Speaker
Description
Kiyoto Shin-mura1, Shumpei Iwasaki1, Kazuya Sasaki1
1Hirosaki University
Current major plans for thermonuclear power generation use the nuclear fusion reaction of deuterium and tritium. Tritium, which is almost absent in nature, must be generated in a fusion reactor by the fission reaction of lithium 6 isotope (6Li) with neutrons. For this purpose, technology for enriching the 6Li isotope is required. In electrodialysis using a solid electrolyte membrane, lithium isotopes diffuse at a rate proportional to the inverse of the square root of their mass number. As a result, theoretically, an isotope enrichment ratio of approximately 1.08 occurs inside the solid electrolyte. Kunugi et al. experimentally demonstrated a 6Li isotope enrichment ratio of 1.08 (Solid State Ionics, 122 (1999), pp. 35-39). However, this mass effect is limited to a short voltage application time. On the other hand, we have clarified that intermittent voltage application sustains a high 6Li isotope enrichment ratio (Journal of the Ceramic Society of Japan, 126 (2018), pp. 331-335). Furthermore, by lowering the temperature of the electrolyte membrane, a large isotope enrichment ratio exceeding 1.08 was achieved through quantum effects (Fusion Engineering and Design, 171 (2021), 112577). However, these methods require long periods of interruption in voltage application, resulting in low lithium transfer rates and a need for improvement. In this study, we investigate the effect of active electrochemical control of the isotope ratio and amount of lithium adsorbed on the electrolyte membrane surface, and clarify that a larger isotope enrichment ratio and 6Li transfer rate can be achieved.
