Introduction  Because of the low temperature parameter, the power generation efficiency of the small modular PWR nuclear power plant is less than 30%.

  Method  In order to improve the efficiency of the nuclear energy utilization, the small modular reactor can be combined with the renewable energy and the advanced supercritical CO₂ cycle was used as the thermal energy conversion device. Based on a supercritical CO₂ cycle with a simple regenerative mode, adding one intercooling and one reheating, a new hybrid power generation system was integrated with a small reactor and a solar energy source and a biomass energy source, and the efficiency of the power generation was analyzed.

  Result  The results show that the power generation efficiency is 34.13% and 41.22% for the system with the inlet temperature of the high pressure turbine at 390 ℃ and 550 ℃, respectively. In addition, the analysis of the safety of the system shows that the CO₂ itself has the nuclear safety property, and the supercritical CO₂ cycle can also be used as the passive waste heat discharge system of the reactor to ensure that the reactor continuously exhaust the decay heat under the severe accident condition.

  Conclusion  Supercritical CO₂ cycle power system integrated with small modular reactor and renewable energy source has good power generation efficiency and nuclear safety.