A refined set of state-to-state dissociation cross sections for the process N + N-2(V,j) --> 3N has been obtained by the quasiclassical trajectory (QCT) method and used in a 1D code describing the expansion of a dissociation-recombination mixture through a converging-diverging nozzle. The relevant vibrational kinetics includes V-V and V-T energy transfers as well as dissociation-recombination processes. The results show strong nonequilibrium vibrational distributions and non-Arrhenius dissociation rates along the nozzle axis as a consequence of the recombination process.