1. WG2

2. §1. Introduction Simplification of the introduction, e.g.: – New structure 1.Background 2.Objectives 3.Scope – Synthesize some of the information Background should include: – §1.1.1 (« risks »), §1.1.2 (« safety »), §1.1.3 and §1.2 – An explanation of the different types of risks associated with geological disposal Add preservation of memory in the specificities of a GDF (§1.1.3)

3. §2. Integration of pre- and post- closure safety in the SC Modify title of §2.1: « The stepwise evolution of the SC » (SC already discussed in §1) Add §2.3 describing the proposed approach for the integration (introduction to §3) Add an explanation in §2.2 of the implications for the management of uncertainties throughout the different phases of repository development Define « handshake » in the glossary Insert explanation and figure on the integration of operational and post-closure safety functions illustrating the « handshake »

4. Pre/Post-closure Interface 4 Operational safety case Operational safety functions Operational end-state (engineering and natural barriers) Post closure safety case Post closure safety functions Post closure initial state Handshake Facility design basis

5. §3. SE, DT & as-built state (1/3) Add an explanation of the figure in §3.1 (How to interprete it ? Not a « geometrical » boundary) Add examples to facilitate the understanding of the different concepts « Initial state » – The term should be clearly defined/explained (§2.3) – Discussion on the initial state that needs to be considered in the post-closure SA throughout the different phases of repository development ( SE vs. DT vs. as-built state) (See 1st & last figures of §3.3) Enlarge the scope of the « parameters »: – Include all parameters that need to be monitored in the management system (not only physical barriers)

6. §3. SE, DT & as-built state (2/3) Robustness not discussed => explain link between SE and robustness Explain what is included in the « safety margins »: – include also all uncertainties associated with construction and operation (e.g. unc. on testing methods, construction methods,…) Explain the different causes of design changes (REX, optimisation, changes in waste characteristics, unexpected conditions,…) 2 nd & 3rd figure of §3.3: Indicate on the figures what the implications are (e.g. « design changes are required », « unacceptable situations »,…)

7. §3. SE, DT & as-built state (3/3) Last figure of §3.3: Use the same format/design as previous figures for the as-built state Add title and numbers for each figure Reformulate last sentence where it is suggested that the proposed approach does not apply to closure works

8. §4. Compliance Control Restructure to clarify the differences between §4 & §5 Operational Limits and Conditions (OLCs) are not mentionned in the document (Parts of the DT ?) How to deal with parameters that can’t be measured ?: – Implications for uncertainty management – Implications for QA –... ? §4.3: Add examples of the different types of parameters associated with requirements that need to be monitored (not only physical parameters)

9. §5. Managing Deviations §5.1: – « Design changes » should be explicitely identified as a possible action – Reformulate the 3rd bullet: Additional margins can be claimed if work is performed to reduce uncertainties (e.g. more detailed characterization of local conditions) The formulation « Reviewing the SC » might be confusing Figure: – Clarify the term « assessment » (= assessment of compliance, not SA) – Closure should appear clearly Deviations from the SE should also be addressed

10. Suggestions for IAEA For electronic publications, link with the definition of key terms would greatly facilitate the comprehension (e.g. pop up of small a box with definition) Suggestion of future IAEA initiative: Activities allowing Member States to share experience and practices and aimed at developing guidance on « requirement management » Consider where this TECDOC would assist or should be referenced from existing IAEA documentation