RE Nygren, Sandia ARIES Town Hall dec UCSD Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy’s National Nuclear Security Administration under contract DE-AC04-94AL General Comments on the Development of Future Fusion PFCs presented by Richard E. Nygren Sandia National Laboratories ARIES High Heat Flux Components Workshop UCSD December 2008

RE Nygren, Sandia ARIES Town Hall dec UCSD Alternates Tokamak/AT Focus: 1. tokamak divertors 2. solid surface PFCs 3. present/ITER-DEMO gap Other:4. alternates 5. liquid surface 6. other fusion pathways BROAD SCOPE

RE Nygren, Sandia ARIES Town Hall dec UCSD Alternates Tokamak/AT ITER divertor TFTR Tore Supra JT-60U DIII-D ASDEX-U JET TEXTOR Non-electric or hybrid applications Wendelstein LHD MAST W7X NSTX BROAD SCOPE C-MOD

RE Nygren, Sandia ARIES Town Hall dec UCSD Tokamak/AT ??? Alternates DEMO-B divertor ITER divertor JT-60U DIII-D ASDEX-U JET TEXTOR DEMO-A divertor Non-electric of hybrid applications Wendelstein LHD MAST W7X NSTX ??? ?? primary alternate C-MOD TFTR Tore Supra ???/CTF BROAD SCOPE

RE Nygren, Sandia ARIES Town Hall dec UCSD Tokamak/AT ??? Alternates DEMO-B divertor ITER divertor TFTR Tore Supra JT-60U DIII-D ASDEX-U JET TEXTOR DEMO-A divertor Non-electric of hybrid applications Wendelstein LHD MAST W7X NSTX ??? ?? primary alternate  ?liquid surface C-MOD  good efficiency  high availability  damage resistance  D/T plasma  solid surface  long pulse ???/CTF BROAD SCOPE

RE Nygren, Sandia ARIES Town Hall dec UCSD Tokamak/AT ??? DEMO-B divertor ITER divertor TFTR Tore Supra JT-60U DIII-D ASDEX-U JET TEXTOR  good efficiency  high availability  damage resistance  D/T plasma  solid surface  long pulse DEMO-A divertor ???/CTF GAP 1 GAP 2 WORKSHOP SCOPE C-MOD  high temperature  high reliability  neutron damage  tritium retention  active cooling

RE Nygren, Sandia ARIES Town Hall dec UCSD  high temperature  high reliability  neutron damage  active cooling  tritium retention GAP 1 GAP 2 WORKSHOP SCOPE

RE Nygren, Sandia ARIES Town Hall dec UCSD GAP X GAP Y physics Tech. tokamak Alt’s.  high temperature  high reliability  neutron damage  active cooling  tritium retention GAP 1 GAP 2 OTHER SCOPE

RE Nygren, Sandia ARIES Town Hall dec UCSD Tokamak/AT ??? DEMO-B divertor ITER divertor TFTR Tore Supra JT-60U DIII-D ASDEX-U JET TEXTOR DEMO-A divertor C-MOD D Maisonnier et al., DEMO and Fusion Power Plant Conceptual Studies in Europe Nucl. Fusion 47 (2007) ISFNT7 K. Lackner SOFT2006 G Federici et al., Key ITER plasma edge and plasma–material interaction issues, JNM 313–316 (2003) PSI J Linke et al., High heat flux testing of plasma facing materials …, JNM 367–370 (2007) V Philipps Plasma–wall interaction, a key issue on the way to a steady state burning fusion device, Phys. Scr. T123 (2006) SOURCES

RE Nygren, Sandia ARIES Town Hall dec UCSD Tokamak/AT ??? DEMO-B divertor ITER divertor TFTR Tore Supra JT-60U DIII-D ASDEX-U JET TEXTOR DEMO-A divertor C-MOD D Maisonnier et al., DEMO and Fusion Power Plant Conceptual Studies in Europe Nucl. Fusion 47 (2007) ISFNT7 K Lackner SOFT2006 G Federici et al., Key ITER plasma edge and plasma–material interaction issues, JNM 313–316 (2003) PSI J Linke et al., High heat flux testing of plasma facing materials …, JNM 367–370 (2007) V Philipps Plasma–wall interaction, a key issue on the way to a steady state burning fusion device, Phys. Scr. T123 (2006) D Whyte The Challenges of Plasma-Surface Interactions for ITER & Beyond, to FESAC Nov 2008 “Greenwald” Panel Report Priorities, Gaps and Opportunities: Towards A Long-Range Strategic Plan For Magnetic Fusion Energy, FESAC Oct 2007 US ReNew Activity Sources

