Officials raced Monday 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, power up 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 plant under control once the cooling system is up and running. In reality, the effort to end the crisis is likely to take weeks.
Late Monday, the deputy director general of Japan's nuclear safety body suggested to reporters why there is so much uncertainty about when the job will be finished.
"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," said Hidehiko Nishiyama of the Nuclear and Industrial Safety Agency.
The nuclear plant's cooling system was wrecked by the massive earthquake and tsunami that devastated northeastern Japan on March 11. Since then, conditions at the plant have been volatile; a plume of smoke rose from two reactor units Monday, prompting emergency workers to evacuate.
In another setback, Tokyo Electric Power, 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.
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.
An official of the U.S. Nuclear Regulatory Commission said in Washington that Units 1, 2 and 3 at the Fukushima plant have damage to their reactor cores, but 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.
Monday's evacuation of workers from the plant came after smoke began rising from the spent fuel storage pool of the problem-plagued Unit 3, Tokyo Electric spokesman Hiroshi Aizawa said. Unit 3 also alarmed plant officials over the weekend with a sudden surge of pressure in its reactor core.
What caused the smoke to billow first from Unit 3 and then from Unit 2 is under investigation, nuclear safety agency officials said. Still, in the days since the earthquake and tsunami, both reactors have overheated and seen explosions.
Traces of radiation from the plant are tainting vegetables and some water supplies, although government and health experts say the radiation amounts do not pose a risk to human health in the short term. But the government has banned the sale of raw milk, spinach and canola from prefectures stretching from the plant toward Tokyo. The government has just started to test fish and shellfish.
The Health Ministry has advised residents of Iitate, a village of 6,000 people about 19 miles 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 1 liter of water.
All told, police estimate around 18,400 people died from the 9.0-magnitude earthquake 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.
Nationwide, official figures show the disasters killed more than 8,800 people and left more than 12,600 missing, but those two lists may have some overlap.
In other developments:
*The World Bank said Japan may need five years to rebuild from the earthquake and tsunami, which have caused up to $235 billion in damage.
*Nissan plans to resume auto and parts production at more Japanese factories this week, but it may be several months before inventories and other elements of the country's auto industry return to normal.