Disposal options [(25), lines 356–379]
The document mentions several disposal options among which “disposal by leaving waste in situ, e.g., foundations of decommissioned buildings”. This is not a disposal option as such ; such an option is not recognized by the AIEA.
- Suppress “b. Disposal by leaving waste in situ, e.g., foundations of decommissioned 366 buildings.”
Exposure situations [section 3.2]
Table 1 (lines 825-826) and the associated text need clarification on several issues:
Natural disruptive events
- In table 1 (and lines 704–707), “natural disruptive events” are associated to an existing exposure situation (together with “inadvertent human intrusion”), whilst natural disruptive events are expected events (could reasonably be expected to occur during the lifetime of the facility). They must be considered in the safety case from the design phase. Thus the protective approach for natural disruptive events should be that of a planned exposure situation. However, the categorization in table 1 is correct for natural disruptive events with very low probability.
- add “unlikely” to “natural disruptive events” in table 1 and line 706 (and 4.4.1 for consistency purpose)
Emergency and/or existing exposure situations
- While the reference to the radiation protection system for emergency situations makes sense during the operating phase of a near-surface repository, this becomes very surprising for the long-term post-closure phase, as it contradicts the principle of passive safety on the long term with a postulated release from institutional control. To this regard, the text « 726 In the context of near-surface 727 disposal of radioactive waste, an actual emergency exposure situation is extremely unlikely, 728 but could lead to an existing exposure situation that requires some form of remediation.” does not refer to the radiological protection system which request active counter-measures to manage an emergency exposure situation. The text lines 735-746 on emergency situation is also clear for the post-closure phase « 745-746 : only abrupt and severe perturbations of the disposal system that are outside the design basis might possibly lead to an emergency exposure situation”: these are situations addressed in the last line of table 1 , « beyond design basis » situations
- supress « (and/or Emergency) » in table 1 for the post-closure phase, 3rdcolumn, 2nd line.
Accidents
- The term accident would worth being clarified as so to avoid misunderstanding between “foreseeable disruptive events” which stands for “altered evolution scenarios” considered for designing a disposal system and those unforeseeable “accidents” like malevolent events which for sure would lead to “severe accidental situations”
- add “severe accidents (eg. malevolent events)” in table 1, 2ndcolumn, 4th line
Typos
the range of 271 design options for near-surface disposal facilities varies from simple to more complex ones 272 and may involve disposal from the surface to depths of several tens of metres. This depth 273 range is not indicative only and is not precise.
→ change for “this range is indicative only” ?