Core activities are important issues to promote an integrated safety case, which are at the centre of the work of the Integration Group for the Safety Case (IGSC). The majority of IGSC members may directly make use of these products at the national level. The results will support directly work on issues addressed by the RWMC. They are also the subject of discussion at meetings of the RWMC.
A "safety case" may be broadly defined as a structured presentation of the evidence, analyses, and lines of reasoning related to the long-term radiological safety of a proposed or actual radioactive waste depository facility. Topical seminars have been held on this topic during the third and fifth IGSC meetings. This is one of the IGSC's most important activities; as such, a policy paper for a general readership (available in English and French) has been published. An international symposium on the safety case was held in January 2007. Symposium participants examined the evolution of the safety case concept (both internationally and in national programmes) and its role in societal dialogue and decision-making processes. The proceedings of the symposium are currently in preparation.
Post-closure Safety Case for Geological Repositories (2004)
Nature and Purpose
Phase one of the Integrated Performance Assessments of Deep Repositories (IPAG-1) produced a report emphasising the lessons learnt from performing IPAs. Phase 2 of IPAG (IPAG-2) focused on the experience of regulatory reviews of integrated performance assessments (IPAs). The third phase of IPAG dealt with Establishing and Communicating Confidence in the Safety of Deep Geologic Disposal: Approaches and Arguments.
Establishing and Communicating Confidence in the Safety of Deep Geologic Disposal (2002)
Approaches and Arguments
The overall goals of this initiative are to analyse existing safety cases or elements of safety cases that are under development, and to identify key concepts; to provide a clear overview of the progress that has been made in the last decade; and to provide for an assessment to identify best practice in this area. Following the distribution of a detailed questionnaire in 2006, information from 17 member organisations has been collected. The report, which is currently in preparation, will help clarify actual differences and similarities in safety cases.
An INTESC workshop took place on 1-3 October 2007 at the NEA offices in Paris, France. The aim of the workshop was to assess, based on the preliminary findings of the INTESC questionnaire results and the outcomes of other current NEA initiatives, the current state of the art in the development of safety cases and where areas of agreement and disagreement may exist. Workshop participants also sought to identify and understand issues that may need further work by the IGSC.
Processes and events affecting the evolution of deep repositories for long-lived radioactive waste are characterised by a wide range of timescales and frequencies. The IGSC organised a workshop on the Handling of Timescales in Assessing Post Closure Safety in Paris in 2002. A policy paper in English and French was issued in 2004. A IGSC topical session in 2005 also examined the issue, which led to the release of a state-of-the-art report Consideration of Timescales in Post-closure Safety of Geological Disposal of Radioactive Waste in 2006.
The Handling of Timescales in Assessing Post-closure Safety (2004)
Lessons Learnt from the April 2002 Workshop in Paris, France
The Handling of Timescales in Assessing Post-closure Safety (2002)
Proceedings of a Workshop held in Paris, France on 16-18 April 2002
In order to provide assurance of the long-term safety of an underground repository, it is necessary to argue persuasively that the long-term containment capability of the geosphere and underground environment are stable and able to provide a firm buffer against natural pertubations. To this end, an international forum on Clays in natural and engineered barriers for radioactive waste confinement was held in 2005, co-sponsored by the NEA. A workshop on Stability and Buffering Capacity of the Geosphere for Long-Term Isolation of Radioactive Waste: Application to Argillaceous Media took place on 9-11 December 2003 in Braunshweig, Germany. A workshop on the Management of Uncertainty in Safety Cases and the Role of Risk took place on 2-4 February 2004 in Stockholm, Sweden. A workshop on crystalline (strong, fractured) rocks was held on 13-15 November 2007 in Manchester, UK.
Using Natural and Engineered Clay-based Barriers
for the Containment of Radioactive Waste
Tours, 14-18 March 2005 (external link)
Stability and Buffering Capacity of the Geosphere for Long-Term Isolation of Radioactive Waste: Application to Argillaceous Media
Proceedings of a Workshop held in Braunshweig, Germany on 9-11 December 2003
Management of Uncertainty in Safety Cases and the Role of Risk
Proceedings of a Workshop held in Stockholm, Sweden on 2-4 February 2004
Gas Generation and Migration in Radioactive Waste Disposal : Safety-relevant Issues
Workshop Proceedings, Reims, France, 26-28 June 2000
Task group on Review of Safety Assessment Methods (restricted)
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Last updated: 28 October 2010