France
National Waste Classification and Policy
As defined by a ministerial decree related to the National management plan of radioactive materials and waste updated every three years, the French waste classification is based on (i) the level of radioactivity and (ii) the half-life of the radionuclides present in the waste. As a function of the level of radioactivity, waste are split into very low level (generally less than 100Bq/g), low level (between a few tens and a few hundred thousand Bq/g), intermediate level (of the order of 1 million to 1 billion Bq/g), high level (of the order of several billion Bq/g). On the basis of the half-lifecan be distinguished so called very short-livedwaste(half-lifeless than 100days), short-lived waste, whose radioactivity is mainly due to radionuclides that have a period not exceeding 31 years, long-lived waste with a significant amount of radionuclides whose half-life is greater than 31 years.The long term management of each type of waste requires the implementation or development of specific facilities, appropriate to the danger it presents and its evolution over time:
Responsibilities inradioactive waste management are defined by law.Andra is the public body in charge of siting, designing, construction and operation of disposal facilities; the waste producers are responsible for their waste which includes the funding of their long term management; the regulator (ASN) defines safety rules and examines applications; a committee of independent experts assesses the progress of studies and research for the French Government and Parliament(CNE); other stakeholders are involved at local and national levels.
Approach to Managing ILW
Intermediate and low level short-lived wastes are being currently disposed of in a near surface facility under operation (Centre de stockage de l’Aube). A previous near surface facility located near the reprocessing plant at La Hague is now in the monitoring phase.
Centre de stockage de l’Aube
Intermediate level long-lived waste are planned to be disposed of in a deep geological disposal facility subject to authorization, along with HLW (Cigéo Project).Site selection has been completed and a public debatewas held in 2013 and 2014.The clay host formation at a depth of around 500m has been investigated in the Meuse/Haute-Marne Underground Research Laboratory. The application is scheduled in the 2015-2017 timeframe. A pilot operational phase is planned from 2025. Waste is currently stored on production sites.
Low level long-lived waste are also the subject of studies and research to develop specific disposal solutions, mainly based on so called low depth or shallow facility (corresponding to IAEA “near surface” type). Geological survey of a potential host clay formation has been carried out in the Aube district. Andra will provide the French Government with a progress report in 2015 to define the terms of continuing the project dealing with both predisposal and disposal options.
Details of Planned Disposal Facilities
Cigéo deep geological disposalproject
The French 2006 waste law provides for deep geological disposal of both high level and intermediate level long-live waste. Andra’sresults of 20years of R&D made it possible to issue detailed project technical requirements. On this basis the industrial design of the future facilities of Cigéo Project is underway with respect in particular to the outcomes of the recent public debate.
Intermediate level long-lived waste arises mainly from spent fuel reprocessing and from the maintenance and operation of nuclear facilities. These include clads and hulls, as well as maintenance waste (used tools, equipment ...) and process waste, as some sludge. The volume of existing waste was 40,000m3 at the end of 2010. The total prospective volume is estimated at 45,000m3 in 2020 and 49,000m3 in 2030.
If licensed the disposal facility will be implemented at a depth of 500m, in the Callovo-Oxfordian clay layer (argillite) which has been investigated in the Meuse/Haute Marne Underground research laboratory. Post-closure safety has been studied at the scale of a million years.The depth of the disposal facility, the absence of exceptional natural resources and the favourable geodynamic context provide for the isolation of waste during very long periods of time. The long-term containment is essentially based on the favourable properties of the host clay layer (geodynamic stability, geological continuity and thickness of the clay layer; low permeability and retardation capability of the argillite; low hydraulic gradients). Post closure safety functions are: (i)oppose groundwater flow; (ii) limit the release of radionuclides and immobilize them within repository; (iii) delay and mitigate the migration of radionuclides.
The underground architecture of the repository contributes to its long term performance and robustness (implementation of disposal drifts in the middle part of the clay layer, location of access shafts and ramps, configuration of disposal zones, etc.).After operation, disposal cells, access drifts and shafts will be sealed and backfilled.
The facility is planned to be constructed and operated over a period of about one century. It will include dedicated disposal zones for intermediate level long-lived waste and high level waste. Access to the underground facility will be provided by vertical shafts and an incline ramp for waste transfer. Disposal cells for intermediate level long-lived waste consist of horizontal tunnels with a 500m length. The cross section of the disposal tunnels makes it possible to stack waste disposal packages. Waste handling will be carried out remotely because of the dose rate within the disposal tunnels.
Along with safety, reversibility of deep geological disposal is required by law. Provisions are included in the design to enhance the retrievability of disposed waste packages. The implementation, the operation and the closure of the disposal facility are conceived as a stepwise and progressive process. Intermediate milestones will be identified until final closure to adapt as necessary the conduct of operation and closure.
Near surface disposal project for “long lived low level waste”
The shallow disposal concept for low level long-lived waste consists of an implementation of disposal cells within a low permeability clay layer at a depth of about 15meters provided the host formation is outcropping. The waste isolation and containment capability is available as long as the geodynamic site evolution does not significantly modify the repository configuration (i.e. via erosion). With regard to its depth and the expected geodynamic conditions, the stability of the repository is estimated to be about 50,000 to 100,000 years.
Low level long-lived waste include graphite waste, waste containing radium and some other waste such as bituminized sludge from the treatment of effluents in nuclear facilities. Most graphite waste comes from the dismantling of former natural uranium gas-cooled reactors. Radium-bearing waste is mostly produced by non-nuclear industrial activities (TE-NORM waste). The volume of existing waste was 87,000m3 at the end of 2010. The total prospective volume is estimated at 89,000m3 in 2020 and 133,000m3 in 2030.
The shallow disposal concept is considered potentially for long-lived waste containing:
Radionuclides with a low mobility and a half-life such that sufficiently low activities have been reached by decay in less than 50,000years. The preservation of physical, chemical and hydraulic conditions limiting radionuclide mobility should be insured. Considered radionuclides have a half-life lower or equal to that of Carbon-14 (5,700years). It covers in particular Radium-226 (1,600 years);
Restricted activity of Plutonium and Americium;
Restricted activity of radionuclides that do not decay sufficiently within 50,000 to 100,000 years such as Thorium-232 and Uranium-238 and Uranium-235;
Restricted activity of long-lived, potentially highly mobile radionuclides.
The French Government has charged Andra to examine different options for managing graphite and radium bearing waste. These options include potential sorting and/or treatment of the waste and their disposal. Andra provided the Government by the end of 2012 with a report outlining different possible management scenarios and an approach for siting. Therefore a field geological survey was launched in 2013. On the basis of geological investigations, continued characterization of waste, specific research on the treatment of waste and safety analysis, Andra will issue a new report in 2015 containing: the feasibility analysis of considered management scenarios for graphite and other waste; a feasibility study of a shallow repository including the scope of waste that might be accommodated and a timetable for its implementation.
Waste acceptance criteria will be adapted to site performance as assessed from the results of geological survey. Design of disposal pits will be adapted to waste characteristics. Waste packaging will be defined in relation with repository design.
References
Inventaire national des matières et déchets radioactifs 2012 : Rapport de synthèse -
Plan national de gestion des matières et des déchets radioactifs -
Projet Cigéo : Centre industriel de stockage réversible profond de déchets radioactifs en Meuse/Haute-Marne - Dossier du maître d’ouvrage 2013 -