For the design of water circulating system of a nuclear power plant (NPP), the increasing of cooling water or the decreasing of water temperature will lead to the increasing of generation capacity; while the power of water circulating pump or the scale of cooling tower will be increased, which will lead to increased investment as a result- and vice versa. This article conducts optimization and sensitivity analysis for cold end system of a nuclear power plant with sea water circulating system, using the minimum annual cost method by dynamic economical analysis. The following factors are taken into account for the optimization: the design of condenser (cooling area, the parameters of cooling tubes, etc.), the scale of cooling tower, the flow rate of circulation water and the diameter of circulating pipes, etc. In conclusion, the optimum scheme of the cold end system is obtained for the double back pressure turbine project. The variation trend of annual cost with changing circulating water amount is also concluded. Finally, this article provides the sensitivity analysis of feed-in tariff.
