Japan nuclear progress amid fears of rain-driven contamination

While the IAEA has said the smoke or vapour rising from one of the overheating reactors at the damaged Fukushima power plant had become less intense, but the overall situation remains very serious.

"There have been some positive developments in the last 24 hours but overall the situation remains very serious," said Graham Andrew, a senior IAEA official.

But ongoing Heavy rain has also intensified fears of radiation contamination too as a Fukushima prefecture official said radiation levels tended to rise when rain fell, warning people to try to stay dry, or to dry off quickly after being in the rain.

Attention has also turned to contamination of food supplies. "The contamination of food and water is a concern," said Gerhard Proehl of the IAEA.

"We consider that now we have come to a situation where we are very close to getting the situation under control," Deputy Cabinet Secretary Tetsuro Fukuyama said.

Over the weekend spinach and milk produced near the Fukushima nuclear plant was found to contain levels of radioactive iodine far higher than the legal limits, although not at levels that would be a risk to human health.

The overall death toll has now risen to 8,450, with 12,931 people missing.

Electricity has been restored to three reactors at the crippled Fukushima nuclear power plant - this should allow the use of on-site water pumps soon. Engineers have been spraying fuel rods with salt water to try to cool them enough to avert radiation leakage.

Villagers living near the plant have been told not to drink tap water due to higher levels of radioactive iodine.

However, bad weather forced the Japanese Prime Minister, Naoto Kan, to cancel a planned visit to emergency workers near the Fukushima plant. It is also making the recovery work a much more grim and difficult task.

Search-and-relief efforts in the prefecture of Miyagi, where the police chief believes the final quake-tsunami death toll could reach 15,000, have been delayed by driving rain.

"We basically cannot operate helicopters in the rain," Miyagi official Kiyohiro Tokairin said.

"We have been using helicopters to deliver relief goods to some places but for today we have to switch the delivery to places that we can reach by road," he said.