Impact of breakwater design in water intake open channels of coastal nuclear power plants on entrainment effects

Abstract

[Objective] The safety of the nuclear power plant cold source is a prerequisite for ensuring the safe and stable operation of generating units. In recent years, frequent incidents of water intake system blockage triggered by large-scale aggregation of marine organisms driven by environmental changes in marine ecosystems have posed serious threats to the safety of nuclear power plant cold source. To systematically enhance the safeguarding capacity of water intake systems while mitigating the impact of intake engineering projects on the marine ecological environment, it is imperative to conduct targeted research on water intake entrainment. [Methods] A three-dimensional hydrodynamic model coupled with a particle migration model was used to systematically investigate the impact of different breakwater designs in water intake open channels of nuclear power plants on the distribution of intake flow fields and the biological entrainment effect of water intake. [Results] The result showed that when the breakwater was designed with a curvature of 90°, the designed water intake velocity was lower than the average tidal flow velocity. The inflow non-uniformity at the intake was approximately 3, and the hydrodynamic conditions demonstrated favorable guiding effects on marine organisms and a lower entrainment rate. Compared to other design scenarios, this configuration could reduce entrainment by approximately 50. 5%. [Conclusion] Different breakwater designs significantly affect the flow field characteristics of open-channel water intake, generating aggregation or guiding effects on marine organisms migrating with the flow near intake structures. This consequently affects biological entrainment during water intake. Appropriate breakwater designs can substantially mitigate the impact of water intake operation on marine organisms while reducing cold source blockage risks. The findings provide method ologies for optimizing the engineering design of water intakes in coastal nuclear power plants and quantitatively assessing water intake entrainment effects, thereby offering a basis for ensuring water intake safety and ecological operation.

Keywords

water intake open channel / breakwater / hydrodynamics / entrainment effect / safety of nuclear power plant cold source / coastal nuclear power plant / particle migration model