Mini-Drones Capture First Look at Fukushima Reactor Damage Since 2011 Meltdown

Tiny drones have provided the first clear view inside a damaged Fukushima nuclear reactor since the 2011 disaster, revealing a breach in the steel containment vessel with melted fuel debris hanging from it. The footage offers crucial data for the decades-long cleanup effort at the Japanese power plant.

TOKYO — Small unmanned aircraft have captured unprecedented footage from within a severely damaged nuclear reactor at Japan’s Fukushima Daiichi power plant, marking the first time officials have gotten a clear view of the pressure vessel’s bottom since the catastrophic meltdown occurred 15 years ago.

The remarkable video reveals a significant breach in the reactor’s heavy steel containment structure, with chunks of what appears to be solidified nuclear fuel material suspended from the opening like massive frozen drips.

These miniature flying devices — each measuring roughly 12 by 13 centimeters and weighing just 95 grams — conducted a two-week exploration mission inside Unit 3 to gather visual evidence, radiation readings, and other critical information. Officials made the footage public on Thursday.

The devastating earthquake and tsunami that struck Japan on March 11, 2011, knocked out power systems at Fukushima Daiichi, leading to core meltdowns in three separate reactors.

Those three units now contain approximately 880 tons of melted radioactive material, with radiation levels that remain extremely hazardous. Tokyo Electric Power Company Holdings, the facility’s operator, managed to extract small samples of melted fuel from Unit 2 last year, though much about the internal conditions remains unknown.

The power company intends to conduct additional remote investigations and sampling operations to study the melted material and create robotic systems for eventual debris extraction — a process specialists estimate will require several more decades.

Getting the drones as near as possible to the pressure vessel’s base represented a key objective for this latest investigation, according to Tokyo Electric Power Company Holdings officials.

Beginning March 5, the remote-controlled aircraft conducted several individual flights, navigating carefully around wreckage, damaged equipment, and other barriers to film the primary containment area, particularly around the pressure vessel’s lower section.

The recorded material displayed ruptured piping and other compromised structures that were once housed within the now-breached pressure vessel. The footage also captured brown and gray masses suspended in formations resembling enormous icicles.

Company representative Masaki Kuwajima confirmed that officials verified the existence of an opening at the vessel’s bottom, stating that the hanging formations, clumps, and deposits are thought to be solidified nuclear fuel debris.

The aircraft also gathered radiation data and measurements to create a comprehensive three-dimensional blueprint of Unit 3’s interior, Kuwajima explained. “We have obtained valuable data that can be used for our future internal investigations and to develop melted fuel debris removal strategy.”

This recent drone operation occurred almost ten years following a previous underwater robotic investigation that produced less detailed images of Unit 3’s internal conditions.