The disposal of high-level radioactive waste in a deep geological repository with the option of retrievability requires monitoring of the waste. In general, monitoring means temporary technical collection of data on the development of the disposal site and the effects on the environment surrounding the disposal site. These monitoring data should give information on whether the repository develops as expected or whether it is necessary to initiate retrieval. This implies that a decision has been made on what measures need to be taken and, then, that a way is found for technical implementation. This is a complex problem in itself because time periods in which data would be collected would be in a high double-digit if not three-digit range. There is no experience with monitoring technologies over such a long period of time as required in nuclear waste management. Furthermore, it can be expected that data collection and interpretation will not be carried out solely by the operator. Protection authorities and supervisory boards as well as scientists and stakeholders will have a strong interest in professional support and advice.

There is another indication of complexity: The basic framework for evaluating the collected data and for ensuring the proper functioning of the monitoring process has to be developed already during the installation phase. After that, the technical options are very limited. This suggests that political and administrative institutions are necessary to maintain the technological infrastructure over long periods of time. In addition to the technical tasks, a stewardship organization must be able to enter into continuous dialogue with civil society and politics. In case of deviation from the expected development of the repository, the institutions have to decide about the interpretation of data: Is there a measurement error, is it necessary to improve the technical features or to retrieve a certain amount of nuclear waste? It can be assumed that after the repository is closed, political and public attention will lessen. It appears necessary to install a system of "checks and balances" which is linked to the monitoring team and which can prepare political and legal decisions of high quality in the near and distant future (from several decades up to three or four centuries). Building these institutions and structures is, besides the technical developments and institutions to maintain the technological know-how, an important aspect of the implementation of a deep geological repository, taking seriously short and mid-term safety issues and integrating the demands in the concept of disposal.

The interdisciplinary workshop "Technical Monitoring and Long-term Governance" aims to examine the problem of "double-complex" monitoring in its many facets – from the perspective of legal sciences as well as engineering, natural and social sciences. This includes the technical aspects of the planning and further development of the monitoring concept as well an analysis of the experiences in established governance-structures such as the long-term stewardship program implemented by the United States Department of Energy.