Tens of thousands of people living around the Fukushima nuclear plant were advised to evacuate yesterday as officials conceded there was no end in sight to radiation leaks.
The Nuclear Safety Commission of Japan recommended the voluntary departure of the 120,000 people living between 20km and 30km from the plant as radiation would continue to be released "for some time", according to the Kyodo news agency.
The Japanese government said yesterday that a lack of supplies in the area, partly the result of transport companies being reluctant to make deliveries because of radiation fears, also meant evacuation was advisable.
"Given how prolonged the situation has become, we think it would be desirable for people to voluntarily evacuate in order to meet their social needs," Yukio Edano, the government's chief spokesman, said.
Meanwhile, the death toll from the earthquake and tsunami on March 11 continued to mount. Police said 10,066 people were confirmed dead and 17,443 people were still missing. More than a quarter of a million remain in evacuation shelters, although inadequate food supplies and medical care are less of a problem than earlier.
Even outside the new voluntary 30km evacuation zone, radiation levels continued to be severely elevated. In Iitate, a village 40km north-west of the plant, radiation was measured at 11.9 microsieverts per hour at 2pm local time yesterday, more than 200 times normal background levels.
Tokyo Electric Power Company (Tepco), the plant's operator, yesterday said achieving a "cold shutdown" of the reactors, when temperatures have fallen to safe levels and pressures are normal, could take more than a month. The plants' No 5 and No 6 reactors have been cooled already, but reactors and spent fuel pools at Nos 1, 2, 3 and 4 remain unstable.
"We are still in the process of assessing the damage at the plant, so we can't put a deadline on when the cooling operations will work again. It may take more than a month, who knows," an unnamed Tepco spokesman told Agence-France Presse.
The company was looking to start using freshwater, instead of seawater, to cool the reactors and spent fuel pools. Concerns have been raised that seawater will cause salt deposits to form on the fuel rods, disrupting cooling. The United States is providing two million litres of freshwater for cooling.
Tepco was criticised by media and the government yesterday after three workers were this week exposed to high levels of radiation while laying cables in the basement of a turbine building at the No 3 reactor. Water seeped through the protective clothing of two of the men, causing burns that forced them to be hospitalised.
Japan's Kyodo news agency said the incident "highlighted the plant operator's lax work management". Banri Kaieda, the minister of economy, trade and industry, described the absence of a person accompanying the three to check radiation levels as "a very big basic oversight". The contractors were not wearing boots that would have protected them from the radioactive water, and they ignored warnings from radioactivity alarms.
The water had 10,000 times the level of radioactivity expected if the reactor had been undamaged, raising fears among officials yesterday the nuclear fuel containment vessel for reactor 3 may be ruptured, another sign that stabilising the plant and keeping radiation leaks to a minimum remains difficult.
Further scares over the spread of radiation emerged yesterday, with China reporting that a container ship, the Mol Presence, was found to be contaminated after it arrived at Xiamen port from Japan. It was unclear if radioactivity was detected on the vessel itself or part of its cargo.
Some reports said the vessel had berthed at Tokyo on Thursday, although a shipping website indicated it had stopped off at Yokohama further south.
With at least two German shipping companies avoiding Japanese ports over radiation concerns, a transport ministry official yesterday asked firms not to overreact. There are fears that supplies could be disrupted if maritime traffic declines, especially as some ports on the north-east coast remain closed because of tsunami damage.
"We are offering accurate and timely information. We ask that services to Tokyo and Yokohama ports continue, based on rational and scientific judgement," the unnamed official said, adding that radiation levels were "very safe".
China yesterday became the latest country to ban food imports from Fukushima and several surrounding districts, following from similar rulings by the United States and Australia among others.
Japan's prime minister, Naoto Kan, apologised yesterday to farmers and business owners affected by the disaster. In a televised address, Mr Kan also thanked the utility workers, firefighters and military personnel for "risking their lives" in efforts to desperately trying to cool the overheated reactors.