IAEA reviews safety assessment of planned French repository

The safety options for France's planned deep geological repository for the disposal of high- and intermediate-level radioactive waste are "overall thorough", an International Atomic Energy Agency review team has concluded. The team also proposed recommendations for further demonstrating the robustness of the disposal system.

The safety options for France's planned deep geological repository for the disposal of high- and intermediate-level radioactive waste are "overall thorough", an International Atomic Energy Agency (IAEA) review team has concluded. The team also proposed recommendations for further demonstrating the robustness of the disposal system.

Cigéo's underground operations will ultimately occupy 15 km2 (Image: Andra)

France plans to construct the Centre Industriel de Stockage Géologique (Cigéo) repository - an underground system of disposal tunnels - in a natural layer of clay near Bure, to the east of Paris in the Meuse/Haute Marne area. The facility is to be financed by radioactive waste generators - EDF, Areva and the French Alternative Energies and Atomic Energy Commission - and managed by waste management agency Andra. The application to regulators to construct Cigéo should be submitted in 2017, with construction itself starting in 2020. The pilot phase of disposal could start in 2025.

Andra has submitted a "safety options dossier" for the Cigéo project to the French regulator, the Autorité de Sûreté Nucléaire (ASN). This sets out the chosen objectives, concepts and principles for ensuring the safety of the facility. The dossier gives Andra the possibility of getting advice from ASN in preparation for the licence application on the safety principles and approach.

At the request of the ASN, the IAEA conducted a peer review from 7-15 November of Cigéo's "safety options dossier". The review was carried out against the relevant IAEA safety standards and proven international practice and experience. It focused on the strategy of research and development and knowledge acquisition, the approach for defining scenarios for operational and post-closure safety assessment. The review also addressed the approach for post-Fukushima actions.

Christophe Kassiotis, head of ASN's waste, research and fuel cycle facilities department, said: "We requested an IAEA review because we wanted an independent international assessment of the safety considerations of the Cigéo project to complement our national assessment."

The IAEA team assessed the strategy of research and development of the project, as well as the methodology of development of scenarios for operational and long-term safety.

The IAEA review team leader, Jussi Heinonen, said there was reasonable assurance about the "robustness of the disposal concept and Andra's ability to develop a safety demonstration". However he added, "We identified a few additional post-closure scenarios and operational design aspects that Andra should consider to further strengthen the confidence in the safety assessment."

Heinonen said the team suggested improvements to Andra's research and development planning and monitoring program development.

The IAEA team said it considers Andra's methodology for evaluating operational safety is comprehensive and systematic. With regard to post-Fukushima actions, the team said Andra has used ASN specifications for the "stress tests" on nuclear installations as a guideline for integrating complementary safety assessments into the design of Cigéo. The team recommended Andra considers "the use of filtration of exhaust air from the underground facility and evaluate the robustness of its design for the removal of high water ingress from tunnels/ramp sections".

The review team said it encourages ASN, Andra and the Institute for Radiological Protection and Nuclear Safety to use the review of the dossier "as a basis to further precise the expectations for the licence application". It added, "This is especially important as the planned Cigéo facility is one-of-a-kind."

Researched and written
by World Nuclear News