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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. Summary of Top- Level Technical Issues for Fusion Nuclear Science and Technology (FNST).
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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
Summary of Top- Level Technical Issues for Fusion Nuclear Science and Technology (FNST) • 1. D-T fuel cycle tritiumself-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 • Functional materials property changes and performance under irradiation and high temperature and stress gradients(includingceramic breeders, beryllium multipliers, flow channel inserts, electric and thermal insulators, tritium permeation and corrosion barriers, etc.) • 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 maintenancewith acceptable machinedown time 2
Highlights of the Top- Level Technical Issues for FNST Will be given this afternoon by : • 1. D-T fuel cycle tritiumself-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 • Functional materials property changes and performance under irradiation and high temperature and stress gradients • Fabrication and joining of structural and functional materials Sharafat • 7. Fluid-materials interactions including interfacial phenomena, chemistry, compatibility, surface erosion and corrosion Smolentsev • 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 maintenancewith acceptable machinedown time Ying 3
Fusion Nuclear Science and Technology(FNST) Fusion Power & Fuel Cycle Technology 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 FluxComponents (divertor, limiter, rf/PFC elements) 3. Vacuum Vessel & Shield Components Other Systems / Components affected by the Nuclear Environment: 4. Tritium Processing Systems 5. Remote Maintenance Components 6. Heat Transport and Power Conversion Systems
Science-Based Framework for FNST R&D involves modeling and experiments in non-fusion and fusion facilities Theory/Modeling/Data Design Codes Basic Separate Effects Multiple Interactions Partially Integrated Integrated Component Design Verification & Reliability Data • Fusion Env. Exploration Property Measurement Phenomena Exploration • Concept Screening • Performance Verification Non-Fusion Facilities (non neutron test stands, fission reactors and accelerator-based neutron sources) Testing in Fusion Facilities • 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
R&D Tasks to Be Accomplished Prior to Demo 1) Plasma - Current Drive/Steady State - Confinement/Burn - Edge Control - Disruption Control 2) Plasma Support Systems - Superconducting Magnets - Fueling - Heating 3) Fusion Nuclear Science and Technology (FNST) • Blanket - Divertors - rf (PFC elements) - VV & Shield 4) Systems Integration Where Will These Tasks be Done?! • Burning Plasma Facility (ITER) and other plasma devices will address 1, 2, & much of 4 • TheBIG GAPis Fusion Nuclear Science and Technology (FNST) • Where, How, and When will it be done?
Stages of FNST Testing in Fusion Facilities D E M O Component Engineering Development & Reliability Growth Engineering Feasibility & Performance Verification Fusion “Break-in” & Scientific Exploration Stage I Stage II Stage III 1 - 3 MW-y/m2 > 4 - 6 MW-y/m2 0.1 – 0.3 MW-y/m2 1-2 MW/m2 steady state or long pulse COT ~ 1-2 weeks 1-2 MW/m2 steady state or long burn COT ~ 1-2 weeks 0.5 MW/m2, burn > 200 s Sub-Modules/Modules Modules Modules/Sectors • 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/m2) • 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
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
Fusion environment is unique and complex:multi-component fields with gradients • 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 Plasma Width (for ST) B BT Inner Edge 0 R Outer Edge Bp Multi-function blanket in multi-component field environmentleads to: • Multi-Physics, Multi-Scale PhenomenaRich Science to Study - Synergistic effectsthatcannotbe anticipated from simulations & separate effects tests. Modeling and Experiments are challenging
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.