[en] In a first part, the author recalls the different steps of the process which started in 1991 with a law introducing the notions of reversibility and irreversibility as options to be studied for deep geological disposal of radioactive wastes, and finally resulted in the choice of a reversible disposal in 2006. He comments how warehousing and reversible disposal are complementary, and comments the on-going work performed within the Andra on reversibility

[en] The author first outlines that reversibility is a technical as well as institutional stake. He recalls the Andra's definition of reversibility, and outlines some specific characteristics (retrievability, possibility of action on the disposal process, possibility to make the design evolve). He discusses some implications of reversibility in terms of technologies, of information and of debate organisation. He indicates aspects which are less taken into account nowadays in the field of technical means and information. He proposes instruments for the process of information of parties (archiving, documentarisation), for the debate (document sharing, debate tools based on participatory documentary spaces). He outlines the importance of documentarisation, indicates different information media (various types of databases) and proposes an example based on 'Folksonomies'

[en] The authors first describe the context of CO₂ geological disposal: temperature increase, reduction of greenhouse gas emissions, choice of the option of CO₂ geological storage, site selection, storage of CO₂ in its supercritical status, current projects. They address the issue of reversibility in a legal perspective (European directive), in terms of physics (evolutions of mineral, supercritical and dissolved CO₂), and in terms of risk management (irreversible trapping, natural reversibility). They discuss the necessary management of uncertainties associated with such storage

[en] The authors discuss the issue of assessment of the economic cost of reversibility. They briefly evoke the approach adopted by the Andra for this assessment, present the analytic approach to reversibility cost, describe the assessment of the cost of a reversible concept comprising the design of a gallery, a modular architecture, and the design of high-activity cell. They discuss the assessment of the economic impact of reversibility on the exploitation mode, the assessment of the cost of an operation of parcel retrieval. They comment the issue of reversibility financing

[en] In this Power Point presentation, the author analyses the origin of the concept of irreversible geological disposal as a closed decision, its principle, and its weaknesses. He analyses the reversible geological disposal as a step-by-step decision which emerged after the irreversible approach has been criticized, which is a compromise, and which has its own weaknesses. He analyses the surface warehousing approach as an iterative model which tries to solve the contradiction of geological disposal (deep storage could contradict a reversibility requirement), but has also its own contradictions

[en] The authors present a digital space (a web site - 'ExploRe') which would allows a community to share a set of pluri-disciplinary information items concerning reversibility, and in which the community members describe the items by using attributes and themes belonging to different points of view

[en] The author discusses the relationship between the notion of reversibility and the concept of geological disposal. Due to the delays of radioactive waste disposal programs, she does not consider as definitive the closure of a geological disposal after decades of operation, and talks about deep perpetuated warehousing rather than reversible geological disposal. She discusses the different aspects of the notion of reversibility as they appear in different countries. It can appear with respect to the decision process, or with respect to the disposal installation. She discusses the concept of geological disposal as the final stage in the management of high-activity and long-life wastes, and relates it with the context of the fifth fundamental IAEA's principle of nuclear waste management which deals with the responsibility towards future generations. She finally outlines the step-by-step character of the geological disposal approach, an approach which is necessarily flexible and reversible

[en] The author proposes a discussion about the notion of reversibility by using the policy theory and by referring to philosophical and political texts written, for example, by Jankelevitch, Castoriadis, Merleau-Ponty, Thucydide or Arendt. He first discusses this notion with respect to irreversibility, notably as it appears in Jankelevitch's works. Then, by referring to an example chosen in the antiquity, he discusses re-examination as a first example of reversibility. He discusses three figures that the notion of reversibility may have in policy: forgetting, forgiving and recollecting. The first ones tend to put something aside. The last one is a struggle against forgetting

[en] As the demand for reversibility in the case of radioactive waste disposal is supposed to meet concerns regarding the ability to retrieve parcels in case of problem, the possibility to make choices for future generations whenever better management solutions would emerge, and the need to act with prudence on this complex issue which corresponds to a commitment on a long term, the authors describe the Andra's approach to reversibility. This approach relies on technical measures aimed at easing the possible retrieval of parcels, and on a decision process which allows the disposal process to be steered in relationship with the progressive development of the storage centre and its step-by-step closure

[en] Addressing the issue of waste disposal reversibility, the authors first outline what needs to be proven (the flexibility of each disposal stage, the availability of technical options integrated from the disposal design), and then give an overview of scientific knowledge allowing the assessment of the potential of reversible management (constraints due to the geological environment, distribution of processes in space and in time, issue of thermal processes and heat release, monitoring of the thermal process, involved mechanical processes and their monitoring, hydraulic processes and their possible consequences, chemical processes such as corrosion and its monitoring). They describe the role of monitoring and surveying for a reversible management. They finally discuss whether reversibility can be proven, whether decision-makers will have the necessary information available