Robot Controlled Laser Cutting

1. The National Nuclear Laboratory Robot Controlled Laser Cutting Demonstration Facility - Case Study Howard Chapman

2. Robot Controlled Laser Cutting Laser cutting has been proposed as a method of size-reduction of active materials for operations such as nuclear decommissioning. Laser cutting combined with semi-automated control is faster and far more efficient than conventional cutting techniques and will produce less secondary waste. Potential for reduced operator exposure to dose from nuclear decommissioning. Ability for surgical removal of active ‘hot spots’ with potential for nuclear decommissioning cost savings of millions

3. Laser Cutting For Nuclear Decommissioning • The use of high powered lasers for decommissioning purposes is a new technology to the nuclear industry. • The NNL robot controlled laser cutting demonstration facility is a first of a kind full-scale replica of an existing active handling enclosure operated by NNL.

4. Laser Cutting For Nuclear Decommissioning • NNL world first achievements in the deployment of robotic laser cutting methods on a nuclear licensed site. • The replica demonstration facility has recently been constructed at the NNL Preston Laboratory and is claimed to be the world’s most advanced permanent robot controlled laser cutting system in an active nuclear environment. • TRL from proof of concept TRL 3, to demonstration in a relevant environment TRL 6. • It was the largest funded project to come out of Innovate UK, with additional funding provided by NDA and BEIS • NNL collaborated with project partners, OC Robotics, TWI, ULO Optics and Laser Optical Engineering. • .

5. KEY OBJECTIVES • Key objective of NNL’s Case Study was to establish a facility using a semi-automated robotic system for active cutting experiments using a 5 KW infra-red laser. • To enable uncertainties on fume generation to be established.

6. ROBOT SYSTEM & HARDWARE NNL’s Robot Controlled Laser Cutting Facility employs an industrial proprietary KUKA robot, with a 5kW infra-red laser. Major world first achievements include; point cloud data acquisition and a semi-automated system that provides path planning and executes a cut without teleoperations in an unstructured active environment. Local access to an automated tool changing station, allowing the robot to switch between environment-scanning equipment and the laser cutting head, which enables selective, semi-autonomous controlled laser cutting for disassembly within an enclosed space.

7. OPERATION • Operation of this system is possible in two modes: • a manual mode, where cuts are pre-planned by operators along a fixed path using KUKA’s Robot Language (KRL) and • a semi-autonomous mode, where the cutting path between two operator selected points is calculated by external control software. • Cutting process within HMI developed as a user-friendly ‘wizard’ • All robot movements simulated virtually before execution • Final cut is simulated, executed without cutting, and then executed with the laser if Operator satisfied with visual checks

8. Semi-autonomous control • The HMI visualises a virtual representation of the robotic arm and the CAD environment. • Allows definition and inspection of the arm's motion during a virtual run along the cut-path. • A collision detection process is used to check that a proposed path does not result in any collisions against the robot and the environment and that the laser is firing towards the protective back-plate. • If collisions are found to occur the simulator requests a new path from the path-planner to check against.

9. Regulations / Standards • The range of UK regulatory requirements addressed during the installation and operation of NNL’s Robot Controlled Laser Cutting Facility included the following; • Fire Precautions Act, • Electricity at Work Regulations, • Control of Substances Hazardous to Health Regulations (COSHH), Pressure Systems Regulations, • Provision and Use of Work Equipment Regulations (PUWER) 1992, • Environmental Permitting Regulations. • The requirements of relevant standards including; • Use of Lasers (BE EN 60825-1 and BS EN ISO 11553-1, • Use of Robots BS EN ISO 10218-1:2011  BS EN ISO 10218-2:2011

10. Overview of hazards for NNL’s Robot Controlled Laser Cutting Facility

11. INTeGRATED Approach to Safety CASE (Ref 1) • The approach for developing the NNL’s Robot Controlled Laser Cutting Facility safety case is summarised as: • Identification of hazards, • Assessment of hazards and identification of suitable safety measures, • Substantiation of safety measures and • Implementation of safety measures. • Ref 1 Laser Cutting For Nuclear Decommissioning: An Integrated Safety Approach - Howard Chapman, Stephen Lawton, Joshua Fitzpatrick, (National Nuclear Laboratory), ATW 63 (2018) Issue 10 October

12. Hazard MANAGEMENT STRATEGY • The foundation of NNL’s Robot Controlled Laser Cutting Facility HMS is based upon a hierarchical approach to safety measures (i.e. ERICPD) which is used to minimise or eliminate the exposure to hazards: • Elimination of the hazards wherever possible, • Reduction of the hazard by substitution with a less hazardous form if possible, • Isolation and Control of the hazard with Passive / Engineering controls to prevent/mitigate the hazard where appropriate, • Reliance upon Personal protective control to mitigate the hazard, and Discipline with procedural controls is the ‘last line’ of defence.

13. Robot Key concerns:Operation of the robot with operators in close proximity, Impact damage, Potential for a radiological and/or chemotoxic release, Stray laser light hazards due to failure of the enclosure containment.

14. Measures The design of NNL’s Robot Controlled Laser Cutting Facility does not permit operation of the robot with operators in close proximity, . There are multiple of safety systems implemented within the robotic system; these focus on Limiting the robot’s movement to a controlled safe working area, Providing additional laser firing safety inputs, and reducing the amount of human intervention required in order to reduce rig downtime. Access door to the cutting enclosure is interlocked with the laser activation and robotic movement to prevent access to the cutting enclosure during usage.

15. MEASURES -Continued The KUKA robot has physical hard-stops installed in each joint to limit robot joint range to prevent any potential damage to the enclosure structure. As an additional work-space control for laser safety, one input to the laser firing system is triggered only if the robot is physically located in a pre-defined cutting area. The robot controller uses PLC logic to determine when the laser should be enabled; these were only set during pre-defined laser cutting programs. Both the laser and robotic systems have dead-man handles that must be used to action any activity. An additional emergency stop system which completely powers down the full system provides further defence in depth.

16. Plant Modification Proposal (PMP) The following documentation was prepared to allow installation and operation of the Springfields Test Facility: 4 PMPs 4 Safety Case memoranda 13 Risk Assessments, including CoSHH, PUWER 7 Operating Instructions Overarching Commissioning safety schedule 57 other documents 13 existing documents required significant updates

17. Any Questions?