Siting a deep geological repository for spent nuclear fuel - a technical endeavour and a social challenge

About 50 % of the electricity in Sweden is generated by means of nuclear energy. A clear legislation and a structure of responsible organisations for implementation, resource allocation, regular review and licensing was set up some 20 years ago. It has remained stable and proved to be able to deliver concrete results of safety related R and D, technical developments, new facilities and public confidence. For the spent fuel a centralized system for interim storage is in operation since 1985 and full-scale laboratories for encapsulation and disposal technology are established since several years. Site investigations for a deep repository are being made at two selected sites with the voluntary participation by the two concerned municipalities. Key decisions concerning the planned system for final disposal may come within the next 5 - 10 years. The spent fuel disposal programme in Sweden is thus approaching the phase of industrial implementation and this will imply new challenges both from a scientific/technological and socio- political point of view. The technological challenges are mainly related to the endeavour needed to enable industrial application and integration of all the RD and D-results obtained so far within the programme. This implies for instance being able to construct and to put into place the multiple-barrier system components with the quality and capacity demanded by safety requirements and industrial operation. To do this in the real world of a deep underground environment and with highly radioactive spent fuel is certainly a demanding task. The socio-political challenges are closely connected to maintaining and reinforcing the local and national confidence in the project and the corresponding ability to take the necessary decisions. One key factor in this respect is the development of a comprehensive and relevant environmental impact assessment in consultation with all stakeholders involved. This implies not only being able to produce high-quality documentation of all aspects related to safety and environmental impact of a deep repository but also being able to interact with the stakeholders in a trustful and efficient way. (authors)