Radioactive waste is produced in all phases of the nuclear fuel cycle and from the use of radioactive materials in industrial, medical, defense and research applications. Disposal in engineered facilities or repositories, located in suitable geological formations, is being developed worldwide as the reference solution for the long-term management of radioactive waste. Societal agreement for deep geological repositories depends on the confidence that it can protect humans and the environment now and in the future.
The safety of a repository is evaluated and documented in a “safety case” that supports decision making at each stage of repository development. It presents underlying evidence and methods that give confidence in the quality of scientific and institutional processes, as well as in the results of analyses.
The Integration Group for the Safety Case (IGSC) is the main technical advisory body to the Radioactive Waste Management Committee (RWMC) on the deep geological disposal, particularly for long-lived and high-level radioactive waste. It was established in 2000 in recognition of the need to foster full integration of all aspects of the safety case.
The mission of the IGSC is to assist member countries to develop effective safety cases supported by a robust scientific-technical basis. In addition to the technical aspects in all developmental stages of repository implementation, the group also provides a platform for international dialogues between safety experts to address strategic and policy aspects of repository development.
To help accomplish its activities, the IGSC is supported by four subgroups carrying out tasks on specific topics. Three subgroups that focus on the feasibility of repositories in three different generic host rock types are: Clay Club, Salt Club and Crystalline Club. A fourth subgroup, the Expert Group on Operational Safety (EGOS), deals with the operational safety of geological repositories.
Having recently celebrated 20 years of activity, the IGSC has released a 20th anniversary brochure reflecting on two decades of evolution of the safety case concept.
Projects of the IGSC provide important fora to co-ordinate international research and development (R&D) programmes to share experience and to develop consensus on the state of the art and; to develop an understanding of specific topics and technical tools to support the safety case.
Since the development of a safety case involves inputs of various disciplines (e.g. engineering, geology, radiological protection, etc.), IGSC activities are organised in the following thematic framework so as to foster consensus on best practices and advance the development of innovative approaches used in all stages of repository implementation:
The IGSC also participates in international projects and work activities to stay abreast of state-of-the-art knowledge and technologies in safe radioactive waste management. Examples of international projects include, but are not limited to Fate of Repository Gases (FORGE), European Joint Programme on Radioactive Waste Management (EURAD) and Implementing Geological Disposal of radioactive Waste Technology Platform (IGD-TP).
The mode of operation of the IGSC is through the following:
The IGSC also co-operates with its counterparts in the European Commission (EC) and the International Atomic Energy Agency (IAEA) to maintain international consistency on geological disposal safety issues. Recent examples include a joint workshop on operational safety of geological disposal with the IAEA and a joint seminar on regulatory review of safety cases with the EC SITEX project (Sustainable Network for Independent Technical Expertise of Radioactive Waste Disposal – Interactions and Implementation).
Assistance is provided to the member countries through national, regional and inter-regional technical co-operation projects, as well as through peer reviews of radioactive waste management programmes. The outcomes of IGSC projects are documented in NEA technical reports that are publicly available.
The Crystalline Club (CRC) is composed of technical experts with experience in evaluating or reviewing the understanding of crystalline rock as host rocks for deep geologic disposal projects. CRC members represent waste management agencies, regulatory authorities, academic institutions, and research and development institutions.
The Clay Club promotes the exchange of information, shared approaches and methods to develop and document an understanding of clay media as a host rock for a repository.