5.2 The context of nuclear waste management

The brief review of the more than 70-year history of nuclear waste management allows four conclusions to be drawn regarding program management and the success or failure of previous nuclear waste management projects:

• No single deep underground waste disposal program worldwide has been successfully implemented to date.

• The complexity and risks of nuclear waste management have been massively underestimated.

• The history of nuclear waste management shows an ongoing shift in concepts and programs in terms of objectives, implementation, safety and planning of measures in the direction of more manageable long-term projects (governance and long-term stewardship).

• The history of nuclear waste management reveals that a purely scientific and technical handling of such programs is not able of meeting the challenges posed by such a high-risk program. Questions such as the governance of a project, co-construction of management and disposal policies and the role of the affected communities have been often neglected by governments in the past.

Past experience suggests that five basic dimensions should be taken into account in the continuation and development of waste management programs:

HISTORICAL FRAMEWORK: societies will have to live with both the radioactive legacy left behind so far and the legacy that is likely to remain. This task represents a particular social, technical, political and financial challenge for future generations. The predicted costs of US$490 billion estimated for the remediation of nuclear contaminated sites in the United States show the magnitude of the problem.182 Modern societies will not be able to avoid taking over the radioactive legacy and providing it with some far-sighted and safer solutions than today. Nevertheless, lessons should be learned from history in order not to repeat mistakes in the management of nuclear waste. This applies to the processes initiated in the search for, and implementation of, solutions and social control over them. It also implies that during the planning and implementation of programs, a safety culture is applied with a sincere commitment to best practices.

SOCIAL FRAMEWORK CONDITIONS AND TIME REQUIREMENTS: The historical examples show that the time requirements for the implementation of waste disposal programs have been massively underestimated worldwide. Nuclear disposal and the planning and implementation of the strategies for deep geological disposal of nuclear waste under consideration today will extend over at least three further generations. If one considers the requirements for monitoring and long-term monitoring of the targeted “repositories”, one can also assume periods of five to ten generations (150 to 300 years). These long periods place special demands on the stability of societies and inevitably lead to considerations as to how the radioactive inventory already stored in extended interim storage facilities can be safely stored, managed and maintained over these periods. This also poses particular challenges to the quality of planning, specific long-term management and the technical design of such longer-term extended storage facilities. There may also be a need to establish extended underground storage facilities for longer storage periods.

COMPLEXITY: The complexity of the disposal of the nuclear legacy is still massively underestimated today. The physical-chemical aging of waste materials and the resulting hazards are still largely unexplored. Similarly, the heterogeneity of the waste inventory and the carrier and consolidation materials involved lead to completely new problems in the introduction of these waste mixtures into underground repositories. For example, a large number of organic substances have been used in cleaning, maintenance or solidification processes for low- and intermediate-level waste. Certain of these mixtures are to be regarded as ignition sources (e.g. bituminized ion exchange resins) and as such represent a particular source of danger when a repository is operated openly.183 In addition, organic waste will play a decisive role in gas formation in closed underground storage facilities. The risks concern not only the planned high-level nuclear waste repositories, but also those for low- and intermediate-level waste. Fire risks and fires are known in underground repositories for chemotoxic waste.184

Another example of new problems from waste mixtures is the large number of stored materials, ranging from radioactive materials, metals and heavy metals, organic materials and degradation products, to corrodible container materials and products (alkali aggregate reactions in concrete), represents a particularly reactive environment in contact with deep waters, pore waters185 or brines of the corresponding host rocks. The resulting chemical milieu of such an underground waste deposit has so far only been the subject of very limited investigations and research and should therefore be examined in greater depth. This also applies to gas formation by bacterial or chemical degradation processes.

The complexity of the planning can be illustrated by a large number of questions for which there is no or only very limited experience today. Questions will also have to be answered as to how underground facilities extending over many square kilometers will behave in the longer term in tension-sensitive underground and to what extent such facilities can be sealed tightly at all. A further question relates to the development of fuel elements during the storage process underground, their long-term development and the potential effects on their possible recoverability. Finally, scientific findings or technical developments and leaps may fundamentally call into question a planned repository system that is currently being implemented. In such a case, too, reference should be made to the above-mentioned considerations on the complexity of a repository system. Many of these fundamental questions require comprehensive and urgent clarification.

POLITICAL FRAMEWORK CONDITIONS: This concerns the proliferation of fissile materials and the recognition that a repository can also be regarded as a ‘plutonium and recyclables mine’ in the long term. This naturally raises far-reaching questions about the intrusion respectively the protection of such repositories. In this sense, the disposal of irradiated highly active fuel elements represents a particular challenge with regard to future socio-political decisions.

GOVERNANCE AND SOCIETY: Finally, two further central factors are to be addressed in waste management projects. Firstly, there are the questions of governance of programs, the central importance of which decision-makers are only slowly becoming aware of (examples of WIPP in the US and Asse II in Germany) and which are indispensable for further confidence-building. Secondly, civil society (especially the affected regions) cannot only be involved in the sense of accompanying participation, but has to be involved in a broader participation and co-determination process for the long-term acceptance of such projects.

183 Buser, M., Wildi, W. 2018, “Abfallkonditionierung in Bitumen: ASN sagt nein!” (Waste conditioning in Bitument: ASN says no). Viewed 2 August 2019, https://www.nuclearwaste.info/abfallkonditionierung-in-bitumen-asn-sagt-nein/ 184 Comité de pilotage Stocamine (Stocamine’s steering group) 2011, Rapport d’expertise (Expert report), viewed 1 August 2019, http://www.stocamine.com/media/1061/Conclusions%20COPIL.pdf 185 Pore water is groundwater or deep water that is stored in the open spaces in sediments between grains or minerals.