UMAN – a pluralistic view of uncertainty management

Abstract

Decisions associated with Radioactive Waste (RW) Management programmes are made in the presence of irreducible and reducible uncertainties. Responsibilities and roles of each actor, the nature of the RW disposal programme and the stage in its implementation influence the preferences of each category of actors in approaching uncertainty management. UMAN (UMAN – Uncertainties Management Multi-Actor Network is a Work Package of the European Radioactive Waste Management Programme – EURAD) carries out a strategic study about the management of uncertainties based on extended exchanges among actors representing Waste Management Organisations, Technical Support Organisations, Research Entities and Civil Society, a review of knowledge generated by past and ongoing R&D projects, and findings of international organisations. UMAN discusses the classification schemes and approaches applied in uncertainty management, and identifies possible actions to be considered in the uncertainty treatment. The relevance for the safety of the uncertainties associated with waste inventory, including spent fuel, near-field, site and geosphere and human aspects, as perceived by each type of actors, and approaches used in their management are explored with the aim to reach either a common understanding on how uncertainties relate to risk and safety and how to deal with them along the programme implementation, or at least arrive at a mutual understanding of each individual view. Finally, uncertainties assessed as highly significant and the associated R&D issues that can be further investigated are being identified.

Reflections on achievements, activities, and emerging issues of strategic nature within the current and future EURATOM RTD programme on radioactive waste management

“…• the management of uncertainties includes the identification of uncertainties (including the issue of completeness), analyse of their potential impact on overall system behaviour and performance and, depending upon the importance of the uncertainties, identifying options to manage them (possibilities to avoid them or to mitigate their effects and/or to reduce their likelihood of occurrence e.g., through design measures; accept uncertainties because of their limited significance and/or their low likelihood of occurrence, etc.). These issues are addressed within the WP UMAN, see [28]. • Within the EURAD WPs, contributions are made to reduce uncertainties and to make the safety arguments more convincing.…”