of preventing a complete meltdown at the nuclear plant.
“In hindsight, we could have moved a little quicker in assessing the situation and coordinating all that information and provided it faster,” Chief Cabinet Secretary Yukio Edano said Friday.
The earthquake and the tsunami also left thousands of people missing.
Rescuers pulled a man alive from a wrecked house Saturday, but reports later said he had returned the building after the disaster and only had been trapped for one day.
Emergency crews at the nuclear plant faced two continuing challenges: cooling the nuclear fuel in reactors where energy is generated and cooling the adjacent pools where thousands of used nuclear fuel rods are stored in water.
Japan’s government on Friday raised the accident classification for the nuclear crisis from Level 4 to Level 5 on a seven-level international scale. That put it on a par with the Three Mile Island accident in Pennsylvania in 1979, and signified its consequences went beyond the local area.
Edano also said Tokyo was asking Washington for additional help, a change from a few days ago, when Japanese officials disagreed with American assessments of the severity of the problem.
The United States has conducted overflights of the reactor site, strapping sophisticated pods onto aircraft to measure radiation aloft. Two tests conducted Thursday gave readings that US Deputy Energy Secretary Daniel B. Poneman said reinforced the US recommendation that people stay 50 miles (80 kilometers) away from the Fukushima plant. Japan has ordered only a 12-mile (20-kilometer) evacuation zone around the plant.
The tsunami knocked out power to cooling systems at the nuclear plant and its six reactors. In the week since, four have been hit by fires, explosions or partial meltdowns.
The events have led to power shortages and factory closures, hurt 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 US car dealers may not get the cars they order this spring.
Low levels of radiation have been detected well beyond Tokyo, which is 140 miles (220 kilometers) south of the plant, but hazardous levels have been limited to the plant itself.
The Science Ministry said radiation levels about 30 kilometers (19 miles) northwest of the Fukushima Dai-ichi plant briefly spiked Friday to 0.15 millisieverts per hour, about the amount absorbed in a chest X-ray. While levels fluctuate, radiation at most points at that distance from the facility have been far below that. The ministry did not have an explanation for the rise.
Police said more than 452,000 people made homeless by the quake and tsunami were staying in schools and other shelters, as supplies of fuel, medicine and other necessities ran short.
