Architecture and management of a geological repository - Andra

11 – Operational Safety11.9 Synthesis of the analysisThe risk analysis performed covers the industrial activities of construction, operation and closure ofthe repository of long-lived radioactive wastes. Conducted together with the design studies, thepurpose of this analysis at this stage in the project’s study is to give technical orientations and proposetested measures to reduce risks guaranteeing reliable operation and allowing the operational safetyfunctions defined by Andra to be satisfied. This systematically conducted analysis has benefitted fromfeedback from existing industrial installations.The assessment of the dosimetry with the installations in operation showed that the doses received bythe personnel and the public would be less than the annual requirements set by Andra, that is, 5 mSvfor the workers and 0.25 mSv for the public.The risk analysis made a distinction between conventional risks, traditionally encountered in anyindustrial installation, the risks related to waste packages, and the risks related to the environmentoutside the repository.In the surface installations, conventional risks exist at a more or less high degree throughout thevarious disposal activities. These are mainly crushing risks (fall of handled loads, being hit by avehicle, …), fall risks related to work at heights, electrization risks, as well as the risk of fire... Theserisks do not justify additional studies at this stage, but will have to be carefully considered during thedetailed design of the facilities and of their equipment.In the underground installations, these risks are also present. Among them, the risk of fire was coveredby an additional study considering its influence on the design of the installations. This study ensuredthat the solutions recommended for the design of the infrastructures and their operation would allowevacuating people under satisfactory safety conditions.The risks related to the waste packages are mainly radiological risks. They are present during theoperating activity of the repository and to a lesser extent during the closure activity. These risks maybe associated with radiological protection defects, with interventions performed in the vicinity of aradioactive source, as well as a fire or a fall affecting the packages themselves. The consideredarrangements which benefit from feedback from similar industrial installations allow these risks to becontrolled.The risks related to the repository environment (earthquake, weather conditions, airplane crash, …),estimated based on the usual practices of French nuclear installations and taking into account the localcharacteristics of the site, do not raise any specific problems.The operational safety analysis conducted did not reveal at this stage elements which could jepoardisethe technical feasibility of the construction and operation, the closure of the repository and itsreversible management by steps (with, in particular, the possibility of reversing the disposal process).DOSSIER 2005 ARGILE -ARCHITECTURE AND MANAGEMENT OF A GEOLOGICAL DISPOSAL SYSTEM482/495