Friday, August 26, 2022

Fukushima debris removal delayed by another year
The work to remove radioactive debris from the Fukushima plant could 
now start as late as March 2024. PHOTO: REUTERS

TOKYO (AFP) - Work to remove nuclear debris from the devastated Fukushima power station in Japan has been delayed again to ensure the safety of the multi-decade project, according to plant operator Tepco.

Tokyo Electric Power (Tepco) had planned to begin extracting radioactive debris from one of the reactors this year - already later than the original 2021 start date.

But the company said Thursday (Aug 25) it needed an "additional preparation period" of up to 18 months, meaning the work could now start as late as March 2024.

Tepco said in a statement that this was necessary "to improve the safety and ensure the success" of surveying inside the reactors and retrieving the debris.

"The timeframe has been adjusted, so that the work will commence in the latter half of fiscal 2023", which ends March 2024, it said.

Engineers are fine-tuning a robotic arm specially designed for the work, including adjusting its speed and precision, Tepco said.

A deadly tsunami on March 11, 2011 caused a meltdown at the Fukushima Daiichi nuclear plant in north-eastern Japan, the world's worst nuclear accident since Chernobyl.

Tepco, the government and a coalition of engineering firms are working to decommission the damaged reactors in a project that is estimated to take as long as 40 years.

Robot issue delays fuel removal from Fukushima nuclear plant

CGTN

Fukushima Daiichi nuclear power plant in Okuma town, Fukushima prefecture, north of Tokyo, February 13, 2021. /AP

The operator of the wrecked Fukushima nuclear power plant said Thursday it is further postponing the start of the removal of highly radioactive melted fuel from its damaged reactors because of delays in the development of a remote-controlled robotic arm.

Tokyo Electric Power Company (TEPCO) had originally planned to begin removing melted fuel from the Unit 2 reactor at the Fukushima Daiichi plant last year, 10 years after the disaster triggered by a massive earthquake and tsunami on March 11, 2011.

That plan was postponed until later this year, and now will be delayed further until about autumn next year because of additional work needed to improve the performance of the robotic arm, TEPCO said.

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

The delay won't affect the overall decommissioning at the plant, which is expected to take 30 to 40 years, TEPCO said. Experts have said the completion target is too optimistic.

During the accident, an estimated 880 tons (about 72.6 tonnes) of highly radioactive nuclear fuel in the three damaged reactors melted and fell to the bottom of their primary containment vessels, where it hardened, most likely mixed with broken parts of the reactor and the concrete foundation. Its removal is by far the toughest challenge of the decommissioning process.

TEPCO has made progress in assessing the condition of the fuel in the reactors in recent years by sending remote-controlled robots inside the primary containment vessels. But 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 continuing need to cool the fuel remaining in the reactors has resulted in massive amounts of treated but still radioactive used cooling water that is being stored in about 1,000 tanks on the grounds of the plant.

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

Source(s): AP

No comments: