Gas-Cooled Fast Reactor System Safety Assessment - 2022
A report by the GIF Risk and Safety Working Group (RSWG).
The "Gas-Cooled Fast Reactor System Safety Assessment" report, prepared by the Gas-cooled Fast Reactor System Steering Committe and the Risk & Safety Working Group, presents a comprehensive safety assessment of the Gas-Cooled Fast Reactor (GFR) system. The report outlines the performance goals, historical development, ongoing safety-related research and development, and the achievement of fundamental safety functions. It highlights key safety functions such as reactivity control, decay heat removal, and confinement of radioactive materials.
The GFR system, featuring high-temperature helium cooling, offers sustainability advantages through improved resource utilization and waste minimization. The proposed reference concept is a 2400 MWth plant with a core outlet temperature of 850°C, driving an indirect combined gas-steam cycle. This high core outlet temperature poses significant challenges, particularly in fuel capability and decay heat removal.
The report also discusses the management of severe accidents, the safety of the fuel cycle, and other risks associated with the GFR system. The establishment of an experimental demonstration reactor, ALLEGRO, is proposed to qualify refractory fuel elements and demonstrate GFR-specific safety systems. The ALLEGRO reactor will operate in different core configurations, transitioning from steel-cladded MOX fuelled pins to all-ceramic fuel elements. The document emphasizes the need for continuous R&D to enhance reactor safety and addresses the key areas for further investigation and improvement.