The RED100 experiment goals are to detect and study neutrino coherent scattering off atomic nuclei. This process was predicted by the Standard Model but has never been observed experimentally because of the very low energy of recoil nucleus. To register so small amount of energy deposited in detector is the primary experimental challenge. We propose to use a two-phase emission detector with liquid xenon as a working medium. This technology can be applied in rare events search that was successfully proved by modern low background experiments looking for Dark Matter. The RED100 experimental setup installation place is the Spallation Neutron Source (SNS) at the Oak Ridge National Laboratory (ORNL). Understanding and reducing backgrounds are very important for the RED100 experiment. The main background sources are cosmic muons and neutrons produced in the SNS target. Neutrons can penetrate through the shielding and, occasionally, mimic a neutrino interaction in the detector. The estimations of neutrons and cosmic muons backgrounds are presented.