Improving in-cell decommissioning12 May 2020
An In-Cell Decommissioning System (IDS), developed with funding from Innovate UK, combines radiometric scanning, remote deployment and virtual reality control.
IN AUTUMN 2017, CAVENDISH NUCLEAR, OC Robotics and the Welding Institute started work to design and test a system that could transform the decommissioning of active cells in redundant nuclear facilities.
Innovate UK funded the £1.5 million project, together with the Nuclear Decommissioning Authority (NDA) and the Department for Business, Energy and Industrial Strategy (BEIS) through a Small Business Research Initiative (SRBI) competition in 2018/19.
Testing of the In-Cell Decommissioning (IDS) system was completed within 12 months. It was followed, in December 2018, with a full demonstration of the system carried out in a purpose-built test cell at Cavendish’s Whetstone Facility. Cavendish proposes to use the system in active tests to decommission a cell at Sellafield.
What is the In-Cell Decommissioning System (IDS)?
The IDS integrates a proven device, tooling and Virtual Reality (VR) control technology to create a turnkey method for decommissioning redundant nuclear reprocessing cells safer, faster and at a lower cost. It represents a significant step-change from the industry norm that can deliver increased benefits compared to typical man entry decommissioning methods.
The IDS combines the robotic Laser SnakeTM arm of OC Robotics, a laser cutting torch supplied by The Welding Institute (TWI), the RadScan® 3D gamma dose-rate scanning technology of Cavendish Nuclear, and the VR expertise of the Babcock group to create a remotely-operated platform that protects workers from radiation while allowing them much greater visibility of congested plant and hazards.
How it works
The IDS maps and characterises the reprocessing cell using 3D LIDAR scan and gamma spectrometry. The data collected is used to create an intelligent and accurate 3D virtual reality model.
The operator then works within the VR cell environment to program, check and refine automated cutting operations.
Once satisfied, the program is downloaded to the deployment system and tools, which size reduce pipework and vessels into small coupons.
Waste coupons are bulk collected and placed into containers using a remotely operated vehicle (ROV) with a clamshell bucket attachment, or they picked and placed using a grab.
The IDS central software broker takes control data from different technologies that collectively form the system and translates it into one common language, which means the operating system to be used to control a range of tools and devices. In effect, this makes the system modular or scalable and transferable to different cells, applications or tasks.
Feedback from inactive trials
Results of inactive trials exceeded expectations with technology demonstrations generating interest from several potential customers in the UK and abroad.
“The demonstration showed that deployment of the equipment would be safer (by removing the operator from the workplace), faster (by increasing the working time during each shift as operators are [located] in a clean, comfortable area), cheaper (by reducing the number of operators required to complete the task compared to baseline [methods]),” said one stakeholder.
“The demonstration showed how human entry would be greatly reduced, and operational staff would be minimised. The scalability and transferability [of the system to suit a variety of applications] comes from the ability to interface with other remotely operated technologies.”
Cavendish Nuclear proposes to use a Brokk 170 with Fanuc CR-14iA/L robot arm attachment for deploying tools to decommission the Sellafield Solvent Treatment Bulge (STB) (see above). The ROV can remotely place down and pick up the robot arm and tools. The robot arm can remotely change tools (LIDAR scanner, RadScan, laser cutting torch, grab, liquor removal device).
A proposed active demonstration involves removing all pipework and vessels from the cell. First, the IDS scans the cell to create a virtual environment. Then the VR user interface is used to program automated cutting operations. Scanning is repeated regularly as the cell environment is continually changing.
Waste collection is performed in between cutting operations using the ROV and various tools (such as a clamshell bucket, scoops, grabs). Waste coupons are deposited into a posting port chute to fill waste containers situated external to the cell.
Laser cutting is initially performed to remove low-level pipework, vessels and obstructions, clearing a path for the deployment device. A liquor removal tool is then used to sample and extract liquid waste from the mixer. The large vessel and some high-level pipework is size reduced to create space around the mixer and remaining pipework. On confirmation of liquor removal, the mixer and remaining pipework are decommissioned.
On removal of all vessels and pipework, laser cutting operations are performed to remove material from the support steel and reduce the weight of the beams before eventually breaking span and completing decommissioning.
The development of innovative technologies and techniques is key to supporting the UK’s Nuclear Sector Deal to realise a reduction of 20% in decommissioning costs of the UK legacy versus the current baseline. In support of this, Cavendish Nuclear is developing and supporting innovations, which deliver practical solutions to the nuclear industry’s most challenging decommissioning projects.
Work has now started to demonstrate different deployment platforms and tools for the IDS. The goal is to prove further the system’s potential to address a range of decommissioning challenges, for example, in reactor decommissioning or to control submersible ROVs in cooling ponds.
Cavendish Nuclear is investing in a programme of improvements that includes:
- Further development of VR software to improve user interface and functions;
- Testing and demonstration of IDS with proprietary robot deployment arms.
In addition to this, Cavendish is speaking to UK site licence companies about the potential opportunities and benefits the system could provide.
Cavendish is also looking to partner with other organisations that have technologies such as VR, robotics, control software, ROVs, laser cutting, cable management, waste tracking and management and LIDAR scanning, which could improve the IDS.
There are also opportunities for IDS to cross into other non-nuclear industries that have hazardous operating environments such as the chemical, oil and gas or pharmaceutical industries.
Benefits of the IDS
Key benefits of the IDS include:
- A fully remote decommissioning system for activities traditionally involving physical human entry solutions
- Fewer people and equipment required
- Reduced human-machine interface
- Improved understanding of a continually changing operating environment
- Quick and easy programming of multiple tasks using a novel VR operator interface
- Low-risk pre-job planning, checking and refinement using VR animated simulations
- Automated operations to ensure accuracy, repeatability and waste form consistency
- Progressive hazard reduction methodology
- Improved waste tracking and packing