H-D-T cryogenic distillation experiments at TPL/JAERI in support of ITER

摘要

The hydrogen isotope separation system (ISS) using cryogenic distillation method is one of the key systems in a fuel cycle loop of a fusion reactor. The ISS for the International Thermonuclear Experimental Reactor (ITER), is characterized by its required flexibility for the variability of feed composition, which is not considered in the existing industrial distillation columns, so that the development of evaluation method of dynamic behavior, which is the base for the establishment of ISS control system, is essential as original technology. At the Tritium Process Laboratory in Japan Atomic Energy Research Institute (TPL/JAERI), H-D-T cryogenic distillation experiments have been carried out to acquire the systematic data for the design of the ISS for the ITER. The value of height equivalent to a theoretical plate (HETP) was estimated to be 5 cm by the results of present experiments and it was adopted in the ITER―ISS design. The in situ, multi-points and reliable high-speed gas analytical system with Laser Raman spectroscopy was successfully demonstrated in the experiment to analyze the hydrogen isotopes of H_2-HD-HT-D_2-DT-T_2 within 1 min with the analysis limit of 1000 ppm, which indicates that this system enables fine control of the ISS. The reliability of this system was also proved through its use without any mechanical trouble for more than 2 years. The analysis codes were developed and improved through the experiments, and it was succeeded to simulate the dynamic behavior of the distillation column. Through a series of the ISS experiments at the TPL/JAERI, effective design and effective operation of the ISS became to be possible.