Modification of coastal currents by power plant intake and thermal discharge systems

Abstract

Powerplant cooling systems that entrain large volumes of seawater in multiple discharge jets can produce changes in the local field of flow. A case history of observed flow modification is provided by dye studies and records of currents around the diffusers of the San Onofre Nuclear Generating Station (SONGS), which entrain a volume of flow on the order of 1000 m 3 s −1. Field observations of dilutions and velocities in the discharge plume agree well with the results of hydraulic modelling of the diffuser system. Synoptic observations and long-term statistical distributions of current speeds and directions show systematic patterns of altered flow around the diffusers that are more complex than the flow in the model because of interactions with flow modification by local beds of giant kelp.