Electrolytic enrichment of tritium with Fe-Ni and Ni-Ni electrodes and estimation of tritium enrichment factor using Fe-Ni electrodes

抄録

The electrolytic separation factors of tritium, (T/H)_water/(T/H)_hydrogen, and the relationship between the tritium enrichment factor, T_f/T_i, and the final volume of water have been evaluated for Fe-Ni and Ni-Ni electrodes. The tritium separation factor for the Fe-Ni electrodes (25.9 ± 3.4) is systematically higher than that with the Ni-Ni electrodes (14.4 ± 4.4) when the electrolysis is conducted under similar conditions. The tritium separation factor with the Fe-Ni electrodes obtained in this study is similar to that obtained in previous studies. Chemically impure mild steel used in this study as a cathode material gives a high tritium separation factor as well as pure iron employed in previous studies. The tritium enrichment factor with the Ni-Ni electrodes shows a wide variation at a given final volume, depending upon the tritium separation factor. On the contrary, the tritium enrichment factor obtained with the Fe-Ni electrodes changes as a function of the final volume. When tritium in the sample is enriched 20–25 times with the Fe-Ni electrodes, a reliable tritium enrichment factor can be obtained directly from the final volume with an accuracy of ±3.5% (2σ) without measuring the deuterium or simultaneous electrolysis of a tritiated reference water.