TOKYO — For the first time since the significant nuclear disaster in 2011, a remote-controlled robot has successfully retrieved a small sample of melted fuel from one of the damaged reactors at the Fukushima Daiichi nuclear power facility, which was severely impacted by a tsunami.
On Saturday, the Tokyo Electric Power Company Holdings (TEPCO), the entity responsible for the management of the plant, announced that its robot, resembling an extendable fishing rod, adeptly collected a piece of debris measuring approximately 5 millimeters (about 2 inches) from the surface of a mound of molten fuel located at the bottom of the No. 2 reactor’s primary containment vessel.
This robotic unit, referred to as “telesco,” successfully secured the melted fuel fragment using its front claws. After its successful extraction, it was safely transferred to a contained environment where it will be stored securely, following the protocol that required workers dressed in full hazmat suits to assist in the process.
The retrieval of this fuel sample denotes a significant milestone; however, the operation will only be deemed complete once it is confirmed that the radioactivity of the sample is within acceptable limits for safe handling, and the debris is appropriately contained. In the event that the radioactivity is too high, the robot will be deployed back into the reactor to collect another piece. TEPCO officials are optimistic that the sample collected will fall within the stipulated safety standards.
The mission began in August and faced several delays, initially intended to be a two-week operation. The first postponement was due to a procedural error that set the timeline back by nearly three weeks. Following this, the robot encountered a malfunction with its dual cameras, which are essential for transmitting visuals back to the control room. This issue necessitated the robot’s removal from the reactor for repairs before the mission could continue on Monday.
The Fukushima Daiichi plant suffered the loss of crucial cooling systems during the earthquake and tsunami in 2011, resulting in the meltdown of three reactors. There are still around 880 tons of highly radioactive molten fuel remaining in the facility. TEPCO has employed several robotic technologies to explore the site and decipher how best to dismantle the plant permanently.
On Wednesday, the telesco managed to collect a piece of melted fuel that is believed to weigh less than 3 grams (0.1 ounces) from just beneath the core of Unit 2, which experienced significant fuel deposition during the catastrophic event over a decade ago. TEPCO has announced that even this minuscule sample can yield vital insights, aiding in the formulation of decommissioning strategies, the development of necessary technology and robotic systems, and enhancing understanding of the incident’s progression.
The Japanese government and TEPCO have projected an ambitious timeline of 30 to 40 years for the complete cleanup. However, experts caution that this timeline might be overly optimistic and could benefit from reevaluation. Currently, there are no definitive plans established for the ultimate removal of fuel debris or its disposal.
