Revisions to Fukushima Daiichi decommissioning roadmap

Announcing on 27 December the fifth revision to the roadmap, the Ministry of Economy, Trade and Industry said trial fuel debris retrieval would begin at unit 2 during 2021. It noted that a "partial submersion" method would be used using a specially-developed robot arm with "side access" into the reactor vessel. "The scale of the retrieval will be gradually enlarged," the ministry said.

The schedule for removing fuel assemblies from the storage pools at units 1 and 2 has been changed due to "a change in methods to suppress the dust dispersion" at those units. Fuel removal at unit 1 has now been postponed by four to five years and by one to three years at unit 2. The removal of all fuel assemblies from units 1-6 is expected to be completed during 2031. Installation of a large cover over unit 1 to suppress dust scattering is also expected to be completed around that time.

The volume of contaminated water generated at the plant has already been significantly reduced, from about 540 cubic metres per day in May 2014 to an average of 170 cu m/day in 2018. The revised roadmap maintains the current target of reducing contaminated water generation to 150 cu m/day in 2020, but sets a new target for reducing this to 100 cu m/day in 2025.

The ministry noted that the overall timescale for the decommissioning of the Fukushima Daiichi plant is unchanged and will be completed "within 30-40 years".

"With regard to the decommissioning and other work under way at Fukushima Daiichi, under the guidance of the government and other stakeholders we have continued our efforts to reduce risks by ensuring that the plant remains stable, implementing multi-layered contaminated water countermeasures, and improving the work environment," said Tokyo Electric Power Company President Tomoaki Kobayakawa in a statement. "The return of people to the local area is progressing steadily, as are reconstruction efforts. To support reconstruction and achieve decommissioning, we will continue with efforts to reduce risks, always keeping safety as our number-one priority."