1. 1 Summary Slides on FNST Top-level Technical Issues and on FNSF objectives, requirements and R&D Presented at FNST Meeting, UCLA August 18-20, 2009 Mohamed Abdou

2. 2 1. D-T fuel cycle tritium self-sufficiency in a practical system 2. Tritium extraction, inventory, and control in solid/liquid breeders and blanket, PFC, fuel processing and heat extraction systems 3. MHD Thermofluid phenomena and impact on transport processes in electrically-conducting liquid coolants/breeders 4. Structural materials performance and mechanical integrity under the effect of radiation and thermo-mechanical loadings in blanket and PFC 5.Functional materials property changes and performance under irradiation and high temperature and stress gradients ( including ceramic breeders, beryllium multipliers, flow channel inserts, electric and thermal insulators, tritium permeation and corrosion barriers, etc. ) 6.Fabrication and joining of structural and functional materials 7. Fluid-materials interactions including interfacial phenomena, chemistry, compatibility, surface erosion and corrosion 8. Interactions between plasma operation and blanket and PFC materials systems, including PMI, electromagnetic coupling, and off-normal events 9. Identification and characterization of synergistic phenomena and failure modes, effects, and rates in blankets and PFC’s in the fusion environment 10. System configuration and Remote maintenance with acceptable machine down time Summary of Top- Level Technical Issues for Fusion Nuclear Science and Technology (FNST)

3. 3 1. D-T fuel cycle tritium self-sufficiency in a practical system Abdou 2. Tritium extraction, inventory, and control in solid/liquid breeders and blanket, PFC, fuel processing and heat extraction systems Morley 3. MHD Thermofluid phenomena and impact on transport processes in electrically-conducting liquid coolants/breeders Smolentsev 4. Structural materials performance and mechanical integrity under the effect of radiation and thermo-mechanical loadings in blanket and PFC Sharafat 5.Functional materials property changes and performance under irradiation and high temperature and stress gradients 6.Fabrication and joining of structural and functional materials Sharafat 7. Fluid-materials interactions including interfacial phenomena, chemistry, compatibility, surface erosion and corrosionSmolentsev 8. Interactions between plasma operation and blanket and PFC materials systems, including ……. Morley 9. Identification and characterization of synergistic phenomena and failure modes, effects, and rates in ………………. Ying 10. System configuration and Remote maintenance with acceptable machine down time Ying Highlights of the Top- Level Technical Issues for FNST Will be given this afternoon by :

4. 4 Fusion Nuclear Science and Technology (FNST) FNST includes the scientific issues and technical disciplines as well as materials, engineering and development of fusion nuclear components: From the edge of Plasma to TF Coils: 1. Blanket Components (includ. FW) 2. Plasma Interactive and High Heat Flux Components (divertor, limiter, rf/PFC elements) 3. Vacuum Vessel & Shield Components 4. Tritium Processing Systems 5. Remote Maintenance Components 6. Heat Transport and Power Conversion Systems Other Systems / Components affected by the Nuclear Environment: Fusion Power & Fuel Cycle Technology

5. 5 Theory/Modeling/Data Basic Separate Effects Multiple Interactions Partially Integrated Property Measurement Phenomena Exploration Non-Fusion Facilities Science-Based Framework for FNST R&D involves modeling and experiments in non-fusion and fusion facilities Design Codes Component Fusion Env. Exploration Concept Screening Performance Verification Design Verification & Reliability Data Testing in Fusion Facilities (non neutron test stands, fission reactors and accelerator-based neutron sources) Experiments in non-fusion facilities are essential and are prerequisites to testing in fusion facilities Testing in Fusion Facilities is NECESSARY to uncover new phenomena, validate the science, establish engineering feasibility, and develop components

6. 6 R&D Tasks to Be Accomplished Prior to Demo 1) Plasma 2) Plasma Support Systems 3) Fusion Nuclear Science and Technology (FNST) 4) Systems Integration - Confinement/Burn - Disruption Control - Current Drive/Steady State - Edge Control - Superconducting Magnets- Heating- Fueling -Blanket - Divertors - rf (PFC elements) - VV & Shield Where Will These Tasks be Done?! Burning Plasma Facility (ITER) and other plasma devices will address 1, 2, & much of 4 The BIG GAP is Fusion Nuclear Science and Technology (FNST) Where, How, and When will it be done?

