The Centre Industriel de Stockage Géologique (Cigéo) deep geologic repository project in Bure, northeastern France, is “technically mature”, but the plans will need additional work before a construction licence application can be submitted in 2019, France’s Nuclear Safety Authority (ASN) said on 15 January. The main additions requested relate to the justification of the storage architecture, sizing the installation to withstand natural hazards, monitoring the facility and managing post-accident situations.
Radioactive waste management agency Andra sent ASN a safety options file in April 2016, on the Cigéo project, which ASN said represented a significant step forward compared with previous ASN notices. ASN president, Pierre-Franck Chevet, said in an interview with Le Monde: "Andra has submitted a very good file. It confirms that the selected clay zone has the required geological characteristics. And it marks significant advances in terms of safety. However, we have reservations on an important subject: that of asphalt waste."
ASN expressed reservations concerning bitumen waste. "The search for the neutralisation of the chemical reactivity of asphalt waste packages must be favoured,” it said. “In parallel, studies to modify the design to exclude the risk of runaway exothermic reactions must be conducted. In any case, the characterisation as soon as possible of these packages of bitumen waste by their producers is a prerequisite. "
The bitumen waste, which will represent approximately 18% (40,000 packages) of all waste stored by Cigéo, is highly flammable. "On this point, Andra must review its plans," Chevet warned. "If this subject is not treated satisfactorily, the storage of this waste will not be authorised by ASN."
The Institute for Radiation Protection and Nuclear Safety (IRSN), the technical branch of ASN, had raised the problem, asking Andra to study two options to remedy it. These were: the possibility of pretreating these wastes to neutralise their flammability before burial; or to review the design of their storage. ASN preferred the first option but said the second should be studied. Cigéo is scheduled to begin operation in 2025. The facility is to be financed by radioactive waste generators - EDF, Areva and the French Alternative Energies and Atomic Energy Commission - and managed by Andra.
Photo: Cigéo repository (Credit: Andra)