1. WORKING GROUP 4 KEY DISCUSSION RESULTS TOPICS 1 & 4 International Workshop on the Safe Disposal of Low Level Radioactive Waste 03 to 05 February 2015, Montrouge, France

2. Topic 1 – Development of Disposal Concept (1)  Waste classification important for communication  Safety case development as key driver for disposal concept development  Waste separation and detailed waste characterization are very important  Optimization  Concept (assessment of alternatives)  Design (assessment of possible improvements)  Radiation protection (ALARA)  Best available technology (BAT) may be a helpful concept, but not applicable for all optimization considerations) IAEA Workshop Paris - February 2015 2

3. Topic 1 – Development of Disposal Concept (2)  Information exchange incl. feedback of experience  Considered extremely useful at all stages of the development of national programs  Details of learning curves in other countries (e.g. use of experience from La Manche > Aube in France) could be very important for other countries  Mechanism in place (e.g. IAEA projects, Joint Convention …)  Helpful, but exchange of information often not systematic and sometimes not going deep enough  Question of how to feed this experience into national programs IAEA Workshop Paris - February 2015 3

4. Task 4 – Post-closure aspects  Institutional control periods between 100 and 300 years applied in all countries present (except Sweden)  End of institutional control period NOT meant as decision taken on behalf of future generation what they have to do  Use is only as a basis for the safety case development  Assessment of post institutional control risks  Realistic scenarios required in particular for intrusion  No „black or white“ issue, optimization principle applies  Especially for existing facilities it may be necessary to retain some level of (e.g. passive) control for a longer term  Retrievability is not seen as general element of near surface disposal concepts IAEA Workshop Paris - February 2015 4