Prediction of the Siltation in the Intake of Nuclear Power Plant Using the Water Depth Monitoring and Coupled Model

Generally, coastal areas where there are dominant tidal currents and topographic change are maintained in equilibrium by the reciprocating motion of tidal currents. However, artificial action on the current for operating a nuclear plant operation at the intake and the outlet breaks the equilibrium of the tides and this in the end results in disturbing the equilibrium condition of bottom topography. This research used the variation of siltation pace acquired from monitoring results to formulate coupled model in order to predict the change of water due to artificial construction in the intake in the future more precisely. As a result of analyzing the water depth change in the intake area according to the survey data of water depth, after dredging work, siltation of 100~140cm/year occurs in the middle of the intake area but siltation of 80~300cm/year is generated at the sides. Furthermore, we can acknowledge the fact that siltation is generated and then come to the equilibrium for short period after artificial dredging work is executed every 2 years. Therefore, we have to examine these phenomena in prediction of siltation using numerical model test. In general, the results of sediment transport is expressed by yearly transformation rate based on linear change, but siltation is generated for short time and then come to the equilibrium after artificial dredging work is executed every 2 years in this study area. Therefore, it is necessary to carry out the model tests in same condition with field condition of dredging period (2 years), and it is presented that the numerical modeling results are similar to the field survey data. In the siltation model test, because a dredging period of 2 years gave an important influence on topography transformation, we eliminated a reappearance error and simulated water depth transformation in intake area using time-dependant coupled model based on survey time in order to represent the topography transformation in the real coast.