In the existing nuclear power plants, almost 60 to 70% of produced heat in the reactor is released to the ambient through the condenser, which can be used as the feedwater of reverse osmosis (RO) desalination plants. Although increasing the temperature of RO feedwater improves the overall performance, the quality of produced water decreases. This difficulty can be solved by blending the high-quality water produced by thermal desalination plants (DPs) with RO products. However, supplying the required energy for driving the thermal DP needs to consume a huge amount of fossil fuel, which is contrary to net zero-emission goals. In this study, three different scenarios, based on the solar plant (SP) (scenario 1), small modular reactor (SMR) (scenario 2), and the hybrid SMR-SP (scenario 3) for supplying the required energy of DP have been suggested. According to the techno-economic evaluation conducted in this study, using the SMR as the auxiliary heat source of the SP in the third scenario can be considered as a promising technology, which is associated with several benefits. However, the average water cost in scenario 2 is 66 centm3, which almost 8.5 and 5% is less than scenarios 1 and 3, respectively.