  Secondary particles produced in spallation reactions of cosmic rays with the
interstellar gas provide valuable information that allow us to investigate the
injection and transport of charged particles in the Galaxy. A good
understanding of the cross sections of production of these particles is crucial
to correctly interpret our models, although the existing experimental data is
very scarce and uncertain. We have developed a new set of cross sections, both
inelastic and inclusive, computed with the {\tt FLUKA} Monte Carlo nuclear code
and tested its compatibility with CR data. Inelastic and inclusive cross
sections have been compared to the most up-to-date data and parameterisations
finding a general good agreement. Then, these cross sections have been
implemented in the {\tt DRAGON2} code to characterize the spectra of CR nuclei
up to $Z=26$ and the secondary-to-primary ratios of B, Be and Li.
Interestingly, we find that the FLUKA cross sections allow us to predict an
energy-dependence of the B, Be and Li flux ratios which is compatible with
AMS-02 data and to reproduce simultaneously these flux ratios with a scaling
lower than $20\%$. Finally, we implement the cross sections of production of
gamma rays, calculated with {\tt FLUKA}, in the {\tt Gammasky} code and compute
diffuse gamma-ray sky maps and the local HI emissivity spectrum, finding a very
good agreement with Fermi Large Area Telescope data.