RE Nygren, Sandia ARIES Town Hall dec UCSD “The themes were defined in terms of knowledge required prior to Demo.... based on sound scientific principles and rigorously tested in the laboratory so that the step to a [DEMO].. taken with high confidence of success. “Greenwald” Panel Report

RE Nygren, Sandia ARIES Town Hall dec UCSD Theme B. Taming the Plasma Material Interface:.. knowledge sufficient to design and build, with high confidence, 8. PWI: Understand and control of all processes that couple the plasma and nearby materials. 9. PFCs: Understand.. materials and processes that can be used to design replaceable components that can survive Other.. :.. necessary understanding of plasma interactions, neutron loading and materials to allow design of.. any other diagnostic equipment that can survive... “The themes were defined in terms of knowledge required prior to Demo.... based on sound scientific principles and rigorously tested in the laboratory so that the step to a [DEMO].. taken with high confidence of success. “Greenwald” Panel Report

RE Nygren, Sandia ARIES Town Hall dec UCSD Theme C. Harnessing fusion power: knowledge.. sufficient to design and build, with high confidence, 11. Fuel Cycle:.. manage the flow of tritium Power:.. temperatures sufficiently high for efficient production of electricity or hydrogen. 13. Materials..: Understand the basic materials science for fusion breeding blankets, structural components, plasma diagnostics and heating components.. high neutron fluence Safety: Demonstrate.. safety …. minimize environmental burdens RAMI [Reliability, Availability, Maintainability & Inspectability] : Demonstrate.. productive capacity …. validate economic assumptions …. “Greenwald” Panel Report

RE Nygren, Sandia ARIES Town Hall dec UCSD “Greenwald” Panel Report Finding 6. Evaluation of current and planned programs and summary of gaps ….. The most significant gaps were: G1. …. G2. … G-5. Ability to predict and avoid, or detect and mitigate, off-normal plasma events … G-9. Sufficient understanding of all plasma-wall interactions …. The science underlying the interaction of plasma and material needs to be significantly strengthened to.. G-10. Understanding of the use of low activation solid and liquid materials, joining technologies and cooling strategies... G-11. Understanding.. the complete fuel cycle, particularly.. G-12. An engineering science base.. effective removal of heat... G-13. Understanding.. low activation materials.. G guarantee safety over the plant life cycle - including.. G efficient maintainability of in-vessel components..

RE Nygren, Sandia ARIES Town Hall dec UCSD “Greenwald” Panel Report Recommendation nine major initiatives. I-1... predictive plasma modeling and validation.., I-2. Extensions to ITER AT capabilities.. burning AT regimes I-3. Integrated advanced burning physics …facility.. dedicated I-4. Integrated experiment for PWI/PFCs.. steady-state.. non-DT I-5... disruption-free concepts.. performance extension device.. I-6... advanced computer modeling and laboratory testing.. single-effects science for major fusion technology issues, I-7. Materials qualification facility … (IFMIF). I-8. Component development/testing program … multi-effect issues in critical technology.. breeding/blanket.. first wall I-9. Component qualification facility.. high availability.. heat flux.. neutron fluence.. DT device.... (CTF).

RE Nygren, Sandia ARIES Town Hall dec UCSD D Whyte FESAC Presentation “The Challenges of PSI for ITER & Beyond” Nov 2008  Quiescent energy exhaust  Transient energy exhaust from plasma instabilities  Yearly neutron damage in plasma-facing materials  Max. gross material removal rate with 1% erosion yield  Tritium consumption Issue/Gap tokamaks ITERCTF DEMO now greatly increasing parameters

