Asia-Pacific

Amid setbacks Japan keeps Fukushima shutdown target

(Agencies)
Updated: 2011-05-17 14:49

TOKYO - Japan's government is set to renew a pledge on Tuesday to bring the crippled Fukushima nuclear plant under control by January, despite revelations that three reactors were plunged into meltdown after the March 11 earthquake and the new risk posed by a massive pool of radioactive water at the site.

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More than two months after the worst nuclear disaster since Chernobyl, officials say the risk of another explosion at the plant has declined but each step towards taking control has been matched by new setbacks. The crisis has also prompted a blank-slate review of Japan's national energy policy.

Tuesday's update comes just over a month since Tokyo Electric Power Co. provided a rough timetable for its efforts to shut down the three unstable reactors at the site and to complete initial steps to limit the release of further radiation from the plant 240 km (150 miles) northeast of Tokyo.

The timetable for taking control of the Fukushima Daiichi crisis has been politically charged from the start. The government of Prime Minister Naoto Kan has been under fire for its response to the magnitude 9.0 earthquake and the massive tsunami that followed. Almost 25,000 people are dead or missing, while almost 116,000 remain displaced and living in shelters.

A string of new details about the state of the plant released in the past week by the facility's embattled operator, Tokyo Electric Power Co, have made it clear that the reactors suffered far more serious damage than previously disclosed.

Uranium fuel rods in the reactors - Nos 1, 2 and 3 - were uncovered for between six to 14 hours after the quake, rapidly heated and melted to the bottom of the steel pressure vessel intended to contain the fuel, officials now say.

In the case of the No 1 reactor, the molten uranium appears to have leaked out of the vessel, scattering high-level radiation through the plant when emergency cooling operations resumed.

In addition, the uranium fuel in the No 3 reactor has not responded to stepped-up efforts to cool its temperature below the boiling point for water.

Another concern is that the No 4 reactor, which was out of service at the time of the quake, was so badly damaged by a hydrogen explosion that workers will have to shore it up with new steel beams and concrete to keep it from collapse.

But the biggest setback has come from the growing pool of radioactive water at the Fukushima site.

Because the reactors were damaged by the quake, the explosions and the core meltdowns, they are leaking most of the water being pumped in to keep them cool.