Considering wind-speed influence, a new acceleration model is established, and a trajectory equation is obtained. The impact-depth models of a cone and end-cover debris are also established based on the cavity expansion theory. Combined with the residual strength theory, a new spherical-tank failure-probability model is established, and the probability model of a domino accident caused by the debris is obtained. Additionally, the influence of different fragment shapes on the domino accident probability in spherical tanks is analysed, and minimum penetration rate of the spherical-tank failure caused by different fragment masses is calculated. Subsequently, using statistics, the correlation between failure-probability and distance between spherical tanks and shape parameters was determined. The results indicate that the debris shape significantly influences the impact-depth of the spherical-tank wall, and impact-depth of the conical-nose geometry is significantly greater than that of the blunt-nose geometry. Moreover, the minimum velocity of the conical-nose geometry penetrating the target is significantly less than that of the blunt-nose geometry. The shape change of the conical-nose geometry has almost no influence on the probability of the domino accident, whereas, that of the blunt-nose geometry significantly influences the domino accident probability. (C) 2020 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.