Robot glitch delays fuel removal from Fukushima nuclear power plant

TOKYO (AP) — The operator of the destroyed Fukushima nuclear power plant said Thursday it was still postponing the start of removing highly radioactive molten fuel from its damaged reactors due to delays in developing a remote-controlled robotic arm.

Tokyo Electric Power Company Holdings originally planned to start removing molten fuel from the Unit 2 reactor at the Fukushima Daiichi power plant last year, 10 years after the disaster triggered by a massive earthquake and tsunami on 11 March 2011.

That plan has been delayed until later this year, and will now be delayed until around next fall due to additional work needed to improve the performance of the robotic arm, TEPCO said.

The giant arm, jointly developed by Britain’s Veolia Nuclear Solutions and Japan’s Mitsubishi Heavy Industries, has been transported to Japan and is being adjusted in a test facility south of the Fukushima power plant.

The delay will not affect the overall decommissioning of the plant, which is expected to take 30 to 40 years, TEPCO said. Experts said the completion target was too optimistic.

During the accident, approximately 880 tons of highly radioactive nuclear fuel in the three damaged reactors melted and fell to the bottom of their primary containments, where they hardened, most likely mixed with broken parts of the reactor and the concrete foundation. Its removal is by far the most difficult challenge of the dismantling process.

TEPCO has made progress in recent years in assessing the condition of fuel in reactors by sending remote-controlled robots inside primary containment buildings. But the data and images provided by the probes are still partial, and experts say it’s too early to imagine when or how the cleanup will end.

The continued need to cool the remaining fuel in the reactors has resulted in massive quantities of treated but still radioactive spent cooling water which is stored in approximately 1,000 tanks on the plant grounds.

The government has announced a plan to start discharging stored water back to the sea after further treatment and dilution in spring 2023, a plan which has been fiercely opposed by local residents, the fishing community and neighboring countries.