Vienna, March 18 (DPA) The International Atomic Energy Agency (IAEA) said Thursday there had been no major negative developments at Japan's stricken Fukushima nuclear plant over the last 24 hours, but warned the situation could change.

"It hasn't got worse, which is positive," senior IAEA technical official Graham Andrew told reporters at the agency's Vienna headquarters.

"But it's still possible that it could get worse," Andrew added.

The situation is "reasonably stable," he said.

Andrew for the time being ruled out a point of no return, after which the situation would be too dangerous for humans to handle.

Operators at Fukushima were dousing overheated spent fuel ponds with water from helicopters and water cannons Thursday.

They also laid a cable to restore electric power to run the cooling and measuring systems that have been down since the massive quake and tsunami struck the plant Friday, the IAEA said. Power could be restored by the weekend, according to Kyodo.

IAEA experts said that engineers and workers at Fukushima have literally been operating in the dark so far.

"There's no lights in these very large buildings, there's no windows," said James Lyons, a senior IAEA safety official.

Only once power is restored would it be possible to determine which systems were still usable, the officials said.

Water levels in two reactor cores have dropped to around half of normal levels, and nuclear fuel is damaged in three of the plant's six reactors that were in operation until Friday and have not been adequately cooled since then. The protective shell of one reactor is likely damaged.

IAEA Director General Yukiyo Amano is currently flying to Japan with a team of six agency experts to examine the situation and to raise the level of cooperation between the IAEA and Japan.

"We wish to go to the sites," he told reporters at Vienna airport. He left it open whether he would personally visit Fukushima.

Although Amano is a former high-ranking Japanese Foreign Ministry official, he has been unable so far to get authorities there to speed up the flow of information to the IAEA and its member states.

Amano was expected to arrive in Tokyo Friday at around 10.40 a.m.