nuclear fuel debris retrieval starts Thursday”>Tokyo Electric Power Company Holdings, Inc. has once again halted its trial retrieval of nuclear fuel debris from the No. 2 reactor at the Fukushima No. 1 nuclear power plant due to camera failures. The cameras attached to the retrieval device were not functioning properly, preventing TEPCO from checking the situation inside the primary containment vessel. The company will investigate the cause of this failure but is unable to provide a timeline for when work will resume.
The trial retrieval of nuclear fuel debris was originally scheduled to begin on August 22nd but was delayed due to a procedural error during preparation. Efforts resumed on September 10th, marking the first trial for debris retrieval since the nuclear accident in March 2011.
The radiation levels inside the containment vessel are extremely high, making it challenging for devices to operate effectively. The plan involved using a device resembling a fishing rod that extends up to 22 meters into the side of the vessel and using a claw attachment at its end to retrieve up to 3 grams of debris. This device had previously been used for photographing inside the No.2 reactor and was adapted for this operation.
TEPCO had attached four cameras to this device so that they could remotely observe and carry out the retrieval operation while monitoring video feeds. However, during a check on Tuesday morning, it was discovered that two cameras on the tip of the device were not displaying video properly, leading to an inability to continue with operations.
During an inspection conducted on Sunday after making contact with debris at bottom of reactor containment vessel, video images were visible.
Following Japan’s Great East Japan Earthquake and subsequent tsunami in March 2011, nuclear fuel from Reactor Nos.1-3 melted and fell down into structures within reactors before solidifying as debris estimated at around 880 tons.
Retrieving this debris is considered one of most challenging aspects in decommissioning efforts aimed at completion by TEPCO and government by year-end March2022