Failure scenarios of process plants are examined in safety talks. Dynamic simulations can be employed to make non-linear dynamic interactions transparent over the boundaries of individual process units and therefore gain importance in the support of safety analyses. They are useful to investigate the effectiveness of countermeasures, contribute to the design of tailor-made shutdown systems and help to avoid over-conservative designs. The validity of fluid dynamic models implemented in model-libraries needs to be ascertained. Adaptions may be required here.