Engineered barrier emplacement experiment in opalinus clay for the disposal of radioactive waste in underground repositories

The EB project aims at demonstrating the technical feasibility and studying the behaviour of near field components of a high level radioactive waste repository in clay rock. The project consists of an in situ test, a series of complementary laboratory tests as well as modelling work. The project is coordinated by ENRESA (Spain) and the work is being executed by the following organizations:AITEMIN and UPC-DIT (Spain) NAGRA (Switzerland) BGR (Germany) The project is co-funded by the European Commission (contract FIKW-CT-2000-00017) and by the Swiss Federal Office for Education and Science. This report includes a synthesized description of the project from its conception until approximately one and a half years after completion of the installation of the large-scale test (October 2000 to November 30, 2003). The project is described in detail in a series of specific reports. Chapter 9, References, includes the titles of these reports. Although each participating group wrote the sections on their particular work, this report is the result of the technical review, and editing carried out by M. Velasco and J. Farias (Technical Secretariat, ST) under the direction of J.C. Mayor (Project Director, ENRESA). In addition to this preface, and the following executive summary, the report is structured on the basis of nine chapters, the general contents of which are indicated below. Chapter 1 describes, in general terms, the different parts of the project, as well as the justification, objectives, expected results, and anticipated uncertainties. This chapter has been written by the ST, but the ideas are those of all the participating groups. Chapter 2 refers to the in situ test, describing the different test components and systems. Exception is made of the Granular Bentonite Material (GBM), which is described in Chapter 3, and of the geophysical systems for the seismic and electric characterization of near field of the clay rock, which are described in Chapter 4. Chapter 3 is exclusively devoted to the GBM: fabrication, emplacement equipments, and hydraulic, mechanical and geophysical (seismic) characterization in conventional laboratory. Chapter 4 refers to the excavation of the experimental drift, and to the geophysical (seismic, electric) and hydrogeological characterization of the near field of the clay rock. Chapter 5 is devoted to the installation of the different in situ test components, systems and instruments. The experimental in situ test results and interpretation is presented in Chapter 6, while their modelling and interpretation is presented in Chapter 7. Chapter 8 includes an assessment of the experiment results and overall conclusions, in relation to the declared project objectives. Chapter 9 consists of a list of references. Although a large number of bibliographic references have been used in this project, each included in the corresponding specific reports, the only references included herein are the specific reports detailing the various tasks performed to date, plus a few other reports considered to be essential. (Author)