World Nuclear Performance Report

Hinkley Point C: Build and Repeat


The Hinkley Point site (Image: EDF Energy)

Now that EPR reactors have started up, we can gain experience in every aspect of the project, from construction to commissioning and operation.

The Hinkley Point C project in Somerset, southwest England, is the first new nuclear power station to be built in the UK for more than 20 years. It will be capable of providing 7% of the country’s electricity supply with two 1.6GWe EPR reactors. Hinkley Point C will avoid around 600 million tonnes of carbon dioxide during its operational life of at least 60 years.

The power station has revitalized the British nuclear supply chain. Construction was fully launched in September 2016 with the completion of the base for the first unit in June 2019 and for the second in June 2020. There now are around 8000 workers on site with 22,000 more workers around Britain involved in supplying the project.

UK adaptation

In common with other reactor designs, the EPR design went through a lengthy UK licensing process before it was approved in December 2012. The process led to significant design adaptations to enable the design to meet specific UK regulatory requirements. In effect the power station is the first-of-a-kind UK EPR.

Replication strategy

Evidence from nuclear construction across the world shows that replication is a significant factor in reducing cost and schedule risk. Experience from Hinkley Point C bears this out, with major productivity gains in work repeated on unit 2. This will benefit the follow-on near identical plant at Sizewell C in Suffolk. The power station is also benefiting from experience gained at Flamanville and Taishan as well as innovations like large-scale prefabrication and the use of digital design



Nigel Cann, Delivery Director at Hinkley Point C

What was the cause of the start-up dates for the reactors being put back recently, with the first unit now scheduled to start in June 2027?

Like any major construction project, we have faced more than two years of restrictions caused by the COVID-19 pandemic. Although we were able to find ways to keep the site open, while keeping workers and the community safe, numbers on site were held back.

At the height of the pandemic, numbers on site fell to around 1,500 and many of our suppliers faced disruption or temporary closures. Other factors have impacted the project, but we estimate the effect of the pandemic alone to be clearly in excess of 12 months.


Hinkley Point C unit 1 (Image: EDF Energy)

Several examples of faster progress on construction of unit 2, from learning from unit 1, have been given. Is unit 2 ‘catching up’ and would this have any impacts on the gap between grid connection for the two units?

During the pandemic, faced with limited availability of people and materials, we deliberately transferred resources from unit 2 to unit 1. In spite of this, major milestones on unit 2 like 'J-Zero' (the completion of the reactor base) and the installation of the second liner ring were completed just 12 months after the same operation on unit 1. We believe that the optimal gap between the two units is around 12 months and we aim to maintain that separation.

There have now been three EPRs that have started-up. Have there been lessons learned from these projects that will benefit the construction remaining at Hinkley Point?

Yes, absolutely. We have a big advantage in learning from the EPRs that preceded us, and there is good knowledge sharing between EPR operators and direct construction experience from EDF and CGN. Now that EPR reactors have started up, we can gain experience in every aspect of the project from construction to commissioning and operation. Many of the techniques at Hinkley Point C have already been influenced by experience from other projects and we continue to learn.How will the experience of Hinkley Point C construction benefit the proposed Sizewell C project?Hinkley Point C will give Sizewell C a big head start, including giving the Sizewell team a completed detailed execution design. This will give Sizewell C certainty over quantities and materials. The philosophy of replication is key to maximizing the benefits of our experience. We like to think of Sizewell C as the third and fourth Hinkley Point C units – our joint aim is to change as little as possible.


(Image: EDF Energy)