A device designed to remove debris from a reactor at the damaged Fukushima nuclear plant was unveiled in Kobe, western Japan, on May 28, 2024. AP Photo
An attempt to retrieve a piece of melted fuel from Japan’s Fukushima Daiichi nuclear power plant was put on hold Thursday due to a technical glitch. The operation involved using an extendable robot to collect a tiny fragment of the debris inside the Unit 2 reactor, which is part of the most challenging phase of the plant's decommissioning. The Fukushima Daiichi plant was severely damaged during the March 11, 2011 earthquake and tsunami, which caused a meltdown in three of its reactors. This latest mission is crucial as it marks the beginning of the fuel debris removal phase, a process expected to take decades.
The operation was called off when workers noticed that five 1.5-meter pipes used to maneuver the robot were placed in the wrong order. Due to the high radiation levels, the mistake could not be corrected within the time limit for safe exposure. The pipes were meant to push the robot inside the reactor and pull it back out once the task was completed. After the error was discovered, the mission was halted, and a new start date has yet to be decided.
The robot, designed to extend up to 22 meters, was supposed to reach the target area inside the reactor and collect a small fragment of the melted fuel using tongs attached to its tip. The mission was planned to last two weeks, during which the robot would gather the sample and return it for analysis. The small fragment, weighing less than three grams, is part of an estimated 880 tons of highly radioactive molten fuel inside the damaged reactors. Analyzing this sample is crucial for developing future decommissioning methods, as well as the technology and robots needed to complete the task.
TEPCO spokesperson Kenichi Takahara expressed disappointment over the mistake, calling it a "basic error." He emphasized that officials are investigating the issue and that the retrieval mission will only resume once the cause of the problem is identified and preventive measures are in place. TEPCO President Tomoaki Kobayakawa echoed this sentiment, stressing that safety is the top priority and that the process will not be rushed.
The decommissioning of the Fukushima Daiichi plant is expected to take 30 to 40 years, a timeline set shortly after the meltdown. However, this target has faced criticism for being overly optimistic. As of now, no specific plans have been made for the full removal of the melted fuel debris or its storage. Nevertheless, understanding the nature of the melted fuel is essential for the safe and effective decommissioning of the plant.
