Sizewell C

MARKETS: Nuclear

CLIENT: Sizewell C Limited

COLLABORATORS: EDF, Balfour Beatty, Bouygues UK, Laing O'Rourke, Tony Gee, Sizewell C Limited

Sizewell C is a new 3.2-gigawatt nuclear power station being built on the east coast of England, one of the first of a new generation of new nuclear plants that will play a major role in decarbonising the UK’s energy.

Our role

As a delivery partner to SZC, we have been supporting the project since 2014, building on our experience as a key delivery partner for EDF Energy’s existing nuclear fleet and Hinkley Point C in Somerset.

In 2019, our teams began the design of enabling works of Sizewell C, to help prepare the main development site for the main civil works and marine works construction. In the time since:

• Determined the optimal layout for the construction site plot plan and sequence of construction on site.
• Supported SZC in the development of the DCO application which was granted by the Secretary of State for Business, Energy and Industrial Strategy in July 2022.
• Developed the detailed design of earthworks, roads, wet and dry utilities, security fencing, temporary buildings and landscaping for the ACA, TCA and MCA comprising some 100km of ducted networks, 80km of water networks, 20km of roads and access ways and 14Mm3 of earthworks cut and fill.
• We have designed upgrades to the Sizewell Branch Line and the development of the new Green Rail Route that will be used to bring workers and materials to the site and reduce freight movements in the local communities.
• We also explored what cost-effective construction techniques could be undertaken as we planned the optimal layout and sequence of construction for efficiency and safety, relying on innovative design solutions.
• We’ve provided considerable engineering support in areas such as managing the Responsible Designer, undertaking Engineering Integration and helping to establish the turbine contract.
• We’ve helped to establish multiple equipment contracts, have conducted multiple replication assessments and are a key component of SZC’s Design Authority providing expert knowledge into the Pre-Construction Safety Report and Hazards Assessments.

In 2023, we were awarded a contract with Sizewell C to design the Conventional Island, Balance of Plant and Heat Sink of the proposed new power station, as well as concept design for permanent roads and networks that will support the construction and long-term operation of the site.

This has given us the opportunity to identify ways to maximise replication from HPC, supporting EDF in reducing construction costs and speeding up the construction process. You can read about our digital design engineering in more depth in the case study:

In 2024, we established our presence at the SZC construction site as we completed the detailed design of the site establishment and earthworks. Our role on the construction site is broad and includes:

• Management of design change and engineering configuration during construction.
• Review and optimisation of the temporary buildings and welfare provision.
• Maintenance of the earthworks and utilises mass balances across the evolving construction site.
• Monthly drone surveys.
• Materials and stockpile management.
• Environmental monitoring in compliance with the DCO.

In addition to our work in civil engineering space we are also supporting SZC across the Nuclear Island and Conventional Island programmes. Along with other organisations across the Sizewell C Consortium, we look forward to continuing our work with EDF to progress Sizewell C and help ensure it plays a vital role in providing clean, reliable energy in the UK’s future energy mix.

Services provided

Our services to EDF in the UK have crossed a number of disciplines, with the engineering team covering the likes of:

• Transportation – logistics, bridge design and rail design.
• Civil engineering, design and analysis – environmental, Tekla.
• Structural engineering.
• Multi-disciplinary building services – architecture, Revit, 4D modelling,.
• Mechanical, electrical, plumbing – PDMS.
• EC&I - HV/AC, BMS, SCADA.

Our role has also included quality and information management, design assurance, requirements management, procurement, estimating, schedule integration, risk management and analysis, cost management, supply chain management and project controls.

Project scope

• Associated developments – road, rail, accommodation campus, freight management, adoptable highways.
• Advanced works – ground investigation, ecological mitigation designs, archaeology, desalination plant, utilities.
• Site establishment – utility networks, water networks, retaining walls, temporary buildings, fencing, site roads and rail.
• Enabling works – 6 lane bridge over the SSSI, ground engineering (cut off wall, dewatering, ground improvement, tunnel access shaft), maritime (temporary and permanent sea defences, mass bulk import facility (jetty), beach landing facility).
• Earthworks – borrow pit, bulk excavation, back fill, stockpile management, landscaping, transportation, treatment.
• Marine and tunnelling – tunnels, marine works, PC heads.
• Main civils – nuclear island, conventional island, heat sink, balance of plant, galleries, development areas, roads and networks in MCA, CRF pipes.
• Sitewide support – bulk materials and products, equipment supply services, logistics and freight management, accommodation and bussing, site infrastructure and facilities, security, common assets.
• Multi-Discipline engineering support provided into the Nuclear Island and Conventional Island/Balance of Plant Programmes as well as the Technical Directorate.

Key benefits

• Sizewell C will generate enough low-carbon electricity to supply six million homes and generate electricity for 60 years.
• 3.2-gigawatt nuclear power station; an essential source for the UK’s Net Zero energy system.
• By replacing fossil-fuel power, it will avoid around nine million tonnes of carbon emissions each year compared to a gas-fired power station.
• The project will support 70,000 jobs across the UK and rely on over 3,000 UK-based suppliers.
• It will create thousands of local jobs and contribute around £4 billion to the regional economy.