Safety Design Guidelines on Structures, Systems and Components for Generation IV Sodium-cooled Fast Reactor systems - 2024
The Generation IV International Forum (GIF) under the Policy Group has supported advancements in safety standards for sodium-cooled fast reactors (SFRs) through its Safety Design Criteria Task Force (SDC TF). The task force developed the Safety Design Criteria (SDC) Report for SFRs in 2013, subsequently revised in 2017, and the Safety Approach Safety Design Guidelines (SDG) in 2016, updated in 2019. The SDG outlines crucial measures for accident prevention, mitigation, and specific design measures aimed at practically eliminating safety risks.
Following its approval, both the SDC Report and the Safety Approach SDG were disseminated to international organisations and national regulatory bodies for review. Building upon this, the GIF SDC TF has initiated the development of SDG for systems, structures, and components (SSC-SDG) to provide a more comprehensive set of safety design recommendations that encompass all plant states including normal operations, anticipated operational occurrences, design basis accidents, and design extension conditions.
The SSC-SDG elaborates on connections between the general recommendations in the Safety Approach SDG and specific SSC designs, filling gaps not previously detailed. It addresses advanced safety measures, such as preventing Anticipated Transient Without Scram (ATWS) and eliminating risks like core uncovering and complete loss of decay heat removal functions. Additional considerations include high temperature and radiation conditions for fuels and materials, as well as challenges posed by sodium fires and sodium-water reactions.
This guideline serves to equip SFR designers with detailed, practical instructions to implement the SDC in the design process, in order to ensure the highest safety levels. It includes a variety of design options reflecting diverse practices among GIF SFR SSC participating states, allowing designers to select appropriate solutions based on specific design characteristics and national regulations. The recommendations are intended to guide but not dictate design choices, underscoring the flexibility in achieving safety compliance. Future expansions of the SDG may further address out-reactor fuel handling and storage, enhancing the scope of safety guidelines.