Japan struggles to cool reactor
Emergency workers are continuing frantic efforts to cool nuclear fuel at Japan's stricken reactors complex.
Police water cannons, heavy-duty firetrucks and military helicopters dumping seawater have all been used at the plant, but it is still not clear if they have had an affect.
US and Japanese officials have given gave differing assessments of the situation at the Fukushima Dai-ichi nuclear plant, 140 miles north of Tokyo.
The top US nuclear regulatory official warned of possible high emissions of radiation while the US ambassador urged Americans within 50 miles of the plant on the tsunami-savaged north-eastern coast to leave the area or at least remain indoors.
Tokyo Electric Power Co, which owns the plant, said it believed workers were making headway in staving off a catastrophe both with the spraying and, especially, with efforts to complete an emergency power line to restart the plant's own electric cooling systems.
"This is a first step toward recovery," said Teruaki Kobayashi, an official at the power company.
He said radiation levels "have somewhat stabilised at their lows" and that some of the spraying had reached its target, with one reactor emitting steam. "We are doing all we can as we pray for the situation to improve," he added.
The troubles at the nuclear complex were set in motion by last Friday's 9.0-magnitude earthquake and tsunami, which knocked out power and destroyed backup generators needed for the reactors' cooling systems.
Four of the plant's six reactors have seen fires, explosions, damage to the structures housing reactor cores, partial meltdowns or rising temperatures in the pools used to store spent nuclear fuel. Officials also said temperatures are rising in the spent fuel pools of the last two reactors.
Nearly a week after the disaster, police said more than 452,000 people are staying in schools and other shelters, as supplies of fuel, medicine and other necessities run low. Both victims and aid workers appealed for more help, as the chances of finding more survivors dwindled.