James Fisher Nuclear (JFN), part of James Fisher and Sons PLC, alongside partners WYG, took to the skies recently and made history with the first ever external Unmanned Aerial Vehicle (UAV) high resolution structural survey of a chimney stack within Sellafield’s high security chemical separation (SEP)active area. This innovative use of drone technology removed the need for time consuming scaffolding construction or bringing in special access vehicles, both of which are costly and require operators to be working at height. The SEP active area contains much of Sellafield Ltd.’s older production facilities and is a very compact part of the site, which presents a number of challenges and obstacles when it comes to carrying out structural inspections. JFN was able to show that its UAV was not just up to the task, it could deliver detailed results faster and at a significant cost saving over traditional methods.
The detailed UAV survey of the chimney stack precisely assessed how the chimney’s cowling, at the very top of the stack, was constructed. This new data will allow Sellafield Ltd to compile an accurate method statement for its safe removal.
Sellafield Ltd’s John Daniel said: “This was certainly an impressive use of UAV technology. Within the first 7 minutes, the JFN and WYG team gave us key information we could not ascertain from the existing drawing record. The new information the UAV has provided helps the project fully understand what is awaiting the demolition team when it reaches the top, and preparations can be made to ensure a safe and efficient transition from climb to demolition can be made.
This is a simple and efficient way to safely inspect areas like this in a fraction of the time and cost needed for scaffolding or bringing in special access vehicle and without staff working at height”
Alex Grainger, Project Manager at WYG, said: “We are delighted to have our Cumbria Nuclear Solution Limited (CNSL) consortium partner, James Fisher Nuclear, on board to support us on this project through our single source contract with Sellafield Ltd. to provide Civil Inspections and Topographical Surveying (CITS) Services to support Sellafield Ltd. achieve their asset management objectives and to inform the decommissioning process.”
A further 2 flights were carried out around all sides of the chimney to provide WYG with sufficient information to create a comprehensive 3D model of the stack. The pilots then carried out a final pass over the top of the stack to look inside the flue itself – a task previously assumed to be too challenging, but which proved to be straightforward.
Mike Rogers, Field service manager for JFN, said: “The inspection could not have gone any better. The project engineers were extremely impressed with the clarity of the photos from the high resolution camera and the detail it captured and it had pretty much answered the questions that they were looking for.”
Having gained such valuable insight into part of the legacy production plant for Sellafield Ltd, in areas that had previously been out of reach, the project team are already organising further UAV inspection of the inside of the stack area to improve their understanding of the cowl structure following analysis of the information JFN and WYG have provided. The upcoming UAV inspection will utilise the capabilities of the new Elios UAV which again has never been used previously on the site, another first for JFN.
JFN is now looking at the possibility of carrying out more surveys on other buildings around the Sellafield site. It is clear that JFN’s UAV fleet is proving its worth in a range of areas and the scope for this form of survey across many other industry sectors is immense.