Tokyo/Fukushima: Premier Naoto Kan for the first time on Saturday examined Japan's tsunami-hit northeast, as authorities said highly radioactive water was leaking into sea from a 12-inch crack in a containment pit at the troubled Fukushima nuclear plant, where IAEA termed the situation as "very serious".

Kan visited an operation base in Fukushima Prefecture to encourage Self-Defense Forces (SDF) personnel and other workers trying to contain Japan's worst nuclear crisis at the plant, three weeks after the monster magnitude-9 quake and tsunami struck the country's northeast leaving nearly 30,000 people dead or unaccounted for.

"By all means, the accident at the Fukushima Daiichi plant needs to be put under control with your collective efforts," Kan told the workers, including those from plant's operator Tokyo Electric Power Company (TEPCO), while thanking them for their "hard work" under "harsh conditions"

"We have to work hard until we reach a point where we can say our country has overcome the quake and the tsunami disaster," he said.

Before visiting the base situated 20 km from the nuclear plant, the Prime Minister flew into Rikuzentakata city in Iwate Prefecture, which was devastated by the twin disaster, on a military helicopter from Tokyo and met the evacuees there.

The Prime Minister's visit to the northeast came as TEPCO said it has found that highly radioactive water was leaking into the sea from a 12-inch crack in a wall of the No.2 reactor at the Fukushima Daiichi nuclear power plant.

The power company said that the level of radiation has been measured at over 1,000 millisieverts per hour.
It said the water was leaking from the crack in the wall of a 2-metre deep pit that contains power cables near the water intake of the reactor, national broadcaster NHK reported.

TEPCO is preparing to pour concrete into the cracked pit to stop the leak of radioactive water.

The radiation detected in water in the basement of the turbine building at the No.2 reactor was about 100,000 times the normal level.

Meanwhile, the IAEA Director General Yukiya Amano warned of a prolonged battle against the nuclear crisis in quake-hit Japan. "...I would say it would take more time than people think," Amano, a Japanese national, said at a press conference in the Kenyan capital Nairobi.