Enhanced snake manipulator cuts costs and improves safety at NRS Dounreay

The University of Nottingham’s (UoN) long-reach snake manipulator has achieved a landmark deployment at Nuclear Restoration Services (NRS) Dounreay, providing unprecedented access to areas inaccessible for decades. The success marks a significant step forward for modular manipulator technology that has been evolving through the Game Changers innovation programme since 2018. 

Developed through the Rolls-Royce University Technology Centre in Manufacturing and On-Wing Technology, the latest version of the snake manipulator represents a clear leap from earlier prototypes. Designed and built by UoN, with input and operational testing opportunities from NRS Dounreay, the device is capable of entering 30 mm apertures, navigating complex geometries, conducting 3D inspections, and carrying a sensor payload. 

In March 2025, the manipulator was operated on site by Ice9 Robotics with support from FIS360 Ltd and AevaSpec, a University of Glasgow spin-out. In a first-of-its-kind demonstration, the robot successfully navigated through a 30 mm aperture into a highly restricted area of the facility, capturing high-quality video and real-time radiation mapping data that will directly shape decommissioning strategies. 

From Prototype to Nuclear-Grade Tool 

The deployment builds directly on a March 2024 trial at NRS Dounreay, where the manipulator was first tested in an active nuclear environment. Learning from that earlier demonstration, the team has made substantial enhancements. These include: 

• Improved LED lighting for sharper, clearer video capture 
• Increased manoeuvrability and payload capacity for greater operational flexibility 
• Integration of a miniaturised gamma radiation sensor from AevaSpec, delivering real-time dose-rate and spectroscopic data alongside visual imagery 

The sensor integration was a particularly important milestone. Co-developed by UoN and AevaSpec, the lightweight gamma detector was mounted without compromising navigability – something rarely achieved in confined-space robotic systems. 

Jason Simpson, Project Manager at NRS Dounreay, emphasised the operational impact: 

“The value of the snake manipulator lies in its ability to access areas previously out of reach, providing the critical data needed to shape decommissioning strategies and reduce risk remotely. By eliminating the need for intrusive investigative work, it delivers significant time and cost savings. For this project alone, the avoided costs exceed £1 million; if applied across other cells in the NDA estate, the potential savings could be truly substantial.” 

Engineering for Confined Space Challenges 

The manipulator’s modular design remains central to its adaptability. Length can be tailored from a few metres up to 20 m, combining low-cost, off-the-shelf components with 3D-printed connectors. Inflatable stabilisation balloons enable the head to lift and hold steady while carrying payloads, while a revolute joint provides fine vertical and rotational control for full 3D inspections. 

Such versatility is crucial in environments like Dounreay, where shielded hot cells, long stretches of ducting, and complex pipe networks were never designed with access or decommissioning in mind. Current solutions – borescopes or camera poles – offer only limited line-of-sight visuals near the ground. High-end snake-arm robots exist but are typically too large, too short in reach, or prohibitively expensive. 

By contrast, UoN’s system delivers a unique combination: small diameter, long reach, sensor integration, and low cost. 

Mark Crichton, Project Engineer at NRS Dounreay, highlighted the importance of the new insights: 

“The Snake ROV surveys have let us build up an invaluable picture of the cell underside infrastructure and services that have thus far evaded us through drawing searches.” 

A Growing Story of Collaboration 

The journey of the snake manipulator reflects years of sustained collaboration across academia, industry, and government. The project originated through the Robotics and AI in Nuclear Hub, where early trials with an aerospace snake robot highlighted the need for greater length and stiffness for nuclear deployment. Further development followed via the FIS360-managed Game Changers programme, with successful feasibility and proof-of-concept trials, leading to funding from the Robotics and AI Collaboration (RAICo) for continued development. Funding from NRS Dounreay then enabled the integration of radiometric sensing, ensuring the system was not just a vision but a working tool in one of the UK’s most challenging nuclear environments. 

Compared with the 2024 demonstration – when the prototype first solved a 40-year-old mystery inside a restricted-access cell – this latest deployment signals a maturing, nuclear-ready technology with clear commercial and cross-sector potential.

Beyond Nuclear 

While nuclear decommissioning is a natural proving ground, the potential applications are broad. Aerospace, defence, petrochemical, and utilities sectors all face the same challenge: how to inspect and assess confined or hazardous spaces without exposing workers to risk. 

By bridging this gap, the University of Nottingham snake manipulator is not only helping to accelerate nuclear clean-up, but also laying the foundation for safer, faster, and more cost-effective inspection across industries.