A tiny amount of melted nuclear fuel was retrieved for the first time the other day from one of the reactors at the disaster-stricken Fukushima No. 1 nuclear power plant. The recovery from the bottom of a containment vessel represents a small first step in the decommissioning process, which is expected to be long and convoluted.

In confronting the harsh realities surrounding the mission, and the journey that lies ahead, plant operator Tokyo Electric Power Co. and the government need a vision for the future.

The three reactors at the wrecked plant suffered core meltdowns during the 2011 earthquake and tsunami disaster. An estimated 880 tons of solidified melted uranium fuel, known as fuel debris, remain. 

Technicians extracted a miniscule sample of highly radioactive rubble. The piece, smaller than 5 millimeters, was retrieved from the No. 2 reactor, which has been relatively well investigated, and placed in a special container to be transported to a research institute for analysis.

The process to remove debris was initially scheduled to start by 2021. Commenting on the hard-won breakthrough, Shinsuke Yamanaka, chairman of the Nuclear Regulation Authority, Japan’s nuclear watchdog body, said, “Only after we finish analyzing the sample can we say that we have taken a small but important step forward.”

The operation that began in August was interrupted due to an error in the sequence of connecting the pipes of the telescopic device used for removal. Shaped like a fishing rod, it can extend to more than 20 meters. After resuming the operation, it was again halted due to a malfunction of the camera to monitor what was happening inside. The sample was finally retrieved on Nov. 2.

The task of removal is unprecedented. Now, TEPCO must take advantage of the knowledge it has accumulated through a series of troubles and failures. Although fuel debris was first confirmed by a camera in 2017 and successfully lifted within the reactor in 2019, the latest operation faced many difficulties, hinting at the enormity of the challenges to be overcome.

In the case of the pipe mishap, no employees of TEPCO were present during the preparation. This again highlighted the old issue of delegating entire tasks and projects to subcontractors, which gave rise to a total lack of awareness and communication deficiencies. These have all been pointed out before.

Thirteen years after the catastrophic accident, it remains questionable whether the lessons that are supposed to have been learned from the missteps and blunders committed are being effectively applied to risk management.

The high radiation levels inside the reactor are harsh on electronic equipment. Technicians are subject to tight operational constraints to minimize exposure. Yamanaka has warned about the possible huge risks involved, saying, “Even small mistakes could potentially lead to significant safety hazards.”

Although the analysis of the retrieved sample will provide some information, it will not reveal the overall picture of the debris. In December 2011, the government and TEPCO outlined a plan to remove all debris from the No. 1, No. 2 and No. 3 reactors within approximately 10 to 15 years and complete the decommissioning by 2051. The feasibility of this plan is questionable.

Shunji Matsuoka, a professor of environmental economics at Waseda University in Tokyo, estimated how long it would take based on data concerning the Three Mile Island nuclear accident in the United States in 1979.

He predicts that the removal could take about 70 to 170 years, which he still considers to be an “optimistic figure.”

Another very vital point is that no method has been decided for disposal of the retrieved fuel debris, and the plant site’s post-decommissioning landscape remains unclear. The plan to complete decommissioning the reactors by 2051 seems unrealistic by any yardstick.

However, establishing a new timeline or vision just like that is also challenging. The utility and the government must continue to engage in dialogue with the local community and national debate on this colossal challenge while keeping in mind the severity of the nuclear disaster and verifying the technology and cost.

--The Asahi Shimbun, Nov. 8