One critical aspect in designing a space mission is the assessment of the level of radiation damage to the equipment that
one can expect during the course of the mission. The radiation environment in L2 orbit, however, has not been studied as
extensively as in the Low Earth Orbit case. Fluka is a Montecarlo software developed by CERN and INFN and
extensively used in high energy experimental physics and engineering, shielding, detector and telescope design, and
cosmic ray studies. In this paper, we make use of FLUKA to model the geometry of the structures surrounding the
detector, in order to analyze the mitigation strategy (i.e.: shielding of the detector assembly) in a well defined case (the
Euclid-NIS instrument, which is in its early design phase). By using a realistic cosmic ray spectrum and composition, we
analyze the resulting dose of ionizing and non-ionizing radiation on the Euclid-NIS detectors, and other effects.