5.15. In safety assessment for the post-closure period, the performance of the geological disposal system under the expected evolution and under certain specific, but less likely, evolutions and events is analysed. Sensitivity analyses and uncertainty analyses should be undertaken to obtain an understanding of the performance of the geological disposal system and its components under a range of evolutions and events. Low probability scenarios that have a potential for major consequences should be explored to understand the robustness of the disposal system. The safety assessment should include some stylized calculations of the consequences of inadvertent human intrusion into the closed disposal facility [1].1 Similarly, a stylized approach could be taken for biosphere calculations (see Appendix II on post-closure safety assessment for further details regarding development of the safety assessment).
1) An IAEA TECDOC on the use of human intrusion scenarios in safety assessment of radioactive waste disposal is in preparation.