French regulator approves repository safety options

The French regulator, Autorité de Sûreté Nucléaire, has issued a positive opinion on the safety options for country's planned deep geological repository for the disposal of high- and intermediate-level radioactive waste. However, it has reservations about the storage of bituminous waste within the facility.

The French regulator, Autorité de Sûreté Nucléaire (ASN), has issued a positive opinion on the safety options for country's planned deep geological repository for the disposal of high- and intermediate-level radioactive waste. However, it has reservations about the storage of bituminous waste within the facility.

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.

Andra submitted a "safety options dossier" for the Cigéo project to the ASN in April 2016. 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.

ASN requested its technical arm, the Institute for Radiological Protection and Nuclear Safety, examine the dossier and provide feedback. It also submitted the file to the International Atomic Energy Agency for review by experts from foreign safety authorities. ASN held a public consultation of its draft opinion between 1 August and 15 September last year.

ASN has now issued its opinion on the dossier, saying it considers that the Cigéo project has "as a whole" reached a "satisfactory technical maturity" at the safety options stage. It also believes that the dossier is "documented and supported, and constitutes a significant step forward compared with previous ASN notices".

However, ASN said some subjects in the dossier require supplements to the construction application that Andra expects to file next year. The main requested supplements focus on the justification of the storage architecture, the design of the facility to withstand natural hazards, monitoring of the installation and management of post-accident situations.

ASN said it had concerns about the storage of packages of bituminous waste within the Cigéo repository due to fire risks. Some 40,000 packages - about 18% of the packages to be stored in the repository - are expected to contain such waste. The regulator said that, "given the current status of studies", bitumens cannot be stored in Cigéo and it has requested further studies into the management of such waste. Andra and the waste-producers will work on alternative options - treating the waste prior to storage in Cigéo or strengthening the design of the dedicated storage areas within the repository.

Soraya Thabet, director of safety at Andra, said: "This opinion is for us positive and confirms our main position on safety. Indeed, the ASN underlined the technological maturity of the project and the quality of the dossier." She noted ASN had made "a number of positive points and negative points. We must take both into account."

Researched and written
by World Nuclear News