The operator of Japan's Fukushima Daiichi nuclear power plant says it has completed the first test retrieval of fuel debris from one of the damaged reactors.

Removal of all debris is considered the most challenging step in the decommissioning of the facility, which was devastated in the 2011 earthquake and tsunami.

Tokyo Electric Power Company began experimenting with the removal of molten fuel mixed with parts of the reactor structure at the No.2 reactor in September.

To do so, workers placed a pipe-like device inside the reactor containment vessel to grab the material from its base.

Last week, the tool succeeded in retrieving several grams of debris.

Radiation levels at a distance of 20 centimeters away were recorded at 0.2 millisieverts per hour. For reference, the guidance for workers at the site is to limit radiation exposure to 24 millisieverts per hour.

The debris was placed in a special container just before noon on Thursday, completing the process.

Retrieval work was slated to begin in 2021, but was delayed due to technical glitches and other problems. There is hope the small amount of debris taken out will provide valuable data for large-scale removal.

An estimated 880 tons of radioactive debris remains across Fukushima Daiichi's No. 1, 2, and 3 reactors.