Wave induced hydrodynamics field around a long submerged groin. The case of the Latina (Italy) nuclear power plant cooling system intake

This study aims to reproduce the hydrodynamics (waves, currents and sediment transport) in the area surrounding the submerged cooling system of the Latina nuclear power plant (Latium region, Italy) in order to investigate the morphodynamic origin of the observed submarine channel. The bathymetry survey of the area revealed the presence of a rip canyon on the east flank of the structure. This structure is made up of two submerged pipelines, 700 m long, covered by a submerged rubble mound and extends to the -6 m isobath. From a morphological point of view, it could be considered as a “long submerged groin”, being the local closure depth of about 8 m. The XBeach numerical model was applied to an idealized bathymetry with a submerged groin in order to confirm the formation of a rip current on the east flank of the structure, which causes loss of sediment seaward. Numerical simulations reveal that the nearshore circulation mainly depends on the incident wave angle and also demonstrate that the rip current occurs for a limited range of mean wave directions.