[en] The authors discuss the role of independent studies in regulatory interactions during the pre-licensing period of a potential High-level Waste proceedings in the United States. They illustrate through examples how independent studies help address uncertainty during regulatory interactions. (A.L.B.)

[en] The main themes of the workshop, which include the topics covered both by the plenary sessions and Working Group sessions, can be stated as follows: Has geo-scientific information been effectively integrated and addressed in safety cases? To what extent (and how) does geo-scientific data influence the development of the safety concept, the repository design, and the safety case? To what extent (and how) does the development of the safety case influence R and D priorities and site investigation or other geoscience activities? The presented synthesis summarises the main points raised on these themes in the course of the workshop. (A.L.B.)

[en] In the working group discussions, three broad topics were addressed by four working groups (AD), with each working group assigned two topics. Topic 1: What are the processes by which information from site characterisation is selected and applied in safety assessment (i.e. scenario development and modelling)? Topic 2: How are the uncertainties in geological data and scaling issues dealt with in repository design and the safety case? (i.e. modelling) Topic 3: How does (and to what extent) the development of the repository design and of the safety case influence site characterisation and R and D priorities? (A.L.B.)

[en] Research and repository implementation projects targeting the geological displacement of LLW/ILW radioactive waste at Bataapati site are producing huge amount of information and documents. More than 44 million data items originating from 5 500 locations, (40 000 objects, 39 000 samples), presented in more than 25 000 documents created by almost 400 experts of 61 companies have been processed and regularly applied. Users soon demanded an easy-to-use, well-designed, self explanatory reporting system, so called Integrated Report System (IRS), supporting the scientific approach as well as their everyday work. (authors)

[en] AMIGO is the acronym for the OECD/NEA project on the topic of Approaches and Methods for Integrating Geological Information into the Safety Case. A key objective of the AMIGO project is to foster awareness of geoscience and its continuing role in the development of a repository safety case. As part of this effort, AMIGO undertook to document current international experience with respect to the practical usage, communication and management of geo-scientific data and information that underpin an explanation of the geosphere and its evolution as relevant to assessing repository performance and safety. This paper summarises the responses and collective experiences of many AMIGO participants captured in a questionnaire that provides a snapshot of the evolving role of geoscience in the preparation and communication of a deep geological repository (DGR) safety case for long-lived radioactive waste. (authors)

[en] Nuclear Waste Management Organization of Japan (NUMO) has proceeded with repository siting, since 2002, based on an open solicitation procedure. While waiting for volunteer municipalities and having no specific site geological information, NUMO has been preparing for expected assessments and designs at the investigation stage. One of the efforts for preparation is the dry run using hypothetical site information. This paper introduces lessons learnt through this dry run. (authors)

[en] The dossier on disposal Feasibility Assessment in Meuse/Haute-Marne, which was submitted by ANDRA to the French Government in June 2005, is the result of a long way from the Preliminary Geo-scientific Survey in 1994 to the Safety Case. An iterative approach was used, three iteration loops were organised between acquisition of knowledge, architecture and design, safety studies and analysis with milestones in 1996 (URL licensing application), 2001 (intermediary report) and 2005 (Dossier 2005 feasibility assessment). At each step the acquired geo-scientific information was used to refine the disposal design and then was transferred to the safety case. Our knowledge has been more and more growing; up scaling and simplification processes have been more and more important issues in qualitative and quantitative safety analyses. (author)

[en] In a safety and feasibility case, statements concerning the safety and feasibility of a proposed facility need to be substantiated to degree that is adequate to justify a positive decision to proceed from one programme stage to the next. Substantiation takes the form of evidence, arguments and analyses, derived, to a large extent, from geoscience. An important set of safety statements is that describing how the various characteristics of the geological environment underpin the safety functions of a repository. This paper gives examples of safety statements under-pinned by geoscience and the potential use of such statements in safety assessment and in the safety and feasibility case. In particular, in order to illustrate the propagation of uncertainties from low-level statements to higher level statements, the impact of a potential future change to a colder climate is considered. The use of safety statements provides a tool to determine in a systematic manner how the safety functions of the repository might be affected by such a change and to derive assessment cases to quantify the impact on humans of any radionuclides and other contaminants released from the repository. (authors)

[en] The Dossier on Disposal Feasibility Assessment in Meuse/Haute-Marne (Callovo-Oxfordian Clay layers), which was submitted by ANDRA to the French Government in June 2005, is the result of a long way from the Preliminary Geo-scientific Survey in 1994 to the Safety Case. An iterative approach was used, three iteration loops were organised between acquisition of knowledge, architecture and design, safety studies and analysis with milestones in 1996, 2001 and 2005. At each step, the acquired geo-scientific data was used to refine the disposal design and then was integrated to the safety case. During raw data acquisition and interpretation, each value and model were discussed and presented in technical reports with its uncertainties of all kind (e.g. ranges of porosity and permeability, uncertainties on head values, etc). From the raw geo-scientific data, a first integration work (putting together measurements, results of modelling, lines of arguments) provided conceptual and phenomenological models which were the basis for description of the evolution of the repository (Phenomenological analysis of repository situations, PARS). (authors)

[en] Boda Clay-stone Formation (BCF) is a middle-Permian, over-consolidated, highly indurated sedimentary formation that has been considered as potential host rock for final disposal of the Hungarian HLW/SF. Between 1994 and 1999 an extensive characterisation programme was performed using URL-based methods in a site which was the world's deepest URL at that time. Following the obligate closure of the URL, a systematic site-selection programme was started at 2003 covering the whole known extension of BCF (>150 km²). Because of the last long-term conceptual plans of characterisation programme created at 1994, the Hungarian Public Agency for Radioactive Waste Management (PURAM) initiated a systematic revision. This work started at September 2007. The new conceptual model helps to review the projects and their connections to the surface and subsurface survey, URL, implementation, operation and closure of repository. (authors)