CARMA II: Advancing Autonomous Radiation Monitoring in Nuclear Facilities

The Continuous Autonomous Radiometric Monitoring Assistant (CARMA) 2 is an advanced robotic system engineered to monitor and map radioactive contamination within nuclear facilities autonomously. Building upon its predecessor, CARMA 1, this next-generation platform offers enhanced robustness and a more rugged design, addressing the evolving needs of the nuclear industry.

Development History

Initiated as a low-cost prototype sponsored by Sellafield Ltd, the CARMA project saw its first deployment with CARMA 1 at Sellafield between December 2017 and January 2018. A notable achievement was in May 2019, when CARMA 1 completed the inaugural autonomous radiometric survey of a former alpha laboratory on the Sellafield site. These successes laid the groundwork for CARMA 2, focusing on improved durability and performance.

Technical Specifications

CARMA 2 integrates the Clearpath Jackal robotic platform with a suite of off-the-shelf components, utilizing the Robot Operating System (ROS) architecture for its onboard 3D mapping capabilities. Key components include:

• LIDARs: Two 20-meter Hokuyo LIDARs for obstacle detection and navigation.

• Depth Cameras: A pair of Orbec depth cameras (front and rear) for 3D mapping and dynamic obstacle avoidance.

• Radiation Detectors: Two Thermo Fisher Scientific DP6 & Radeye SX detectors can identify alpha, beta, and gamma radiation.

• Graphical User Interface: A custom interface facilitating path planning, allowing users to define survey areas and monitor the robot’s progress.

• State-Machine: Manages the robot’s high-level behavior, enabling functionalities such as contamination avoidance.

• Radiation Costmaps: Integrates radiation data into the robot’s navigation system to inform movement decisions.

• Control Base-Station: A redesigned hardware component providing a central point for controlling and monitoring the robot.

• Variable Height Probe: Allows the radiation detector’s height adjustment for optimal data collection.

Applications

CARMA 2 is tailored for the nuclear industry, with primary applications including:

• Radiometric Surveys: CARMA 2 is conducting autonomous surveys of nuclear facilities, including legacy sites. Notably, in May 2019, it completed the first autonomous radiometric survey of an alpha laboratory at Sellafield.

• Contamination Detection and Avoidance: Equipped to detect and avoid alpha and beta contamination, a feature not commonly found in previous robotic systems. This capability significantly reduces the risk of spreading radioactive materials during surveys.

• Radiation Heatmaps: Generating visual representations of radiation levels in surveyed areas.

• Skills Gap Mitigation: Automating monotonous radiation surveying tasks helps address the shortage of qualified workers in the nuclear industry, allowing skilled personnel to focus on more critical operations.

• Area Coverage Planning: Utilizing a custom-designed, graphically controlled area coverage planner to control the robot’s movements precisely, ensuring comprehensive coverage of designated areas.

Advantages

CARMA 2 offers several benefits over traditional radiation surveying methods:

• Autonomous Operation: Reduces the need for human involvement in hazardous environments.

• Improved Accuracy and Repeatability: Precise movements and consistent data collection enhance survey accuracy.

• Reduced Risk to Personnel: Minimizes radiation exposure to human workers by automating surveys.

• Increased Efficiency: Conducts surveys more frequently and meticulously than human operators, leading to greater efficiency.

• Cost Savings: Potentially lowers the cost of radiation surveys by automating tasks and reducing reliance on human resources.

Disadvantages

While CARMA 2 presents numerous advantages, potential limitations include:

• Limited Terrain Navigation: Primarily designed for indoor environments, it may face challenges navigating complex or uneven terrain.

• Cost Considerations: Initially conceived as a low-cost prototype, the exact cost of CARMA 2 is not publicly available.

• Technological Dependence: Any robotic system relies on technology and may be susceptible to malfunctions or software glitches.

Future Developments

Planned advancements for CARMA 2 include:

• Outdoor Version: they are developing an outdoor variant in collaboration with Sellafield Ltd, expanding its applicability to a broader range of environments.

• Commercialization: A Knowledge Transfer Partnership with Nuvia Ltd is underway to explore the commercialization of the CARMA platform.

Testing and Validation

CARMA 2 has undergone rigorous testing and validation procedures to ensure reliability and performance, including simulation-based assessments and evaluations on the physical platform. These efforts aim to identify and address potential issues, providing effective operation in real-world scenarios.

Conclusion

CARMA 2 signifies a significant advancement in autonomous radiation monitoring technology. Its capabilities in conducting autonomous surveys, detecting and avoiding contamination, and generating radiation heatmaps offer substantial benefits for the nuclear industry. By automating routine tasks and reducing human exposure to hazardous environments, CARMA 2 enhances nuclear facilities' safety, efficiency, and cost-effectiveness. The development of an outdoor version and ongoing commercialization efforts further expand the potential applications of this technology.

CARMA 2 can potentially revolutionize radiation safety and environmental monitoring in the nuclear industry. Its ability to provide granular, accurate, and repeatable radiation surveys can lead to better decision-making and improved safety protocols. Moreover, the successful implementation of CARMA 2 paves the way for the broader adoption of autonomous robotic systems in hazardous environments, not only within the nuclear sector but also in other industries where human safety is paramount. As technology continues to advance, further improvements and innovations in autonomous monitoring