Tokyo Electric Power Co. will start a demonstration project as early as Thursday to remove a small amount of radioactive debris from its wrecked nuclear power plant in Fukushima.

The operator of the Fukushima No. 1 nuclear power plant, which suffered a meltdown after a massive earthquake and tsunami overwhelmed the facility in 2011, will start the experimental removal process at reactor No. 2 on Thursday, so long as necessary inspections are completed on time, an official from the company said in a news conference Monday.

It’s a step forward for the utility and the government, which estimates the complete decommissioning of the facility will take three to four decades. Removal of the deadly debris has proved challenging, requiring the development of a robotic arm that can fish out radioactive fuel, metal cladding and other structures in the reactor that melted, cooled and solidified together. Tepco has delayed the start of procedure in the past.

About 880 metric tons of fuel debris remain in the three reactors that suffered a meltdown, according to estimates by the International Research Institute for Nuclear Decommissioning. The initial demonstration will retrieve less than 3 grams of the debris.

A robotic arm that looks like a fishing rod will be operated from a remote room into reactor No. 2, before a metal claw-like grip will be lowered down to retrieve a small amount of debris, the company said on its website. Tepco has selected the No. 2 reactor to demonstrate the method and plans to remove debris in reactors No. 1 and No. 3 in the future.

It is estimated that the cleanup at Fukushima, the site of the worst nuclear disaster since the 1986 Chernobyl accident, will cost around ¥23 trillion ($157 billion). Tepco also started a process to release treated wastewater from the facility last year, as part of its decommissioning efforts.