Architecture and management of a geological repository - Andra

5 – Repository ModulesTable 5.1.1Functions and main Components of B cell (or module)FunctionsPeriodConcrete liningCell SectionSeal in the access driftCell airlockTransferring the packages to theirrepository locationMechanically supporting thestructuresProtecting man against radiationFor retrieving disposal packagesOperationsOperation andmonitoringOperation andmonitoringOperation andmonitoringPreventing water circulation After closure XRestricting the release ofradionuclides and immobilizing themin the repositoryDelaying and reducing the migrationof radionuclidesLimiting mechanical deformation inthe Callovo-Oxfordian argillitesAfter closure X xAfter closureXXXxXAfter closure x XSplitting up the repository After closure XLegend: X essential component in performing a functionx contribution of a component to a function* Module separation of the repository does not, strictly speaking, constitute a safety function, but is a device adopted with safetyobjectives in mindxX5.1.2.3 Solutions adopted abroadSeveral countries are studying underground repository solutions for similar waste to French categoryB waste, in clay type environments.In Switzerland, NAGRA 62 is studying the feasibility of an underground repository in an argillite withmineralogical characteristics similar to that of the Bure site, but with stronger mechanical properties.The concept adopted is a tunnel whose dimensions are around 9 m high by 7 m wide. The disposalpackages are stacked in these tunnels on 2 or 3 levels. NAGRA has not chosen to minimize the spacesbetween the packages and the disposal cell and has preferred to fill the gaps with a mortar afteremplacement of the packages (Figure 5.1.7). The cell is then closed with a concrete plug [44].62 National Cooperative for the Disposal of Radioactive WasteDOSSIER 2005 ARGILE -ARCHITECTURE AND MANAGEMENT OF A GEOLOGICAL DISPOSAL SYSTEM169/495