| Chair(s): |
Bastian GRAUPNER, Switzerland |
Secretary: |
Shogo NISHIKAWA (shogo.nishikawa@oecd-nea.org) |
|---|---|---|---|
| Vice-Chair(s): |
Simon NORRIS, United Kingdom | ||
| Member(s): | All NEA member countries* | ||
| Russia (Suspended*) | |||
| *Russian Federation suspended pursuant to a decision of the OECD Council. | |||
| Full participant(s): |
European Commission Under the NEA Statute | ||
| Observer(s)(International Organisation): |
International Atomic Energy Agency (IAEA) By agreement | ||
| Date of creation: | 01 January 1991 | ||
| End of mandate: | 31 December 2024 |
Mandate (Document reference):
Mandate (Document extract):
Extract from document NEA/RWM/CLAYCLUB(2022)2/FINAL
Background
Repository development for long-lived radioactive waste is a strategic area in the Progamme of work of the Nuclear Energy Agency (NEA) Radioactive Waste Management Committee (RWMC) and an area of historical strength for the RWMC.
In the context of geological repositories, argillaceous (clay-rich) media are being considered in numerous NEA member countries as potential host rocks for subsurface disposal of radioactive waste. These media have a number of favourable attributes, including the following: significant lateral continuity, very low rock mass hydraulic conductivities, self-sealing of fractures, solute migration dominated by diffusive transport processes, a capacity to chemically retard radionuclide migration, and amenability for self-analogues studies of hydrogeologic stability.
To evaluate these geological media and, notably, to quantitatively assess the potential migration of radionuclides to the environment, an understanding of the physical and chemical processes that govern groundwater, gas and solute transport through host rocks is a key issue. In that context, the NEA established the Working Group on Measurement and Physical Understanding of Groundwater Flow through Argillaceous Media in 1991. Over a decade later, the name of the group was changed to the Expert Group on the Characterisation, the Understanding and the Performance of the Argillaceous Rocks as Repository Host Formations (“Clay Club”).
Despite the wide spectrum of argillaceous media and various stages of repository programme development around the world, common issues related to the reliable characterisation and role of argillaceous media in a repository safety case have provided a basis for a directed and meaningful programme of work achieved through workshops, regular meetings, joint industry conferences, and seminal state-of-the-art NEA reports.
Scope
The Clay Club emphasises the pooling of resources, the sharing and synthesis of understanding and experiences, as well as the communication of findings to various audiences.
The Clay Club also promotes an exchange of information on approaches and methods utilized to develop and document an evolving understanding of clay media as a host rock for repository.
Objectives
The Clay Club provides advice to the Integration Group for the Safety Case (IGSC) on major and emerging issues related to the understanding of the multi-scale characterisation, numerical model simulation and barrier performance of argillaceous media. In particular, the Clay Club addresses recommendations, trends and information gaps concerning the following issues:
Working methods
The functional operation of the Clay Club is discussed and refined during its plenary meetings. In addition to discussions that evaluate its programme of work and review progress on specific activities, the Clay Club may also periodically undertake more in-depth evaluations to assess the effectiveness of the Clay Club and update the overall direction of the programme of work. Any decision(s) of the Clay Club are made in its plenary meetings or through written procedure by mutual agreement.
Membership
The Clay Club is a task-oriented expert group. It is composed of senior technical specialists with experience in assembling and/or reviewing the understanding of argillaceous media as host rocks for deep geological repository projects. Members represent waste management agencies, regulatory authorities, academic institutions, and research and development institutions. Clay Club members possess a level of seniority in their organisations such that they can mobilise resources as contributions to Clay Club initiatives.
Interactions
Through the IGSC, the Radioactive Waste Management Committee (RWMC) and the Secretariat, the Clay Club will co-operate with the NEA standing technical committees and their subsidiary bodies when relevant. It may also collaborate with the NEA Data Bank.
Deliverables
The Clay Club will produce relevant reports, presentations or workshops with the support of the Secretariat.
