Tokyo (CNN) -- Japan will likely need two to three more months to bring an end to the disaster at the Fukushima Daiichi nuclear power plant, a nuclear industry official said Saturday.
Takashi Sawada, the deputy director of the Atomic Energy Society of Japan, said Saturday that it was likely to take that long to restore normal cooling systems for the damaged reactors at Fukushima Daiichi.
The plant's coolant systems were knocked out by the March 11 tsunami, causing three reactors to overheat and producing what Japan's government has designated a top-scale nuclear accident.
Sawada's organization is an association of nuclear engineers, scientists and professors, and it issued a Friday report that he called "our best effort to imagine what the core looks like."
That report concluded that the zirconium alloy sheaths that surround the reactor's fuel rods ruptured in the three units, sending pellets of molten uranium tumbling to the bottom of the reactors. The pellets are since believed to have cooled and solidified at the reactor bases, according to the report.
The plant's owner, the Tokyo Electric Power Company, has said it can't provide a timeline for bringing the crisis to an end and would not discuss Sawada's assessment Saturday.
"We are trying to do our utmost at this moment," a company official told CNN.
But an adviser to Prime Minister Naoto Kan said the government wants to see some sort of plan by the end of April.
"We will set up a goal for the cooling process soon," the adviser, Goshi Hosono, said during an appearance on the BS Asahi satellite network Saturday morning.
Japanese nuclear regulators declared the Fukushima Daiichi accident a Level 7 on the International Nuclear Event Scale this week, putting the crisis on par with the April 1986 fire and explosion at the Chernobyl plant in the former Soviet Union. While authorities said the amount of radioactivity released was only 10 percent of the amount that spewed from Chernobyl, it was far beyond the threshold for a Level 7 event.
More than 78,000 people who lived within 20 kilometers (12.5 miles) of the plant were ordered to flee their homes. Another 60,000-plus living in the next 10 kilometers were told to shelter indoors, And Japan's government ordered residents of several towns outside that danger zone that they would soon be evacuating due to the possibility of long-term health risks from radioactive particles released from the plant.
Tokyo Electric has said it has to drain highly radioactive water from the basements and service tunnels of the reactor units' turbine plants before it can work on restoring normal cooling systems. But workers are also pumping up to 7 tons (1,850 gallons) of water into the reactors every hour as an interim measure, and an unknown portion of that is leaking back into the plant.
At the plant on Saturday, workers continued preparations to start pumping water from the No. 2 turbine plant into a treatment facility for low-level radioactive waste. More than 9,000 tons of less-contaminated water that had been held there was dumped into the Pacific Ocean last week in what Japanese officials called an emergency measure to make room for fluid that had been leaking into the sea until April 6.
Crews have been laying fresh pipes to the treatment center and hope to start transferring water from unit 2 on Sunday, the company said. But its capacity could be only a fraction of the volume now sloshing around in the turbine building basements, and engineers are still pouring hundreds of tons of water into the reactors every day to keep them cool.
The treatment center could hold up to 30,000 tons of water, Tokyo Electric said -- but that could be only a fraction of the volume now sloshing around in the turbine building basements, the company said.