Japan’s Fukushima Daiichi nuclear plant has stabilized, officials say

Just over four months after it was crippled by an earthquake-generated tsunami, Japan’s Fukushima Daiichi nuclear power plant has stabilized and workers are on track for achieving a cold shutdown within six months, government and utility officials say.

Officials made a positive prognosis after scaling several hurdles in decommissioning the facility, which was damaged on March 11 when a tsunami disabled the plant’s cooling system. The flooding led to partial meltdowns of the reactors, which released radioactivity in the atmosphere and prompted the evacuation of tens of thousands of nearby residents.

In recent weeks, engineers have established an improvised cooling system to circulate water to cool the damaged reactors. They have also set up a system to decontaminate radioactive water from the process. Nitrogen injections at the four damaged reactors are helping to prevent more explosions, officials said this week.

Photos: Japan earthquake

But officials from the Tokyo Electric Power Co., which runs the plant, warn that even if a cold shutdown -- when the reactor cores no longer burn off coolant water -- is reached by early 2012, the final cleanup could still take a decade or more. The plant will eventually be encased in concrete as a safety precaution.

“We still don’t have a schedule for the work to decommission this plant, and that’s planning that we have to do right now,” Goshi Hosono, the minister handling the central government’s response to the crisis, told reporters in Tokyo on Tuesday.

The latest update on the status at the plant comes as pressure continues for Prime Minister Naoto Kan to step down in light of his perceived poor handling of the crisis and lingering public health concerns.

In recent days, the Japanese media reported that more than 140 beef cattle suspected of being contaminated from ingesting straw laced with radioactive cesium were shipped from the Fukushima region to consumers nationwide. Officials have since suspended all shipments of beef cattle from the region.

Cautious government officials say it will take several more months to determine whether 80,000 evacuated residents will be able to return to their homes. The Fukushima Daiichi plant is located about 150 miles north of Tokyo.

“During the time that I’ve been involved in this effort, we’ve encountered every kind of difficulty, so I don’t think we have room to be optimistic,” Hosono said. He added that he hoped “we can achieve some specific results” in returning residents by year’s end.

Meanwhile, an embattled Kan has called for a major review of Japan’s energy policies and has favored a large reduction in the nation’s reliance on nuclear power.

The effects of Japan’s nuclear disaster continue to be felt elsewhere. This week, U.S. Nuclear Regulatory Commission Chairman Gregory Jaczko urged his agency to decide within the next three months how to enact safety changes to improve the disaster response at nuclear power plants throughout the United States.

Photos: Japan earthquake

john.glionna@latimes.com