Every mm counts – Scaffold modelling brought to perfection
Each measuring a substantial 47m across and stretching 65m high, the two Nuclear Island inner containment liners being built at Hinkley Point C have a total combined internal surface area of approximately 26,000m2. That’s a lot of steel to coat.
Industrial asset protection specialist KAEFER is responsible for delivering the Liner Coating Package for the Hinkley Point C Project. This involves the painting of internal surfaces of both nuclear reactors, including providing the necessary access to undertake the operations: over 171 tonnes of scaffolding!
Both containment liners are made up of five components: a cup at the base, three separate rings then topped off with a dome. KAEFER identified an opportunity to construct the scaffolding on site before each steel component was lifted into position. “Our engineers worked closely with the sites main civil engineering works contractor, Bylor, and its engineers located in Paris, to make sure the design was compatible with the lifting parameters,” explained Thomas Hurst, KAEFER’s Temporary Works Coordinator and Designer for the Hinkley Point C site. “This ensured the design was revised and accepted within only two weeks of being instructed. Our initiative means that the scaffold can remain in place for subsequent liners, further reducing costs and programme for the clients.”
The successful use of 5D BIM technology allowed KAEFER to design and build the 44m radial scaffold to just 100mm safety factor. In combination with the latest surveying technology, the team was able to base the scaffold accurately to 5mm, allowing for the 100mm factor of safety to be perfectly maintained.
The seamless integration of KAEFER’s scaffold design and operational teams ensured that a suitable solution was developed for the client from the start. Scaffold build operations were also accelerated by designing the buttresses of the scaffold to be used as loading bays. This allowed for the scaffold equipment to be lifted onto the working lifts by crane, reducing manual handling and programme time.
The liner components are constructed in rings in an adjacent bunker. When built, the liner ring is lifted over the erected scaffold onto the working platform where KAEFER teams coat the internal surfaces. Once painting is complete the liner rings are then lifted into place in the reactor.
“We were able to develop the design to mm accuracy and instantly share the 3D models with the client to enable the solution to satisfy both KAEFER and Bylor’s operational requirements,” said Thomas. “This allowed the client’s critical path lift operations a greater wind tolerance, further reducing the risk to site and the project to achieve these critical path milestones. Working with KAEFER’s operations team we were able to identify and implement build opportunities which allowed the project to be delivered safely and ahead of schedule.”