Sizewell C’s main contractor, the Civil Works Alliance (CWA), has awarded Amentum a £22.3m contract to design marine and tunnelling works for the nuclear power station in Suffolk.
The contract will run for 10 years, comprising three years of design followed by seven years of design support.
Offshore tunnels and fish return system
Amentum’s scope includes the design of three 3.5km offshore tunnels, marine shafts, tunnel-to-shaft connections, marine heads and onshore galleries. It will also design connections to the main civil works and a system to return fish to the sea when they are incidentally drawn into the cooling system.
Amentum said the cooling system will circulate “enough water to fill 4,200 Olympic swimming pools every day”.
The CWA comprises Balfour Beatty, Bouygues Travaux Publics, Laing O’Rourke and Sizewell C.
Experience from Hinkley Point C
Amentum said it will subcontract major tunnelling design support to Jacobs and 3D reinforced-concrete detailing to Adda.
Amentum senior vice-president Loren Jones said: “We will bring proven nuclear design experience, replicating and enhancing lessons learned from Hinkley Point C, where we led equivalent scope.”
Jones added: “Working together again enables us to maintain continuity, leverage experience from Hinkley Point C to optimise the design, and reduce delivery risk on one of the UK’s most significant infrastructure projects.”
Hinkley Point C recently published photographs showing the retrieval of the tunnel boring machine used to complete its 620m fish return tunnel.