Because they can go where humans can’t, robots are especially suited for safely working with hazardous nuclear waste. But first, those robots need to become like the humans they are replacing, with arms and fingers that can closely mimic the movements of a person.
Now, scientists at the U.S. Department of Energy’s (DOE) Argonne National Laboratory have designed and tested a remote-controlled, dual-arm telerobotics system with human-like capabilities that has the potential to revolutionize hazardous waste clean-up and holds potential for broader applications. Designed as part of a multi-laboratory, multi-institution project, the telerobotics system was successfully tested in a mock, nonradioactive setting at DOE’s Oak Ridge National Laboratory (ORNL). Along with Argonne and ORNL, the Oak Ridge Office of Environmental Management (OREM), the University of Illinois Chicago (UIC), Northwestern University, and United Cleanup Oak Ridge, LLC, (UCOR) are collaborators on the three-year project launched in 2023.
The technology is still in the prototype stage. The long-term goal is to use the collaborative robots, or “cobots,” and emerging digital technologies to help clean up nuclear waste in dormant nuclear facilities overseen by DOE’s Office of Emergency Management. The technology also has potential for uses beyond DOE nuclear waste sites.
In the nuclear industry, hot cells and glovebox systems were for decades the traditional method for handing radioactive materials. Hot cells are heavy shielded concrete cells with mechanical manipulators to handle highly radioactive materials. Remote operators can also use tong-like manipulators to move the materials within the hot cell. A glove box is a securely sealed container found inside the hot cell, with openings that allow laboratory operators to access attached gloves to maneuver and study hazardous materials.
However, these systems are no longer useful since they rely on obsolete, manually operated technology and cannot be moved to task sites. Argonne’s mobile robotic hot cell system, which can easily be deployed on site, would essentially roboticize the current method.
The recent demonstration of the Argonne-designed robot was held at a long-closed ORNL radiochemical processing facility that houses diverse radiochemical waste materials. In the demonstration, the goal was to use the telerobotic technology to handle the mock nuclear waste canisters contained in a hot cell within the ORNL facility. Equipped with remarkably dexterous, multi-fingered arms, the robots successfully opened the mock nuclear waste canisters, inspected and sorted their contents and closed the containers.
During the weeklong demonstration, team members received hands-on training to perform specific tasks, such as manipulating the robot’s arms to open a plastic bottle.
“Along with Argonne, the entire robotics community has been developing innovative new robotics technologies. But there have been very few actual demonstrations of the telerobotic system’s capabilities,” said the system’s designer, Young Soo Park. “This highly successful demonstration proved the technical feasibility of this first-of-a-kind concept implementing a complex, dexterous, telerobotic system for practical applications.”
The new robotics system runs on Argonne’s mixed-reality digital twin software platform. The system integrates virtual models, sensory display, and hardware control technology. Digital twin technology acts as a bridge between the real and virtual worlds, creating a digital replica, or twin, of a physical object. The digital twin supports optimization in all phases of the remote operation system, including design, training, operation, and analysis.
Seated at a digital workstation, operators equipped with a virtual reality headset and touch-sensitive haptic gloves can control the robots physically and virtually at the same time. When the operator moves its arms, the dual-armed robot mimics the movements. The touch-sensitive gloves allow the operator to effectively touch and feel objects in a natural way. Sensors on the gloves provide operators with direct feedback that helps improve the precision and accuracy of the task.
“Our first aim in telerobotic system design is to facilitate a ‘telepresence,’ to make the operator feel as though they are present within the hot cell, able to manipulate the objects with both hands, and to experience multimodal sensory feedback in a direct, natural way,” Park said.
The robotic hot cell technology could eventually replace hot cells and glove box systems for a wide variety of hazardous materials handling applications. The mobile telerobotic system can move from one hot cell to the next. Operators can robotically handle, sort, and inspect hazardous waste from a remote location without removing the materials from the cell.
“The telerobotic system can also be used in other applications where a physical telepresence is required,” Park said. “Examples include industrial applications such as construction and maintenance of facilities and social service applications such as medical and health care systems. Also, the robotic hot cell can be used to replace hot cells and glove boxes in scientific and industrial applications such as in laboratory experiments and materials processing.”
The team’s diverse expertise and close collaboration is key to the project’s success. Argonne developed the digital twin software, built the dual-arm robot system and successfully tested its teleoperation. Northwestern University developed the prototype for dexterous multi-fingered manipulation of the robotic arms. UIC developed the integrated automation system. ORNL is developing the mobile hot cell structure for remote handling systems. UCOR, the cleanup contractor for DOE’s Oak Ridge Reservation, manages environmental safety and health throughout the project. DOE’s Office of Emergency Management will oversee progress through completion.
