蒸汽发生器是核电站核心设备之一，蒸汽发生器传热管的完整性及其传热性能直接关系到核电站的安全性和经济性。蒸汽发生器二次侧内部结构复杂、排污率低，随着二回路给水带入腐蚀产物等杂质，容易导致传热管积污和垢下或缝隙腐蚀，影响到蒸汽发生器的安全可靠性。影响二回路系统腐蚀的因素很多，包括流体化学条件如pH、材料、流速、水力条件等，其中pH控制是减缓系统腐蚀的最方便和重要手段。通过对碱化剂的发展历史、碱化剂的选择进行分析，同时介绍了秦山地区对二回路胺进行改进，使用混合胺提高整个二回路各系统的pH，使之在最佳水平，有效抑制了二回路材料腐蚀以减少腐蚀产物进入蒸汽发生器。混合胺的应用更有利于二回路腐蚀的控制，是以后二回路腐蚀控制的一大趋势。

Steam generator (SG) is one of the core equipment of a nuclear power plant(NPP) and also the pressure boundary of primary circuit. The integrity and heat transfer performance of heat transfer tube of SG have a direct impact on the safety and economy performance of NPP. Due to the complex internal structure of SG and low polludant discharge ratio, some corrosive foreign material from feedwater area of secondary circuit are easy to lead to the heat transfer pipe fouling and corrosion beneath the scale or crevice, which will finally affect the safety and reliability of the SG. There are many factors affecting the secondary circuit corrosion, including chemical conditions of fluid, materials of equipment, flow rate of fluid, hydraulic conditions etc. The pH control of the secondary circuit is the key to reduce system corrosion. By analyzing the development history of the alkalizing agent and the selection of the alkalizers, the paper introduces an improvement use of amines in Qinshan NNP. It improves the pH value of the whole secondary circuit to the best level by using the mixed amines, which can effectively mitigate the corrosion of the secondary circuit materials and reduce the corrosion products into SG. Based on the research and application of amine characters and the achievement of mixed amines, it is concluded that the application of mixed amines will be more conducive to the control of secondary circuit corrosions, and will be a stream trend of secondary circuit corrosion protection control in the future.