Thermal-hydraulic analysis of energy storage and intermediate heat transfer systems for tokamak fusion reactors

The pursuit of sustainable and clean energy has intensified global interest in nuclear fusion, particularly through tokamak reactors, which are seen as promising candidates for safe and efficient energy generation. A crucial aspect of their development is the study of the Balance of Plant (BoP). It includes all the systems belonging to the main heat transfer chain, devoted to the plasma power removal and to its conversion into electricity. This research involves BoP thermal-hydraulic analyses, focusing on the cooling system behavior, carried out by using RELAP5 system thermal-hydraulic code. Specifically, a study of the Intermediate Heat Transfer System (IHTS) design is proposed, which couples the primary circuit with the Power Conversion System (PCS). This study includes the sizing of the primary and secondary heat exchangers, verified under steady-state conditions within a comprehensive numerical model of the IHTS. Given the pulsed nature of tokamak operation, alternating between plasma pulses and dwell phases, particular attention is given to transient analysis. These transient conditions pose challenges to reactor operations, influencing its efficiency, thermal stability, and safety. For this, the study includes an investigation of thermal storage systems designed to accommodate plasma power variations. The primary goal is to develop a pre-conceptual design for main cooling system components and the evaluation of the BoP response under normal operating conditions. This research allows the understanding of energy transfer and heat management in fusion reactors, contributing to the optimization of tokamak design and operation. These insights and data aim to support the development of tokamak fusion reactors.