TEPCO removing empty tanks to advance Fukushima plant decommissioning work

TOKYO — The operator of the Fukushima Daiichi nuclear power plant continues to demolish tanks emptied by the release of treated radioactive water into the sea, aiming to use the freed-up space to build facilities to advance decommissioning work.

Nearly 15 years after the nuclear accident triggered by a massive earthquake and tsunami, Tokyo Electric Power Company Holdings Inc is still coping with radioactive water generated in the process of cooling melted reactor fuel, although the daily buildup is on track to be the smallest in the current fiscal year.

The discharge of treated water into the Pacific Ocean began in August 2023, as more than 1,000 tanks installed at the site to store the wastewater were deemed to be taking up too much space and hindering progress in decommissioning work.

The first tank dismantling following the water release took place in February 2025 in an area known as J9. After workers finished removing a dozen tanks there by September, they moved on to the adjacent area known as J8, where nine tanks stand.

Each of the nine tanks is 12 meters tall and 9 meters wide, with a capacity of 700 tons. Removing the tanks in the two sections will free up about 2,900 square meters.

The utility plans to use the land to build facilities to store melted fuel debris to be retrieved from the No.3 reactor and to conduct maintenance for debris removal devices.

Some 880 tons of debris are estimated to remain in the Nos. 1 to 3 reactors that suffered core meltdowns in the world's worst nuclear crisis since the 1986 Chernobyl disaster. Hydrogen explosions damaged the buildings housing the Nos. 1, 3 and 4 units.

TEPCO and the government plan to start full-fledged removal of debris at the No. 3 reactor no earlier than fiscal 2037, pushing back the early 2030s target due to the time needed for preparation.

Radiation levels inside the empty tanks have been confirmed to be lower than the average air dose level outside, indicating that contamination was relatively low, according to the operator.

Disassembled tank parts will be cut into small pieces using gas cutting torches and stored in cargo containers on the power plant premises.

© KYODO