Tokyo Electric Power (Tepco) has unveiled new plans to contain the crisis at the Fukushima Daiichi plant after admitting it faced greater challenges than first disclosed, according to Reuters.
The utility said it dropped an initial plan to stabilize the reactors by flooding them in water after last week's discovery of a leak in the main vessel of the plant's No. 1 reactor.
Tepco said it would now try to cool the reactors by continuously circulating the water already there. It said it still aimed to complete initial steps to limit the release of further radiation from the plant 240 km (150 miles) northeast of Tokyo and to shut down its three unstable reactors by January 2012.
The updated plan sketched out the new methods which would in particular focus on how to clean up the large amount of water contaminated by radiation.
Bringing the reactors to a state of "cold shutdown", where the uranium fuel at the core is no longer capable of boiling off the water used as a coolant, would allow officials to turn to the challenge of cleaning up the site and eventually removing the fuel from the six scrapped reactors. That process could take more than a decade.
New details about the state of the plant released in the past week by the facility's embattled operator have made it clear that the reactors suffered far more serious damage than previously disclosed.
Uranium fuel rods in three 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.
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. The growing pool of radioactive water, enough to fill 36 Olympic-sized pools, at the Fukushima site is the big challenge now and major focus of the revised plan of attack.
Most of that radioactive water has pooled in buildings and trenches at the complex, but outside experts have raised concern it could still spill into the groundwater and the nearby Pacific.