【作者】 曹林园； 田珏； 辛长胜； 王辉；

【Author】 Linyuan Cao;Jue Tian;Changsheng Xin;Hui Wang;China Institute of Atomic Energy;

【机构】 中国原子能科学研究院；

【摘要】 玻璃纤维滤芯具有耐高温、耐腐蚀、截流量大、过滤精度高等优势,因此在核电站冷却剂水质控制中有广泛的应用。受水质及使用时间影响,玻璃纤维滤芯在使用过程中往往会释放二氧化硅。在压水堆运行工况下,二氧化硅及其析出物极易沉结在燃料包壳上,引发包壳材料的腐蚀,严重影响到核电站的安全运行[1]。本文采用静态浸泡法研究了玻璃纤维滤芯在模拟压水堆冷却剂硼锂水溶液中释放二氧化硅的行为,探讨了浸泡时间、温度、pH、过滤精度对SiO2释放行为的影响。试验结果表明:SiO2浸出率随浸泡时间延长而迅速减小,经过60天后,逐渐趋于稳定值,表明滤芯表面生成一层胶体保护膜。浸泡温度对浸出率影响较大,浸出速率随温度的升高显著增大,在浸泡最初的4天,25℃时浸出速率(8.6mg/gd)比70℃时(98.2mg/gd)约低一个数量级,说明在二氧化硅浸出过程不是单一的离子扩散反应,或网络溶解反应,而是两者共同参与或更复杂的多种机制共同控制的过程[2];相同条件下,玻璃纤维的过滤精度越高,释放出SiO2的速率越小。更多还原

【Abstract】 This study is focused on the leach behavior of nuclear standard glass filter element in mimic coolant. The effect of temperature, pH value of the coolant, filtration accuracy on the evolution of SiO2 were investigated using static immersion method. The results showed that, the SiO2 leaching rate was rapidly decreased, and tended towards stability over 60 day attributed to the formed colloid stable film on the surface of filter. With increasing the temperature, the SiO2 leaching rate obviously increased. It’s 8.6mg/gd at 25℃, and about an order of magnitude lower than that at 70℃(98.6mg/gd),demonstrating the process of SiO2 evolution was not simple ion diffusion or dissolution reaction, but controlled by both reactions, even more complex. At the same condition, the higher filtration accuracy was, the rate of SiO2 evolution was lower.更多还原