蒸汽发生器传热管失效分析及防护措施

Analysis and Preventive Measures for Steam Generator Heat Transmission Tube Failure

蒸汽发生器是核动力装置中一个非常重要的热量交换设备,也是整个核动力装置中的薄弱环节。在核动力装置的停堆事故中,有一半以上是由于蒸汽发生器破损引起的,严重影响到整个核动力装置的安全性和可靠性。如何使传热管不过早破损,延长蒸汽发生器的使用寿命是当前面临的重要课题之一。文章通过对蒸汽发生器传热管所用奥氏体不锈钢材料的分析,结合国内外相关事故分析报告,确定了传热管破损的类型为穿晶型应力腐蚀破坏。通过对腐蚀产物、工作环境以及管束应力的分析,找出蒸汽发生器传热管发生应力腐蚀开裂的影响因素,同时提出相应的防护措施。

Steam generator is a very important heat-exchange device,and also the vulnerable spot of a nuclear power plant.There was more than one half of the shut-down heat accidents were caused by breakage of the steam generator.This seriously affects the safety and reliability of a nuclear power plant.How to prevent the tube from breakage not too earlier and extend the life of the steam generator is one of the major problems confronted at present.Countercheck of the steam generator tubes was done by material composition analysis,Combining relevant domestic and international accidents analysis report,it can confirm that the corrosion type of the tubes is the cross grain stress corrosion.The influencing factors of stress corrosion are confirmed by analysis of corrosion product,working environment and stress status.At the same time,protective measures were provided.