The neutron flux induced by radioactivity at the Gran Sasso underground
laboratory is revisited. We have performed calculations and Monte Carlo
simulations; the results offer an independent check to the available
experimental data reported by different authors, which vary rather widely. This
study gives detailed information on the expected spectrum and on the
variability of the neutron flux due to possible variations of the water content
of the environment.Comment: 14 pages, 3 figures, systematic uncertainties adde