19 Novembre 2013
November 19, 2013
Day 2 of nuclear fuel removal at Fukushima
Tuesday marked the 2nd day of nuclear fuel removal from a damaged reactor building at the Fukushima Daiichi nuclear power plant.
The storage pool at the Number 4 reactor building holds 1,533 units of nuclear fuel. 1,331 of them are highly radioactive spent fuel and the rest are unused.
It took workers about 3-and-a-half hours to transfer 4 units of unused fuel into a special fuel transport container placed into the pool.
Tokyo Electric Power Company officials say the units are being hoisted slowly from their racks to avoid small bits of debris.
It says underwater cameras monitor the process when the fuel units are placed in the container.
TEPCO says because the process takes time it began the work on Tuesday at 9AM, one hour earlier than scheduled, and will extend the operation by 2 hours to about 9PM.
Officials say they hope to move 18 units on Tuesday. If a total of 22 units are transferred by the end of Tuesday's operation, the container will be raised out of the pool with a large crane on Wednesday.
Nov. 19, 2013 - Updated 06:48 UTC
TOKYO (Kyodo) -- The operator of the crippled Fukushima Daiichi nuclear power plant said Tuesday that work to remove fuel from the spent fuel pool at the No. 4 reactor building had entered a second day.
On Monday, workers successfully extracted four unused fuel assemblies from the fuel rack and placed them in a transportation container that will be taken to a different pool at the plant, which will provide more stable conditions for keeping the fuel cool.
The spent fuel pool, located on the top floor of the reactor building, holds 1,533 fuel assemblies, including 202 unused ones. TEPCO plans to finish the removal work by the end of 2014.
A fuel assembly is a bundle of fuel rods comprised of zirconium metal tubes with pellets inside. The pellets, made of uranium, serve as the actual fuel for nuclear reactors.
Once the transportation container is filled with 22 fuel assemblies, workers will load it onto a trailer and take it to another pool around 100 meters away. It is expected to take about a week to complete the work cycle.
The mission requires extreme prudence, as it is an unprecedented attempt to remove fuel from a building that saw its roof and walls blown up by a hydrogen explosion in the 2011 nuclear crisis.
As for preparations to achieve the task, TEPCO has cleared large pieces of rubble that fell on the upper floor of the reactor building as a result of the explosion and created a huge steel-framed cover to blanket the reactor building.
During the nuclear crisis triggered by a huge earthquake and tsunami on March 2011, the Nos. 1 to 3 reactors experienced core meltdowns.
The No. 4 unit, however, only suffered a hydrogen explosion as all of its fuel was stored in the spent fuel pool because the reactor was undergoing periodic maintenance work at the time.