Osaka: Engineers at a stricken nuclear plant in Japan managed to connect an electricity cable to one of the reactors Saturday and battled to restore power to the cooling system to avert a full-blown meltdown.
The announcement offered some hope of a breakthrough in efforts to prevent a major radiation leak from the troubled facility, although it is not yet clear whether the cooling system will work properly even if the power comes back on.
The government meanwhile said it had discovered abnormal levels of radiation that exceeded the legal limit in milk and spinach from areas near the stricken plant, but they posed no immediate threat to humans.
Electricity was expected to be restored to reactor No. 2 at the Fukushima plant on Sunday, more than a week after it was rocked by a massive earthquake and tsunami, the nuclear safety agency said.
"The line itself was connected to the reactor No. 2 but electricity has not been restored yet," said agency spokesman Fumiaki Hayakawa.
"If the power is turned on without checks it may malfunction. They are checking the facility now. If no problem is found at the facility today, the power will resume as early as tomorrow (Sunday)."
Reactor No. 1 usually shares the same electricity line so the cable could in theory restore power to both units.
After that, engineers will start laying cables to the other four reactors -- a complicated operation that is taking longer than initially expected.
Once power is back up, the radiation-suited Fukushima engineers hope they can get vital cooling systems online. In the meantime, they have been dumping water by hose and by air on the reactors to cool the fuel rods.
"Although we are doing our best, unfortunately we cannot say when electricity will be restored," said a TEPCO official.
There are six reactors at the plant, which is located about 250 kilometres (155 miles) northeast of Tokyo and has already leaked radiation, prompting the government to order an evacuation within a 20 kilometre (12 mile) radius.
Emergency services resumed spraying water at the number three reactor using specially equipped fire trucks and said they were stepping up the dousing, aiming for round-the-clock operations.
Defence Minister Toshimi Kitazawa said surface temperatures at the plant "seem to be stable" at no more than 100 degrees Celsius (212 degrees F).
Tonnes of water have been used to douse overheating fuel rods in what the head of the UN International Atomic Energy Agency (IAEA) has described as "a race against time" to prevent a major disaster.
Plant operator TEPCO has not ruled out the last-resort option of entombing the plant in sand and concrete as the Soviet Union did with the Chernobyl plant in 1986, but says it is still focusing its efforts on cooling the facility.
Four of the plant`s six reactor units -- numbers one to four -- have been in danger of spewing dangerous amounts of radioactivity, following a series of hydrogen explosions and fires at buildings housing the troubled reactors.
A 9.0-magnitude earthquake on March 11, followed by monster tsunami waves and aftershocks, knocked out the power supply, including generators for emergency use, at the plant on the Pacific coast.
TEPCO said Saturday that its engineers had bored holes in the roofs of the buildings housing reactors five and six to avoid a potential explosion of hydrogen gas.
Japan`s nuclear safety agency on Friday raised the Fukushima crisis level from four to five on the international scale of gravity for atomic accidents, which goes up to seven.
The move puts Fukushima on the same level as the 1979 accident at Three Mile Island in Pennsylvania and makes it the worst ever in Japan.
Japan has said radiation levels from the plant pose no health threat outside the 20-kilometre exclusion zone, despite slightly elevated levels in Tokyo earlier in the week.
Government spokesman Yukio Edano told reporters Saturday that milk contaminated with radiation was found in Fukushima prefecture, while tainted spinach was discovered in neighbouring Ibaraki prefecture.
But Edano urged consumers to remain calm, noting that even if a person were to drink the contaminated milk for a year, the radiation level would be the equivalent of a single hospital CT scan.
Traces of radioactive iodine were found in tap water in Tokyo and several areas near the atomic power complex, a science ministry official said, but the levels were well below the legal limit.
The IAEA, which has sent a radiation monitoring team to Japan, said Friday that levels detected in the capital did not pose any harm to human health.
Despite the reassurances, Britain, France and other countries have advised their citizens to leave Tokyo and many foreigners have fled the capital, fearing that a larger radiation leak might reach the sprawling city.