Exergy Analysis of a Small Modular Reactor Nuclear Power Plant Under Constant and Pure Sliding Pressure Operation

Abstract This study proposes a pure sliding pressure operation (SPO) scheme for a small modular reactor (SMR) nuclear power plant (NPP). The operation range considered is from 30 % to 100 % full power (FP). Subsequently, exergy analysis was conducted under constant pressure operation (CPO) as well as SPO. For this, a thermodynamic model of the SMR NPP had been established using EBSILON software, version 16.0. Exergy destruction and efficiency were estimated for the entire system and variable components. The results reveal that control valve throttling under CPO contributes significantly to turbine exergy destruction, accounting for 31.11 % at 30 %FP condition. This issue can be effectively avoided by implementing SPO. Among all components, the reactors have the highest exergy destruction, followed by the steam generators (SGs) and the turbine. Switching the secondary circuit to SPO results in exergy efficiency improvements of 0.16 %, 0.56 %, and 0.97 % at 90 %, 60 %, and 30 %FP conditions, respectively. Additionally, feed water pumps (FWPs) power consumption decreases by 10.29 %, 40.52 %, and 68.92 % respectively at 90 %, 60 % and 30 %FP conditions. However, there is little change in the exergy destruction of the primary circuit components. The research can serve as a valuable reference for optimizing the thermal performance of the NPP.