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Keyword:fuel debris
Hole of about 3 meters confirmed at bottom of reactor pressure vessel of Unit 3 at Fukushima Daiichi Nuclear Power Station
Tokyo Electric Power Company (TEPCO) announced on August 27 that a hole approximately 3 meters in diameter has been confirmed at the bottom of the reactor pressure vessel of Unit 3 at the Fukushima Daiichi Nuclear Power Station. The pressure vessel is a steel container that held nuclear fuel before the accident, with a cylindrical shape and a diameter of about 5.5 meters. This is the first time since the core meltdown accident at Units 1 to 3 of the Fukushima Daiichi Nuclear Power Station in 2011 that the specific size and shape of such a hole have been confirmed on the pressure vessel. The hole is believed to be related to the falling of melted nuclear fuel during the 2011 accident. After the accident, the containment vessel of Unit 3 has maintained a relatively high water level for an extended period, and access routes into the containment vessel are limited. TEPCO previously used a micro drone measuring approximately 12 centimeters per side...
2026-08-28
TEPCO replaces faulty motor of robotic arm at Fukushima Daiichi Unit 2
Tokyo Electric Power Company (TEPCO) began replacing the faulty motor of the robotic arm used for fuel debris retrieval trials at Unit 2 of the Fukushima Daiichi Nuclear Power Station on August 26. The robotic arm, approximately 22 meters long, is planned for use in the third fuel debris retrieval trial. During a previous operational inspection inside the reactor building of Unit 2, TEPCO found that the motor driving the robotic arm had malfunctioned, preventing the brake from releasing and the arm from extending. As the robotic arm is already installed on site, workers will enter the "front chamber" in front of the containment vessel to perform the replacement manually. The company stated that radiation levels in the work area will be strictly controlled to prevent workers from receiving excessive exposure. After this replacement, TEPCO will...
2026-08-27
Trial lifting of damaged fuel assembly completed at Unit 2 of Japan's Fukushima Daiichi Nuclear Power Station
Tokyo Electric Power Company (TEPCO) announced on August 18 that a trial lifting of a damaged fuel assembly in the spent fuel pool of Unit 2 at the Fukushima Daiichi Nuclear Power Station has been completed. The assembly was damaged in a fall 45 years ago and was subsequently repaired with wire. This trial lifting was conducted to confirm whether it can be safely handled during the subsequent removal operation. A total of 615 fuel assemblies are stored in the Unit 2 fuel pool, including 587 spent fuel assemblies and 28 unused fuel assemblies. The removal work began on June 2, and the fuel assemblies will be transferred to the shared fuel pool within the plant site. As of August 17, 35 fuel assemblies had been removed. Despite interruptions during the operation, Tokyo Electric Power Company...
2026-08-20
New Decommissioning Plan for Fukushima Daiichi: Priority on Internal Investigation of Unit 3 Before Fuel Debris Retrieval
The Nuclear Damage Compensation and Decommissioning Facilitation Corporation of Japan released on August 6 an outline of the 2026 edition of the "Decommissioning Strategic Plan," proposing technical approaches for the decommissioning of Tokyo Electric Power Company's Fukushima Daiichi Nuclear Power Station. The plan highlights that, for the large-scale retrieval of melted fuel debris at Unit 3, expected to commence in or after fiscal year 2037, priority should currently be given to internal investigations of the reactor building to provide a more reliable basis for subsequent engineering plans. The plan states that the fuel debris retrieval method being studied by TEPCO still requires further improvement in certainty, with the key prerequisite being an understanding of the actual internal conditions of the reactor. Due to the high radiation levels of the water inside the unit following the accident...
2026-08-07
Third fuel debris retrieval test at Fukushima Daiichi Unit 2 postponed due to robotic arm malfunction
The robot used by Tokyo Electric Power Company (TEPCO) for the third experimental fuel debris retrieval at Fukushima Daiichi Nuclear Power Station Unit 2 malfunctioned during an on-site operational test, forcing the cancellation of the plan originally scheduled to start after July 2026 if all went well. The company stated it will reassess the relevant procedures. The malfunction occurred in part of the large robotic arm equipment used to collect fuel debris. During an operational test in the reactor building of Unit 2, TEPCO found an abnormality in one of the motors driving the robotic arm, causing the brake to fail to release and the arm to be unable to extend. The company is currently studying the replacement of the faulty motor. The third experimental retrieval plan was to use a large robotic arm...
2026-07-31