Fukushima Debris Removal: A Tiny Step With Big Implications

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Tokyo Electric Power Company (TEPCO) plans to resume test retrieval of melted nuclear fuel (debris) at Fukushima Daiichi as early as this spring. In November 2024, for the first time since the 2011 disaster, a small amount of debris — just 0.7 grams — was successfully collected. This is an almost imperceptible fraction of the estimated 880-ton total, equivalent to one in 1.2 billion.

March 11 marks 14 years since the Great East Japan Earthquake and nuclear accident. Despite the passage of time, decommissioning remains an immense challenge due to high radiation exposure. Yet, even this tiny retrieval is a milestone toward the ultimate goal of dismantling the plant.

In February, the media was once again granted access to Unit 5 at Fukushima Daiichi. A Sankei Shimbun reporter entered the facility, continuing 2024's coverage.

Clad in protective suits, workers move cautiously, keeping low to the ground. Above them, the control rod drive mechanisms hang down. Directly beneath the reactor pressure vessel is a tangle of intricate structures — a truly confined space with hardly any room to move.

Fukushima's First Debris Retrieval

Debris was successfully retrieved from Unit 2, identical in size to Unit 5, for the first time since the accident. Although the operation was delayed by three years, it proved, both in Japan and internationally, that debris removal is possible. The initial extraction faced setbacks due to basic errors, making for a difficult start. However, gaining access to the meltdown-affected reactor was a major breakthrough.

*Fukushima Daiichi Nuclear Power Station's Unit 1, where decommissioning work is underway. February 27, Fukushima Prefecture. (©Sankei by Masamichi Kirihara)*

Nuclear fuel debris remains inside Units 1 to 3. Emitting lethal radiation, it is sealed within the containment vessels, making human access impossible. Instead, retrieval must rely entirely on remotely operated robots.

Even extracting a single fragment in such a confined space using a fishing rod-like device is almost miraculous.

Nevertheless, the government and TEPCO aim for full debris removal. The national decommissioning roadmap sets 2051 as the target, although the date lacks a solid scientific and technical foundation.

As long as debris remains inside the reactors, dismantling the buildings or even completing the discharge of ALPS treated water remains impossible. For Fukushima residents, full decommissioning is still a distant goal.

TEPCO considers the Unit 2 retrieval a trial run, using it to build expertise for large-scale removal planned at Unit 3 in the early 2030s.

A national research institute confirmed that the retrieved debris contained uranium from nuclear fuel. Further analysis could provide insights into its composition, hardness, and how the meltdown unfolded.

Utilizing Robotic Arms

A second debris retrieval operation is set for this spring, targeting a different location from the initial extraction. In FY2026, TEPCO plans to deploy a robotic arm with a broader range of motion than the fishing rod-like device used in the initial debris retrieval. If successful, it would mark another step forward in the highly complex decommissioning process.

Beside Unit 2 stands Unit 1, its steel framework still exposed since the accident. Preparations for future debris retrieval are progressing rapidly, with a large cover being installed over the building. Looking toward the landward side, over 1,000 storage tanks filled with ALPS treated water come into view. In February, at an area known as J9, TEPCO began dismantling empty tanks once used for water discharge.

"Debris retrieval may be a small step, but decommissioning is steadily progressing," said a TEPCO official.