Japan PM sombre as further radiation leak possible

High radiation in water found at Unit 3 of the troubled Fukushima Daiichi nuclear plant may have originated at the reactor core, Japan's Nuclear and Industrial Safety Agency says.

So far, however, there is no evidence the containment vessel has been cracked or damaged, said agency spokesman Hidehiko Nishiyama, who appeared to be backing down slightly from a previous remark that there was a good chance the reactor had been damaged.

The statements came the day after three workers at the unit were hurt when they stepped into water found to be 10,000 times more radioactive than normal. Two suffered radiation burns and were taken to Fukushima Medical University Hospital, while the third didn't require treatment.

Japanese Prime Minister Naoto Kan sounded pessimistric in a televised address to the country Friday.

"The situation today at the Fukushima Daiichi power plant is still very grave and serious," Kan said. "We must remain vigilant. We are not in a position where we can be optimistic. We must treat every development with the utmost care."

He apologized to farmers and business owners around the plant for any damage He also thanked utility workers, firefighters and military personnel for "risking their lives" to cool the overheated facility.

The prime minister was speaking two weeks to the day after a magnitude-9.0 earthquake and subsequent tsunami set in motion unprecedented damage and explosions at the Daiichi nuclear site.

Uncertainty halted work at the overheated plant, where dozens of people had been trying to stop it from leaking dangerous radiation.

The high level of radiation in water at the site "could be a very dangerous and ominous sign, because if there is a breach, even a small one, radioactive material can begin to leak into the environment, [and] really change some of the parameters," reporter Steve Futterman told CBC News from Tokyo.

The nuclear safety agency has ordered the plant operator, Tokyo Electric Power Co., to improve radiation management, the Kyodo News reported on its website.

The government, which had originally told residents within a 20-kilometre radius of the stricken plant to leave, on Friday encouraged those within a 30-kilometre radius to leave voluntarily because the release of radiation from Daiichi is expected to carry on for sometime, Kyodo reported.

Engineers have been working round the clock trying to gain control of the plant 220 kilometres northeast of Tokyo two weeks after a magnitude-9.0 quake triggered a tsunami that engulfed the facility and knocked out itscrucial cooling system.

The plant has been releasing radiation, with elevated levels of radiation turning up in raw milk, seawater and 11 kinds of vegetables, including broccoli, cauliflower and turnips.

After several days of concern about elevated radiation levels in Tokyo tap water, lower levels were reported late Friday at a Tokyo water purification plant, the Tokyo metropolitan government said.

The government's Bureau of Waterworks detected 51 becquerels of radioactive iodine per kilogram of water sampled Friday morning at the Kanamachi water purification plant in the capital's Katsushika Ward.

That's within the normal range for consumption and below the central government's limits of 100 becquerels for safe consumption by infants and 300 becquerels for adults, the local government said.

Tap water in several areas of Japan — including Tokyo — had earlier been found to have radiation levels considered unsafe for infants, who are particularly vulnerable to cancer-causing radioactive iodine, officials said.

The scare caused a run on bottled water in the capital, and prompted city officials to distribute the products to families with babies, Futterman reported.

"Once they gave this warning a couple of days ago … it set the alarm bells going, and people don't want to use tap water now."

Distribution centres in Tokyo continued to hand out bottles of water to families with children under a year old, he said.

Officials are also grappling with a humanitarian crisis in the northeast, where hundreds of thousands of survivors remain camped out in schools and civic buildings two weeks after the tsunami swallowed up swaths of the coast. Much of the frigid northeast remains in despair and devastation, with the country struggling to feed and house homeless survivors, clear away debris and bury the dead.

Some 660,000 households are without water, and more than 209,000 lack electricity. Damage could rise as high as $310 billion US, the government said, making it the most costly natural disaster on record.

Police said the official death toll jumped past the 10,000 mark Friday. With the cleanup and recovery operation continuing, and more than 17,400 listed as missing, the final number of dead was expected to surpass 18,000, taking into account overlapping figures.

At the Fukushima nuclear plant, fires, explosions and spikes in radiation have hampered efforts to contain the nuclear crisis. High radiation levels have forced repeated evacuations, and more than two dozen workers have been injured, according to NISA.

Operators have been struggling to keep cool water around radioactive fuel rods in the reactor's core after the earthquake and tsunami cut off power supply to the plant and its cooling system.

Damage may have been done to the Unit 3 core when a March 14 hydrogen explosion blew apart its outer containment building. This reactor, the most troubled at the six-unit site, holds 170 tonnes of radioactive fuel in its core.

Previous radioactive emissions have come from intentional efforts to vent small amounts of steam through valves to prevent the core from bursting.

Meanwhile, damage to factories was taking its toll on the world's third-largest economy and creating a ripple effect felt worldwide. Nissan Motor Co. said it may move part of its engine production line to the United States because of damage to one of its plants.

"There is no doubt that we have immense economic and financial damage," Finance Minister Yoshihiko Noda said. "It will be our task how to recover from the damage."

At the port of Sendai, new Toyota cars lie crushed in piles. At the airport, flooded by the tsunami on March 11, U.S. marines used bulldozers and shovels to shift wrecked cars that lay scattered like discarded toys.