Sizewell C has secured planning permission for a tunnel segment factory in Avonmouth, Bristol, where around 400 jobs will be supported in the production of 38,000 precast concrete segments and tunnel heads for the nuclear project’s three marine tunnels.
The facility will bring the former Hinkley Point C tunnel production site back into use, retaining existing infrastructure and drawing on the experience of teams involved in the Somerset nuclear project.
The expansion will include new concrete batching plants, cranes, storage areas, offices, welfare facilities and parking.
Early works are already under way, with the Civil Works Alliance employing 55 people at the site, alongside a further 86 supply chain workers. Subject to planning conditions being met, full production is expected to begin in 2028.
Finished tunnel components will be transported to Suffolk by rail and sea, supporting Sizewell C’s target of moving at least 60% of construction materials using these routes.
Nigel Cann, Sizewell C chief executive, said: “It’s also another great example of how we’re using the learnings from Hinkley Point C, which has seen significant advancements through off-site prefabrication, and taking them to the next level. By reusing existing infrastructure and experienced teams, we can reap the benefits across safety, quality, cost, and schedule.”
Sizewell C has already placed almost £5bn of work with more than 1,000 UK suppliers.



