Fukushima operator gives first glimpse of fuel rod removalNovember 19, 2013 in Technology / Energy & Green Tech
The operator of the crippled Fukushima nuclear plant Tuesday offered the first glimpse of the operation to remove its fuel rods, the most dangerous job since the runaway reactors were brought under control two years ago.
Video footage supplied by the company showed Tokyo Electric Power (TEPCO) workers with protective suits inside a reactor building as a crane lowered a huge metal cask into a storage pool filled with uranium and plutonium rods.
The nuclear fuel rods are bundled together in 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.
Removal of the fuel rods is a tricky but essential step in the decommissioning of the complex, which is expected to take decades.
On Monday, the company said it expects to remove 22 assemblies over two days, with the entire operation scheduled to run for more than a year.
The huge crane, with a remote-controlled grabber, is hooked onto the assemblies, placing them inside the 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
TEPCO said the work was on schedule with the 22 assemblies expected to be placed inside the cask by Tuesday evening.
The reactor which the pool serves—No. 4—was not in operation on March 11, 2011, when a massive earthquake triggered a killer tsunami that swept the Fukushima nuclear plant, triggering meltdown and explosions.
But the pool was heavily damaged and left at the mercy of earthquakes, storms or another tsunami.
The fuel assemblies needed to be kept in a more stable facility, but experts have warned that slip-ups in the removal operation could trigger a rapid deterioration in the situation.
TEPCO's efforts to contain the crisis have faced a string of setbacks and mechanical glitches which stoked widespread criticism of its handling of the worst nuclear accident in a generation.
The work that began Monday 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.
© 2013 AFP
"Fukushima operator gives first glimpse of fuel rod removal" November 19, 2013 http://phys.org/news/2013-11-fukushima-glimpse-fuel-rod.html