Workers started removing radioactive fuel rods from a reactor building at the wrecked Fukushima nuclear plant on Monday, plant owner Tokyo Electric Power Co. said. The painstaking and risky task is a crucial first step toward a full cleanup of the earthquake- and tsunami-damaged plant in northeastern Japan.
The removal of the rods is the most difficult and dangerous process undertaken since runaway reactors were brought under control two years ago, after being hit by an earthquake and tsunami that claimed nearly 16,000 lives.
The rod removal follows months of setbacks and glitches that have stoked widespread criticism of the utility's handling of the crisis, the worst nuclear accident in decades.
The Unit 4 reactor was offline at the time of the March 2011 disaster, and its core did not melt as Units 1 through 3 did. But hydrogen explosions blew out the roof and walls of the Unit 4 building and weakened the structure, leaving it vulnerable to earthquakes.
Tokyo Electric, widely known as TEPCO, has since reinforced the building, but experts say keeping so many fuel rods in a storage pool in the building still poses a major safety risk.
"The operation is an important step toward decommissioning Fukushima Dai-ichi, which would take 30 to 40 years," TEPCO president Naomi Hirose said in a video message on the company's website.
Monday’s work is just a small first step in what will be an extremely complex process. Engineers will have to remove the misshapen cores of three reactors that went into meltdown.
Over the course of two days, the company said it expects to remove 22 rods. But it is expected to take at least until the end of 2014 to finish moving the 1,533 sets of fuel rods, including 202 unused sets, to a safer location. Each set includes 60 to 80 fuel rods containing uranium-based fuel pellets.
A crane with a remotely controlled grabber will be lowered into the pool and hook onto the rods, then place them in a fully immersed cask.
The 91-ton cask will then be hauled from the pool, loaded onto a trailer and taken to a different storage pool about 300 feet away.
Experts have warned that slip-ups could quickly cause the situation to deteriorate. Even minor mishaps would create considerable delays in the already long and complicated decommissioning.
While such operations are routine at other nuclear plants, the disaster has made conditions far more complex, TEPCO has said.
"We will continue with the work from tomorrow and proceed, paying close attention to safety," the company said in a statement.
Months of setbacks at the plant have included multiple leaks from tanks storing radioactive water and a power outage caused when a rat electrocuted itself on a circuit board.
TEPCO's management of the problems has been criticized as haphazard and uncoordinated, with one government minister saying it was like watching someone playing the carnival game Whac-a-Mole.
Experts say the fuel-rod sets may have been damaged or jammed by small pieces of debris that fell into the pool during the explosions. Some have also raised concern about the possibility of an earthquake occurring during the removal work.
Two other reactors, Units 5 and 6, were offline at the time of the disaster and eventually went into normal shutdown. They are also expected to be decommissioned.
Al Jazeera and wire services