Tokyo Electric Power Company Holdings (Tepco) on Tuesday morning began a second experimental operation to remove nuclear fuel debris from a damaged reactor at its Fukushima No. 1 power plant.

Tepco aims to remove 3 grams of debris at maximum from the meltdown-stricken No. 2 reactor within about two weeks. This time, the company plans to go closer to the center of the reactor containment vessel than during the first experimental work last year.

Constituents of the collected debris will be analyzed for research to realize full-scale removal.

As with its first debris removal work, the company plans to insert a fishing rod-shaped remote-controlled device into the containment vessel. A claw gripper attached to the tip of the device will catch debris at the bottom of the reactor vessel.

Tepco replaced a camera attached to the telescopic device after the first debris retrieval work was halted due to camera problems. The company also improved the gripper.

Tuesday's work began at 9 a.m. The company started its attempt to retrieve some debris after the device passed through an isolation valve located near the containment vessel shortly after 10 a.m.

The first round of debris removal was supposed to start in August last year. But an error in the order of pipes attached to the device was discovered just before the start of the work.

After the first round was launched the next month, it was suspended due to the camera issues. In November that year, Tepco succeeded in retrieving 0.7 gram of debris.

Some 880 tons of nuclear fuel debris is estimated to remain in the No. 1 to No. 3 reactors at the plant, where meltdowns occurred following a powerful earthquake and tsunami that struck northeastern Japan in March 2011. Tepco plans to begin full-scale debris removal operations at the No. 3 reactor in the 2030s.