Tepco said that a crane used to move spent fuel rods at the meltdown-hit Fukushima No. 1 nuclear plant stopped working Wednesday because operators tried moving it while the brake was applied.
The crane stopped moving at around 9:30 a.m. Wednesday as workers were preparing to lift a batch of fuel rod assemblies from the spent-fuel pool in the No. 4 reactor building.
After investigating the cause, Tokyo Electric Power Co. said the crane stopped due to an electric current surge to the motor while the brake was on.
Tepco began extracting 1,533 fuel rod assemblies from the pool in the heavily damaged building in November.
As of Wednesday, it had transferred 550 assemblies to a pool in a more stable building around 100 meters away.