RE Nygren, Sandia ARIES Town Hall dec UCSD D Whyte FESAC Presentation “The Challenges of PSI for ITER & Beyond” Nov 2008 Lack basic understanding and diagnosis of PSI processes in fusion devices → Uncertain extrapolation Heat exhaust is primary design point for edge materials, since this Is directly related to fusion power density Thermal efficiency.. high ambient T → Fundamentally different Physical Chemistry.. completely unexplored in fusion devices Energy sustainment chasm to CTF & DEMO Rapid dissipation of plasma thermal energy poses major challenges in any Demo consequences of large particulate removal on.. plasma.. & safety Tokamak edge plasmas feature extreme spatial gradients and fluctuations levels,.. erosion prediction & control very difficult It is hard to overstate the importance of ambient temperature for fuel control & T retention 30+ years of experience.. we should be worried/excited.. in particular the effects of having “hot walls”

RE Nygren, Sandia ARIES Town Hall dec UCSD Power plant conceptual studies in Europe D. Maisonnier, D. Campbell, I. Cook, Nucl. Fusion 47 (2007) 1524–1532 [ISFNT7]

RE Nygren, Sandia ARIES Town Hall dec UCSD Power plant conceptual studies in Europe D. Maisonnier, D. Campbell, I. Cook, Nucl. Fusion 47 (2007) 1524–1532 [ISFNT7]

RE Nygren, Sandia ARIES Town Hall dec UCSD Power plant conceptual studies in Europe D. Maisonnier, D. Campbell, I. Cook, Nucl. Fusion 47 (2007) 1524–1532 [ISFNT7]

RE Nygren, Sandia ARIES Town Hall dec UCSD Power plant conceptual studies in Europe D. Maisonnier, D. Campbell, I. Cook, Nucl. Fusion 47 (2007) 1524–1532 [ISFNT7]

RE Nygren, Sandia ARIES Town Hall dec UCSD High temperature He-cooled divertor Need for work on divertor systems

RE Nygren, Sandia ARIES Town Hall dec UCSD In contrast to the rest of the world, a typical preference of US technology people has been  one step to high tech DEMO (reactor prototype)  parallel R&D for materials and blankets (CTF) Whose DEMO?

RE Nygren, Sandia ARIES Town Hall dec UCSD In contrast to the rest of the world, a typical preference of US technology people has been  one step to high tech DEMO (reactor prototype)  parallel R&D for materials and blankets (CTF) Whose DEMO? We have a great challenge to develop the needed technology! ITER activity is a revealing as we observe the need for definition and integration in the design along with the need to move forward in building the machine!

RE Nygren, Sandia ARIES Town Hall dec UCSD J. Linke et al., JNM 367–370 (2007) 1422–1431 We develop PFCs using single effects tests

RE Nygren, Sandia ARIES Town Hall dec UCSD We are good at developing issues We tend to  be optimistic (we are in fusion after all)  enjoy identifying issues and pondering problems  look toward R&D programs Hey – nice issue Congratulations on your new issue. You rAPER Raised some important issues I We love issues

RE Nygren, Sandia ARIES Town Hall dec UCSD GAP 3: Technology Culture tests Material B Material A properties 2 joining properties mockupsprototypes tests prototypes rad effects testing PFC tests PWI tests Material A tokamak coupons lab tests test PFC design validation manufacturing development QA development scale up Vendor qual. manufacturing acceptance components PWI & PFC tests component dev./qual M a t ’l s d e v el o p m e n t We develop one-of-a kind units with anecdotal mockup tests.

RE Nygren, Sandia ARIES Town Hall dec UCSD A realistic “fully funded” technology program, will involve a strong winnowing of choices for PFC materials and divertor technology simply because of the time to develop and prove specific robust components for a DEMO. GAP 3: Technology Culture Configuration d e v e l o p m e n t PWI & PFC tests component dev./qual M a t ’l s d e v e l o p m e n t STs, others Ergodic div. Super-X div.Liquid PFCs

RE Nygren, Sandia ARIES Town Hall dec UCSD PROGRAM & DESIGN INTEGRATION knowledge.. sufficient to design and build, with high confidence, Recall some excerpts from the “Greenwald” panel report: 9. PFCs: Understand.. materials and processes … design replaceable components that can survive.. I-3. Integrated advanced burning physics …facility.. dedicated I-4. Integrated experiment for PWI/PFCs.. steady-state.. non-DT I-8. Component development/testing program … multi-effect issues in critical technology.. breeding/blanket.. first wall

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