CFD simulations investigating the effect of ventilation airflow on hydrogen release behavior in an underground mining tunnel were performed using FLACS hydrogen. Both dispersion and combustion scenarios of a hydrogen release coming from a severed distribution pipeline were investigated. Effects on the hydrogen dispersion such as ventilation strength and the mechanism of air flow supply (a ?pull? or ?push? fan) and mine opening surface roughness, surface cavities and obstructions were explored. Results showing the effect of changing the position of the leak, adding a cavity on the ceiling of the tunnel and changing the roughness of the walls are given. Overpressure sensitivity to the ignition delay was also considered. From the results, for the varied ventilation regimes and spatial scenarios, it is difficult to identify the optimal ventilation strategy giving the safest conditions for hydrogen distribution and refueling in an underground mine.