铀部件贮存容器内气氛控制方法研究

Atmosphere Control Methods in Storage Container with Uranium Assembly

目的研究不同气氛控制方法对铀部件贮存容器内气氛演化及铀部件腐蚀情况的影响,获得优化的气氛控制方法。方法采用虚拟表面反应的方法建立铀材料与环境气氛反应、有机材料释放水分、干燥剂吸水的计算方法,计算提高容器密封性能、干燥剂及分散放置、有机材料干燥剂处理等气氛控制措施单独使用及联合使用的7种工况下容器内湿度控制及氧含量情况,以及铀部件的腐蚀增重情况,对比分析了各种气氛控制措施的效果。结果经研究可知,对于含铀部件的贮存容器,仅提高其密封性能反而会导致容器内缺氧,从而加速铀部件的腐蚀;放置干燥剂是较好的气氛控制方式,分散放置的效果更好;采用分散放置干燥剂的同时对有机材料进行干燥处理的气氛控制措施效果最好,不仅铀部件的腐蚀速率最低,而且可以长时间保持有氧低腐蚀速率状态。结论得到了含铀部件贮存容器内多组分气氛演化规律及铀部件腐蚀情况变化的计算方法,对比研究了多种气氛控制方法在气氛控制及降低铀部件腐蚀方面的效果,获得了优化的气氛控制方法。

The work aims to study the influence of different atmosphere control methods on atmosphere evolution and corrosion of uranium assembly in uranium assembly storage containers, and obtain the optimized atmosphere control method. The method of virtual surface reaction was used to establish the calculation method of reaction between uranium material and environmental atmosphere, water release of organic materials and water absorption by desiccant. The humidity control and oxygen content in the container and the corrosion weight gain of uranium assembly were calculated under seven working conditions of separate use and combined use of such atmosphere control measures as improving the sealing performance of the container, drying agent and dispersion placement, drying agent treatment of organic material and so on. The effects of various atmosphere control measures were compared and analyzed. According to the research, only improving the sealing performance of the storage container containing uranium assembly would lead to anoxia in the container, thus accelerating the corrosion of uranium assembly. Desiccant placement was a better way to control the atmosphere, and the dispersion placement had a better effect. The atmosphere control measures of drying organic materials while dispersing desiccant had the best effect, as not only the corrosion rate of uranium assembly was the lowest, but also the state of aerobic low corrosion rate could be maintained for a long time. The evolution law of multi-component atmosphere in the storage container containing uranium assembly and the calculation method of corrosion change of uranium assembly are obtained. The effects of various atmosphere control methods on atmosphere control and reduction of corrosion of uranium assembly are compared and studied, and the optimized atmosphere control method is obtained.