Jul 18, 2025
Containment dome for Hinkley Point C unit 2 has been installed.
The dome of the containment building has been installed at the second unit of the Hinkley Point C nuclear power plant being built in the UK. This marks the completion of major civil engineering work on the reactor buildings.
Using one of the largest cranes in the world, Big Carl, the dome—which has a diameter of nearly 47 meters, a height of 14 meters, and weighs 245 tonnes—was lifted and placed onto the 44-meter-high reactor building.
The dome consists of 38 prefabricated panels that were transported to Hinkley Point C and assembled in an onsite factory.
Work will now start on welding an air-tight seal between the dome and the reactor building, which will be covered with 7,000 tonnes of concrete.
Construction of the first of two 1,630 MWe EPR reactors at Hinkley Point C began in December 2018, with the second unit starting a year later. The dome for unit 1 was installed in December 2023.
EDF Energy noted that construction on unit 2 was paused during the Covid-19 pandemic, but teams are working to catch up. Their progress is aided by innovations and lessons learned from unit 1, allowing unit 2 to be built in 20-30% less time.
Despite the second dome being lifted 18 months after the first, unit 2 is further along than unit 1 at the same stage. EDF Energy reported that 30% fewer workers accomplished 40% more on unit 2 than on unit 1, with prefabrication nearing 60%. Additionally, more equipment has been installed and 300 tonnes of internal steel have been added, compared to just 10 tonnes at the same stage for unit 1.
"Restarting the industry has been difficult, but the second of our two identical units shows the significant advantages of repeating a design," said Stuart Crooks, CEO of Hinkley Point C. "Repeating designs is the most efficient way to build new nuclear, with time savings already at 20-30%. Our experience and innovation will also benefit Sizewell C from the beginning."
Sizewell C will have two EPRs and will essentially mirror the Hinkley Point C plant, aiming to be built more quickly and at a lower cost due to the knowledge gained from this first new nuclear construction project in the UK in nearly 30 years.
Using one of the largest cranes in the world, Big Carl, the dome—which has a diameter of nearly 47 meters, a height of 14 meters, and weighs 245 tonnes—was lifted and placed onto the 44-meter-high reactor building.
The dome consists of 38 prefabricated panels that were transported to Hinkley Point C and assembled in an onsite factory.
Work will now start on welding an air-tight seal between the dome and the reactor building, which will be covered with 7,000 tonnes of concrete.
Construction of the first of two 1,630 MWe EPR reactors at Hinkley Point C began in December 2018, with the second unit starting a year later. The dome for unit 1 was installed in December 2023.
EDF Energy noted that construction on unit 2 was paused during the Covid-19 pandemic, but teams are working to catch up. Their progress is aided by innovations and lessons learned from unit 1, allowing unit 2 to be built in 20-30% less time.
Despite the second dome being lifted 18 months after the first, unit 2 is further along than unit 1 at the same stage. EDF Energy reported that 30% fewer workers accomplished 40% more on unit 2 than on unit 1, with prefabrication nearing 60%. Additionally, more equipment has been installed and 300 tonnes of internal steel have been added, compared to just 10 tonnes at the same stage for unit 1.
"Restarting the industry has been difficult, but the second of our two identical units shows the significant advantages of repeating a design," said Stuart Crooks, CEO of Hinkley Point C. "Repeating designs is the most efficient way to build new nuclear, with time savings already at 20-30%. Our experience and innovation will also benefit Sizewell C from the beginning."
Sizewell C will have two EPRs and will essentially mirror the Hinkley Point C plant, aiming to be built more quickly and at a lower cost due to the knowledge gained from this first new nuclear construction project in the UK in nearly 30 years.