TOKYO (Reuters) - Japan expects to stop pumping radioactive water into the sea from a crippled nuclear plant on Saturday, a day after China expressed concern at the action, reflecting growing international unease at the month-long nuclear crisis.
"The emptying out of the relatively low radiation water is expected to finish tomorrow (Saturday)," a Tokyo Electric Power Co (TEPCO) official said late on Friday.
TEPCO is struggling to contain the worst atomic crisis since Chernobyl, with its engineers pumping low-level radioactive seawater, used to cool overheated fuel rods, back into the sea for the past five days due to a lack of storage capacity.
China said it will closely monitor Japan's actions to regain control of the plant and demanded Tokyo provide swift and accurate information on the crisis which began on March 11 when a magnitude 9 earthquake and tsunami struck.
"We hope that Japan will act in accordance with international law and adopt effective measures to protect the marine environment," Chinese Foreign Ministry spokesman Hong Lei said in a statement on Friday.
China said it had detected 10 cases of ships, aircraft or cargo arriving from Japan with higher than normal levels of radiation since mid-March.
It said traces of radioactivity had been found in spinach in three Chinese provinces, and state news agency Xinhua reported trace levels of radioactivity detected in 22 provinces.
Japan also faces calls to revive its disaster-hit economy to prevent a knock-on impact on the global economy.
G20 finance leaders will ask Tokyo for a plan to resuscitate its economy as they see the economic damage from the earthquake as a risk to global growth, Takatoshi Kato, a former IMF deputy managing director, told Reuters in an interview on Friday.
The earthquake and tsunami left 28,000 people dead or missing, and damaged six nuclear reactors north of Tokyo.
The world's third largest economy is now in a "severe condition," the Japanese government said on Friday.
A major 7.1 aftershock on Thursday night rocked Japan's east coast, killing three people, injuring 141 others, and leaving four million homes without power. It also prompted a brief evacuation of workers from the damaged Fukushima Daiichi nuclear plant.
TEPCO said there had been no damage to its plant, which until two days ago was leaking highly radioactive water.
South Korea has also criticized Japan, accusing it of incompetence for failing to notify its neighbors that it would pump radioactive water into the sea.
"They should have given notice but didn't, perhaps because they just didn't get around to think of it, but it is a question of their incompetence," Prime Minister Kim Hwang-sik said in answer to a question in parliament on Thursday.
Several countries have restricted food imports from Japan over radiation fears and some South Korean schools have closed fearing toxic rain.
Compounding Tokyo's problems, Japan's economy is reeling from the worst disaster since World War Two and the disruption to Japanese supply chains is reverberating around the world.
The world's largest automaker Toyota Motor Corp said it plans to idle some of its U.S. plants, while Honda Motor Co Ltd has extended reduced U.S. production until April 22.
Power blackouts and restrictions, factory shutdowns, and a sharp drop in tourists have hit the world's most indebted nation, which is facing a damages bill as high as $300 billion, making it by far the world's costliest natural disaster.
Many economists expect Japan to slip into recession this year, and the central bank warned on Friday that power shortages and supply disruptions will leave the economy weak for some time.
"Japan's economy is suddenly in a severe condition due to the effects of the earthquake," said the Cabinet Office after releasing a survey of hotel and restaurant staff and taxi drivers, showing a record fall in confidence to levels last seen during the depths of the global financial crisis.
In an obvious sign of the downturn, taxis park in long lines in central Tokyo each night, their drivers staying warm by idling the motor as they wait forlornly for a fare.
Some ministers at Friday's cabinet meeting called for an end to a campaign of "jishuku" (self restraint) by ordinary people that was adopted immediately after March 11 to cut fuel or electricity use and discourage stockpiling of necessities.
The Tokyo area and regions further north make up half of Japan's economy, Nomura research shows. Thursday's aftershock forced two companies, including electronics giant Sony Corp, to stop production due to power cuts.
However, Japan's top automakers Toyota and Nissan Motor Co plan to resume production at all domestic factories in stages starting on Monday, although output levels will be at half of original plans.
The U.N.'s nuclear watchdog, the International Atomic Energy Agency (IAEA), said there were signs of progress in stabilizing the Fukushima plant, though the situation remained very serious.
The agency said radiation in the region around the plant, as measured by gamma dose rates, had peaked in the early days of the crisis, and aside from a rise on March 22, had since fallen to "a level very close to background.
Utility TEPCO said it was continuing to inject nitrogen into one of its Fukushima reactors to prevent a repeat of last month's hydrogen explosions and resin spraying continued to prevent radioactive particles on debris from spreading
"We are doing everything we can to bring the situation under control. As for when (the situation will end) we are not at a stage to give a time frame yet," said a TEPCO official.
Officials say it could take months to bring the reactors under control and years to clear up the toxic mess left behind.
The government has set up a 20-km (12-mile) exclusion zone around the plant, banned fishing along much of the northeast coast and set up evacuation centers for the tens of thousands forced to leave their homes following the crisis.
Additional reporting by Mayumi Negishi, Yoko Nishikawa, Kiyoshi Takenaka, Leika Kihara and Chang-Ran Kim in Tokyo, Ben Blanchard and Sui-lee Wee in Beijing, Jack Kim in Seoul; Writing by Michael Perry; Editing by Andrew Marshall