Power lines to all six nuclear reactor units at Japan's quake-stricken Fukushima Daiichi complex have been connected, its operator said, but electricity has not yet been turned on.

Tokyo Electric Power Co (TEPCO) warned on Tuesday that equipment still had to be checked before power could be properly reconnected, which would mark a significant step in bringing the reactors back under control.

Engineers have also been able to cool a spent fuel pool that was nearly boiling, bringing it back to 105 degrees after dumping 18 tonnes of seawater into a holding pool.

However fears have been raised over the possibility of radiation in seawater near the reactors in northeastern Japan, with reports that some radioactivity has been detected in the sea.

Experts are concerned about sea water that has been used to cool the reactors and their spend fuel ponds after the 9.0 magnitude earthquake and subsequent tsunami on March 11.

Radioactive iodine in the sea samples was 126.7 times the allowed limit, while caesium was 24.8 times over, Kyodo news agency said. But TEPCO said that still posed no immediate danger.

"I'm interested to know how this water is being disposed... if it is being disposed or just allowed to drain to sea," Najmedin Meshkati, a nuclear and environmental expert at the University of Southern California, told the Reuters news agency.

"This is now radioactive waste water. Has there been any measurement of its radiation effect?"

Officials have acknowledged that some of the water used to cool the reactors spilled back into sea.

Hidehiko Nishiyama, deputy director-general at the Nuclear and Industrial Safety Agency, said the radioactivity in the sea could be both from water used to cool the plant and airborne particles from the reactors.

"Personally, I think the latter is more likely," he told a news conference.




That is from a 33-minute-ago news release from Aljazeera.