Assessing long-term coastal flooding risk for Magnox nuclear power stations

A series of flood extent maps have been generated to assess the long-term vulnerability of selected Magnox sites (Oldbury-on-Severn, Berkeley and Wylfa) to flooding. These flood extent maps have been computed using the LISFLOOD-FP inundation model. Additional boundary conditions to include wave overtopping rates from extreme waves at Wylfa have been provided by the SWAB wave model. Each flood extent map is based upon a combination of increasing mean sea level (0.0 m to 1.0 m in 0.1 m increments) and extreme water levels (1:1, 1:2, 1:5, 1:10, 1:20, 1:25, 1:50, 1:75, 1:100, 1:150, 1:200, 1:250, 1:300, 1:500, 1:1000 and 1:10000 years) due to combined tide and surge, and extreme waves heights (Wylfa only). When used individually, and within the ARCoES Decision-Support System, these maps provide additional detail to support of Magnox’s long-term resilience planning for the defuelling, decommissioning and management of these nuclear power stations.