Tome Architecture and management of a geological repository - Andra

5 – B waste repository zonePosition ducentre degravitéHPosition du point d’impactFigure 5.6.9Scenario of a disposal package dropping onto the cell floorSimulations demonstrate that the concrete envelope of the disposal package absorbs about 90% of thekinetic energy generated by the package drop. The primary packages take the remaining 10%.In both instances, these values are below the primary package envelope burst level (35%).However this conclusion needs to be tempered by the fact that simulations cannot predict withcertainty the behaviour of the primary package lid crimping (B2 packages) and the behaviour of theseal between the container’s body and lid. Real drop tests will remove these uncertainties and ifnecessary indicate the required adaptations to disposal package design.Figure 5.6.10 Plastic deformations of the B2.1 primary package (6-metre drop on an angle 36 )Given the results of the above-mentioned simulations and modelling uncertainties, radioactive materialrelease scenarios have been envisaged for disposal packages containing B2 waste.They show that the dose received at the surface installations, 500 m from the air extraction shaft wouldbe less than 0.001 mSv. This negligible dose would not have any consequences for man and theenvironment.36The primary package is shown in its initial pre-drop position, that is, vertical with the lid upwards to enhance visualisation of thedeformations.Dossier 2005 Granite - ARCHITECTURE AND MANAGEMENT OF A GEOLOGICAL REPOSITORY150/228