Co-existence of nuclear-renewable energies in a single hybrid power plant has been considered as an efficient and economical option to significantly reduce environmental impacts due to combination of two clean and climate-friendly decarbonized energy sources. The concept refers to an innovative system to balance the fluctuating renewable energy source such as wind, hydro and solar with the constant, base load nuclear output in order to smooth the energy production and to respond to the increasingly varying electricity demand. In the literature, few works have been reported on hybridization of a solar power plant with a small modular nuclear reactor (SMR) employing the proven pressurized water reactor technology wherein steam Rankine cycle is used for power conversion system at relatively low pressure. The current work suggests an integration of a SMR and a concentrated solar power plant (CSP) equipped with a thermal energy storage (TES) in which supercritical CO?Brayton cycle is adopted for power generation. The nuclear energy loop transfers heat to the electrical generation loop and the solar heat serves for raising the incoming gas temperature at the turbine inlet. The implementation of the thermal energy storage system enables continuous gas heating and non-stop plant operation. The proposed hybrid configuration is aimed at benefiting the technological advancements in exchangers and gas turbines to reach the plant thermal efficiency as high as feasible. The plant’s performance at design point is simulated by Engineering Equation Solver software. The simulation data present the potential enhancements of the suggested nuclear-solar hybrid plant’s thermodynamic efficiency in comparison to a single nuclear plant. In addition, advantages of utilization of SCO? Brayton cycle instead of classical steam Rankine cycle in such innovative hybrid system is also investigated. It is highlighted that hybrid operation could provide a substantial gain for cycle efficiency, up to 9-10 points, compared to single nuclear one’s, with possibly slightly improved performance for SCO? compare to Steam.