1. Challenges in developing a Safety Case WG5

2. How to Develop a Safety Case SC can be a tool for providing information to stakeholders other than regulators (eg public), but can also be used as a weapon by opponents Need to explain the purpose and the process to the public, particularly the iterative nature of optimisation on the journey from siting /concept through detailed design, commissioning & operation. Prescriptive regulations must be developed based on emerging operating experience unrealistic expectations? How do we communicate risk and uncertainty

3. Waste Acceptance Criteria Derived from the Safe Operating Envelope defined by the Safety Case. Derivation of WACs must be Specific, Measurable, Achievable, Realistic & Timely Need a defined variation process, with impacts of variations assessed by a defined process

4. Inventory & key radionuclides Certainty of inventory can be a key issue in making a safety case particularly limiting inventories Appropriate conservatism vs pessimism Calculation of impact is based on a nominal national inventory Impact assessment will determine key radionuclides Safety in operation is governed by the adherence to WACs

5. New types of waste Requires re-assessment internally, how is the significance of the modifications tied into regulatory approval. Need a clear process for triggering regulatory approval based on both qualitative and quantitative criteria

6. Developing Skilled Personnel Production of SC for repositories require a particular skill Retention of operational experience and transfer of knowledge ie what parameters are the Safety Case particularly sensitive to? How do you sell these particular opportunities to following generations Use of sub-contractors – can be a double edged sword

7. Consideration of Climate Change and other long-term impacts Yes, it should be considered

8. Licensing process and responsibility for Safety WG5

9. Decision Making Process Clear, transparent, staged process from siting, concept, detailed design, construction, operation etc leading to a optimised solution Regulatory approval process should be the same for disposal facilities as for other Nuclear facilities – ie should not be influenced by other non-technical factors

10. Challenges – Regulator & Operator Unique Regulatory perspective for Waste disposal – Regulator wants a viable disposal option for radioactive waste – ie regulator becomes a proponent How to maintain transparent independence? Operator faces similar challenges in implementing the Safety Case and WACs while safely managing the disposal option Regulator is in the position of regulating the integrated waste lifecycle – potentiqal conflict

11. Challenges – Regulator & Operator Meeting compressed timelines to match requirements for increased waste disposal requirements from decommissioning and new build Finite resources – people and capital, therefore require clear strategic national priorities How is the regulator involved in the pre-licensing phase

12. Responsibilities Fundamental responsibility for safety always rests with the operator. Government (strategic national plan), Regulator – clear regulatory framework; assessment of licence applications Operator – identifying options & developing safety case(s) showing compliance with regulatory framework Responsibility for public engagement will change through the process i.e. whomever is making the decision at that time

13. Review of Safety Case Identification of suitably qualified and experienced resources - Just as production of SC requires different skills, so does the assessment. Use of TSOs or experts from the supply chain Use of international expertise and operating experience Retention of expertise through operation and particularly post-operation phase. Periodic review may be onerous but could be important in maintaining capability