Specializing in nuclear clean-up, British Nuclear Group delivers accelerated nuclear clean-up programs in a safe and cost-effective manner to its customers in the United Kingdom and overseas. The company works on highly complex facilities and projects, including new plant construction, to enable accelerated hazard reduction and facility decommissioning, along with waste management services.
One process the company must deal with when a nuclear plant is decommissioned is the cleaning and decontamination of painted metal storage bins or “skips” used for storing contaminated parts in ponds. These skips have to be cleaned down to their base metal to remove contaminated paint and corrosion, leaving the skip suitable for reprocessing. The skips are then sent to a company that recovers 95% of the metal, which is then melted and reused in building new nuclear plants. After processing, only 5% of the metal is left over to be stored.
Search for an Automated Solution
The skips were being cleaned via manual labor, which took excessive time since the workers could only safely work in the area for limited amounts of time due to contamination issues -- and manual cleaning is an inherently slow process.
British Nuclear needed a more efficient, faster, and safer method for cleaning the skips. They began searching for an automated system that would quickly and accurately remove contaminated paint and corrosion from the surface of the nuclear fuel skips.
The company turned to KMT Robotics Solutions to design and implement a faster, safer, and more efficient automated solution. KMT built and supplied a new ultra-high pressure waterjet cleaning system based on its Cutting Box Blaster system, typically used to remove coatings, grease, and other substances from metal surfaces.
The system built for British Nuclear Group is comprised of a single floor-mounted ABB IRB 4400F robot by ABB Robotics. The robot is designed for extremely fast medium to heavy handling with rapid maneuverability. The compact design and protected versions enables use in situations where conventional robots cannot work, such as foundry and spraying applications. The foundry plus versions are IP67-protected and can be washed with high-pressure steam, making them ideal for use in harsh environments.
The cleaning head is attached to the robot and produces a pressurized stream of water that is forced through a Rotojet cleaning head with a set of rotagint nozzles. This produces a cone-shaped cleaning jet that, when combined with the movement of the robot or the worktable, provides optimum coverage for cleaning a surface. In the British Nuclear application, the part is mounted onto a rotating table so that it can be spun while the robot positions the cleaning head to the correct path and finally the rotojet nozzles rotate to give the system an all-encompassing efficient cleaning capability.
Productivity, Safety Benefits
The system is housed in the Cutting Box Blaster, which can also be equipped with various configurations of worktables to ensure even more cleaning productivity and flexibility. The Cutting Box Blaster is a safe, ergonomic, sound-insulated system with accommodations for ease of clean-up.
“By converting the skips to low-level nuclear waste instead of intermediate-level waste, the robotic cleaning solution from KMT provides substantial savings in storage costs,” said Paul Etchells, UK sales manager for KMT Robotic Solutions. “British Nuclear Group will also be able to double the number of skips that can be cleaned in a day, while greatly reducing the need for personnel to work in radiation-contaminated environments.”
British Nuclear Group was able to double the number of skips being cleaned over the previous manual method while significantly improving employee safety and working conditions.
”British Nuclear Group chose KMT as preferred supplier because they sought a dependable product, both operationally and in production terms, and one which could fulfill a strict specification,” said Ulf Andersson, KMT Robotic Solutions project manager. “We have nearly 15 years’ combined experience of developing and building advanced robotic systems. The fact that we could also guarantee a rapid delivery of a specially-adapted system was also an influencing factor,” he added.