Abstract <p>A Monte Carlo model of an experiment with the universal trap of ultracold neutrons at the PIK reactor has been developed. The project assumes that in one installation two traps are installed on the same axis: material and magnetic. By rotating the trap system around an axis, it is possible to carry out gravitational capture of UCNs either into a material or into a magnetic trap. Thus, on one installation it is possible to compare the material and magnetic storage of UCNs under the same conditions. The motivation for such an experiment is the disagreement in the results of measuring the neutron lifetime in material and magnetic traps. As a result of the simulation, the sensitivity of the experiment at the PIK reactor was obtained.</p>