page 1 of 11 Progress developing an evaluation methodology for fusion R&D ARIES Project Meeting March 4, 2008 M. S. Tillack

page 2 of 11 We have adopted readiness levels as the basis for our evaluation methodology TRL CategoryGeneric Description 1 Concept Development Basic principles observed and formulated. 2 Technology concepts and/or applications formulated. 3 Analytical and experimental demonstration of critical function and/or proof of concept. 4 Proof of Principle Component and/or bench-scale validation in a laboratory environment. 5 Component and/or breadboard validation in a relevant environment. 6 System/subsystem model or prototype demonstration in relevant environment. 7 Proof of Performance System prototype demonstration in an operational environment. 8 Actual system completed and qualified through test and demonstration. 9 Actual system proven through successful mission operations.

page 3 of 11 GAO encouraged DOE and other government agencies to use TRL’s ( a direct quote ), to… “Provide a common language among the technology developers, engineers who will adopt/use the technology, and other stakeholders; Improve stakeholder communication regarding technology develop- ment – a by-product of the discussion among stakeholders that is needed to negotiate a TRL value; Reveal the gap between a technology’s current readiness level and the readiness level needed for successful inclusion in the intended product; Identify at-risk technologies that need increased management attention or additional resources for technology development to initiate risk-reduction measures; and Increase transparency of critical decisions by identifying key technologies that have been demonstrated to work or by highlighting still immature or unproven technologies that might result in high project risk”

page 4 of 11 How can we apply this to fusion energy? 1.Use criteria from utility advisory committee ( and not physical components ) to derive issues 2.Relate the issues criteria to fusion-specific, design independent technical and R&D needs 3.Define “Technical Readiness Levels” for the key issues and R&D needs 4.Define the end goal (design or facility) in enough detail to evaluate progress 5.Evaluate status, gaps, R&D facilities and pathways 1.Use criteria from utility advisory committee ( and not physical components ) to derive issues 2.Relate the issues criteria to fusion-specific, design independent technical and R&D needs 3.Define “Technical Readiness Levels” for the key issues and R&D needs 4.Define the end goal (design or facility) in enough detail to evaluate progress 5.Evaluate status, gaps, R&D facilities and pathways

page 5 of 11 1) Utility Advisory Committee “Criteria for practical fusion power systems” Have an economically competitive life-cycle cost of electricity Gain public acceptance by having excellent safety and environmental characteristics  No disturbance of public’s day-to-day activities  No local or global atmospheric impact  No need for evacuation plan  No high-level waste  Ease of licensing Operate as a reliable, available, and stable electrical power source  Have operational reliability and high availability  Closed, on-site fuel cycle  High fuel availability  Capable of partial load operation  Available in a range of unit sizes J. Fusion Energy 13 (2/3) 1994.

page 6 of 11 2) The criteria for attractive fusion suggest three categories of technology readiness 1.Economic Power Production (Tillack) a.Control of plasma power flows b.Heat and particle flux handling c.High temperature operation and power conversion d.Power core fabrication e.Power core lifetime 2.Safety and Environmental Attractiveness (Steiner) a.Tritium inventory and control b.Activation product inventory and control c.Waste management 3.Reliable Plant Operations (Waganer) a.Plasma diagnosis and control b.Plant integrated control c.Fuel cycle control d.Maintenance 12 top-level issues

page 7 of 11 The intent is to be comprehensive based on functions rather than physical elements Power flows 1.Economic Power Production a.Control of plasma power flows b.Heat and particle flux handling c.High temperature operation and power conversion d.Power core fabrication e.Power core lifetime Power deposition Power conversion

