1. Safety and Environment Overview Harnessing Fusion Power: Panel Members: Phil Sharpe, INL (Panel Chair, Safety Lead) Laila El-Guebaly, U. Wisconsin (Environment Lead) Barry Sullivan, DOE-OFES (Champion) Catherine Fiore, MIT Kofi Korsah, ORNL Jim Marra, SRNL Nermin Uckan, ORNL ReNeWS HFP Theme Workshop, 2-4 March 2009, UCLA

2. Safety and Environment Slide 1 Harnessing Fusion Power FESAC Priorities Panel Report - S&E Considerations “Safety [and Environment]: Demonstrate the safety and environmental potential of fusion power: to preclude the technical need for a public evacuation plan, and to minimize the environmental burdens of radioactive waste, mixed waste, and chemically toxic waste for future generations.” Derived from Fundamentals Safety Principles, manifested in various legal contexts, and is more generally stated as: “Safety Fundamentals establish the principles ensuring protection of workers, the public, and the environment from harmful effects of ionizing radiation and toxic chemical compounds.” [IAEA Safety Standard Series No. SF-1, IAEA, Vienna (2006).]

3. Safety and Environment Slide 2 Harnessing Fusion Power Identified S&E Issues a.Computational tools are needed to analyze the response of a fusion system to an off-normal event or [postulated] accident. b.Understanding and quantifying the fusion source term will be required for licensing activities. c.Qualification of fusion components in the fusion DEMO environment will be required to validate the design and demonstrate safety roles of key components. d.A waste management strategy for fusion must be developed. e.Experience with large scale remote handling will be important prior to DEMO “Safety and Environment are clearly cross-cutting, and this task must be closely coordinated with all science and technology issues.” Motivates close integration of safety and design

4. Safety and Environment Slide 3 Harnessing Fusion Power Prioritization of S&E Issues FESAC Priorities Panel consensus established S&E as a Tier 3 Priority: Tier 3: Solutions foreseen but not yet achieved, moderate extrapolation from current state of knowledge, need for quantitative improvements and substantial development for long term RF launchers and other internal components Plasma modification by auxiliary systems Control Safety and Environment Magnets The Panel also categorizes S&E as an area where the US is presently strongly competitive in international fusion community, yet danger exists of loosing leadership or competitiveness...

5. Safety and Environment Slide 4 Harnessing Fusion Power Gaps Identified in S&E Basis for defining gaps: Imminent control of fusion power plants ensures public protection and is executed by various levels of regulation. Nuclear hazards are controlled by regulatory authorities such as the NRC in the US. Regulatory paradigm is shifting balance from “Worst-case Scenario” analyses toward the “Risk-informed” safety basis, potentially requiring a larger number of analyses in the context of probabilistic safety assessments. In terms of available energies in postulated accidents, fusion is quantifiably less hazardous than fission, thereby application fission-based regulations is overly restrictive. Engineered safety systems are applied in plant design, although level of demonstration is not yet established (even for ITER).

6. Safety and Environment Slide 5 Harnessing Fusion Power Gaps Identified in S&E, cont. Gap: Component Qualification Required to validate plant/DEMO design and functionality of key safety components (e.g. primary confinement boundary such as vacuum vessel and penetrations) and passive features (e.g. blowdown overpressure protection, vault inerting, etc.) Integrated component testing in a high fluence fusion environment is required for demonstration (establish fusion-specific codes and standards) Highly dependent upon detailed design.

7. Safety and Environment Slide 6 Harnessing Fusion Power Gaps Identified in S&E, cont. Gap: Safety Analysis and Source Term Requires computational tools and database of materials response to postulated off-normal of accident conditions Needs for some level of integrated testing in severe conditions, consistent with energy and materials inventory limits (as with ITER, e.g. ICE and EVITA, magnet arcing, dust explosion…) Dependent upon conceptual design specifications for type and quantity of materials, limits for physical processes, general component layout or configuration, and effect of periodic refurbishment (reduces inventories)

8. Safety and Environment Slide 7 Harnessing Fusion Power Gaps Identified in S&E, cont. Gap: Waste Management Use of low activation materials to minimize/eliminate high level waste; yet substantial quantities of low-level waste are anticipated Requires de-tritiation of materials for recycling/re-use strategies Dependence upon conceptual design… insofar as materials, fluences, and maintenance periods are considered

9. Safety and Environment Slide 8 Harnessing Fusion Power FESAC Priorities Panel identifies S&E as an overarching issue separate from yet implicit to any particular topical area or technical realm. Safety issues (and subsequent validation/demonstration requirements) are inherently responsive to design options, hence general initiatives derived from safety considerations are limited until commencing design efforts (for next steps as well as DEMO/power plant). Gaps Identified in S&E, cont. Environmental issues can be addressed with a more generalized approach…

10. Safety and Environment Slide 9 Harnessing Fusion Power Current State of Safety and Environment: ITER is undergoing licensing as an experimental nuclear facility. Three general stages: –Safety Options Report- completed and reviewed by ASN (Autorit é de Sûreté Nucl é aire) in 2002 –Preliminary Safety Report (RPrS), and associated documents- DAC and DARPE lead to construction permit after review and public hearings –Safety File (Final Safety Report - FSR) for operational rules before nuclear start-up leads to operations permit RPrS and FSR utilize computational tools and materials database/validation experiments for safety assessment of reference events (postulated accident scenarios, includes TBM’s). ITER design is of sufficient maturity to allow defensible assessment. A standard framework is needed to ensure consistent safety assessment and appropriate regulatory oversight as designs mature for next-step devices and DEMO/plants.

11. Safety and Environment Slide 10 Harnessing Fusion Power Current State of Safety and Environment, cont.: Waste management options at present - Geologic repository, seabed/ice field disposal, or transmutation… These options are not considered suitable for proving fusion energy as environmentally benign. Alternative, straightforward science-based solutions are needed for regulatory, policy, and public acceptance aspects. Application of suitable Codes and Standards has yet to be settled. Decision by ITER-IO to apply ESPN design code to VV was context- driven (French regulations for fission-based nuclear facility) yet this code is possibly too restrictive. Designs of sufficient maturity, with integration/feedback from safety assessments and integrated component testing, are required to progress fusion codes and standards.

12. Safety and Environment Slide 11 Harnessing Fusion Power Overview of S&E Research Thrusts: S&E research thrusts are broad reaching and reflect the overarching nature of fusion safety and environmental issues. Identified thrusts are generally thematic rather than specifically focused initiatives. 1.Extension of the US Fusion Safety Standard to next-step devices and DEMO plant conceptual designs; lead an effort towards an international fusion safety framework 2.Develop recycle and clearance-based solutions to fusion’s waste stream; refine strategies of de-tritiation of materials 3.Enhance design integration through safety in maturing designs of next-step devices and DEMO/plants 4.Methods for monitoring/removing radioactive materials during DEMO/plant operation Stay tuned for further discussion during the S&E session…