Liberaware's Micro-drone Conducts Internal Investigation of Fukushima Daiichi Unit 3 PCV
Liberaware successfully completed a planned investigation of the Fukushima Daiichi Unit 3 PCV using its micro-drone from March 5-19, 2026. The drone captured the first images of potential structures at the bottom of the Reactor Pressure Vessel (RPV), marking a major milestone for decommissioning.
📋 Article Processing Timeline
- 📰 Published: April 28, 2026 at 20:00
- 🔍 Collected: April 28, 2026 at 11:31
- 🤖 AI Analyzed: April 28, 2026 at 12:05 (33 min after Collected)
Liberaware Co., Ltd. (Headquarters: Chiba City, Chiba; CEO: Hongkyu Min; hereinafter 'the Company') announces that its micro-drone was deployed in the internal investigation of the Fukushima Daiichi Nuclear Power Station Unit 3 Primary Containment Vessel (PCV), conducted by Tokyo Electric Power Company Holdings, Inc. (Headquarters: Chiyoda-ku, Tokyo; President: Tomoaki Kobayakawa; hereinafter 'TEPCO'). The investigation was successfully completed as planned from March 5 to March 19, 2026.
In this investigation, the Company's drone was deployed to confirm the status of the pedestal interior and penetration holes that could serve as access routes for fuel debris removal. It successfully captured footage near the bottom of the Reactor Pressure Vessel (RPV) in Unit 3 and confirmed structures likely to be the RPV bottom for the first time.
Background and Achievements:
Understanding the conditions deep within the reactor is essential for the decommissioning of the Fukushima Daiichi Nuclear Power Station and the removal of fuel debris. The interior of the PCV is narrow and dark, requiring investigation equipment to be installed through small-diameter penetration holes (X-53 penetration). Consequently, the micro-drone developed by the Company—measuring 130mm x 120mm and weighing only 95g—was adopted, enabling access to areas that were difficult to reach with conventional equipment.
The drone required for this project needed to be not only small and lightweight but also equipped with numerous functions and performance features. With TEPCO's support, the Company developed a vehicle that embodied these requirements using proprietary technology.
During the investigation period, on March 17, the drone directly photographed structures believed to be the RPV bottom and succeeded in confirming the damage and deposits on upper structures such as CR guide tubes and CRD housings. The fact that the drone approached the RPV bottom and succeeded in direct photography is an extremely important advancement for the entire decommissioning project and contributed to the acquisition of valuable data for formulating future decommissioning plans.
Micro-drone Information:
- Dimensions: 130mm x 120mm x 40mm
- Weight: 95g (including battery)
- Communication: Wireless
- Flight Time: Approx. 13 minutes (Planned for 10 minutes per mission)
- Camera: 2.7K, 60fps
- FOV: Diagonal 140°, Horizontal 135°, Vertical 107°
- Lighting: 2 LEDs (380lm total)
- Radiation Resistance: Approx. 200Gy
- Other: IP52 equivalent, two camera types (horizontal and vertical)
Main Investigation Areas:
- Pedestal outer perimeter
- Pedestal interior
- Near the RPV bottom
Future Developments:
Capturing images of structures believed to be the RPV bottom and other internal states is not only a demonstration of the Company's technological achievements but also a significant step forward in decommissioning efforts. Based on the mission to 'Create a safe society for everyone,' the Company will continue to analyze the captured video data and proceed with point cloud generation to further support safety improvements through technology in TEPCO's operations. The Company will continue to integrate its unique drone and digital twin technologies to provide new value in all sites where human investigation is difficult.
In this investigation, the Company's drone was deployed to confirm the status of the pedestal interior and penetration holes that could serve as access routes for fuel debris removal. It successfully captured footage near the bottom of the Reactor Pressure Vessel (RPV) in Unit 3 and confirmed structures likely to be the RPV bottom for the first time.
Background and Achievements:
Understanding the conditions deep within the reactor is essential for the decommissioning of the Fukushima Daiichi Nuclear Power Station and the removal of fuel debris. The interior of the PCV is narrow and dark, requiring investigation equipment to be installed through small-diameter penetration holes (X-53 penetration). Consequently, the micro-drone developed by the Company—measuring 130mm x 120mm and weighing only 95g—was adopted, enabling access to areas that were difficult to reach with conventional equipment.
The drone required for this project needed to be not only small and lightweight but also equipped with numerous functions and performance features. With TEPCO's support, the Company developed a vehicle that embodied these requirements using proprietary technology.
During the investigation period, on March 17, the drone directly photographed structures believed to be the RPV bottom and succeeded in confirming the damage and deposits on upper structures such as CR guide tubes and CRD housings. The fact that the drone approached the RPV bottom and succeeded in direct photography is an extremely important advancement for the entire decommissioning project and contributed to the acquisition of valuable data for formulating future decommissioning plans.
Micro-drone Information:
- Dimensions: 130mm x 120mm x 40mm
- Weight: 95g (including battery)
- Communication: Wireless
- Flight Time: Approx. 13 minutes (Planned for 10 minutes per mission)
- Camera: 2.7K, 60fps
- FOV: Diagonal 140°, Horizontal 135°, Vertical 107°
- Lighting: 2 LEDs (380lm total)
- Radiation Resistance: Approx. 200Gy
- Other: IP52 equivalent, two camera types (horizontal and vertical)
Main Investigation Areas:
- Pedestal outer perimeter
- Pedestal interior
- Near the RPV bottom
Future Developments:
Capturing images of structures believed to be the RPV bottom and other internal states is not only a demonstration of the Company's technological achievements but also a significant step forward in decommissioning efforts. Based on the mission to 'Create a safe society for everyone,' the Company will continue to analyze the captured video data and proceed with point cloud generation to further support safety improvements through technology in TEPCO's operations. The Company will continue to integrate its unique drone and digital twin technologies to provide new value in all sites where human investigation is difficult.