Fuel debris removal from Fukushima reactors delayed

In Fukushima Daiichi units 1 to 3, the fuel and the metal cladding that formed the outer jacket of the fuel rods melted, then re-solidified as fuel debris. Unit 4 does not contain any used fuel or fuel debris as it had already been defuelled before the accident.

There is an estimated total of 880 tonnes of fuel debris in units 1-3. To reduce the risk from this fuel debris, preparations are under way for retrieving it from the reactors. The aim had been to begin retrieval from unit 3, from which used nuclear fuel has already been removed. The retrieved fuel debris will be stored in the new storage facility that will be constructed within the site.

Plant operator Tokyo Electric Power Company Holdings Inc (Tepco) succeeded in extracting small samples of fuel debris from the unit 2 reactor in November 2024 and in April this year.

However, Tepco has reportedly concluded after studying the specific removal method that it would take around 12 to 15 years just to prepare for the work.

"The difficulty of retrieving the first handful of debris has become apparent," Toyoshi Fuketa, head of the decommissioning work at the Nuclear Damage Compensation and Decommissioning Facilitation Corporation (NDC) told a press conference on 29 July, Kyodo reported.

Tepco has presented two plans to prepare for the fuel debris removal. One option involves demolishing a radioactive waste disposal building next to unit 3, while the other would keep the building in place.

In a statement, Tepco said: "Fuel debris retrieval is an extremely vital task for moving forward with decommissioning not only because it will reduce risk at the Fukushima Daiichi Nuclear Power Station but also because it presents unprecedented technological challenges. TEPCO will proceed with difficult tasks for the fuel debris retrieval step by step while prioritising safety as it aims to finish decommissioning in 30-40 years, as laid out in the Mid-and-Long-Term Roadmap, and fully complete the decommissioning of the Fukushima Daiichi Nuclear Power Station."