FUKUSHIMA, Japan (AP) — Officials are racing to restore electricity to Japan's leaking nuclear plant, but getting the power flowing will hardly be the end of their battle: With its mangled machinery and partly melted reactor cores, bringing the complex under control is a monstrous job.
Restoring the power to all six units at the tsunami-damaged complex is key, because it will, in theory, drive the maze of motors, valves and switches that help deliver cooling water to the overheated reactor cores and spent fuel pools that are leaking radiation.
Ideally, officials believe it should only take a day to get the Fukushima Dai-ichi nuclear under control once the cooling systems are up and running. But it could take days or weeks to get those systems working.
"We have experienced a very huge disaster that has caused very large damage at a nuclear power generation plant on a scale that we had not expected," Hidehiko Nishiyama, deputy director general of Japan's Nuclear and Industrial Safety Agency, told reporters late Monday.
The nuclear plant's cooling systems were wrecked by the massive earthquake and tsunami that devastated northeastern Japan on March 11. Since then, conditions at the plant have been volatile; plumes of smoke rose from two reactor units Monday, prompting workers to evacuate units 1-4.
The crews resumed the work early Tuesday, plant spokesman Motoyasu Tamaki said.
In another setback, the plant's operator said Monday it had just discovered that some of the cooling system's key pumps at the complex's troubled Unit 2 are no longer functional — meaning replacements have to be brought in. Tokyo Electric Power Co. said it placed emergency orders for new pumps, but it was unclear how long it would take for them to arrive.
If officials can get the power turned on, get the replacement pumps working and get enough seawater into the reactors and spent fuel pools, it would only take a day to bring the temperatures back to a safe, cooling stage, said Ryohei Shiomi, an official with the Nuclear and Industrial Safety Agency.
And if not?
"There is nothing else we can do but keep doing what we've been doing," Shiomi said.
In other words, officials would continue dousing the plant in seawater — and hope for the best.
An official of the U.S. Nuclear Regulatory Commission said in Washington that Units 1, 2 and 3 have all seen damage to their reactor cores, but that containment is intact. The assessment dispels some concerns about Unit 2, where an explosion damaged a pressure-reducing chamber around the bottom of the reactor core.
"I would say optimistically that things appear to be on the verge of stabilizing," said Bill Borchardt, the commission's executive director for operations.
What caused the smoke to billow first from Unit 3 and then from Unit 2 on Monday was under investigation, nuclear safety agency officials said. In the days since the earthquake and tsunami, both units have overheated and seen explosions outside their reactor cores.
Workers were evacuated from the area to buildings nearby, though radiation levels remained steady, the officials said. It was a setback in efforts to rewire the plant, where officials had hoped to finish connecting all six reactor units to the grid on Tuesday.
Problems set off by the disasters have ranged far beyond the shattered northeast coast and the wrecked nuclear plant, handing the government what it has called Japan's worst crisis since World War II. Rebuilding may cost as much as $235 billion. Police estimate the death toll will surpass 18,000.
Traces of radiation are tainting vegetables and some water supplies, although in amounts the government and health experts say do not pose a risk to human health in the short term. That has caused the government to ban sale of raw milk, spinach and canola from prefectures over a swath from the plant toward Tokyo. The government has just started to test fish and shellfish.
Tokyo Electric said radioactive iodine about 127 times normal levels and radioactive cesium about 25 times above the norm were detected in seawater 100 yards (meters) off the Fukushima nuclear plant.
Despite that concentration, a senior official at the International Atomic Energy Agency said the ocean was capable of absorbing vast amounts of radiation with no effect and that — comparatively — the radioactivity released so far by the plant was minor.
"The quantities are tiny compared to the reservoir of natural radioactivity in the oceans," said Graham Andrew, senior adviser to IAEA chief Yukiya Amano.
The Health Ministry has advised Iitate, a village of 6,000 people about 19 miles (30 kilometers) northwest of the plant, not to drink tap water due to elevated levels of iodine. Ministry spokesman Takayuki Matsuda said iodine three times the normal level was detected there — about one twenty-sixth of the level of a chest X-ray in one liter of water.
"Please do not overreact, and act calmly," Chief Cabinet spokesman Yukio Edano said in the government's latest appeal to ease public concerns. "Even if you eat contaminated vegetables several times, it will not harm your health at all."
Edano said Tokyo Electric would compensate farmers affected by the bans on milk, spinach and canola.
The World Health Organization said Japan will have to do more to reassure the public about food safety.
"Walking outside for a day and eating food repeatedly are two different things. This is why they're going to have to take some decisions quickly in Japan to shut down and stop food being used completely from zones which they feel might be affected," WHO spokesman Gregory Hartl said.
The troubles at Fukushima have in some ways overshadowed the natural catastrophe.
The World Bank said Monday that Japan may need five years to rebuild from the disasters, which caused up to $235 billion in damage, saying the cost to private insurers will be up to $33 billion and that the government will spend $12 billion on reconstruction in the current national budget and much more later.
All told, police estimate around 18,400 people died from the 9.0-magnitude quake and tsunami. More than 15,000 deaths are likely in Miyagi, the prefecture that took the full impact of the wave, said a police spokesman.
Police in other affected prefectures declined to provide estimates, but confirmed about 3,400 deaths. Nationwide, official figures show the disasters killed more than 8,900 people and left more than 12,600 missing, but those two lists may have some overlap.
The disasters have displaced another 452,000, who are in shelters.
Yamaguchi reported from Tokyo. Associated Press writers Jeff Donn, Shino Yuasa, Mayami Saito and Elaine Kurtenbach in Tokyo, and Matthew Daly in Rockville, Md., contributed to this story.
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