The fuel removal process in reactor No 3 began just a day after prime minister Shinzo Abe visited the Fukushima nuclear plant on Sunday in order to inspect the decommissioning work.
The delicate operation represents the first time the Tokyo Electric Power Co (TEPCO) has pulled out fuel rods from inside a highly contaminated building containing the melted-down reactor, and comes four years behind schedule.
To remove the rods, workers are using a remotely operated crane from a control room about 1,640 feet away from the reactor building that houses the rods because radiation levels there remain high.
Tepco said the operation to remove the fuel rods, which are in uncovered pools, would take two years, adding that transferring them to safer ground would better protect them in the event of another catastrophic natural disaster.
About an hour after the work began, the first fuel unit was safely stored inside the cask, TEPCO spokesman Takahiro Kimoto said. "We will watch the progress at the site as we put safety first".
"We had to proceed carefully (to remove debris), and we needed to take measures as dust would waft up and increase radiation readings", she told AFP. The company also said the more critical part would be the removal of molten fuel from inside the damaged reactors. This is considered the most hard part of the massive clean-up operation and is not expected to begin until 2021.
In February, a remote-controlled robot with tongs removed pebbles of nuclear debris from the Unit 2 reactor but was unable to remove larger chunks, indicating a robot would need to be developed that can break the chunks into smaller pieces. The move is being hailed as a milestone in the decades-long process to decommission the plant.
The company also faces other hard challenges, including working out how to dispose of large quantities of contaminated water stored in containers at the plant site. The fuel units in the pool located high up in reactor buildings are intact despite the disaster, but the pools are not enclosed, so removing the units to safer ground is crucial to avoid disaster in case of another major quake similar to the one that caused the 2011 tsunami. The man, who worked mostly at the Fukushima Daiichi plant over 28 years and died of lung cancer, was responsible for measuring radiation at Fukushima Daiichi. The utility plans to repeat the procedure in the two other reactors that suffered meltdowns. Tepco also said transferring the fuel rods - almost 1,500 of them still inside the storage pools of the three reactors that melted in 2011 - to safer ground would better protect them in the event of another catastrophic natural disaster.