Scaffolding Success at Hinkley Point C

When supporting the building of the first in a new generation of nuclear power stations safety, agility, and innovation are top priority.

KAEFER UK & Ireland is responsible for delivering the Containment Liner Coating Package for the Hinkley Point C build. This involves the blasting and specialist coatings of internal surfaces of both nuclear reactor containment buildings, including providing the necessary access to undertake the operations. Both containment liners are made up of five components: a cup at the base, three separate rings, then topped off with a dome. In its entirety each containment liner is 65m tall.

In April 2021 KAEFER built a 171 tonne, 160m circumferential scaffold onto the Slab 8 construction area at Hinkley Point C. This then had the second 17m high liner ring for Hinkley Reactor 1 lifted over it– allowing contractors, including the KAEFER painting team, access before it was lifted into its final position on top of Liner 1 in November 2021. Read about the precision requirements for that project here.

Before lifting the second 47m ring into position in November an equipment hatch was required to be welded to the liner by the Hinkley Point C team. Waiting for this work to have been carried out would have delayed a critical element of the build project so KAEFER stepped in to provide a solution where others had said it couldn’t be done, allowing the project timelines to be met.  In March 2022 the KAEFER team devised an innovative suspended scaffold for the ring which was built on the ground and then lifted into position: allowing for the welding of the equipment hatch onto the ring liner, and the project to continue to schedule.

In August 2022 the same KAEFER scaffold on Slab 8, was reused and the 12m-high liner ring three was lifted over it, again allowing the KAEFER team and other contractors access to it before it was lifted to its final position on top of ring two in December 2022. Hinkley Point C project milestones had required the planned timeline to be shortened so when the third ring was lifted into position on top of ring two in December 2022 it still required additional work.

The KAEFER temporary works team were tasked with designing a scaffold to allow for the blasting and painting operations to ring three, as well as to provide access to aid with both the installation of the polar crane and the final dome top.

Initial discussions on the project began in November 2022 and involved stakeholders NNB, Bylor, Tissot, APCO Technologies, site operations, and the KAEFER coatings team.  Design considerations included loading onto the existing platforms in the liner, the available weight loadings of the liner itself due to the concrete pours on the external sides of the liner, suitable access being provided for the range of trades which needed to work on the ring, and the tie points for the scaffold, all needed to be reflected in the design.

A plan was devised by the KAEFER temporary works team to use stillages and load them with the tower components to build them in situ on the existing platforms. “A challenge presented itself when the planned crane was moved out of service for several weeks, meaning a new crane and material store had to be arranged,” explained Paul Ferrand, Operational Delivery Lead for KAEFER UK & Ireland at Hinkley Point C. “This required daily coordination with several stakeholders to organize deliveries with crane time booked in advance: on a busy site like Hinkley Point C this can be difficult.” Availability of Hinkley Point C riggers to support the crane tasks was also limited during the day, this, combined with working at height safety requirements minimizing available working areas below the scaffold, meant there was only one available option: the KAEFER team moved to night shifts.

Incident first response manpower availability at Hinkley Point C is reduced overnight so KAEFER collaborated with Bylor’s HSE team, creating a viable rescue plan from the working platform to ensure safety of the KAEFER team members. A designated platform, within reach of a specified crane, was established and a brief with all teams took place so they all knew the procedure. A test run of the process was performed with a successful lift and landing accomplished.

With the scaffold build now fully under way it was imperative to keep the motion going. “We attended daily coordination meetings during the day and ensured this information was handed over to the night shift teams,” said Paul. “Ongoing design amendments continued throughout the programme to modify the scaffold for crane operations.” Thanks to the KAEFER temporary works team’s agility, disruption to other trades was minimised allowing for project timelines to be met.

Once the scaffold build was completed it was handed over to the KAEFER containment team to encapsulate the structure. Over 2,400m² of flame retardant shrink wrap material was used to create an enclosed habitat for the KAEFER coatings team to complete blasting works. This habitat contained the garnet blasting medium used in the coating’s preparation works. The habitat also protects the three-coat phenolic epoxy-polyamide PIC 100 coatings scheme as it cures. The KAEFER coatings team is applying this scheme to 26,000m² of steel across the inside of both containment liners.

The scaffold build and containment took, including down time for bad weather and crane availability, 52 nights. “These efforts allowed project critical operations to continue, meaning Hinkley Point C is one step closer to providing zero-carbon electricity for around six million homes,” said Paul. “We’re proud to be playing our part and it’s a good feeling to know that whatever challenges we’re set, our team are equipped ready to handle them.”

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