THE IMPORTANCE OF EXERGY ANALYSIS OF NUCLEAR REACTORS FOR THE ENERGY TRANSITION PROCESS

Resumo

The transition to low-carbon energy systems underscores the critical role of nuclear power as a reliable and dispatchable electricity source. This study presents a comparative exergy assessment of nuclear reactors and hybrid configurations, aiming to identify the main sources of irreversibility and propose strategies for improving exergy efficiency. A systematic literature review (2015–2025) was conducted to compile normalized data on thermal and electrical outputs, exergy destruction rates, and subsystem performance across nuclear technologies, such as Nuclear Power Plants (NPPs) and Small Modular Reactors (SMRs), including cogeneration and desalination hybrid systems. Exergy analyses highlight that the highest irreversibilities typically occur in reactor cores, steam generators, turbines, and condensers. To confirm these facts, a bibliographic research methodology was adopted involving publications on exergy analysis applied to nuclear energy generation and cogeneration systems and other supplies. The aim was to build a study and verify what are the main irreversibilities involved in these systems and mainly what are the components that affect their efficiency. A time window of the last ten years was selected and preference was given to publications in indexed journals with an impact on the scientific community. The results of the analyzes showed that the main irreversibilities are connected to reactor cores, steam generators, turbines, and condensers, due to high thermal gradients, mismatched heat exchange, and non-ideal expansion processes. Based on this result, case studies can be carried out in the future to delve deeper into such irreversibilities and the means to mitigate them and how technology influences the efficiency of systems.