Tokyo: Workers at Japan`s Fukushima nuclear plant today began moving fuel rods from a reactor building, in their most difficult and dangerous task since a tsunami crippled the facility in 2011.
Operator Tokyo Electric Power (TEPCO) said it had begun the process of removing the uranium and plutonium rods from a storage pool -- a tricky but essential step in the complex`s decades-long decommissioning plan.
The operation follows months of setbacks and glitches that have stoked widespread criticism of the utility`s handling of the crisis, the worst nuclear accident in a generation.
The work pales in comparison with the much more complex task that awaits engineers, who will have to remove the misshapen cores of three other reactors that went into meltdown before being brought under control two years ago.
The fuel rods are bundled together in so-called assemblies which must be pulled out of the storage pool where they were being kept when a tsunami smashed into Fukushima in March 2011. There are more than 1,500 such assemblies in the pool.
Over the course of two days, the company said it expects to remove 22 assemblies, with the entire operation scheduled to run for more than a year.
"At 15:18 (0618 GMT), we started to pull up the first fuel assembly with a crane," a company spokesman said today.
The huge crane, with a remote-controlled grabber, is being lowered into the pool and then hooked onto the assemblies, placing them inside a fully immersed cask.
The 91-tonne cask will then be hauled from the pool to be loaded onto a trailer and taken to a different storage pool about 100 metres (yards) away.
Experts have warned that slip-ups could trigger a rapid deterioration in the situation. Even minor mishaps will 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.
"This is an important process that is an inevitable part of the decommissioning process, but it includes work that could pose a great risk," the Citizen`s Nuclear Information Center, an independent energy think tank, said in a statement.
"We expect TEPCO and the Nuclear Regulation Authority to work with vigilance... And we demand disclosure of information" about the work, it added.
Hiroaki Koide, assistant professor at Kyoto University`s Research Reactor Institute, said the timing of the fuel rod removal was crucial as "the reactor`s storage pool is in an unstable condition".
Koide added that the whole decommissioning process would involve tasks that pose "unprecedented challenges".