July 20 (Bloomberg) -- Tokyo Electric Power Co. said it’s on track to bring its crippled Fukushima Dai-Ichi nuclear station to safe status as soon as October and plans to start removing rods from the spent fuel pools within three years.
The utility known as Tepco issued a monthly update to its so-called road map to bring under control the worst atomic crisis since Chernobyl 25 years ago. Four months after an earthquake and tsunami knocked out cooling and power at the plant, Tepco said stable cooling has been achieved at the station 220 kilometers (137 miles) north of Tokyo.
Getting the reactors cool, preventing more hydrogen explosions and reducing the amount of radiation being emitted were the initial targets of the road map announced in April. No schedule was given for removing the melted fuel and decommissioning the reactors in Fukushima prefecture, where 160,000 people have been forced to flee their homes.
“No country has ever removed fuel from the pools inside such damaged buildings,” Japan’s nuclear crisis management minister Goshi Hosono said at a press conference yesterday. “It will be a challenge, and it is difficult to give a time frame.”
Three of the plant’s six reactors melted down and a fourth reactor building was damaged in one of the explosions that hit the complex in the early days of the disaster.
Thinking in Decades
“The problem is the melted fuel inside the reactors,” said Hironobu Unesaki, a nuclear engineering professor at Kyoto University, said by telephone. “That is something you need to think about in terms of decades.”
Tepco’s road map envisages bringing the reactors to a safe status known as cold shutdown within six to nine months from when the plan was unveiled on April 17. The government and the utility said they will stick to that time frame.
The government yesterday described cold shutdown as a state where the temperature at the bottom of a pressure vessel is held at 100 degrees Celsius (212 Fahrenheit) or below, and radiation emissions from the containment vessel are under control.
During the first phase, which lasted three months, much of the work has been focused on decontaminating highly radiated water that flooded basements and trenches around the damaged reactors as the utility doused the units to keep them cool.
Water overflowed from damaged reactors, impeding efforts to bring the situation under control. Since Tepco’s decontamination unit started last month, its operation has been intermittently halted due to leaks and other malfunctions.
--With assistance from Alex Devine in London. Editors: Alex Devine, Tony Barrett
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