Analysis on the influencing factors of radioactive tritium leakage and diffusion from an indoor high-pressure storage vessel

Radioactive tritium leakage from high-pressure storage vessels is a common nuclear leakage event. Different leakage conditions have different effects on tritium diffusion, resulting in different degrees of radioactive hazards. This study focuses on tritium leakage from high-pressure storage vessels and analyzes the influence of different leakage orifice shapes, leakage positions, and the presence of obstacles in the scene space on tritium leakage diffusion. The results show that there is little difference in the radial diffusion velocity of tritium gas along the jet axis between circular and square leakage orifices. The radial diffusion velocity of tritium gas in the long-axis direction of the rectangular leakage orifice is larger than that in the short-axis direction, and the larger the aspect ratio of the rectangle is, the greater the difference is in the diffusion velocity. In addition, leakage from the storage vessel below the air inlet is beneficial to the dilution of tritium, whereas leakage from the air vents leads to a slow decrease in the tritium concentration. The obstacles present in the tritium scene space hinder the migration of tritium gas and prolong the time for the tritium concentration to reach stabilization. This study provides a theoretical basis for the disposal of tritium in tritium leakage accidents by analyzing the influence of different leakage conditions in storage vessels on tritium gas diffusion.