7. 7 Initial exploration of coupled phenomena in a fusion environment Uncover unexpected synergistic effects, Calibrate non-fusion tests Impact of rapid property changes in early life Integrated environmental data for model improvement and simulation benchmarking Develop experimental techniques and test instrumentation Screen and narrow the many material combinations, design choices, and blanket design concepts Uncover unexpected synergistic effects coupled to radiation interactions in materials, interfaces, and configurations Verify performance beyond beginning of life and until changes in properties become small (changes are substantial up to ~ 1-2 MW · y/m 2 ) Initial data on failure modes & effects Establish engineering feasibility of blankets (satisfy basic functions & performance, up to 10 to 20 % of lifetime) Select 2 or 3 concepts for further development Identify lifetime limiting failure modes and effects based on full environment coupled interactions Failure rate data: Develop a data base sufficient to predict mean-time- between-failure with confidence Iterative design / test / fail / analyze / improve programs aimed at reliability growth and safety Obtain data to predict mean-time-to- replace (MTTR) for both planned outage and random failure Develop a database to predict overall availability of FNT components in DEMO Stages of FNST Testing in Fusion Facilities Sub-Modules/Modules Stage I Fusion “Break-in” & Scientific Exploration Stage IIStage III Engineering Feasibility & Performance Verification Component Engineering Development & Reliability Growth Modules Modules/Sectors DEMODEMO 1 - 3 MW-y/m 2 > 4 - 6 MW-y/m 2 0.5 MW/m 2, burn > 200 s 1-2 MW/m 2 steady state or long pulse COT ~ 1-2 weeks 1-2 MW/m 2 steady state or long burn COT ~ 1-2 weeks 0.1 – 0.3 MW-y/m 2

8. 8 MISSION FNSF (CTF/VNS) MISSION The mission of FNSF is to test, develop, and qualify Fusion Nuclear Components (fusion power and fuel cycle technologies) in prototypical fusion power conditions. The FNSF facility will provide the necessary integrated testing environment of high neutron and surface fluxes, steady state plasma (or long pulse with short dwell time), electromagnetic fields, large test area and volume, and high “cumulative" neutron fluence. The testing program on FNSF and the FNSF device operation will demonstrate the engineering feasibility, provide data on reliability / maintainability / availability, and enable a “reliability growth” development program sufficient to design, construct, and operate blankets, plasma facing and other FNST components for DEMO. FNSF will solve the serious tritium supply problem for fusion development by a- not consuming large amounts of tritium, b- breeding much of its own tritium, c- accumulating excess tritium (in later years) sufficient to provide the tritium inventory required for startup of DEMO, and d- developing the blanket technology necessary to ensure DEMO tritium self sufficiency

9. 9 Fusion environment is unique and complex: multi-component fields with gradients R BpBp BTBT 0 B Inner Edge Outer Edge Plasma Width Neutron and Gamma fluxes Particle fluxes Heat sources (magnitude and gradient) – Surface (from plasma radiation) – Bulk (from neutrons and gammas) Magnetic Field (3-component) – Steady field – Time varying field With gradients in magnitude and direction Multi-function blanket in multi-component field environment leads to: -Multi-Physics, Multi-Scale Phenomena Rich Science to Study - Synergistic effects that cannot be anticipated from simulations & separate effects tests. Modeling and Experiments are challenging (for ST)

10. 10 The most Challenging Phase of Fusion Development still lies ahead – the development of Fusion Nuclear Science and Technology is the Biggest GAP  Achieving high availability is a challenge for Magnetic Fusion Concepts Device has many components Blanket/PFC are located inside the vacuum vessel  Tritium available for fusion development other than ITER is rapidly diminishing Any DT fusion development facility other than ITER must breed its own tritium, making the Breeding Blanket an Enabling Technology Where will the initial inventory for the world DEMOs (~ 10 kg per DEMO) come from? How many DEMOs in the world?  FNSF is a Required and Exciting Step in Fusion Development. (Building FNF in the US, parallel to ITER, is a most important element in restoring US leadership in the world fusion program.) Each country aspiring to build a DEMO will most likely need to build its own FNF — not only to have verified breeding blanket technology, but also to generate the initial tritium inventory required for the startup of DEMO.  We must start now the R&D modeling and testing in non-fusion facilities for US Selected Blanket Concepts. This R&D is needed prior to testing in ANY fusion facility. What is needed to qualify a test module for ITER is the same as that required for a test module, or a base breeding blanket, on FNSF. Such R&D takes > 10 years.