**6. Conclusions**

In this chapter, a fragmentation simulation model for risk assessment due to the explosion of a cylindrical tank is presented. According to the literature, fragmentation models exclusively use accident data. In addition, parameters for which there is insufficient information available are assumed with a uniform distribution. These are the main shortcomings of existing fragmentation models. These shortcomings have been remedied by applying the proposed fragmentation model. The simulation of fragment scattering is considered through the issue of uncertainty in the estimation of geometric and kinematic parameters. Fracture probabilities were estimated without available accident data for the considered tank type. Fragmentation mechanics enabled the definition of characteristic trajectories and the definition of limit values for coefficients *kL* i *kD*. Introducing the initial acceleration into the analysis, we came to know about the correlation of certain geometric and kinematic parameters of the fragment. Most of the influential parameters are accompanied by epistemic uncertainty, so the initial velocity cannot be estimated on the basis of the explosive energy of the tank, nor can the initial launch angle of the fragment be assumed by a stochastic distribution. Fragments weighing up to a few hundred kilograms are best represented by the Weibull distribution, and the most probable range of the fragments is between 670 *m* and 680 *m*. The risk matrix is given per square meter for an area of 4 *km*<sup>2</sup> .The probability of impact of the fragment in the base target of 10 *<sup>m</sup>*<sup>2</sup> is from 1.6<sup>10</sup><sup>5</sup> to 2.1<sup>10</sup><sup>5</sup> .
