March 3-4, 2008/ARR 1 Power Management Technical Working Group: TRL for Heat and Particle Flux Handling A. René Raffray University of California, San Diego ARIES Meeting UCSD, La Jolla, CA March 3-4, 2008

March 3-4, 2008/ARR 2 Heat Flux and Particle Flux Handling 1.Scope Consequences of particle flux and heat flux on plasma facing components Accommodation of threats by PFC’s while providing required lifetime at operating conditions compatible with reasonable power cycle efficiency Accommodation of neutron volumetric heat deposition not considered here (gray area with “High Temperature Operation and Power Conversion”) 2.Key science challenges (theory + experiments) -Material thermomechanics at high temperature (armor+structure) -Thermal-hydraulic behavior at power producing conditions -Armor mass loss mechanisms (overlap with “Power Core Lifetime”) -Ion implantation -Tritium permeation (overlap with “T inventory & Control”)? 3.Key facilities High heat flux test facility (e.g. e-beam) Plasma particle flux test facility (PISCES-like, others) Integrated heat flux + plasma test facility Fusion test facility (ITER, CTF) DEMO

March 3-4, 2008/ARR 3 Technical Readiness Level for Heat Flux and Particle Flux Handling

March 3-4, 2008/ARR 4

5 More Detailed Definition of TRL’s for Heat Flux and Particle Flux Handling TRL 1. The basic principles guiding the heat and particle flux handling in a fusion power plant are formulated. The magnitude, time scale and footprint of the anticipated fluxes are characterized and bounded, through system studies. The likely effects on the PFC behavior, including heat and mass transfer mechanisms, are hypothesized and their relative importance estimated through system studies. TRL 2. Possible PFC concepts that could handle the anticipated heat and particle flux conditions are explored, including armor, structural material and coolant choices and possible integrated configurations. The critical properties and constraints affecting the design are characterized. TRL 3. Experimental data from coupon-scale heat flux and particle flux experiments are obtained for candidate armor materials to demonstrate their potential ability to accommodate the anticipated plasma facing conditions. Models are developed to characterize and understand the governing heat transfer and mass transfer processes and to help in extrapolating the small- scale test results to prototypical conditions.

March 3-4, 2008/ARR 6 More Detailed Definition of TRL’s for Heat Flux and Particle Flux Handling TRL 4. Bench-scale submodule testing of PFC concept is performed in a laboratory environment simulating heat fluxes or particle fluxes at prototypical levels over long times (the heat and particle fluxes need not be integrated). The submodule should represent a unit cell of the PFC concept including armor, structural material and coolant. The testing time should be of the order of the expected operating lifetime. The operating conditions (temperature, pressure, flow rates,..) should cover the expected prototypical conditions. TRL 5. Integrated module testing of the PFC concept is performed in an environment simulating the integration of heat fluxes and particle fluxes at prototypical levels over long times. The module should include the integration of a number of unit cells of the PFC concept. The testing time should be of the order of the expected operating lifetime. The operating conditions (temperature, pressure, flow rates,..) should cover the expected prototypical conditions. TRL 6. Integrated testing of PFC concept subsystem is performed in an environment simulating the integration of heat fluxes and particle fluxes at prototypical levels over long times. The subsystem should include an integrated unit of modules in a prototypical arrangement, including the integration of the subsystem to any cooled structural support. The testing time should be of the order of the expected operating lifetime. The operating conditions (temperature, pressure, flow rates,..) should cover the expected prototypical conditions.

March 3-4, 2008/ARR 7 More Detailed Definition of TRL’s for Heat Flux and Particle Flux Handling TRL 7. The PFC system is tested in a fusion machine and its operation demonstrated under prototypical conditions. The test unit should represent the complete PFC system as expected in a power plant. TRL 8. The PFC system is tested in a fusion machine and its operation demonstrated under prototypical conditions over long operating times. The test unit should represent the complete PFC system as expected in a power plant. The testing time should be of the order of the expected operating lifetime. Complementary qualification testing of the system in a fusion-like environment through a series of post end-of-life tests is performed to qualify the component. TRL 9. The PFC system is fully incorporated in a Demonstration fusion reactor and its performance demonstrated to end-of-life under fully prototypical conditions in a fully integrated mode with all system interfaces.