April 3, 2011: Japanese engineers grappling on Sunday to control the world's worst nuclear crisis sinceChernobyl tried to seal a crack leaking radiation into the Pacific sea from a crippled reactor.
The drama at the six-reactor Fukushima Daiichi complex has dragged into a fourth week, unsettling the global nuclear industry and compounding Japan's suffering after an earthquake and tsunami that left about 27,500 people dead or missing.
Radiation has leaked into the sea, food, drinking water and air. It is hindering efforts to cool overheating fuel rods work at the plant and regain control of the damaged reactors.
Experts say that beyond the disaster zone, there is minimal risk to human health further afield in Japan or abroad.
But the nation is staring at months of work to control the plant, followed by years of cleaning up and containment in the worst atomic crisis since Chernobyl in 1986.
"The Japanese people's main concern is when the leakage of radioactive substances will stop," said Goshi Hosono, a ruling party lawmaker and aide to embattled Prime Minister Naoto Kan.
At the weekend, plant operator Tokyo Electric Power Co (TEPCO) found a crack in a concrete pit at the No.2 reactor, generating readings of 1,000 millisieverts of radiation per hour in the air inside.
The leaks did not stop after concrete was poured into the pit, so TEPCO was turning to water-absorbent polymers to prevent more contaminated water escaping.
The crack may be one source of leaks that have sent radiation levels in the sea soaring to 4,000 times the legal limit.
To cool damaged reactor No. 2, engineers were looking at alternatives to pumping in water, including an improvised air conditioning system, spraying the reactor fuel rods with vaporized water or using the plant's cleaning system.
"We must not let our guard down as the situation at the nuclear plant is unpredictable," said Japan's chief cabinet secretary Yukio Edano, who has been the government's main public face since the March 11 disaster.
Under enormous pressure over its handling of the crisis and prior safety preparations, TEPCO confirmed on Sunday two of its employees missing since the March 11 disaster had been found dead in a basement, presumed killed by the tsunami.
Journalists peppered officials with questions over why the 21- and 24-year-old men's bodies had not been found earlier and how they came to die, while others survived, as they were checking installations after the quake.
Asia's biggest utility, TEPCO shares have fallen 80 percent during the crisis and its chief executive has been in hospital.
Several hundred Japanese protested against nuclear power at the company's headquarters in Tokyo on Sunday.
The damage from the 9.0 magnitude earthquake and ensuing tsunami that hit the northeast coast may top $300 billion -- the world's costliest natural disaster.
Prime minister Kan toured the devastated north on Saturday, offering refugees government support for rebuilding homes and livelihoods in towns where vehicles still sit on rooftops and former residential areas are now wastelands of mud and debris.
Farmers in the countryside surrounding the reactor are fretting that consumers in Japan will reject their crops, given their origin in Fukushima province.
"There is no way we will be able to sell anything," said 73-year-old farmer Akio Abiko. "People in Tokyo are just too sensitive about this kind of thing."
Some unhappy farmers came to Tokyo from Fukushima at the weekend, using Geiger counters to show their produce was safe.
Though more than three weeks have passed, about 164,000 people remain in evacuation centers. Harrowing stories are still emerging of just what happened when the tsunami hit.
Civil servant Takako Suzuki, 40, narrowly escaped when water rose to within a few inches from the ceiling of an evacuation center she had rushed too. "I was thinking 'if the water rises a little bit, I'm finished' - but fortunately the water suddenly stopped rising and began receding," she recounted to Reuters.
Suzuki spent a night huddled with 11 other survivors in the deep water, bodies floating around them.
Thousands of Japanese and U.S. soldiers have been conducting searches for bodies using dozens of ships and helicopters to sweep across land still under water along the northeast coast.
The teams hope when a large spring tide recedes it will be easier to spot bodies in a nation where proper treatment of the dead is paramount in Buddhist culture.
The consequences for the world's third largest economy are big. There is sure to be a short-term hit on gross domestic product, though the reconstruction push is expected to act as a stimulus and compensate that later in the year.
Japan's manufacturing slumped to a two-year low in March. Disruptions to its globally-renowned automobile and technology sectors have affected supply chains the world over.
(Additional reporting by Chizu Nomiyama and Ruairidh Villar in Tokyo, David Dolan in Fukushima and Damir Sagolj in Rikuzentakata; Writing by Paul Eckert and Andrew Cawthorne, editing by Jonathan Thatcher)