Risk and Safety Working Group

The GIF Risk and Safety Working Group (RSWG) facilitates collaboration among member countries to share expertise, methodologies, and best practices in risk and safety assessments for Generation-IV reactors. It also works towards the development of international safety criteria, guidance and methodologies for Generation-IV nuclear reactors, providing designers of Generation IV systems with concepts and methods that can help guide their R&D activities in a way that promotes a strong safety basis and efficient licensing of advanced nuclear technologies.

The group play a key role in providing methodologies and analysis that will support Generation IV goal of improved safety of Generation IV Nuclear Energy Systems:

Generation IV nuclear energy systems operations will: excel in safety and reliability, have a very low likelihood and degree of reactor core damage, eliminate the need for offsite emergency response.

Goals and reasons for establishing the GIF RSWG

In short the goal of the GIF RSWG is to establish the basis for safety approach and reference requirements for the safety design of GEN-IV technologies’ structures, systems, and components consistent with the Generation IV safety goals.

The RSWG was formed to promote a homogeneous and effective approach to assuring the safety of Generation IV nuclear energy systems. The six Generation IV reactor concepts that have been selected by the GIF members, potentially present a diverse set of design and safety issues. A number of these issues are significantly different from those presented by the earlier generations of light water reactors. The overall success of the Generation IV program depends on, among other factors, the ability to develop, demonstrate, and deploy advanced system designs that exhibit excellent safety characteristics. While the RSWG recognizes the excellent safety record of nuclear power plants currently operating in most GIF member countries, it believes that progress in knowledge and technologies, and a coherent safety approach, hold the promise of making Generation IV energy systems even safer and more transparent than this current generation of plants.

The RSWG is focused on defining the attributes that are most likely to help meet the Generation IV safety goals:

Generation IV nuclear energy systems will aim to achieve the following safety goals:

  • to excel in safety and reliability;
  • to have a low likelihood and degree of reactor core damage;
  • to eliminate the need for offsite emergency response.

History and Membership

GIF RSWG was established in 2004. It has 9 countries and Euratom as active members.

Partner organisations and sister initiatives.

The International Atomic Energy Agency (IAEA) is an observer in the RSWG. 

The group also closely cooperates with the Working Group on New Technologies (WGNT) that is under the OECD-NEA Committee on Nuclear Regulatory Activities (CNRA).

RSWG Leadership and Technical Secretariat

Portrait of GIF RSWG Chair Dr Hummel

Dr
David HUMMEL

RSWG
RSWG Co-Chair

Dr. David Hummel is a Research Scientist in the Advanced Reactors Directorate at Canadian Nuclear Laboratories (CNL). He received his Masters and PhD degrees from McMaster University in Engineering Physics. In 2015 he joined the Containment Response Section of what was then the Fuel & Fuel Channel Safety Branch at CNL’s Chalk River site. Dr. Hummel has since served as project leader, principal investigator, or researcher on multiple projects concerning advanced reactor safety within CNL’s Federal Nuclear Science & Technology program. He has also contributed to the organization of multiple Canadian Nuclear Society (CNS) conferences, most recently chairing the Fifth International Conference on Generation IV and Small Reactors (G4SR-5). He is the Chair of the CNS G4SR Technology Division.

Dr
Christoph DÖDERLEIN

RSWG
RSWG Co-Chair
Portrait of Dr Marina Demeshko from the GIF Technical Secretariat

Dr
Marina DEMESHKO

GIF TS
RSWG
GIF Technical Secretary

Marina Demeshko has been a Nuclear Safety Specialist at the Division of Nuclear Safety Technology and Regulation, NEA/OECD, since 2018. She also serves as the Technical Secretary for the Generation IV International Forum (GIF), supporting the Risk and Safety Working Group. Throughout her career, Marina has gained extensive experience in nuclear research, engineering, and safety regulation. Prior to joining NEA, she was a Deputy Director at a scientific-technical support organization, where she led key safety assessment and regulatory oversight projects. Marina holds a Ph.D. in Engineering from Osaka University, Japan.

GIF RSWG List of Publications

Below are summaries and links to the principal GIF RSWG publications. Additionally, you can access all safety-related resources through the "Resources and Events" menu or by using the button below.

A Risk-informed Framework for Safety Design of Generation IV Systems (June 2023)

This paper is intended to provide an example of risk-informed approach as an iterative process, complementary to the traditional deterministic approach, for a comprehensive search of event sequences including their expected frequency and consequences to understand the risk. The approach can also support safety classification of plant equipment and defence-in-depth (DiD) assessment.

