[en] A large part of French radioactive waste benefit from disposal routes that are operational or under development. However, some types of waste are now questioning their long-term management modalities with a view to proportionality to their harmfulness: waste with a very low activity level to be generated by future decommissioning and dismantling, wastes with intermediate characteristics such as 'low activity level and long-lived waste'. The search for disposal solutions in line with the graded approach recommended by the IAEA requires a better understanding of the harmfulness of waste and an analysis of the reasonable need for containment and isolation from man and the biosphere. This need results in appropriate characteristics of long-term barriers and in durations on which the performance of these barriers can be assessed. (authors)

[en] According to the Act (28 June 2006), interim storage is a research route for the sustainable management of HLW and intermediate level long lived radioactive waste (ILW) in France, along with partitioning/transmutation and reversible disposal in a deep geological formation. Interim storage is intended to play a complementary role to the geological reversible repository. ANDRA is responsible for defining and coordinating the research on both interim storage and reversible disposal of HLW/ILW. A long storage duration as considered before 2006 (up to 300 years) is no more an objective for the research. The paper details the role of interim storage complementary to the reversible repository, with respect to the origin and characteristics of various HLW and ILW to be considered. In particular, it will make it possible for HLW to benefit of thermal decay. ANDRA cooperates with the operators of existing storage facilities at production sites. Working groups have been created. The objectives are the following: - to learn from the experience gained at designing, building and operating the facilities, - to check the capability of existing and projected facilities to meet with the requirements of the National plan for the management of the radioactive matters and waste. In 2008, French waste producers updated the National inventory of radioactive waste and matters. According to the Act, they have incorporated an inventory of their storage facilities. ANDRA has made a review of these inventories to provide the Government with an evaluation of needs for new facilities. ANDRA has also investigated new design options of storage facilities on both production and disposal sites. On the repository site, interim storage above ground and in shallow geological formation have been studied. The waste packages are stored as produced, eventually secured in handling cask, or over-packed for disposal in steel (HLW) or concrete containers (ILW). A service life as long as one hundred years may be required. A selection of storage options has been proposed to the French government for extended studies. It is based on their versatility regarding the waste package characteristics and the constraints arising from the transportation and the disposal operations. Special attention has been drawn to waste package monitoring i.e. the eventual release of gas, ageing phenomena, etc. The robustness facing internal or external aggressions and costs have been equally taken into account. ANDRA has also initiated an analysis of the physicochemical phenomena which may affect the durability of storage facilities and stored waste packages. It evidenced thermal, mechanical, chemical and radiological couplings which rule ageing processes. A research program has been launched including laboratory experiments and numerical simulations, consistent with this analysis. (authors)

[en] The French law of 30 December 1991 and the implementing decrees provide for taking into account the reversibility in the study of geological disposal. This takes place within the framework of a 15 year research program. The research in this field implies both the assessment of technological possibilities for retrieving waste packages safely from the repository and the assessment of the consequence of delaying the closure of the repositories on the long term safety. This research program aims at proposing to the decision makers, by the year 2006, an open range of relevant options with regards to reversibility. (author)

[en] Andra is currently in the license application process for a deep geological disposal facility for high level waste (HLW) and intermediate level waste (ILW) in a clay formation, the Callovo-Oxfordian, in the eastern part of France. This process started in 2011 by the development of an industrial design phase that consists of a proposed overall underground architecture for the repository and the definition of the operating principles, and the name given to the project was defined: the “Centre industriel de stockage en milieu géologique” (Cigéo, Industrial Center for Geological Disposal). The files and in particular the safety case that will support the license application result from a continuous increase in knowledge, project development, and associated safety assessment for several decades. Since the French Act in 1991 on the long term plan for the management of ILW and HLW in France, Andra is running a comprehensive research project including a broad combination of laboratory research, surface and drilling based site investigations, research in the Bure URL and model development. The preparation of the license application is thus the result of a stepwise accumulation of knowledge and iterative process including several safety cases as well as their regulatory review. The safety case development plays a key role in supporting the development of the technical solutions to manage HLW and ILW. It is based on successive “knowledge/design /safety” iterations. Each iteration involves scientific and technological knowledge acquisition, study of the layout designs consistent with this knowledge and safety assessment. Each safety case is associated with key milestones (reliability, siting, underground research, industrial design development, safety options, licensing) based on the “knowledge/design /safety” iteration providing lessons learnt. The successive iterations gradually help to guide the choice toward design solutions, R&D programmes, and safety studies. Andra collects and documents knowledge R&D data and analyses residual uncertainties in the knowledge. (author)

[en] The ―Cycle Impact‖ approach was launched at the end of the 1990s on the French Nuclear Safety Authority’s initiative (ASN): EDF, in collaboration with its industrial French partners Orano and Andra, has to identify and anticipate actions in order to guarantee a consistent nuclear fuel cycle management in the mid-term. The impacts of fuel design, characteristics and management and nuclear reactors fleet evolutions on the whole supply chain should be studied: NPPs, front-end and back-end facilities, interim storage and logistics. The objective of the ―Cycle Impact‖ exercise is to demonstrate that the choices made by industrial stakeholders on these evolutions, bearing in mind their interdependence and nuclear time frames, do not create unacceptable consequences regarding the entire French fuel cycle. It also allows ASN to have an overview of future regulatory requests to be examined. After two previous exercises performed in 2000 and 2007, the ―Cycle Impact‖ file 2016, made of 47 deliverables, coordinated by EDF in collaboration with Orano (formerly Areva, French company providing front-end, back-end and logistics services) and Andra (National Agency for Radioactive Waste Management), was submitted in June 2016. The fuel cycle consistency on a 15-years period was analyzed and forecasts until 2040 were made to ensure the absence of cliff-edge effect. Based on four scenarios of nuclear-sourced electricity production and associated fuel reprocessing-recycling strategies parameters like spent fuel pools level of occupancy and transportation casks availability had been studied. Hazard sensitivity analyses had been performed. On request of the ASN, the file had been assessed by the French technical support organization (IRSN). An expert report including opinions and recommendations was produced and commitments were taken by the industrial actors. The report was subjected to a peer review by the Advisory Committee of experts (GP) for laboratories and plants including experts from waste, nuclear reactors and transports committees. Following the recommendations issued during the meeting of the Advisory Committee on 2018 May 25th, ASN has identified actions to be undertaken by each party in a letter on 2018 October 25th. With the goal of improving nuclear transparency, summary of the IRSN report, GP opinion and ASN stance has been published. (author)