The selection of a location for the disposal of radioactive waste, used sources and spent nuclear fuel in the Republic of Croatia began to be considered as early as 1988. However, in the last 10 years, intensive activities have been undertaken regarding the selection of this location. One possible location is Čerkezovac in the Trgovska Gora area, which is located in the Una River basin and less than 1 km away from the border with Bosnia and Herzegovina. It is planned to establish a Radioactive Waste Management Center in Čerkezovac, where all spent radioactive sources located at two sites in Croatia, all institutional waste owned by Croatia, as well as low and intermediate level radioactive waste from the Krško Nuclear Power Plant, would be accommodated. According to the ESPOO Convention (Art. 1, paragraph VIII), transboundary impact implies any impact, not exclusively of a global nature, within the jurisdiction of the signatory state caused by a planned activity, whose physical origin is wholly or partially within the jurisdiction of another signatory state. The majority of the influential surface area of the radioactive waste disposal site (assuming a distance of 5 km from the Čerkezovac site in the Trgovska Gora area) is located within the territory of Bosnia and Herzegovina. This influence could have negative implications on the natural values and protected areas in the Una River valley in Bosnia and Herzegovina, as well as the life of the population.In this paper, based on the analytical-synthetic research approach, the basic physical-geographical characteristics of the Una River basin have been determined. During the analysis, it was concluded that the connection of physical-geographic components within the Una River basin created a series of natural values that formed the basis for the designation of protected areas. This refers to the fluvial and karst landforms that dominate this area, as well as phytogeographic formations, which stand out for their uniqueness and irreplaceability, morphography and morphometry, and the degree of preservation of physical-geographic phenomena and processes. The results of the research can contribute to a better understanding of the potamological characteristics of the Una, its hydrological significance, as well as the need for environmental protection in the context of the possibility of nuclear waste disposal in the border zone of the Una basin. The processing of all parameters relevant to the study and cartographic representation in this paper were performed in the ArcGIS software package.