An aide to embattled Prime Minister Naoto Kan said the government’s priority was to stop radiation leaks which were scaring the public and hindering work on cooling overheated nuclear fuel rods.

“We have not escaped from a crisis situation, but it is somewhat stabilized,” said Goshi Hosono, a ruling party lawmaker. “How long will it take to achieve (the goal of stopping the radiation leakage)? I think several months would be one target,” Hosono said on a nationwide Fuji TV program on Sunday.

Plant operator Tokyo Electric Power Co (TEPCO) found a crack in a concrete pit at its No.2 reactor in the Fukushima Daiichi complex at the weekend, generating readings of 1,000 millisieverts of radiation per hour in the air inside.

The leaks did not stop after concrete was poured into the pit, and TEPCO turned to water-absorbent polymers to prevent any more contaminated water from going out.

The latest effort to staunch the flow of radioactive water into the Pacific started on Sunday afternoon. Workers then topped the polymers with more concrete.

“We were hoping the polymers would function like diapers but are yet to see a visible effect,” said Hidehiko Nishiyama, deputy director general of the Nuclear and Industrial Safety Agency.

Officials believe the crack could be one source of the radiation leaks that have hobbled efforts to control the six-reactor complex and sent radiation levels in the sea soaring to 4,000 times the legal limit.

The battle to cool overheated reactors and avoid dangerous meltdowns of the highly radioactive fuel rods has seen workers hose saltwater into reactors, but this has left the facility awash with contaminated saltwater, preventing workers getting closer to the reactors.

Nishiyama said fresh water was now being pumped into No. 1, 2 and 3 reactors using external power, which was more stable than the emergency generators previously being used. He said the three reactors were now generally stable.

Premier Kan is under intense pressure to steer Japan through its worst crisis since World War Two, but after three weeks many Japanese are angry that the humanitarian disaster seems to have taken a back seat to the nuclear crisis.

Unpopular and under pressure to quit or call a snap poll before the disaster, Kan has been criticized for his crisis management.

When Kan visited the devastated fishing port of Rikuzentakata on Saturday, survivors struggling to rebuild their lives complained that he had not visited them earlier.

More than 163,710 people are living in shelters, with more than 70,000 people evacuated from a 20 km no-go zone area the nuclear plant, and another 136,000 people living a further 10 km out have been told to leave or stay indoors.

Harrowing stories are still emerging of just what happened on the fateful afternoon of March 11.

Civil servant Takako Suzuki, 40, narrowly escaped when water rose to within a few inches from the ceiling of an evacuation center she had rushed to. “I was thinking ‘if the water rises a little bit, I’m finished’ — but fortunately the water suddenly stopped rising and began receding,” she said.

Suzuki spent a night huddled with 11 other survivors in the deep water, bodies floating around them.

“Grown in Fukushima” has become a warning label for those nervous of radiation which has already been found in some vegetables close to the nuclear plant.

“There is no way we will be able to sell anything,” said 73-year-old farmer Akio Abiko. “People in Tokyo are just too sensitive about this kind of thing.”

A group of farmers came to Tokyo from Fukushima at the weekend, using Geiger counters to show their produce was safe.