The dome for Hinkley Point C’s first reactor building has been successfully lifted into place. The major milestone closes the roof on the first reactor building, allowing the first nuclear reactor to be installed next year. The power station’s two nuclear reactors will provide reliable zero-carbon electricity for six million homes, boosting Britain’s energy security for decades to come. Engineering teams lifted the 245-tonne steel dome precisely into place on top of the reactor building on 15 December. The achievement ends 2023 on a high as the 14m-tall dome sits on top of the 44m high reactor building.

The lift, starting at 7.20am, was carefully planned to take advantage of a weather window to allow the 1.5hr-long manoeuvre to be completed in low wind conditions. The dome is the top part of the reactor building’s inner containment – a steel cylinder encased in concrete. Measuring 47m in diameter, it is wider than the dome of St Paul’s Cathedral – and made up of 38 prefabricated panels which were shipped to Hinkley Point C and welded together in an on-site factory.  Prefabrication and modular construction are key features of Hinkley Point C’s construction.

Earlier this month, the 750-tonne “Polar Crane” was lifted into place in a single piece above the reactor building’s third – and final – steel liner ring. This internal crane will rotate 360deg above the reactor and be used for re-fuelling and installing equipment.

Simon Parsons, Nuclear Island area director, said: “Building the first nuclear power station in a generation is a challenging job and the success of this complex operation is due to the determination and commitment of our fantastic teams. Lifting the dome allows us to get on with the fitting of equipment, pipes and cables, including the first reactor which is on site and ready to be installed next year.”

Nuclear Minister Andrew Bowie said: “This is a major milestone in building Britain’s first nuclear reactor in a generation, and a key part of the UK Government’s plans to revitalise nuclear. Generating enough zero-carbon power for six million homes, Hinkley Point C will reduce our reliance on imported energy and support the UK’s shift to ‘net zero’.”

Big Carl’s latest lift highlights the progress being made at Hinkley Point C, where 10,000 workers and 3,500 British companies are building the power station.