TEPCO Begins Removing Spent Fuel at Fukushima
Nov. 19, 2013—Tokyo Electric Power Co. has begun removing used fuel from the concrete storage pool in the reactor 4 building of the Fukushima Daiichi nuclear power plant and placing it into steel casks. The fuel will be transferred to a common used fuel storage pool outside the reactor buildings.
Emptying the used fuel pools is an important milestone in decommissioning the nuclear power plants, a process expected to take decades.
The March 2011 nuclear accident at Fukushima followed a 45-foot-high tsunami that washed over the plant in the wake of a historically strong earthquake off Japan’s east coast. Loss of electric power to the facility led to overheating nuclear fuel in three of the six reactors, meltdown of their cores and ultimately the release of radiation into the environment.
Before beginning to take out the used fuel, TEPCO workers cleared debris from the reactor building and the storage pool and inspected the fuel rods for possible corrosion, the company said. Preparation also included reinforcing the building against future earthquakes and building a special crane to lift and move the fuel. The crane has sensors that will shut it down if a strong earthquake occurs.
Removal of fuel began this week as workers transferred the first 22 of more than 1,500 fuel assemblies, or collections of fuel rods, into a steel cask. The 10-foot-long hollow rods contain uranium fuel pellets.
To remove the fuel rods, workers lower a cask into the pool and move the fuel into it. Once full, the container is closed and the used fuel is transferred to the common pool.
Emptying the reactor 4 storage pool is expected to take more than a year.
“Moving spent fuel into long-term storage is a routine task that TEPCO has undertaken more than 1,200 times over the years,” TEPCO President Naomi Hirose said in a video, adding that “the circumstances at Fukushima Daiichi require special care.”
TEPCO has posted a video on its website outlining the fuel removal process.