Helium gas permeability of SiC/SiC composite used for in-vessel components of nuclear fusion reactor
Helium gas permeability of SiC/SiC composite used for in-vessel components of nuclear fusion reactor
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DOI：
10.1016/j.fusengdes.2005.01.002
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发表时间：
2005-04
影响因子：
1.7
通讯作者：
T. Hino;E. Hayashishita;Y. Yamauchi;M. Hashiba;Y. Hirohata;A. Kohyama
中科院分区：
文献类型：
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作者：
T. Hino;E. Hayashishita;Y. Yamauchi;M. Hashiba;Y. Hirohata;A. Kohyama
由于碳化硅是一种低活性材料，氦气冷却剂的温度可高达1100K，因此，碳化硅/碳化硅复合材料是聚变堆包层材料的候选材料。然而，到目前为止，对碳化硅/碳化硅复合材料的氦气渗透性的测量还很少。利用由高压室和低压室组成的真空系统，对几种方法制备的碳化硅/碳化硅复合材料的氦气透过率进行了测量，并讨论了其在包层中的应用。用纳米粉末浸渍-瞬时共析(NITE)工艺制备的碳化硅/碳化硅复合材料的磁导率很低，为10−11m2/S，并测量了磁导率随热循环的变化。渗透率的增加幅度不大。在氦密度平衡的基础上，分析了氦气通过碳化硅/碳化硅冷却剂管道和包层模块第一壁的泄漏流量。结果表明，在包层组件上安装泵浦，可以降低聚变反应产生的氦产生率，从而降低聚变等离子体的泄漏率。这样，即使使用了碳化硅/碳化硅包层组件，也可以避免由于氦气泄漏而导致的燃料稀释。
SiC/SiC composite is a candidate material of blanket in fusion reactors since silicon carbide is a low activation material and the temperature of helium coolant can be taken high, 1100K. Helium gas permeability of SiC/SiC composite, however, has been little measured so far for this purpose. For SiC/SiC composites made by several methods, the helium gas permeability was measured using a vacuum system consisting of high and low-pressure chambers, and its application for the blanket was discussed. The permeability of SiC/SiC composite made by the method called as nano-powder infiltration and transient eutectoid (NITE) process was observed to be very low, 10−11m2/s. A change of the permeability owing to heat cycles was also measured. The increase of the permeability was observed to be not large. The leak flux of helium through the SiC/SiC coolant pipe and first wall of blanket module was analyzed based upon the density balance of helium. It is shown that the leak rate into fusion plasma can be taken lower the helium production rate due to fusion reactions if the pumping is attached to the blanket module. Then, the fuel dilution due to the helium leak may be avoided even when the SiC/SiC blanket modules are employed.