IGSC co-operative projects

Co-operative projects are highly specialised activities, which address issues of interest to a subset of Integration Group for the Safety Case (IGSC) member institutions.

Argillaceous Media (Clay Club)

The Clay Club examines those various argillaceous rocks that are being considered for the deep disposal of radioactive waste, ranging from soft clays to indurated shales. These rocks exhibit a wide spectrum of characteristics which make them useful as barriers to the movement of water and solutes and as repository construction materials. Studies include clay media characterisation and modelling.

Three key initiatives have now been completed:

1. The Feature, Events, Processes catalogue: Agillaceous media (the FEPCAT report) is now available. The Clay Club acknowledges the limitation of the database in time: and in particular that the recently published reports are not formally included.
2. A catalogue of characteristics. The catalogue consists of a brochure and a CD-ROM containing all data tables in Excel format.
3. The self-healing study that aims to establish a state-of-the art document on the self-healing of clay media, is currently being finalised.

The Clay club initiative on long-term natural tracers profiles (CLAYTRAC) completed the data collection stage of the project in late 2006. The project aims to provide an overview of available data sets regarding long term natural tracers' profiles. The added value of that work compared to studies dealing with individual sites in isolation lies in the comparison and integration of data, results and conclusions from a variety of sites and formations. A report on this subject is currently in preparation.

Features events and processes (FEP) database

The FEP database assembles features, events and processes for geological disposal as an aid to national programmes to identify, classify and screen FEPs in safety assessment. The database consists of two main parts:

• The International FEP List - a comprehensive and structured list of factors relevant to the assessment of long-term safety of nuclear waste repositories.
• Project Databases - a collection of FEP lists and databases, with references, compiled during repository safety assessment studies.

A NEA publication on the Features, Events and Processes (FEPs) for the Geologic Disposal of Radioactive Waste was released in 1999.

Sorption project

The first workshop on this topic was organised in Oxford in May 1997 and included researchers, both modellers and experimentalists, investigating performance assessment and sorption. In parallel with this activity, a comprehensive status report was commissioned to summarise the current knowledge in the field of sorption modelling.

The Sorption Project, Phase II, was a "benchmarking" exercise to interpret selected well-characterised datasets for sorption onto complex materials of interest to safety assessments of radioactive waste disposal systems using several different modelling approaches in use at various organisations.

Thermodynamic Data Base (TDB)

The Thermochemical Data Base (TDB) project aims to make available a comprehensive, internally consistent, internationally recognised and quality-assured chemical thermodynamic database. A new phase of the project is now under way to develop a guidance document on the application of sorption models in safety assessments for the deep disposal of radioactive waste.

Related links

IGSC overview

IGSC core activities

IGSC technical activities

Working Group on the Characterisation, Understanding and the Performance of Argillaceous Rocks as Repository Host Formations (the "Clay Club")

E-mail contact: igsc@oecd.org