Fukushima nuclear debris removal to begin as early as August

Crucial work at devastated plant has been delayed for three years

AYAKA OTAKA, Nikkei staff writer, May 31, 2024,

TOKYO — Trial removal of melted fuel rods at the tsunami-hit Fukushima Daiichi nuclear plant will begin as early as August, Tokyo Electric Power Co. Holdings announced on Thursday, a critical step in a decommissioning process that is expected to take decades.

Removal of the fuel rods, which is now three years behind schedule, had been slated to start by October, but TEPCO now says it will happen between August and October. Necessary equipment will be set up at the plant in northeastern Japan as early as July.

“We will continue to proceed with the work carefully, with safety as our top priority, so as not to impact the surrounding environment,” said Akira Ono, the TEPCO official in charge of decommissioning efforts.

The radioactive debris consists of fuel and other materials that melted, then cooled and solidified, after the plant lost power in the devastating March 2011 tsunami. An estimated 880 tonnes of debris are in reactor units 1 to 3.

As the melted fuel is highly radioactive, people cannot come near it, and removal must be done in small amounts to prevent leakage during the process.

A device similar to a fishing rod will be used to carry out the work. On Tuesday, a video was released showing the device being tested at a Mitsubishi Heavy Industries shipyard in Kobe, using a full-scale model of a nuclear reactor.

According to TEPCO, a 3- to 4-meter cable with a mechanical claw will be hung from the device down towards the bottom of the reactor. Less than 3 grams can be collected at a time.

Shortening shifts to reducing workers’ exposure to radiation will be necessary. The trial removal is expected to take about two weeks.

Removal was originally to be carried out in 2021. The plan was to use a robot arm to remove the debris, but development of the arm was delayed. A large amount of non-fuel debris blocking access also caused delays………………………………

The government has said that it will take 30 years to 40 years from the 2011 incident to decommission the plant.

The reactor building cannot be dismantled unless the debris is removed. Cooling water, as well as rainwater, that comes in contact with the debris becomes contaminated.

TEPCO began releasing treated wastewater in August 2023, but as long as the debris remains, the cycle of water being contaminated and requiring treatment and release will continue.

Some critics say the government’s decommissioning plan is unrealistic. The process could take more than 100 years, say some scientists in the Atomic Energy Society of Japan. After the Chernobyl nuclear disaster in the former Soviet Union, decommissioning was abandoned, and a shelter structure was built to completely cover the area with radioactive waste.

There is also the issue of how to dispose of soil and rubble contaminated by scattered radioactive materials. The government has promised to transport this waste outside of Fukushima prefecture by 2045, but a destination has not been decided. https://asia.nikkei.com/Spotlight/Environment/Fukushima-nuclear-debris-removal-to-begin-as-early-as-August