Kongsberg Maritime Ltd, the UK arm of Norwegian maritime and offshore technology specialist Kongsberg Maritime, has received the award for ‘Best application of an innovative solution with tangible
savings/benefits (SME)' at the UK Nuclear Decommissioning Authority (NDA) Estate Supply Chain Awards, held in Manchester this November.
David Craigie, the product designer holding the award.
The award was presented for the design and manufacture of a High Temperature CCTV camera System for inspection of the Dounreay Fast Reactor Sphere (DFR). The project was scoped by the DFR fuels disposition
team who are tasked with the removal of the remaining breeder fuel from the reactor vessel, leading ultimately to the dismantling of the DFR. The camera was required to provide a visual insight into the
internal conditions of the reactor vessel, last seen, only partially, in the early sixties. The information produced by the camera has potentially saved millions of pounds and thousands of man-hours.
"Despite highly challenging conditions inside the DFR, the camera system was operated successfully and survived a THREE month campaign of testing, with the resulting footage proving essential to forming
the strategy of fuel removal," comments Bill Baxter, Manufacturing Site Manager, Kongsberg Maritime Ltd. "Though the entire system was designed from the ground up, our experience in developing underwater
cameras for the offshore oil & gas industry helped us to overcome the significant challenges of this project."
The detailed footage has mitigated many of the project risks associated with the challenge of removing the remaining breeder fuel material in the DFR whilst enabling modifications to be made to the
standard existing tooling before entering into active decommissioning operations. It has also provided a firm figure for the quantity of fuel to be recovered and returned to the national stock storage
facility at Sellafield. The project had the desired effect of de-risking the entire operation from the health and safety viewpoint and forms part of the critical path of decommissioning the Dounreay site.
Kongsberg Maritime designed the camera system to survive the harsh nitrogen inert atmosphere in the reactor at temperatures of up to 100 degrees centigrade and predicted radiation levels up to 20 sieverts/hr.
The camera also had to look up towards the ceiling of the reactor cavity in order to work out the best way to clean up the entire vessel, meaning a separate moveable camera head had to be designed. The
system was to be deployed through a 228mm diameter port at a distance of 5m through a gland sealing arrangement and the camera had to be capable of zooming this distance while providing useable, recordable
"We designed the system with a unique cooling arrangement and developed an additional interchangeable head with a 45 degree mirror attachment in order to get a view of the reactor ceiling, whilst ensuring
the system could be cleaned for re-use in subsequent operations," explains Baxter. "It was originally thought that we could use Stainless Steel for the camera housing, but after thorough testing we chose
a glass-filled nylon material for its thermal properties. An innovative Vortex cooler in conjunction with the nitrogen protected the critical parts of the system, enabling the camera to operate reliably
inside the reactor, resulting in the highly valuable footage now being used to support the complex long-term DFR decommissioning project."