The article presents the results of research carried out in order to create conditions for ensuring the safe operation of irradiated fuel assemblies (SFAS) in the holding pools of research nuclear reactors using a passive cooling system operating on the principle of thermosiphons. The results of experimental studies in the mode of natural circulation of the coolant of the storage mine of the research nuclear reactor IVV-2M (IVV-2M, temperature regimes at various points of the SHK under different cooling modes and loading of the mine) in case of loss of power supply during partial loading of the mine, when unloading the entire core into the mine. A three-dimensional model of a storage shaft heat exchanger has been developed, which allows analyzing thermal and hydraulic characteristics at various environmental parameters, and various modes of temperature and velocity distribution in the heat exchanger have been modeled. To assess the reliability of cooling of irradiated fuel assemblies in the de-energization mode, a three-dimensional model of the storage mine was constructed and a simulation of the coolant cleaning and cooling system and ventilation system was carried out. A device with thermo-couples for measuring temperature at various points in depth has been developed and manufactured, taking into account the structural features of the storage mine. The scheme of operation and design of the proposed experimental installation of a system of passive heat removal of irradiated fuel assemblies is proposed.