Safety Design Criteria (SDC) for Generation IV Very High Temperature Reactor (VHTR) System (June 2023)

This report focuses on SDC for VHTR system with the objective of establishing reference requirements for the safety design of VHTR structures, systems, and components consistent with the GIF safety goals and basis for safety approach. The report is developed in collaboration with the VHTR System Steering Committee.

Safety Design Criteria (SDC) for Generation IV Gas-Cooled Fast Reactor System (September 2022)

This report was prepared by the GFR Conceptual Design and Safety Project of the Generation IV International Forum (GIF).
The objective of the GFR SDC is to present reference criteria for the safety design of structures, systems and components of an GFR system with the aim of achieving the safety goals of a Generation-IV reactor system. The reference criteria are systematically and comprehensively explained in the SDC.

Gas-Cooled Fast Reactor System Safety Assessment (September 2022)

A necessary step in the development of a commercial GFR is the establishment of an experimental demonstration reactor for qualification of the refractory fuel elements and for a full-scale demonstration of the GFR-specific safety systems. The proposed demonstration reactor for the reference GIF GFR concept will be ALLEGRO: A low power reactor (50 - 150 MWth) with the ability to operate in different core configurations starting from a “conventional” core featuring steel-cladded MOX fuelled pins and followed with all-ceramic fuel elements in the latter stages of operation.

Basis for the Safety Approach for Design & Assessment of Generation IV Nuclear Systems (revision, 2 July 2021)

This report is an update for the first version of GIF Basic Safety Approach that was published in 2008 as the first major product of the Risk and Safety Working Group (RSWG). It reflects the experience gained from development and application of the Integrated Safety Assessment Methodology (ISAM) to Gen-IV design tracks and the lessons from the Fukushima Dai-ichi accident as articulated in the new requirements issued by various international organizations such as the IAEA and OECD. The report also provides a high-level summary of the safety related achievements of the past ten years to supplement the objectives, principles, and attributes discussed in the original report to continue guiding the ongoing R&D activities.

Safety Design Criteria for Generation IV Lead-Cooled Fast Reactor System (2021)

This LFR Safety Design Criteria (SDC) document was prepared to identify a set of criteria specifically tailored to the Generation IV LFR system. The objective of the report is to present a set of reference criteria for the safety design of structures, systems and components of LFRs with the aim of achieving the safety goals of the Generation IV reactor system, and to support licensing processes. A set of eighty-two reference criteria for the LFR system is systematically and comprehensively laid out in the SDC. The document was prepared by the LFR provisional System Steering Committee, endorsed by the GIF Risk and Safety Working Group (RSWG), and approved by the GIF Experts Group. The LFR SDC consists of the following parts: (i) Chapter 1 describes the background, objectives, and formulation of principles; (ii) Chapter 2 outlines the safety approach to the LFR as a Generation IV reactor system; and (iii) Chapters 3 through 6 describe the criteria for the overall safety design and safety design of specific structures, systems and components of LFRs.

Lead-cooled Fast Reactor (LFR) System Safety Assessment (2020)

This document was prepared as a safety assessment for the Generation IV LFR system. The objective of the report is to review and identify the main safety advantages and possible challenges of the technology, to assess the current status of safety-related research & development (R&D) activities, and to identify future R&D needs for the LFR system. In preparing this analysis, the LFR pSSC has placed emphasis on the assessment of the fulfillment of the Generation IV goals, to highlight the attractiveness of the LFR technology for future extensive implementation. The report concludes that gaining safety and operational experience feedback through licensing and operation of demonstration plants is a prerequisite to bring the LFR to the industrial deployment. 

Sodium-Cooled Fast Reactor (SFR) System Safety Assessment (2017)

This document was prepared as a safety assessment document for the Generation IV SFR systems, through the feedbacks between RSWG and SFR System Steering Committee. The main aim of this document is to identify strengths of the Generation IV SFR system based on proven technology and equipment as well as areas that need further development to satisfy the GIF safety and reliability goals. Contents of this document include “performance goal”, “feedback from operation experiences”, “ongoing safety-related R&D”, “management of design extension conditions”, and “summary of progress needed”.

