Robotic Aerial Vehicle Captures Dramatic Footage of Fukushima Reactors

Video and photos taken by a Honeywell T-Hawk micro air vehicle show damage with unprecedented detail

3 min read
Robotic Aerial Vehicle Captures Dramatic Footage of Fukushima Reactors

Editor's Note: This is part of IEEE Spectrum's ongoing coverage of Japan's earthquake and nuclear emergency.

A robotic aerial vehicle hovering at the crippled Fukushima Dai-ichi nuclear plant has captured close-up video and photos that reveal the extent of the destruction in greater detail than previously seen.

Tokyo Electric Power Co. (TEPCO), the plant's operator, is using a T-Hawk [photo below], a remote operated flying machine created by U.S. firm Honeywell, to get a closer view of the severely damaged reactors.

honeywell t-hawk fukushima nuclear plant japan emergency

The T-Hawk, known as a micro air vehicle, or MAV, uses a ducted-fan propulsion system that allows it to hover in place like a helicopter and fly into tight spaces where other aircraft can't go.

Last Friday, TEPCO workers, with assistance from Honeywell employees trained to pilot the T-Hawk, used the vehicle to survey the reactor buildings of Units 1, 3, and 4. TEPCO released the images the next day.

"What these images show is that the magnitude of the hydrogen explosions was incredible," said Stewart B. Minahan, executive director of operations for the Nuclear Energy Institute, an industry group.

Minahan, who has 35 years of experience with boiling water reactors, say the images are "very clear," and although they don't provide any new insight into the disaster, they show details that he hadn't seen before.

One of the elements most clearly visible is a round yellow structure sitting on the operating floor of Unit 4. The structure, Minahan says, is the drywell dome, the top part of the reactor's containment structure. When a boiling water reactor is in refueling mode -- as it was the case with Unit 4 -- workers use a crane to remove the dome and place it over concrete blocks on the floor. It's also possible to see fuel-handling machines, used to move fuel from the reactor into spent fuel pools.

But he says no parts of the reactors themselves are visible. "In my opinion, it will be hard to see them," he says. "These buildings had multiple floors, which collapsed because of the explosions."

TEPCO has used manned helicopters, high-altitude drones, and ground robots to obtain images of the facility. But the T-Hawk, because pilots can hold it in place and use its camera to zoom in on features, is giving TEPCO a better look of damages in and around the buildings.

Developed as part of a DARPA project, the machine is currently used in Iraq and Afghanistan for surveillance, route planning, and other missions. It weighs in at 7.7 kilograms (17 pounds), and pilots can control it manually or set up autonomous flight paths from up to 9.6 kilometers (6 miles) away and for up to 40 minutes at a time.

Honeywell, based in Morris Township, N.J., said in a release that three of its employees have flown five missions so far, capturing hours of video and dozens of photos. There are two T-Hawk units flying in Fukushima and two as back-up. Honeywell said that, in addition to cameras, they are carrying radiation sensors, though TEPCO hasn't yet released any data from them.

Below, some of the images (all taken on April 15) made public:

Unit 3, roof of reactor building

fukushima dai-ichi nuclear power plant emergency damage

Unit 4, upper side of spent fuel pool, reactor building

fukushima dai-ichi nuclear power plant damage emergency

Unit 4, seashore side of reactor building

fukushima dai-ichi nuclear power plant emergency damage

Unit 4, operation floor of reactor building 2

fukushima dai-ichi nuclear power plant damage emergency

Below, videos taken on April 15 [Editor's note: TEPCO says the videos show Units 1, 3, and 4, but they appear to show only Unit 4; the videos have no audio]:

This story was updated April 21.

Images: TEPCO; Honeywell. Videos: TEPCO

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Robot with threads near a fallen branch

RoMan, the Army Research Laboratory's robotic manipulator, considers the best way to grasp and move a tree branch at the Adelphi Laboratory Center, in Maryland.

Evan Ackerman
LightGreen

This article is part of our special report on AI, “The Great AI Reckoning.

"I should probably not be standing this close," I think to myself, as the robot slowly approaches a large tree branch on the floor in front of me. It's not the size of the branch that makes me nervous—it's that the robot is operating autonomously, and that while I know what it's supposed to do, I'm not entirely sure what it will do. If everything works the way the roboticists at the U.S. Army Research Laboratory (ARL) in Adelphi, Md., expect, the robot will identify the branch, grasp it, and drag it out of the way. These folks know what they're doing, but I've spent enough time around robots that I take a small step backwards anyway.

The robot, named RoMan, for Robotic Manipulator, is about the size of a large lawn mower, with a tracked base that helps it handle most kinds of terrain. At the front, it has a squat torso equipped with cameras and depth sensors, as well as a pair of arms that were harvested from a prototype disaster-response robot originally developed at NASA's Jet Propulsion Laboratory for a DARPA robotics competition. RoMan's job today is roadway clearing, a multistep task that ARL wants the robot to complete as autonomously as possible. Instead of instructing the robot to grasp specific objects in specific ways and move them to specific places, the operators tell RoMan to "go clear a path." It's then up to the robot to make all the decisions necessary to achieve that objective.

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