Sniffing out radiation

In the most-viewed YouTube video for the month of November 2017, a Boston Dynamics Spot robot—which is bright yellow and about the size and shape of a Golden Retriever—uses a clawlike arm mounted atop its back to turn a doorknob before prancing through a doorway.

Viewers of the video were fascinated both by Spot’s door-opening abilities and by the way that the robot moved. With its four legs, Spot sauntered with a smoothness that didn’t call to mind the jerky motions of R2-D2 or C-3PO (the famed Star Wars robots). Instead, the robot’s fluid gait made it resemble an animal—a dog, say.

The ability to move nimbly on four legs isn’t merely a matter of aesthetic appeal, explains Jeff Hyde, a researcher at Los Alamos National Laboratory. As a part of the Laboratory’s Modern Manufacturing Methodologies group, Hyde works to deploy new types of robots—including several Spot robots—at Los Alamos, using the robots’ unique abilities to support the Laboratory’s national security mission.

Before the Spot robots came on the scene, researchers were working to deploy wheeled robots at Los Alamos. They suspected that robots fitted with radiation-detecting equipment could support the Laboratory’s radiological control technicians (RCTs), who use specialized tools to detect and monitor radiation levels in places where radioactive materials are present. RCTs play a crucial role in ensuring that the Laboratory achieves its mission safely. 

Although the wheeled robots could monitor hazardous areas, they suffered from limitations. “Wheeled robots are very temperamental,” Hyde says. “They would do turns that would damage flooring, or they’d damage cables by rolling over them, or they’d end up in corners and get stuck.”

The wheeled robots’ limitations were such that they never achieved widespread deployment at the Laboratory. It wasn’t until Hyde’s team acquired a Spot robot in 2021 that the goal of augmenting RCT work with robots became feasible.

Spot robots are designed to operate autonomously. With their quadrupedal design, Spot robots can turn on a dime, mount or descend stairs, and avoid obstacles. The Spot robots have also proved durable. In one test, working in a secured area of the Laboratory, Hyde’s team exposed a pair of Spot robots to a very high dose of radiation, determining that the robots could function even when faced with radiation levels far above what a human being would be exposed to at Los Alamos.

Next, Hyde and his colleagues developed a custom payload that could be carried by a Spot robot and used to monitor for radiation. This payload consisted of a Los Alamos computer, LiDAR (or light detecting and ranging, which allows the robot to “see”), and an alpha-beta detector paired with a scintillation counter to measure radiation.

Fitted out, the Spot robots proved well-suited to completing truck radiation surveys. RCTs are sometimes called upon to scan the beds of delivery trucks that have carried hazardous materials such as depleted uranium—a tedious and physically demanding process that involves moving a radiation detector over the truck bed at a rate of around 5 centimeters per second. A Spot robot outfitted with a Los Alamos–designed payload can complete this task autonomously, bolstering efficiency and safety.

Other potential applications for Spot robots include general area radiation surveys. These surveys are conducted as a matter of course in facilities containing nuclear material, and they involve mapping radiation levels and tracking changes in those levels over time—a task that could be completed quickly and accurately by a Spot robot with a gamma-ray detector. Spot robots could also be used to scan facility floors for radioactive contamination, characterize radioactive objects, and assist with emergency response efforts (by going into areas that first responders suspect could be hazardous to enter). 

Of course, Spot robots have limitations: they can’t climb ladders, for example. Even so, Hyde says that RCTs have been quick to see how the Spot robots can supplement their work, all the better to achieve the Laboratory’s mission. “The goal of the Spot robots is to augment tasks that are dangerous, tedious, or require high precision,” Hyde says. “We want to free up our RCTs, which will allow them to better support our mission.” ★