Super-Critical Water-cooled Reactors (SCWR) Risk and Safety Assessment White Paper (2017)

This white paper provides an overview of activities in the application of the Integrated Safety Assessment Methodology (ISAM) to the GIF Super-Critical Water-cooled Reactor (SCWR) design tracks. It also documents the identified future R&D needs for the conceptual design of SCWR systems to improve risk and safety performance of SCWRs.

Gas-cooled Fast Reactor (GFR) Risk and Safety Assessment White Paper (2016)

This paper presents the application of the Integrated Safety Assessment Methodology (ISAM), developed by the Generation IV International Forum (GIF) Risk and Safety Working Group (RSWG), to the Gas-Cooled Fast Reactor (GFR). Developed in the framework of the Euratom project SARGEN_IV, under the supervision of the GFR System Steering Committee (SSC) and RSWG, the paper compiles information that has been generated within the project and has been collected in the GFR-related Euratom projects GCFR STREP and GoFastR. After presenting a short overview of ISAM, the design of GFR and its demonstrator ALLEGRO are reported in more detail and then the results of the ISAM application are summarized.

Sodium-cooled Fast Reactor (SFR) Risk and Safety Assessment White Paper (2016)

This paper, prepared jointly by Generation IV International Forum (GIF) Risk and Safety Working Group (RSWG) and the SFR Systems Steering Committees (SSCs), presents the status of the Integrated Safety Assessment Methodology (ISAM) for Sodium-cooled Fast Reactor (SFR) for further research and development. The intent is to demonstrate the adequacy of safety related design; to identify R&D needs to qualify safety related provisions, and to recommend directions for optimizing its risk and safety performance. The three main objectives of this work, identified during the first workshop which brought together SSC representatives and RSWG members, are: capturing in the short-term salient features of the design concepts that impact their safety performance; identifying crosscutting studies that assess safety design or operating features common to various GIF systems; and suggesting beneficial characteristics of the design of future nuclear power plants that should be addressed in subsequent GIF activities.

Very High Temperature Reactor (VHTR) Risk and Safety Assessment White Paper (2015)

The purpose of this paper is to investigate the feasibility of applying the Integrated Safety Assessment Methodology (ISAM) to the VHTR system. Developed by the Generation IV International Forum (GIF) Risk and Safety Working Group (RSWG), ISAM consists of a set of tools to aid in safety design of advanced reactor concepts. This paper summarizes the ISAM tools, provides an overview of VHTR technology, and the preliminary assessment of ISAM tools in application to VHTR safety design.

Lead-cooled Fast Reactor (LFR) Risk and Safety Assessment White Paper Revision 8 (2014)

This document presents the application of the Integrated Safety Assessment Methodology (ISAM), developed by the Generation IV International Forum (GIF) Risk and Safety Working Group (RSWG), to the Lead-Cooled Fast Reactor (LFR). The document includes a summary of the existing common features of the three LFR reference systems (ELFR, BREST, SSTAR), and then presents an application of ISAM to the ALFRED demonstrator since, for this system, a consistent set of information has been disclosed and is available for the application. After presenting a short overview of ISAM and a short summary of the three reference LFR systems, the ALFRED design is reported in more detail and then the results of the ISAM application are summarized.

ISAM (2011) and ISAM GDI (2014)

A principal focus of the Generation IV (Gen IV) International Forum’s Risk and Safety Working Group charter is the development and demonstration of an integrated methodology that can be used to evaluate and document the safety of Gen IV nuclear systems. The first RSWG report issued in 2008 presented the “Basis for the Safety Approach for Design & Assessment of Generation IV Nuclear Systems.”  Following its mandate, in 2011, the RSWG prepared a document that describes the methodology, called the Integrated Safety Assessment Methodology (ISAM), for use throughout the Gen IV technology development cycle.  To help facilitate the use of the methodology, in 2014, the RSWG developed a supporting Guidance Document for ISAM (GDI) to provide the users with further help for the ISAM implementation.

Basis for the Safety Approach for Design and Assessment of Generation IV Nuclear Systems 
Revision 1 (2008)

This document, the first major work product of the Generation IV International Forum (GIF) Risk and Safety Working Group (RSWG), presents the findings and recommendations of the group based on its work to date. Much additional work remains to be done by the RSWG. However, the objectives, principles, attributes, and tools presented in this document are intended to immediately provide designers of Generation IV systems with concepts and methods that can help guide their R & D activities in a way that promotes the safety basis and efficient licensing of advanced nuclear technologies.