Thermal-hydraulic challenges in liquid-metal-cooled reactors

This chapter provides an overview of the thermal-hydraulic challenges that can present themselves in liquid-metal-cooled reactors with a focus on pool-type reactors. After a brief description of the important process of identification of the challenges, the chapter continues with explanations of challenges concerning the basic, core, pool, and system thermal-hydraulic phenomena. The basic phenomena are turbulent heat transfer, thermal fluctuations and striping, mechanical fluctuations, bubble transport, particle transport, and solidification. Afterward, the challenges with respect to core, pool, and system thermal hydraulics are subdivided into challenges under normal operation, off-normal operation, and severe accidents. Finally, the challenges with respect to the development of guidelines are described.