IAEA ANSN RWMTG National Workshop: Application of IAEA Methodology and Tools for the Safety Case and Safety Assessment for Predisposal Management of Radioactive Waste - Part 2 Bali, Indonesia, 9-13 September 2013 Frederic Ledroit IRSN - France Definition, Role and Documentation of the Safety Case

IAEA Outline of the Presentation Preamble Overview of Safety Case Specific issues Evolution of the safety case; Graded approach; Defense in depth; Reliability; Expected lifetime of the facility; Long term storage; Summary and conclusions. 2

IAEA PREAMBLE 3

IAEA 4 What is a Safety Case? The collection of arguments and evidence, including the outcome of safety assessment, in support of the safety of a facility or activity The basis for the safety considerations in respect of siting and locating facilities, construction, operation and decommissioning of the facility, including the justification for changes The basis for interaction and dialogue between the operating organization and the regulatory body 44

IAEA IAEA Requirements for Safety Case, Safety Assessment … GSR Part 5, GSG-3: Safety Case A collection of arguments and evidence in support of the safety of a facility or activity. This will normally include the findings of a safety assessment and a statement of confidence in these findings. GSR Part 4, GSG-3: Safety Assessment 1. Assessment of all aspects of a practice that are relevant to protection and safety; includes siting, design & operation of the facility. This normally includes risk assessment and probabilistic SA. 2. Analysis to predict the performance of an overall system and its impact, where the performance measure is the radiological impact or some other global measure of the impact on safety. 5

IAEA 6 1. Government responsibilities 2. National Policy & Strategy 3. Regulatory Responsibilities 4. Operator Responsibilities 5. Safety/Security 6. Interdependences 7. Management systems 8. Waste minimization 9. Characterization and classification 10. Waste treatment 11. Waste storage 12. Waste acceptance for processing, storage and/or disposal 13. Prepare safety case and supporting safety assessment 14. Safety case scope and regulatory compliance 15. Safety case documentation 16. Periodic safety review 17. Facilities location and design 18. Facility construction and commissioning 19. Facilities operation, maintenance, emergency preparedness 20. Decommissioning 21. Nuclear safeguards 22. Existing facilities GSR Part 5, Safety Requirements for Predisposal Management of RW 1.Introduction 2.Protection of Human Health & Environment 3.Responsibilities 4.Steps in the Predisposal Management of RW 5.Development and Operation of RWM Facilities & Activities

IAEA Safety requirements for SA and SC The safety case (SC) shall: Include a description of how all the safety aspects of the site, the design, operation, shutdown and decommissioning of the facility, and the managerial controls satisfy the regulatory requirements Demonstrate the level of protection provided and shall provide assurance to the regulatory body that safety requirements will be met Include arguments justifying the approaches taken in the safety case on the basis of information that is traceable Document the arguments at a level of detail and to a quality sufficient to demonstrate safety 7

IAEA 8 GSG-3: Safety Guide for SC and SA 1.Introduction 2.Demonstrating the Safety of RW Management 3.Objectives and Development of the Safety Case 4.Safety Assessment 5.Specific Issues Evolution of the SC Graded Approach Defence in Depth Reliability Expected Facility Lifetime Long Term Storage 6.Documentation and Use of the Safety Case 7.Regulatory Review Process Stakeholder and Regulatory Involvement Application of Management System C. System Description D. Safety Assessment G. Limits, Controls and Conditions H. Integration of Safety Arguments E. Iteration and Design Optimization F. Management of Uncertainty A. Safety Case Context B. Safety Case Strategy

IAEA Preparation and review of SC and SA Systematic methodology Supports appropriate waste management decisions Demonstrate compliance with applicable safety requirements and criteria for the lifecycle of the facility Ensure confidence in the safety of the facility or activity Safety guidance on SC and SA (GSG-3) 9

IAEA Specific issues (GSG-3) Evolution of SC Graded approach Defence in depth Reliability Expected facility lifetime and activity duration Long term storage 10

IAEA OVERVIEW OF SAFETY CASE 11

IAEA Objectives and Roles of SC and SA (GSG-3) Integrating scientific and other information Demonstrating safety (incl. uncertainties) Demonstrating compatibilities with next waste management steps (e.g. disposal) Aiding decision making on the authorisation/ licensing of the facilities Other information and arguments that support continued development, use or eventual decommissioning of the facility 12

IAEA Purpose of safety case Demonstrate that all planned activities can be carried out in a safe manner The SC concept will be of particular importance for large predisposal waste management facilities such as national centres for the processing and storage of radioactive waste. Provide guidance for the design, engineering and planning of operations to ensure safety Input to regulatory process, including evidence of compliance and arguments for confidence building International Course on Management of Waste, Clausthal-Zellerfeld, Germany, 6-15 October

IAEA Development and content of SC and SA Some countries do not use the term SC in a formal way, but the approaches and processes to demonstrate safety similar The operator shall prepare a safety case and a supporting safety assessment. In the event of a step by step development or in the event of the modification of the facility or activity, the SC and its supporting SA shall be reviewed and updated as necessary. Regulatory body is responsible to derive and document in a clear and unambiguous manner the criteria on which the regulatory decision making process is based 14

IAEA Safety Case content Waste types and the rationale for the chosen/proposed waste management options Facilities and the site, based on traceable information Managerial and regulatory controls over the facilities Plans regarding the development, operation and shutdown and decommissioning of the facilities Safety assessment (SA) Other information and arguments supporting the development, use or decommissioning of a facility 15

