燃料棒保护管充钠技术研究

Study on Method to Fill Sodium into Fuel Test Capsule

快堆用燃料研发中需对燃料棒保护管进行充钠。根据充钠要求和金属钠的特点,利用真空、控温、惰性气体保护的方法,设计了专用的充钠装置和惰性气体手套箱。通过连接实验优选了聚四氟乙烯(PTFE)垫圈,解决了充钠装置与燃料棒保护管在高温下连接时的密封问题,同时避免了硬连接时对燃料棒保护管的损伤。7次模拟充钠实验量的平均绝对偏差(MAD)为0.03g,平均相对标准偏差(MRSD)为0.08%,符合燃料棒保护管的充钠要求。工业CT扫描结果、解剖实验结果和残钠对比分析结果均表明,充钠效果满足燃料棒保护管的需求。单次充钠耗时平均为2h,可实现小批量的燃料棒保护管充钠。同时,该装置也可应用于其他液态金属在细管中的充灌操作。

Sodium filling into fuel test capsules is essential in the fuel research for fast reactor. According to the filling requirement and the properties of sodium, a sodium fill- ing device and an inert-gas glove box which adopted vacuum, temperature-controlling and inert gas protection were designed. PTFE ring which could avoid the damage of hard connection was tested to solve the seal problem between sodium filling device and fuel test capsules at high temperature. The filling amount MAD and MRSD of seven simulate experiments were 0.03 g and 0.08%, respectively, which meet the demand of sodium filling into fuel test capsules. The results of industrial CT scanning, dissection and remained sodium comparison show that the sodium filling is satisfied. A single sodium filling process costs 2 h averagely, so it is practical for meeting the small sodium filling demands. This sodium filling device can be applied to other liquid filling into a thin pipeline as well.