Drone images reveal hole in Fukushima reactor vessel

Saturday 21 March 2026 - 07:50

By: Dakir Madiha

Drone images reveal hole in Fukushima reactor vessel

Tiny drones deployed inside a damaged reactor at Japan’s Fukushima Daiichi nuclear plant have captured the first clear images of the bottom of Unit 3’s pressure vessel, revealing a large hole in the thick steel structure and hanging masses believed to be melted nuclear fuel.

The footage, released by Tokyo Electric Power Company Holdings, provides new insight into the aftermath of the March 2011 earthquake and tsunami that triggered meltdowns in three reactors at the facility.

The images were recorded by micro-drones measuring about 12 by 13 centimeters and weighing 95 grams. Operated remotely, the devices were sent into the reactor over a two-week mission that began on March 5. They navigated through debris and damaged equipment to reach the primary containment area and the base of the reactor vessel.

The visuals show broken pipes, structural damage, and clusters of brown and gray material suspended near the breach. TEPCO spokesperson Masaki Kuwajima said the hole was confirmed and that the hanging material is likely solidified melted fuel debris.

The Fukushima site still contains at least 880 tonnes of melted fuel across its three damaged reactors, with radiation levels remaining extremely high. Although small samples were retrieved from Unit 2 last year, much of the internal condition of the reactors remains unknown.

During the mission, the drones also collected radiation readings and structural data to help build a detailed three-dimensional map of the reactor interior. The information will support future inspections and guide the development of strategies to remove the fuel debris.

TEPCO plans to deploy additional remote probes and conduct further sampling to better understand the material and design specialized robots for its eventual removal. Experts warn that the cleanup process could take decades due to the complexity and hazardous conditions.

The latest images mark a significant step forward, improving on earlier robotic missions that provided only limited views inside Unit 3 nearly a decade ago.