This talk presents the study done for the realization of a compact photo-neutron source at the Beam Test Facility of the DAFNE e+/e- collider, in Frascati (Italy), by using high energy electron beam (510 MeV) on a suitable Tungsten target. The neutron field around the source has been characterized experimentally. The measured photo-neutron yield and the energy spectrum are compared to the respective predictions obtained by Monte Carlo codes (FLUKA, MCNP and GEANT4). Some differences in the code prediction capabilities emerged, motivating the interest to pursue deep investigations on the photo-nuclear physics implementation in each of these codes. More in detail, a systematic and direct comparison of relevant physics parameters (i.e total cross sections) as implemented in the three used codes to reference and suitably chosen experimental values (when available) have been started. This study is still on-going. Preliminary results will be also presented and discussed.