Coastal management to safeguard nuclear power stations

Nuclear energy has a vital role to play in securing a supply of net zero energy for the UK. Nuclear power stations are usually situated by the coast, because they need a constant supply of cooling water, and are designed to withstand the kinds of storms that only occur once in every 10,000 years. As EDF has shown, defending against such severe and unlikely events doesn’t have to involve massive concrete structures; it’s possible to work with and enhance the resilience that natural coastal systems provide.

Sizewell B in Suffolk uses naturally resilient beaches, sand dunes and offshore sandbanks, supplemented by defences that are designed to blend into the natural environment. 
Meanwhile, Dungeness B in Kent (now in its decommissioning phase) uses beach recycling – a process involving the capture and retrieval of beach shingle that has washed past the station. 

WSP leads the beach recycling process and acts as an external, independent coastal advisor for Dungeness B and Sizewell B, analysing detailed topographical surveys to look for significant change in the form or behaviour of the shore, which might affect resilience. We also engage with Natural England, the Environment Agency and other coastal stakeholders to help promote a joined-up approach to management along the coast.

How can nature be better than concrete? Setting Sizewell B back from the coast when it was built between 1987 and 1995 provided a natural buffer from the sea, with the added benefit of creating a wide open space that’s accessible for people to enjoy. In the event of a storm, the beach and dunes may be cut back but the sea remains a safe distance from the power station. Beaches and dunes then have the opportunity to recover naturally during calmer seasons, replenished by natural supplies of sand and shingle. 

Enhancing natural protection

Should extra protection ever prove necessary, Sizewell B also has two constructed sea defences. Close behind the shore is a man-made sand dune, which is covered in vegetation and designed to blend in with naturally occurring dunes. In the event of a severe storm, this can provide an increase of material to the beach, helping counter erosion and boost the dissipation of wave energy. Behind the dune is a wide grassy hinterland, well used by beach visitors. During an extreme storm surge this would prevent the largest waves from reaching the station. Finally, a second, more substantial built defence sits along the boundary of the station. This carefully constructed, sloping defence is covered in grass and shrubs; it provides a final safeguard without diminishing the natural setting.

EDF and their predecessors have also avoided intrusive defences in the distinctive and iconic environment of Dungeness B, where the landscape comprises many square miles of low shingle ridges, relics of shoreline change over millennia.  Here the station is protected by capturing and returning shingle that has been washed away from its frontage. The shingle is used to maintain a ridge immediately behind the shore, which adds resilience against erosion by naturally feeding the beach, when necessary, and against a coastal storm by acting as a physical barrier between waves and the station. 

By working with and enhancing natural processes at Sizewell B and Dungeness B, EDF Energy is able to provide its power stations with the protection they need while preserving valuable ecology and providing amenity space for people to enjoy. With WSP’s external expertise monitoring the geomorphological processes at work, EDF can be reassured that this important part of its safety system is functioning effectively.