冷却剂加锌对核电结构材料腐蚀行为的影响

Corrosion Behavior of Nuclear Structural Materials in Zn-added Coolant

选用与压水堆(PWR)核电站一回路冷却剂接触面积最大的结构材料690合金和316LN锻造不锈钢为研究对象,在模拟PWR一回路水化学环境下,采用静态高压釜浸泡方法和高温电化学方法研究冷却剂中加锌对这2种结构材料腐蚀行为的影响。研究发现,冷却剂加锌能明显抑制材料的均匀腐蚀速率和腐蚀产物释放速率。高温水中,以醋酸锌形式加锌,锌离子浓度为(10～50)ng/g时,能有效抑制腐蚀速率和腐蚀产物释放速率,加锌50ng/g以上,加锌浓度对腐蚀速率和腐蚀产物释放速率的影响趋于稳定。

316 LN and 690 Alloy, the structural materials with the largest contact area with the primary circuit coolant of the nuclear power plant, were selected as the research objects. Under the simulated pressurized water reactor(PWR) primary circuit water chemical condition,we used a static autoclave immersion method and a high temperature electrochemical method to study the effect of zinc concentration on the corrosion behavior of these two structural materials. The results show that zinc addition can obviously inhibit the corrosion rate of materials and the corrosion product release rate. Compared with Zn-free conditions, when zinc concentration is 10~50 ng/g, the zinc addition can effectively reduce the corrosion rate and corrosion product release rate of 316 LN and 690 Alloy.