The thermodynamic and cost-benefit-analysis of miniaturized lead-cooled fast reactor with supercritical CO₂ power cycle in the commercial market

The lead is considered as a more attractive material of coolant than lead/bismuth because of higher availability, lower price and fast neutron spectrum in recent years. In this paper, the thermodynamic analysis and cost-benefit-analysis of miniaturized lead-cooled fast reactor (LFR) composing different power cycles have been investigated to examine the optimization result of the miniaturized system in the commercial market. The study proposes a design of such the miniaturized LFR system for a first step implementation of the technology. First, the typical cycles include the reheating recompression supercritical CO₂ Brayton cycle (hereinafter referred to as S-CO₂ cycle), the traditional steam Rankine cycle and the helium (He) Brayton cycle. Second, main parameters of thermodynamic analysis and economic analysis are based on the National Standards of Chinese Industry and the realistic financial and cost estimating assumptions in China. Third, the reheating recompression S-CO₂ Brayton cycle is the optimal option to the LFR. The main results demonstrate that the thermal efficiency of the reheating recompression S-CO₂ Brayton cycle is 43.72%. The efficiency of the LFR generation system comprising reheating recompression S-CO₂ Brayton cycle is 41.53%. Both of them are greater than the efficiencies of steam Rankine cycle (38.62%, 36.69%) and He cycle (37%, 35.41%). Finally, the electricity production costs (EPC) of LFR generation system is obtained as $0.0536/(kW·h), which is lower than the average electricity price in China ($0.0632/kW·h). The payback period of the investment is 31.4 years while the lifespan is 40 years. The profit of company undertaking the LFR generation system is $6.3 million. Therefore, it can be found that the reheating recompression S-CO₂ Brayton cycle is the primary choice of the LFR system, and its profit for commercialization of the system is beneficial.