Photo/Illutration Decommissioning work continues at the No. 3 reactor at Tokyo Electric Power Co.’s Fukushima No. 1 nuclear power plant in Okuma, Fukushima Prefecture, on Jan. 24. (Asahi Shimbun file photo)

The removal of highly radioactive fuel from one of the reactors at the crippled Fukushima No. 1 nuclear plant will not begin in earnest for at least another 12 years, delaying the start of the vital piece of the decommissioning project.

The delay is due to a waste processing facility near the reactor that will first need to be demolished, a nuclear advisory agency said on July 29.

More space is needed for equipment that will solidify and then remove lumps of fuel that melted inside the plant’s No. 3 reactor, so plans for large-scale removal are being delayed until after the year 2037, the Nuclear Damage Compensation and Decommissioning Facilitation Corp. said.

The NDF advises on decommissioning work.

Although originally expected to begin in the early 2030s, after examining the proposed removal method, it became clear that preparations will take at least 12 to 15 years, the NDF said.

Currently, the central government and plant operator Tokyo Electric Power Co. are working  to “complete the decommissioning of the plant by 2051.” The setback to the fuel removal schedule means the 2051 plan may also be delayed.

In the March 2011 accident following the Great East Japan Earthquake and tsunami, three reactors at the Fukushima nuclear power plant melted down.

The cores and basements of the buildings are estimated to contain 880 tons of debris comprising melted fuel rods, fuel casings and other components, much of the material highly radioactive. Removal of the debris is considered the most challenging part of the decommissioning process.

In November 2024 and in April of this year, debris removal was trialed in the No. 2 reactor, but only about 0.9 gram of material was retrieved.

Until now, the NDF has been considering three methods for removal: partial submersion, which involves spraying water on the debris while removing it; full submersion, which involves filling the reactor with water; and the filling and solidification method, which involves solidifying the debris with filler material and then scraping it out.

The full submersion method is difficult to implement because the damage to the building of No. 3 reactor is severe. Water will simply drain out.

Therefore, the NDF has determined that this method would be too challenging for a range of reasons.

Instead, the NDF recommended that TEPCO combine the partial submersion method with the filling and solidification method, which can suppress radiation levels.

TEPCO accepted the proposal and has decided to adopt this approach, the NDF said.

Specifically, small holes will be made in the upper part of the No. 3 reactor building and filling materials will be injected into the debris as needed. The plan is to crush the resulting material into smaller pieces and remove them one by one.

Removal will need the construction of devices that enable the debris to be pulled out while containing radioactive materials that would otherwise be scattered, the NDF said.

The combination method will need a large area for equipment to be built. This space is unavailable currently. So first, the nuclear waste processing facility located to the north of No. 3 reactor must be demolished.

This facility stores highly radioactive waste, and the demolition itself may take a considerable amount of time.

(This article was written by Yusuke Ogawa and Fumi Yada.)

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