Fig. 1. Schematic diagram of geometric model(a) Nuclear hydrogen production system, (b) Simplified gas storage tank model

Fig. 2. Computational mesh (color online) (a) Mesh generation, (b) Mesh independence verification

Fig. 3. The relationship between tank pressure and diffusion distance

Fig. 4. Concentration change in the horizontal line of the leak (color online)(a) Concentration distribution of leakage under different tank pressures, (b) Concentration difference between maximum and minimum tank pressures during leakage

Fig. 5. Illustration of diffusion independent surface of combustible hydrogen cloud at 25 ℃

Fig. 6. Changes of leakage level parameters with distance to the leakage port at different temperatures (color online) (a) Variation of hydrogen flow velocity, (b) Variation of hydrogen temperature, (c) Variation of hydrogen concentration

Fig. 7. Changes of tank related leakage parameters over time (color online) (a) Variation of tank pressure, (b) Variation of mass flow rate, (c) Variation of hydrogen mass

Fig. 8. Changes in the volume and mass of combustible hydrogen clouds in the atmosphere over time (color online)(a) Volume of combustible hydrogen cloud, (b) Mass of combustible hydrogen cloud

Fig. 9. Hydrogen concentration distribution contour under the worst conditions (color online)

Fig. 10. Separation distance under the worst conditions (color online)