卧式蒸汽发生器传热管的腐蚀破损及其防护措施

Corrosion Damages and Protection Measures of Horizontal Steam Generator Heat Transfer Tubes

俄罗斯巴拉科夫（Balakovo）核电站卧式蒸汽发生器传热管破损的原因是锅水中所含杂质（氯离子、硫酸盐等）在传热管表面上浓缩形成了一层多孔腐蚀产物的沉积层。为了使卧式蒸汽发生器长期可靠运行，应满足管子表面上清洁度的要求和二次侧水化学指标。介绍了田湾核电站卧式蒸汽发生器传热管在运行前所发生的点蚀和应力腐蚀，参考WWER—1000型卧式蒸汽发生器的运行经验，在田湾核电站卧式蒸汽发生器的设计和运行时采取了多项防护措施。

The cause of damage of horizontal SG heat transfer tubes of Russian Balakovo NPP was metal corrosion as a result of concentration of corrosive impurities （chlorides, sulphates etc.）in SG water in the layer of porous deposits of corrosion products on the tubes. It can be made to realize long term and reliable operation of horizontal SG, providing for the tubes surface cleanness provision and the secondary side water chemistry target. This paper describes pit and stress corrosion cracking of horizontal SG tubes in Tianwan NPP prior to operation. In the design and operation of Tianwan NPP horizontal SG, the operation experience of WWER-1000 is taken into account, using several protection measures.