A Japanese government organization has held the first meeting of an expert panel to discuss challenges in removing nuclear fuel debris at the crippled Fukushima Daiichi power station.

Such debris is a mixture of molten nuclear fuel and pieces of metal structures. Removing it is said to be the biggest problem in decommissioning the plant.

Experts estimate that there is a total of 880 tons of nuclear fuel debris in the No. 1, 2 and 3 reactors of the plant, which suffered meltdowns in the 2011 quake and tsunami disaster.

The government and the plant's operator, Tokyo Electric Power Company, plan to start removing the debris from the No. 2 reactor in the second half of fiscal 2023 on a test basis.

But only several grams of it is expected to be taken out during the process.

The government's Nuclear Damage Compensation and Decommissioning Facilitation Corporation set up an expert panel to help determine how to carry out full-scale removal. Its first meeting was held on Wednesday.

The panel of 10 experts from Japan and abroad includes Fuketa Toyoshi, former chairman of the Nuclear Regulation Authority; researchers on radioactive waste and architectural technology; and the former head of Switzerland's nuclear regulator.

For the removal, the organization has so far proposed several methods: one involves taking the debris out after the reactor building is covered by a structure and filled with water.

Another involves building the covering structure but not filling the building with water, and removing debris in the air.

The panel will examine the options' safety and technological feasibility for about one year. TEPCO is to choose a method based on the panel's assessment and other analyses.