The integration of seawater desalination system with nuclear power plant: Operational flexibility enhancement and thermo-economic performances

To accommodate the high penetration of renewable power, nuclear power plants (NPPs) should participate in peak shaving services, which has become a key issue restricting the efficient and reliable operation of NPPs. To enhance the operational flexibility efficiently, the seawater desalination system is integrated within a NPP in this paper. Thermo-economic performances of the proposed system were evaluated. When the main steam, inlet reheat steam, and outlet reheat steam of the NPP are extracted to drive the LT-MED desalination system, and the output power ratios of the integrated system can be decreased to 12%, 65%, and 61%. Therefore, the operational flexibility of the NPP can be effectively enhanced with the integration of desalination system. Then, the capacity and configuration of the LT-MED system were optimized, and gain output ratio and water production cost were used to evaluate performances of the integrated system. The water production cost reaches its minimum value of 0.64 $/m³, when the LT-MED desalination system decreases the output power ratio of the integrated system to 65%. The exergy efficiency of the integrated system is 7.9%, 18.3%, and 25.6% higher than that of AP1000 when the extraction steam is main steam, outlet reheat steam, and inlet reheat steam.