Safety Design Guidelines On Safety Approach And Design Conditions for Generation IV Sodium-Cooled Fast Reactor Systems - 2019 - Rev. 1

Safety Design Criteria (SDC) for Generation-IV (Gen-IV) Sodium-cooled Fast Reactor (SFR) systems have been developed by an SDC Task Force (TF), under the auspices of the GIF Policy Group (PG). Following approval by the PG, the SDC Report was distributed to international organisations and national regulatory bodies for review.

The following needs were identified by the SDC TF members:
- Development of detailed guidelines to support practical applications of SDC.
- Expansion of selected topics, specifically on:
 - Practical elimination (PE) of some accidents.
 - Design basis of specific components (e.g., containments).
- Clarification of technical issues such as:
 - Prevention and mitigation measures against sodium fire and sodium-water reaction accidents.
 - Implications of the fact that the reactor core is not in its most reactive configuration.

In response, the PG and the GIF Senior Industrial Advisory Panel recommended the TF to:
- Develop guidelines for application of the SFR SDC.
- Pursue quantification of key criteria to demonstrate the safety advantages of Gen-IV SFRs over current LWR designs.

The objective of this report is to provide recommendations and guidance on how to comply with the GIF SFR Safety Design Criteria. It presents examples for the measures stated in criteria as the best practices to help the designers achieve high levels of safety. The guidelines are placed below the SDC in the hierarchy of safety standards as depicted in Figure 1 below. Initially, the guidelines will focus on specific safety concerns, such as reactivity characteristics of SFRs and heat removal issues. In the future, the guidelines will be extended by taking into account additional issues, such as fuel handling and storage. These guidelines deal only with safety issues; security considerations are dealt by the Proliferation Resistance and Physical Protection Working Group (PRPPWG) of GIF or by national regulators.

The guidelines, except Chapter 4 “Guidelines for application of safety design criteria,” provide recommendations and guidance on how to comply with the SFR SDC, which are generally applicable for Generation-IV SFR systems. Chapter 4 covers specific issues to be considered in the design of structures, systems and components (SSCs) with examples of design provisions. 

The TF expects that these issues and examples will be appropriately considered when applied to specific features of individual designs. Recommendations in this document are expressed as ‘should’ statements. It is recommended to adopt the stated measures or equivalent alternative measures.