Transfer Phenomena of Tritium on Ceramic Breeder Materials

本文作者量化了各种锂陶瓷增殖材料中的水分捕获量，并比较了包层中由于吸附和在晶体颗粒中扩散而引起的氚库存。除了高温包层中大量的H_2或H_2O向吹扫气体外，由于吸附作用而在爆破处的氚存量远大于由于在晶粒中扩散造成的氚存量。因此，可以认为，氚在晶体颗粒中的扩散系数给出了包括表面传质阻力在内的值。目前的工作还发现，锂床中的水是在利用氢同位素的氦扫气进行同位素交换反应过程中产生的。预计氚在增殖包层循环中的行为很大程度上受到水的存在的影响。因此，了解在包层吹扫气体中添加氢气时发生的水形成现象是很重要的。

Present author has quantified the amount of water captured in various lithium ceramic breeder materials and compared the tritium inventory at the blanket due to sorption with that due to diffusion in the crystal grain. Tritium inventory at the blaket due to sorption is much larger than that due to diffusion in the crystal grain unless otherwise a large amount of swamping of H_2 or H_2O to the purge gas is applied in the high temperature blanket. Therefore, it can be considered that the diffusivity of tritium in the crystal grain obtained from the tritiated water release experiments gives the value including the mass transfer resistance at surface.It is also found by the present work that formation of water in the lithium oxide bed occurs in the course of the isotope exchange reaction experiments using He sweep gas with hydrogen isotopes.It is anticipated that behavior of tritium in the breeding blanket cycle is largely affected by existence of water. Accordingly, it is important to understand the water formation phenomenon occurs at addition of hydrogen to the blanket purge gas.