Architecture and management of a geological repository - Andra

5 – Repository ModulesTable 5.3.1Functions and principal components of the spent fuel cellFunctionPeriodMetal sleeveSwelling clay engineeredbarrierMetal plug and shielded trapdoorCell plugSpacersModule sealingAccess drift back-fillingTo transfer the packages to theirdisposal location;Operations XTo mechanically support the Operations andstructuresmonitoringXTo protect personnel from radiationOperations andmonitoringx X xTo enable packages to be retrieved Operations andfrom disposalmonitoringXxTo stop water from circulating After closing x x XTo limit the release of radioactivenuclides and hold them within the After closing x X XrepositoryTo retard and reduce the migrationof radioactive nuclidesAfter closing x xTo limit mechanical deformation inthe argilites of the Callovo-After closing x x x x x XOxfordian clayTo dissipate the heatAll x x XTo divide up the repository After closing XKey : X essential component in the fulfilment of a functionx contribution made by a component to a function* Strictly speaking, module separation of the repository does not constitute a safety function, but it is a design principle adopted withsafety objectives in mind.5.3.2.4 Solutions adopted or being studied in other countriesThe direct disposal of spent fuels in clay formations is under study in Belgium and Switzerland. TheAmerican (Yucca Mountain), Swedish and Finnish concepts should also be mentioned although theycorrespond to different geological contexts.• BelgiumThe concept of direct disposal of spent fuels studied by the ONDRAF is presented, in the SAFIR2(2001) report, as an adaptation of that used for vitrified waste. Since that date, the concept hasevolved.The disposal package consists of a stainless steel container (AISI 316) holding in cladding, forcriticality reasons, a single assembly.DOSSIER 2005 ARGILE -ARCHITECTURE AND MANAGEMENT OF A GEOLOGICAL DISPOSAL SYSTEM234/495