Workers were close to restoring power to a nuclear plant's overheating reactors on Sunday as the toll of dead or missing from Japan's worst natural disaster in nearly a century neared 21,000.
Amid the devastation on the northeast coast left by a March 11 quake and tsunami, police reported an astonishing tale of survival with the discovery of an 80-year-old woman and her 16-year-old grandson alive under the rubble.
"Their temperatures were quite low but they were conscious. Details of their condition are not immediately known. They have been already rescued and sent to hospital," a spokesman for the Ishinomaki Police Department said.
They were in the kitchen when their house collapsed but the teenager was able to reach food from the refrigerator, helping them survive for nine days, broadcaster NHK quoted rescuers as saying.
But with half a million tsunami survivors huddled in threadbare, chilly shelters and the threat of disaster at the Fukushima No. 1 nuclear plant stretching frayed nerves, the mood in the world's third-biggest economy remained grim.
Food contaminated with radiation was found for the first time outside Japan -- where milk and spinach have already been tainted by a plume from Fukushima -- as Taiwan detected radioactivity in a batch of imported Japanese fava beans.
The discovery of traces of radioactive iodine in Tokyo tap water, well to the southwest of the crippled atomic power plant on the Pacific coast, compounded public anxiety but authorities said there was no danger to health.
The Fukushima plant was struck on March 11 by a massive earthquake and tsunami which, with 8,199 people confirmed killed, is Japan's deadliest natural disaster since the Great Kanto quake levelled much of Tokyo in 1923.
Another 12,722 are missing, feared swept out to sea by the 10-metre (33-foot) tsunami or buried in the wreckage of buildings.
In Miyagi prefecture on the northeast coast, where the tsunami reduced entire towns to splintered matchwood, the official death toll stood at 4,882.
Miyagi police chief Naoto Takeuchi, however, told a task force meeting that his prefecture alone "will need to secure facilities to keep the bodies of more than 15,000 people", Jiji Press reported.
Cooling systems that are meant to protect the Fukushima plant's six reactors from a potentially disastrous meltdown were knocked out by the tsunami, and engineers have since been battling to control rising temperatures.
The radiation-suited crews were striving to restore electricity to the ageing facility 250 kilometres (155 miles) northeast of Tokyo, after extending a high-voltage cable into the site from the national grid.
A spokesman for Japan's nuclear safety agency said electricity had apparently reached the power distributor at the No. 2 reactor, which in turn would feed power to the No. 1 reactor.
Plant operator TEPCO confirmed an electricity supply had been restored to the distributor but said power at the reactor unit was not back on yet.
Engineers were checking the cooling and other systems at the reactor, aiming to restore power soon, TEPCO said late on Sunday.
"It will take more time. It's not clear when we can try to restore the systems," spokesman Naohiro Omura said.
Fire engines earlier aimed their water jets at the reactors and fuel rod pools, where overheating is an equal concern, dumping thousands of tonnes of seawater from the Pacific.
Six workers at the Fukushima plant have been exposed to high levels of radiation but are continuing to work and have suffered no health problems, TEPCO said.
According to the charity Save the Children, around 100,000 children were displaced by the 9.0-magnitude quake and tsunami, and signs of trauma are evident among young survivors as the nuclear crisis and countless aftershocks fuel their terror.
"We found children in desperate conditions, huddling around kerosene lamps and wrapped in blankets," Save the Children spokesman Ian Woolverton said after visiting a number of evacuation centres in Japan's northeast.
"They told me about their anxieties, especially their fears about radiation," Woolverton said, adding that several youngsters had mentioned the US atom bomb attacks on Hiroshima and Nagasaki, which they know from school.
The government has insisted that there is no widespread threat of radiation. But the discovery of the tainted fava beans by Taiwanese customs officers will do nothing to calm public anxiety that has already spread far beyond Japan.
Several governments in Asia have begun systematic radiation checks on made-in-Japan goods, as well as of passengers arriving on flights from the country.
But Tsai Shu-chen of Taiwan's Food and Drug Administration stressed that the radioactive iodine and caesium-137 found on the fava beans were well below national safety levels.
In the disaster epicentre of northeast Japan, authorities have been battling to get more fuel and food to survivors enduring freezing temperatures.
At shelters, some grandparents are telling children stories of how they overcame hardships in their own childhood during and after World War II, which left Japan in ruins.
"We have to live at whatever cost," said Shigenori Kikuta, 72.
"We have to tell our young people to remember this and pass on our story to future generations, for when they become parents themselves."
There was better news for residents in Rikuzentakata, where construction teams began erecting 36 prefabricated units, the first of many more temporary houses being built for the tsunami homeless.
"They won't be very big, but whatever they are, it will be better than being in here," said great-grandmother Tokiko Kanno, who has been sleeping on a school stage.