Removal of nuclear fuel debris from Fukushima plant to begin within 15 years

Removal of nuclear fuel debris from unit 3 of Japan’s Fukushima Daiichi nuclear power plant will begin no earlier than 2037. Engineers working at the site of the 2011 nuclear accident have presented two options for accessing the melted nuclear fuel debris. Together, units 1 and 2 contain approximately 880 tonnes of destroyed nuclear fuel. The complete decommissioning of the power plant is estimated to take 30-40 years.

Japanese energy company Tokyo Electric Power Company Holdings (TEPCO) has presented specific options for accessing the destroyed nuclear fuel in unit 3 of the Fukushima Daiichi nuclear power plant. It will begin removing this nuclear waste from unit 3 and estimates that preparatory work will take 12-15 years. The company had originally announced that the process would start in the early 2030s. As part of the preparations, TEPCO will have to build supporting infrastructure, particularly additional buildings to house the equipment that will remove material from the unit’s containment vessel.

"Removing fuel debris is an extremely important task for advancing the decommissioning of the power plant. This is not only because it will reduce risks at the Fukushima Daiichi nuclear power plant, but also because it presents unprecedented technological challenges," TEPCO said in a press release.

The first three units at Fukushima Daiichi contain around 880 tonnes of nuclear fuel debris. It melted during the accident and then solidified again. Last year, TEPCO successfully collected a sample of the melted material using a robot and sent it for expert analysis. The company plans to transport the debris removed from the reactors’ cores to a new storage facility to be built within the power plant site.

Cleaning up after the nuclear accident

Fukushima Daiichi nuclear power plant was hit on 11 March 2011 by a tsunami triggered by a powerful earthquake off Japan’s east coast. The ensuing accident, caused by the loss of electricity supply and flooding of backup power sources, ranks alongside the 1986 Chernobyl nuclear power plant accident on the nuclear accident scale. The accident affected four units at the plant. Units 4, 5 and 6 were offline at the time, and no nuclear fuel had been loaded into their reactors. Unit 4, however, shared a ventilation system with unit 3, so leaking hydrogen also caused an explosion there.

"TEPCO will tackle the challenging task of removing fuel debris step by step, with safety as its top priority. The aim is to complete decommissioning within 30–40 years, as set out in the medium- and long-term plan," the company added.

Removal of the nuclear fuel debris is part of the third phase of the accident cleanup. The first phase involved cooling the nuclear reactors, while the second involves removing spent nuclear fuel from the individual units. In 2023, TEPCO also began discharging nearly 1.4 million tonnes of decontaminated radioactive water into the ocean.