Co-existence of nuclear-renewable energies in a single hybrid power plant is considered as a possibly efficient and flexible option to significantly reduce environmental impacts due to combination of two climate-friendly decarbonized energy sources. The concept refers to an innovative system, which locally balances the fluctuating renewable energy source such as solar, by the steady base load nuclear output, thereby smoothening the energy production. This hybrid system also features a thermal energy storage (TES) and the whole combination allows accommodating the daily and seasonally varying electrical grid demand (which specification is likely to sharpen with the increased penetration of renewables energies). In the literature, many works address hybridization of solar and fossil thermal sources or solar and other renewable sources, such as geothermal or biomass. Several concepts of hybridization of nuclear and fossil thermal sources have been also investigated. On the other hand, few works have been reported on hybridization of a solar power plant with a small modular nuclear reactor (SMR). In such a system, the proven pressurized water reactor technology is usually considered and a steam Rankine cycle is used as the power conversion system, the operating pressure being lowered compared to conventional PWRs.

Inline, the current preliminary work investigates integration of a SMR with a concentrated solar power plant (CSP) equipped with a TES. However, a supercritical CO2 Brayton cycle is originally applied for power generation. The nuclear energy loop transfers heat to the thermodynamic cycle and the solar heat allows upgrading the turbine inlet temperature. Implementation of the TES enables continuous scO2 heating and thereby non-stop plant operation. The proposed high temperature hybrid configuration is aimed at benefiting from the technological advances as regards key components such as heat exchangers and gas turbines so that high performances are considered along the plant thermal efficiency optimization process. An alternative option based on hybridization of a SMR, a low temperature solar power plant, an absorption chiller and a cold energy storage, is also investigated.