  $\textbf{Background}$ More than half of all the elements heavier than iron
are made by the rapid neutron capture process (or r process). For very
neutron-rich astrophysical conditions, such at those found in the tidal ejecta
of neutron stars, nuclear fission determines the r-process endpoint, and the
fission fragment yields shape the final abundances of $110\le A \le 170$
nuclei. The knowledge of fission fragment yields of hundreds of nuclei
inhabiting very neutron-rich regions of the nuclear landscape is thus crucial
for the modeling of heavy-element nucleosynthesis.
  $\textbf{Purpose}$ In this study, we propose a model for the fast calculation
of fission fragment yields based on the concept of shell-stabilized
prefragments defined with help of the nucleonic localization functions.
  $\textbf{Methods}$ To generate realistic potential energy surfaces and
nucleonic localizations, we apply Skyrme Density Functional Theory. The
distribution of the neck nucleons among the two prefragments is obtained by
means of a statistical model.
  $\textbf{Results}$ We benchmark the method by studying the fission yields of
$^{178}$Pt, $^{240}$Pu, $^{254}$Cf, and $^{254,256,258}$Fm and show that it
satisfactorily explains the experimental data. We then make predictions for
$^{254}$Pu and $^{290}$Fm as two representative cases of fissioning nuclei that
are expected to significantly contribute during the r-process nucleosynthesis
occurring in neutron star mergers.
  $\textbf{Conclusions}$ The proposed framework provides an efficient
alternative to microscopic approaches based on the evolution of the system in a
space of collective coordinates all the way to scission. It can be used to
carry out global calculations of fission fragment distributions across the
r-process region.