page 8 of 11 Generic DescriptionFusion-specific Description 1 Basic principles observed and formulated. System studies define tradeoffs and requirements on temperature, effects of temperature defined: chemistry, mechanical properties, stresses. 2 Technology concepts and/or applications formulated. Materials, coolants, cooling systems and power conversion options explored, critical properties and compatibilities defined. 3 Analytical and experimental demonstration of critical function and/or proof of concept. Data in static capsule tests and convection loops, modeling of transport phenomena, high-temperature mechanical properties measured. 4 Component and/or bench-scale validation in a laboratory environment. Loop operation at prototypical temperatures with prototypical materials for long times. Thermomechanical analysis and tests on in-vessel elements (e.g., first wall). 5 Component and/or breadboard validation in a relevant environment. Forced convection loop with prototypical materials, temperatures and gradients for long exposures. 6 System/subsystem model or prototype demonstration in relevant environment. Forced convection loop with prototypical materials, temperatures and gradients for long exposures integrating full power conversion systems. 7 System prototype demonstration in an operational environment. Prototype power conversion system demonstration with artificial heat source. 8 Actual system completed and qualified through test and demonstration. Power conversion system demonstration with fusion heat source. 9 Actual system proven through successful mission operations. Power conversion systems operated to end-of-life in fusion reactor with prototypical conditions and subsystems. Generic DescriptionFusion-specific Description 1 Basic principles observed and formulated. System studies define tradeoffs and requirements on temperature, effects of temperature defined: chemistry, mechanical properties, stresses. 2 Technology concepts and/or applications formulated. Materials, coolants, cooling systems and power conversion options explored, critical properties and compatibilities defined. 3 Analytical and experimental demonstration of critical function and/or proof of concept. Data in static capsule tests and convection loops, modeling of transport phenomena, high-temperature mechanical properties measured. 4 Component and/or bench-scale validation in a laboratory environment. Loop operation at prototypical temperatures with prototypical materials for long times. Thermomechanical analysis and tests on in-vessel elements (e.g., first wall). 5 Component and/or breadboard validation in a relevant environment. Forced convection loop with prototypical materials, temperatures and gradients for long exposures. 6 System/subsystem model or prototype demonstration in relevant environment. Forced convection loop with prototypical materials, temperatures and gradients for long exposures integrating full power conversion systems. 7 System prototype demonstration in an operational environment. Prototype power conversion system demonstration with artificial heat source. 8 Actual system completed and qualified through test and demonstration. Power conversion system demonstration with fusion heat source. 9 Actual system proven through successful mission operations. Power conversion systems operated to end-of-life in fusion reactor with prototypical conditions and subsystems. 3) Example TRL table: 1c. High temperature

page 9 of 11 4) An evaluation of readiness requires identification of an end goal For the sake of illustration, we are considering Demo’s based on mid-term and long-term ARIES power plant design concepts, e.g.  Diverted high confinement mode tokamak burning plasma  Low-temperature or high-temperature superconducting magnets  He-cooled W or PbLi-cooled SiC f /SiC divertors  Dual-cooled He/PbLi/ferritic steel blankets or single-coolant PbLi with SiC f /SiC  700˚C or 1100˚C outlet temperature with Brayton power cycle

page 10 of 11 5) Example evaluation: High temperature operation and power conversion Concept development is largely completed for DCLL. Limited data on ex-vessel parts of power conversion system ( e.g., HX) For TRL4: Need full loop operation at high temperature in a laboratory environment This is typical of many issues; some are more advanced, but most are stuck at TRL=3 ARIES-AT power conversion TRL is probably at 2. 3 Analytical and experimental demonstration of critical function and/or proof of concept. Data in static capsule tests and convection loops, modeling of transport phenomena, high-temperature mechanical properties measured. 4 Component and/or bench-scale validation in a laboratory environment. Loop operation at prototypical temperatures with prototypical materials for long times. Thermomechanical analysis and tests on in-vessel elements (e.g., first wall).

page 11 of 11 Status of documentation TRL tables have been drafted, to be presented today Report:  Outline, Introduction, Methodology complete  Description of issues nearing completion  Definition of the end goal for the evaluation needs completion  Preparing to run through an example evaluation of the whole system  We should obtain community input on TRL definitions to ensure accuracy and buy-in. Town meeting? PPT progress report to DOE in preparation