The award-winning WallRover B platform fitted with the Viridiscope payload allows at-height inspection, sampling and characterisation at nuclear sites. The WallRover B uses its unique patented downforce generator technology to confer transformational mobility and allows the side-sponson mounted Viridiscope sampling tool suction head payload to be remotely and precisely transported up diverse vertical structures. Photons from the laser sputter material from the surface it is fired at, and the sputtered debris is transported by suction along a 20m long hose into the laser and debris collection box, whilst preventing particulate plume production from the surface. The samples collected from a large surface area can then be analysed by commercially available counting systems for α, β and γ activity, and radio-nuclides that have ingressed into the surface can be identified in under 10 minutes. The unique WallRover B platform and Viridiscope payload combination is potentially safer, cleaner and faster than methods currently used for elemental characterisation, and radioactive samples can be collected from structures made from diverse materials, including: brick, concrete, plaster, plastic and wood.
Kym, Susan and John at Viridian Consultants Ltd have designed and developed a 3-D printed Viridiscope® tool, (shown below, top left), that features a lightweight 0.6kg hand-held unit that incorporates a Nd:YAG (Neodymium-doped Yttrium Aluminium Garnet) laser head attached to a 20 metre long fibre optic cable and connected to the Nd:YAG laser located on the ground. The laser head is mounted within the hollow chamber of the Viridiscope tool, and debris sputtered from a surface is transported by suction along a co-axial 20 metre long debris collection pipe to the debris collection box located on the ground, (shown below, top right). The 3-D printed Viridiscope tool has been successfully side-sponson mounted and trialled on a WallRover B unmanned wall climbing vehicle, (shown below, bottom left), and Sellafield Ltd funded the development of the Viridiscope tool. The WallRover B is controlled by a game-pad hand controller, (shown below, bottom right) that is attached to the WallRover B OCU (Operator Control Unit). Attached co-axially to the 25 metre long power and communications cable, that interconnects the WallRover B and its OCU, is the 20 metre long fibre optic Nd:YAG laser cable and the 20 metre long debris collection pipe.
Innovate UK has funded the trial deployment of the Viridiscope fitted to a WallRover B supplied by Sellafield Ltd at sites with different decommissioning projects, including the waste repository at Drigg, Socatec Analytical Laboratory, Experimental Reactor Dragon at Winfrith, a decommissioned nuclear reactor at Trawsfynydd, and an EDF operated nuclear power plant at Hinkley Point B. Viridian Consultants Ltd has also partnered with 3 NDA supported site licensed companies - LLW Repository Ltd, Magnox Ltd and Sellafield Ltd and EDF Nuclear Generation. During 3 months of deployment trials the WallRover B Viridiscope system was used at 4 sites where 350 samples were collected with collection times of between 2 and 5 minutes with a throughput time of less than 10 minutes at heights of up to 8 metres.
Detailed at-height inspections and characterisation currently requires operators to use scaffolding, but the unique WallRover Viridiscope combination should enable cheaper, faster, safer and cleaner inspection and characterisation of nuclear sites in the near future.
For more information on the Viridiscope please visit: http://www.viridian-tc.co.uk/
or email Kym at: firstname.lastname@example.org