Architecture and management of a geological repository - Andra

11 – Operational SafetyGiven the measures envisaged to counter the risk of a cage falling down the shaft, such a level ofdamage to the package does not seem likely. However, an additional precaution would be to ensure theabsence of water (or other hydrogenated fluid) in the shaft to rule out the possibility of this riskentirely. This would mean prohibiting the installation of pipes in the waste transfer shaft and alsoproviding a water evacuation system at the bottom of the shaft.The other dangerous situations envisaged [55] do not appear to bring about a risk of criticality.• SummaryA summary of the analysis (cf.Table 11.2.2) is presented per type of activity (construction, operation,closure). The potential retrieval of disposal packages has also been envisaged.Table 11.2.2Summary of radiological risks associated with the disposal processRisksActivitiesFailure of radiological protectionassociated with equipmentFailure of radiological protectionduring the course of an operationRadiological protection failure /loss of package containmentassociated with a fire in a cell ofthe surface installationsRadiological protection failure /breach of package containmentassociated with a primary packagefalling in the surface installationsRadiological protection failure /loss of package containmentassociated with transporter orhandling vehicle fire.Radiological protection failure /breach of package containmentassociated with a B waste packagefalling during emplacement orremoval.Radiological protection failure /loss of package containment /criticality 161 associated withuncontrolled displacement or acage falling down the shaft whentransporting a transfer cask.SurfaceinstallationsOperationsTransfersurface /U/GinstallationsUndergroundinstallationsClosurePotentielpackageretrievalx x x xx x x xxx(B and barespent fuel)x x xxxxxRisk to be taken intoaccountNegligible riskNot applicableRisk is the subject ofan additional study161 The risk of criticality only concerns used fuel.DOSSIER 2005 ARGILE -ARCHITECTURE AND MANAGEMENT OF A GEOLOGICAL DISPOSAL SYSTEM451/495