Efficiency and safety in nuclear power plants from a mechanical engineering perspective

Nuclear power plants (NPPs) are pivotal to low-carbon electricity generation, but their sustainability depends on advancing both thermodynamic efficiency and engineering-based safety. From a mechanical engineering perspective, the performance of turbines, pumps, heat exchangers, and structural materials directly dictates reliability. Conventional pressurized water reactors (PWRs) and boiling water reactors (BWRs) operate with thermal efficiencies of only 32–35%, constrained by coolant conditions, while advanced high-temperature gas-cooled reactors (HTGRs) and molten salt reactors (MSRs) can exceed 40%. Exergy analyses consistently identify steam generators, condensers, and turbines as the main sites of irreversibility, emphasizing the need for component-level optimization. Safety remains equally critical. Lessons from Three Mile Island, Chernobyl, and Fukushima underscore the vulnerability of active safety systems and the necessity for passive cooling, reliable pumps and valves, and radiation-resistant materials. Recent advances in computational fluid dynamics (CFD), additive manufacturing, and high-performance alloys are redefining both efficiency and safety margins. Furthermore, climate change—through heatwaves, droughts, and extreme events—poses growing risks to reactor cooling and resilience. This review concludes that integrating thermodynamic optimization, passive safety systems, advanced materials, and digital monitoring technologies is essential for next-generation NPPs. Key research gaps include hybrid thermodynamic cycles, AI-driven diagnostics, and climate adaptation strategies, offering critical directions for academia and industry alike.