IAEA Scope of the safety case for predisposal Relevant facilities / activities:  Processing of radioactive waste  Clearance and Discharges  Storage facilities  Transport  Intervention situations (e.g. old storage facilities) All types of wastes  low level to high level waste  disused sealed sources  NORM International Course on Management of Waste, Clausthal-Zellerfeld, Germany, 6-15 October

IAEA SPECIFIC ISSUES: - Evolution of the safety case - Graded approach - Defense in depth - Reliability - Expected lifetime of the facility - Long term storage 17

IAEA Introduction During facility lifecycle, the safety case will evolve in five main stages: Concept and siting; Design; Construction and commissioning; Operation and modifications; Shutdown and decommissioning. 18

IAEA Concept and siting (cont.) The output of the safety case at this stage of development is justification that the facility or activity should, in principle, be undertaken and that it appears safe to do so. 19

IAEA Design During the design development and construction, the safety case will be further developed to provide a mature assessment of the engineering and of the impact of the facility or activity; The safety case should demonstrate that: Likelihood of a component of the system failing is low, In the event of degradation, the loss of a safety function of one component does not jeopardize the safety of the whole system. 20

IAEA Design (cont.) The output of design stage of the safety case development is justification that the facility or activity, as designed, can be safely constructed and operated. 21

IAEA Construction and commissioning During commissioning, specific attention should be paid to the performance of structures, systems and components important to safety. A safety commissioning schedule should be prepared, detailing: Test to be undertaken, Results expected to ensure, that all aspects of the facility important to safety are adequately tested. 22

IAEA Construction and commissioning (cont.) The safety case at this stage should demonstrate that the as constructed facility meets the safety requirements specified in the final design. This should include the impact of any modifications to the design, which have been implemented during the construction stage. 23

IAEA Operation Any significant differences between the actual and predicted performance of the facility or activity should be identified and the reasons investigated. All discrepancies should be justified. If there are safety implications, then a re-examination of the related structures, systems and components important to safety should be carried out. 24

IAEA Operation (cont.) The safety case should update information about the management system with particular emphasis on: Organization and procedures that are in place to assure the safety of operations, Record keeping and tracking system covering data, information and the records of decision, That there is sufficient expertise to operate the facility or activity, Interdependencies. 25

IAEA Operation (cont.) Periodic review should be mandatory at periods determined by the regulatory body; Periodic safety reviews may also be required to justify: Life extension of the facility beyond its original design life, Changes in the ownership or management of a facility, Changes in regulations. 26

IAEA Operation (cont.) The aim of the operational safety case is to justify that the facility can be operated safely for a specific period and can then be safely decommissioned. 27

IAEA SPECIFIC ISSUES: - Evolution of the safety case - Graded approach - Defense in depth - Reliability - Expected lifetime of the facility - Long term storage 28

IAEA Introduction Predisposal waste management includes a wide range of facilities or activities, and characteristics of waste processed, which may pose different degrees of hazard and risk; A graded approach to safety assessment should be used, therefore, which recognizes these different levels of hazard and risk. 29

IAEA Graded approach The scope and level of detail of the safety assessment carried out for any particular facility or activity shall be consistent with the magnitude of the possible radiation risks arising from the facility or activity. It could be expected that greater levels of effort should be put into developing safety cases and safety assessments for a large treatment facility than for a small low-level waste storage facility. 30

IAEA Graded approach: Criteria When undertaking a safety assessment, it is necessary to ensure that: Assessment is based on an appropriate level of understanding of the system and its potential behavior, All safety relevant issues are considered and addressed. The degree of detail required in the safety assessments should be determined by first undertaking relatively simple safety assessments that provide an indication of the potential levels of risk. 31

IAEA Graded approach: Criteria (cont.) Various criteria may be used to help in determining the level of understanding that should be expected for a particular facility or activity; Criteria may be: Safety significance, Complexity, Maturity. 32

IAEA Safety significance Safety significance will usually be the most important criterion; Use of this criterion will necessitate consideration of facility or activity performance in terms of: Releases from normal operation, Potential consequences of anticipated operational occurrences and reasonably foreseeable accidents, Potential significance of low probability events with potentially high consequences. 33

IAEA SPECIFIC ISSUES: - Evolution of the safety case - Graded approach - Defense in depth - Reliability - Expected lifetime of the facility - Long term storage 34

IAEA Defense in depth: Concept The defense in depth concept is centered on several levels of protection including successive barriers and other safety functions preventing the release of radioactive material to the environment and minimizing exposures; The concept includes: Maintaining the effectiveness of the barriers by averting damage to the facility and to the barriers themselves; Further measures to protect the public and the environment in case of unexpected malfunction or degradation of barriers. 35

IAEA SUMMARY AND CONCLUSIONS 36

IAEA Summary During facility lifecycle, the safety case will evolve in several stages, starting from concept development and siting, and ending with shutdown and decommissioning; Different stage will put its specific to the context and outputs of the safety case; Predisposal waste management includes a wide range of facilities or activities, and characteristics of waste processed, which may pose different degrees of hazard and risk; Criteria such as safety significance, complexity and maturity may help to recognize different levels of hazard and risk, and assists in application of the graded approach; 37

IAEA Summary Consideration should be given to combining physical barriers and administrative controls into an effective defense in depth strategy; The most important safety functions are usually fulfilled by means of passive barriers. The level of reliability demanded of any component will depend upon the safety demands made of the component and the defense offered by other components in the system; The expected lifetime of the facility needs to be sufficient for the activity being undertaken and may need to include some contingency; 38

IAEA Summary Special consideration needs to be given to long term storage; This includes issues on the storage time frame, importance of passive safety features, waste retrievability and management systems. 39

IAEA 40 Thank you for your attention!