关键词: 氚送气管, 离子源管, 中性化管, 泄漏, 扩散

Abstract: The leak of tritium will cause radiation hazard for public safety and environment, therefore the leak of tritium contained pipes should be analyzed. The tritium contained pipes of the ITER gas injection system are analyzed in this paper. An estimation on the air equivalent leak rate at the tritium alarm threshold (3×10⁵ B_q·m^-3 for environment, 1×108 Bq·m‒3 for pipes) is given for the leak of the tritium supply pipe, the neutralizer pipe and the ion source pipe. The results show that the leak of the tritium supply pipe has highest risk. Although the tritium supply pipe operates at a pressure lower than that in the surrounding enclosure, leak rate higher than 3.2×10^-8 Pa·m³ ·s^-1 will trigger the tritium alarm due to high tritium concentration. To the contrary, the ion source pipe operates at a much higher pressure than that in the surrounding enclosure but has low tritium concentration. It will trigger the tritium alarm at leak rate higher than 6.1×10^-6 Pa·m³ ·s^-1 . The leak hazard of tritium contained pipes of gas injection system is not negligible, and real time monitoring and protecting is necessary. 

Key words: Tritium supply pipe, Ion source pipe, Neutralizer pipe, Leak, Diffusion