TEPCO has removed all of the used fuel assemblies from the unit 4 spent fuel pool at the Fukushima Daiichi nuclear power station. Some fresh, unirradiated fuel remains in the pool, but is scheduled for removal by the end of 2014.
Work to empty the unit 4 spent fuel pool, which contained a total of 1533 fuel assemblies (1331 used and 202 unused) began on 18 November 2013.
The operation involved moving the assemblies from the spent fuel pool into a transport cask, which was transported across the site and unloaded at a shared pool storage facility.
This process was repeated 63 times until all 1331 of the used fuel assemblies and 22 of the fresh fuel assemblies had been removed from the pool.
TEPCO says that 180 unused fuel assemblies are left in the pool and that the removal operation will continue. The radiation dose from this fresh fuel is low enough for it to be handled manually, TEPCO said. This will simplify the operation.
Photo: Cask transfer at common pool, November 2013 (Source: TEPCO)