5 Novembre 2014
November 5, 2014
THE ASAHI SHIMBUN
Tokyo Electric Power Co. has removed all the spent nuclear fuel from the pool in the No. 4 reactor building at the Fukushima No. 1 nuclear power plant.
The utility plans to finish extracting all the fuel rods from the building by the end of this year, completing the most critical phase of the decommissioning of the reactor.
The operator of the crippled plant said that it will have successfully removed by Nov. 5 the last of the 1,331 spent fuel rods in the pool. There were a total of 1,535 fuel rods in all in the building when the extraction process began. The operation continues there with 24 of the 204 unused fuel rods having already been removed.
The No. 4 reactor was offline for a regular inspection when the Great East Japan Earthquake and tsunami struck northeastern Japan in March 2011. The building’s roof and walls were subsequently blown off in a hydrogen explosion.
Due to the failure of the cooling systems, concerns arose that the 1,535 fuel rods stored there could face exposure to the open air and discharge large amounts of radioactive materials into the atmosphere.
TEPCO started a full-fledged operation to remove the nuclear fuel assemblies in the storage pool in the No. 4 reactor building in November last year, using a special cask receptacle.
The utility’s mid- and long-term road map for decommissioning the Fukushima plant outlined three phases. The removal of fuel rods from the pools in the reactor buildings is part of the second phase.
The work at the No. 4 reactor is running ahead of that in the plant's No. 1 to No. 3 reactor buildings.
The reactor No. 4 building was exposed to less contamination compared to those housing the other reactors, all of which suffered meltdowns. High levels of radiation have prevented plant workers from entering the other reactors.
TEPCO recently started removing the canopy installed over the No. 1 reactor building in the first step in work to remove debris and nuclear fuel from inside the structure. The utility is also surveying the interior of the No. 2 reactor building with robots while removing debris at the No. 3 reactor building using remote-controlled machines.