9. Conclusion

The safety of a surface disposal facility, a concept used in several countries, is based on the isolation and containment of waste using a three-barrier system: the waste packages, the storage structures and the site. The quality of the waste packages and storage structures, by limiting contact between water and radionuclides and retaining any radionuclides transported by water, are the key safety factors during the main radionuclide decay phase. During this phase, which is expected to last around 300 years, the operator will be responsible for monitoring and maintenance. Radiological risks after the monitoring period, particularly in the event of human intrusion, will be reduced by limiting the maximum activity of long-lived radionuclides in waste packages admitted to the repository.

The assessment of the safety of a deep geological repository will be based firstly...