The study focuses on modeling a device designed for conducting experiments under low reactor neutron fluence rate conditions. The relevance of the work is driven by the challenges of accurately measuring low reactor neutron fluence rates, which are critical for the safety and efficiency of nuclear reactors and for conducting research in various scientific fields. To create a directed neutron flux, a horizontal collimation channel of the Prizm-AN irradiation device with a radioisotope capsule neutron source of the internal bounded neutron (IBN) type is being investigated. The paper presents the results of particle transport modeling using the PHITS and SOURCES-4C codes, which allowed for the evaluation of the generated neutron fluence rate parameters and the effective dose rate of radiation. The obtained results confirm the functionality of the proposed device and its compliance with radiation safety requirements, making it suitable for conducting experiments similar to those performed on reactor installations.