Hinkley Point C tunnels ready for connection to Bristol Channel

The news marks a major step in the construction of the nuclear power station’s cooling water system.

Six shaft liners have been installed through the intake and outfall heads – ready for final connection to the 8km of tunnels. The 5,000-tonne head structures were lowered onto the seabed in 2022 and will circulate water to the nuclear power station.

The 270-tonne liners have been installed 25m below sea level and feature a world-first “isolation cap”. This will allow work to be safely carried out in the tunnels during the power station’s construction and operation.

Miners will now make the final connection between the tunnels and the liners, which will allow water to start flowing into the power station on the west Somerset coast.

Three Herrenknecht EPB TBMs were used to build a total of 8.8km of tunnels – two 3.5km-long intake tunnels with a 6m internal diameter and a 1.8km-long outfall tunnel with a 7m diameter. The tunnels run 33m below the seabed. The intake tunnels have six segments per ring, while the outfall tunnel has eight.