Workers start to remove Fukushima fuel rods

TEPCO has begun work to remove 566 highly-radioactive fuel rod assemblies from reactor building number 3 of its devastated Fukushima Daaichi nuclear power plant.

Three units at the plant suffered a meltdown in 2011 after it was struck by a 13 m tsunami that wiped out power for cooling. In Unit 3, water in the pressure vessels subsequently evaporated, exposing fuel rods inside the reactor, which then reacted with the resulting steam to produce hydrogen which ignited, blowing the roof off the reactor building.

Eight years on, workers have started to remove fuel from a storage pool in the same building that houses the melted down reactor. Efforts until now have been spent surveying the site, removing debris from the pool and installing radiation shielding and a fuel-handling crane that can be operated remotely to prevent workers being exposed to the site’s high-levels of radiation.

On 15 April, workers began using the crane to pick up assemblies one by one and transfer them to a cask. Once seven assemblies are placed inside, a lid is attached and the cask is loaded onto a truck, which carries them out of the building for storage in another pool. The company said it expects to complete the removal of all 566 assemblies in March 2021.

The so-called common pool that will house the assemblies from Unit 3 is already home to 1,331 assemblies moved out of Unit 4, which was offline and all its fuel in storage when the tsunami struck. The building did not escape the devastation though, as hydrogen vented from Unit 3 is thought to have flowed through exhaust pipes into Unit 4, where it ignited.

The government hopes to finish cleaning up the whole site within 30 to 40 years, though some experts have warned that is an underestimate. The Japan Centre for Economic Research said the total costs of the operation could reach as high as US$660bn.