Architecture and management of a geological repository - Andra

11 – Operational Safety11.8.1.2 Data related to the simulation studies and to the fall testsThe simulation studies were conducted with the same approach as for the studies of a fall in a shaft(cf. § 11.7.1.2). The software used takes into account the complexity of the occurring phenomena(materials subjected to plastic deformations and even breakage) and the variety of materials making upthe disposal package.The fall tests were carried out on a thick reinforced concrete slab covered with anchored steel plates.The demonstration models used are identical in terms of dimensions and mass to the disposal packagesas shown in Section 4.1, however, the packages contain no radioactive material.11.8.1.3 Simulated evaluation of the mechanical consequences of a disposal package fallingThe purpose of the simulations is to estimate whether the damages caused to the primary packages bythe fall of the disposal package will eventually result in a loss of containment and a release ofradionuclides.• Energy balanceThe energy balance shows that the greatest part of the incident kinetic energy is transformed duringthe impact into an internal deformation energy. The concrete container of the disposal package absorbs90 % of the incident kinetic energy. The primary packages receive the remaining 10 %.• Consequences of the fall on the primary packagesGenerally, the results (cf. Table 11.8.2) are given for the metallic canister of the primary package mostexposed at the moment of the fall, which is the one in the immediate vicinity of the point of impact.The criteria retained is the deformation of the canister of the primary package as compared with theacceptable characteristic value (ACV) of the material this canister is made of.Table 11.8.2Deformations observed on the metallic canisters of B waste primary packagessubsequent to a fall in a disposal cellPackage typeDescriptionof the fall(m)Maximumdeformation ofthe canister ofthe primarypackage(%)ACV(%)B2.1Fall on acorner of the 8 35B5.2lidHeight of fall6 m9 35The results indicate limited damage to the upper part of the primary package envelope with amaximum deformation value of close to 10%, significantly less than the allowable characteristic value.There is therefore no risk of this envelope rupturing.DOSSIER 2005 ARGILE -ARCHITECTURE AND MANAGEMENT OF A GEOLOGICAL DISPOSAL SYSTEM479/495