The Japanese government has asked residents who live within 30 kilometres of the Fukushima Dai-ichi nuclear power plant to leave voluntarily, after experts said radioactive water that left emergency crew members with serious radiation burns may have leaked from a reactor.
If the water did leak from a reactor, it raises the possibility that it seeped into the ground around the plant.
However, the evacuation plan is not mandatory. Chief Cabinet Secretary Yukio Edano told reporters that many nearby residents have already left, but as the country deals with the massive loss of life and destruction from the earthquake and tsunami, travelling has its own difficulties.
''The distribution of goods is stalled, and it is rather difficult to maintain their daily lives over a long period of time,'' he said, according to a Kyodo News report.
Earlier, Prime Minister Naoto Kan warned that the situation at the Fukushima nuclear plant was "very grave and serious" as crews halted work to contain the crisis Friday.
"We are not in a position where we can be optimistic. We must treat every development with the utmost care," the prime minster said.
According to Japan's Nuclear and Industry Safety Agency, suspicions of a breach were raised after workers replacing a cable at the Unit 3 reactor were found to have stepped in water that was 10,000 times more radioactive than normal.
As a result, two of the exposed workers were hospitalized.
Officials fear that the water leaked out of a breach in the stainless steel chamber of the Unit 3 reactor core. The radioactive water may also have spilled from the reactor's spent fuel pool, which is insulated with several metres of heavy-duty concrete.
As officials probed the reactor, however, the pressure and temperature inside the core where the fuel rods are stored appeared to be stable and not close to meltdown levels.
Watching developments from Montreal, Gordon Edwards, president of the Canadian Coalition for Nuclear Responsibility, described the situation as "very bad."
The container around the reactor's core is the "last line of defence" preventing irradiated gasses and vapors from escaping into the environment, he said, so a breach means a "continuous" and "uncontrolled" leak of radioactive material.
Workers haven't pinpointed the source of the leak, Edwards said, but the "worst possibility" would be a "completely unrepairable" melt-through at the bottom of the reactor's core.
"They may have to seriously consider just burying this entire reactor in mountains of sand and concrete as they did in Chernobyl finally," he said. "At this point in time you want to prevent as much as possible this radiation from getting into the environment."
Meanwhile, Japan's prime minister apologized to business owners and farmers for the crisis, as locals near the reactor were asked to leave the region.
Many food exports from the region have been halted and products like milk have been found to have higher radiation levels.
Underscoring the worsening nuclear emergency situation, Japan's top government spokesperson advised the approximately 130,000 still living near the crippled power plant to seriously consider leaving the region.
"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 said, insisting he was giving advice and not extending the formal evacuation order that covers a 20-kilometre zone around the Fukushima plant.
As the crisis continues at the crippled nuclear facility approximately 220 kilometres northeast of Tokyo, officials are continuing their efforts to deal with the humanitarian crisis triggered by the devastating earthquake and ensuing tsunami that struck the country on March 11.
In their latest count, police say the official toll of the twin disasters now exceeds 10,000 people. Another 17,400 are still listed as missing, and more than a quarter of a million people have been displaced from their homes.
The Japanese government has said damages will likely wind up costing more than US$310 billion, making this the world's most expensive natural catastrophe on record.
With files from The Associated Press
