Briefing to DOE Office of Science on Fusion Chamber Technology

1. Briefing to DOE Office of Science on Fusion Chamber Technology Prepared on behalf of the US Fusion Chamber Technology Community by Mohamed Abdou ForDr. Ray Orbach, Dr. Anne Davies, andDr. Roberto Peccei Washington, D.C., June 3, 2003

2. Chamber Technology (CT) Research must continue to be a key element of the US Fusion Energy Sciences Program under all scenarios of budget level and research focus • CT Research plays a central role in understanding and defining the key scientific and engineering questions, including direction of plasma physics research, that need to be addressed for fusion to be viewed as viable (“headlights”) • CT research is the key to demonstrating the principles of tritium self-sufficiency, the fundamental premise of fusion as an exhaustible/renewable energy source • Most of the key issues related to practicality and attractiveness (safety, power density, environmental impact, economics) of fusion energy are Chamber-related • Proceeding with ITER makes Chamber Research even more critical. The dominant features of DT burning plasma are: • burning tritium, which must be supplied, • emitting neutrons, which must be safely captured, and • producing high heat fluxes, which must be handled. All of these features require Chamber Technology (first wall, blanket, shield, etc.) that will work reliably in the“neutron-tritium-vacuum- magnetic field” environment Question: What should we do to communicate this message to those who influence fusion policy outside DOE?

3. The importance of Chamber Technology has been clearly recognized by all Fusion Advisory Panels, Planning Studies (e.g. the latest 35-yr plan by FESAC), and all the world fusion programs • This is why the fusion community was shocked (and fusion’s critics delighted) by the FY04 budget submission (terminating Fusion/Chamber Technology). • This situation can undermine the credibility of any fusion research or fusion energy development plans, with devastating consequences to the US Fusion Program’s ability to make progress. FESAC Letter to Dr. Orbach: “However, design and construction of ITER will be extremely demanding with regard to fusion technology. Thus FESAC is puzzled by the elimination in FY2004 budget of funding for fusion technology. This loss will seriously compromise US participation in ITER as well as other burning plasma research activities.” The community appreciates Dr. Orbach’s efforts to move the fusion program forward. We also appreciate the efforts by Dr. A. Davies and OFES staff to rectify the situation. But we need to provide a reassuring message to the U.S. Chamber Community, especially young scientists, and to our international partners.

4. TheChamber serves 2 of the 3 fundamental functions of fusion energy systems: • breed sufficient tritium to assure that the plasma is self-sustained and that fusion is a “renewable” energy source • high-temperature power extraction in a practical, reliable, safe, and economical fusion energy system. CT Research: … • embodies the scientific and engineering research required to understand, develop, design, test, build, and operate safely and reliably the systems that“hold” and surround a burning plasma, • includes all components and functions from the edge of the plasma to the magnets: the first wall, conducting shells, breeding and non-breeding blankets, cooling systems, radiation shielding, vacuum vessel, electric and thermal insulators, tritium permeation barriers, and structure, • provides state-of-the-art predictive capabilities for many technical disciplines required for the fusion program: neutron/photon transport, neutron-material interactions, heat/mass transfer, thermofluid MHD, thermal hydraulics, structural mechanics, thermomechanics, thermo-dynamics, chemistry, radioactivity, decay heat, engineering scaling, reliability methodology, etc, • develops key non-structural materials (e.g. solid breeders, neutron multipliers, insulators, etc.) and material systems interactions, and • is made up of scientists and engineers who must understand and help resolve the competing requirements of high performanceplasma operation with the material, engineering and safety limits of the chamber, as well as the production of sufficient tritium and efficient reliable energy. The kind of training needed to perform research and engineering within this highly constrained fusion system takes many years of education and experience. (Building competence takes decades)

5. Importance of the Chamber Technology Research for ITER and DEMO (selected examples) • All of the chamber component design ideas for ITER came from CT Research activities that started in the 80’s (BCSS, FINESSE, INTOR, IEA, etc.). The ITER Chamber design took the longest of all the major systems because of the need to resolve many scientific and technological challenges. • An understanding of the CT for the step beyond ITER will be crucial in setting relevant physics programs in ITER, in the same way that the CT constraints for ITER were critical in shaping the physics programs of present plasma experiments • CT Research provides training and development of skills for people that go on to lead other programs. (The head of the US Safety Program, the Head of the Vacuum Vessel Division in KSTAR, and the Head of the PFC components in Europe and ITER, for example, were all students trained in the US Chamber Technology Research Program. Many of the fusion leaders and university professors in Europe and Japan were trained as part of the US CT Research Program). • CT research results were a major driver for starting physics research on steady state and disruption-free plasmas • CT methods for predicting radiation fields allowed optimized shield design and a huge size reduction of ITER and power plants; methods for testing materials in fission reactors • CT Research also develops innovative concepts for better plasma performance and more attractive fusion systems. As one example, the concept of liquid walls, originally advanced as a power handling innovation, has also been embraced by plasma physicists as an effective tool to control edge recycling and MHD stability ITER is not only a burning plasma experiment, but also an experiment to test technologies in the fusion environment. CT has a leading role in both the basic device and the blanket testing mission

6. Tritium supply and self-sufficiency are “Go-No Go” issues for fusion energy, as critical NOW as demonstrating a burning plasma • There is no practical external source of tritium for fusion energy development beyond a few months of DT plasma operation in an ITER-like device. It takes tens of “neutron-poor” fission reactors to supply one fusion reactor. • There is NOT a single experiment yet in the fusion environment to show that the DT fusion fuel cycle is viable. Test blanket program in ITER is vital. • ITER has now set the schedule for test blanket modules beginning “day 1” of operation. R&D must start immediately .

7. 30 CANDU Supply w/o Fusion 25 20 Projected Ontario (OPG) Tritium Inventory (kg) 15 1000 MW Fusion 10% Avail, TBR 0.0 10 ITER-FEAT (2004 start) 5 0 1995 2000 2010 2015 2020 2025 2030 2035 2040 2045 2005 Year Powerful DT Burning Plasma Experiments such as ITER Must Breed their own Tritium • Tritium Consumption in Fusion Is HUGE! • 55.8 kg per 1GW.year fusion power • Production & Cost from fission are LIMITED & EXPENSIVE! • CANDU Reactors: 27 kg over 40 years, $30M/kg (current) • Fission reactors: few kg per year, $200M/kg!! (projected cost) World Tritium Supply Exhaustedby 2025 by ITER at 1000MW at 10% Availability or ITER at 500 MW at 20% Availability Conclusion Chamber technology is not just for power reactors. It is essential for continuing burning plasma and fusion research

8. Recent History of US Chamber Technology • The US Chamber Program enthusiastically worked on CDA and EDA phases of ITER, playing critical roles • The Chamber Program suffered a MAJOR Budget cut in 1996. OFES and the community worked very hard to maintain a “bare minimum of critical skills “ (skills that took 30 years to develop) • Over the past few years, CT research focused on developing innovative ideas for the Chamber that could substantially improve the plasma performance and our vision of fusion Now, a New Emphasis is required: As we move forward with joining ITER, the CT community is ready to restructure its activities to best support the new initiatives

9. New Emphasis for Chamber Research with rejoining ITER • Test Blanket Module Program – Restart tritium breeding blanket test module R&D program for ITER reflective of the US priorities on chamber systems. This is critical as the ITER plan calls for testing from day-1 of operation in 2013, and a decision on blanket test modules by 2005 in order to initiate design, fabrication and out-of-pile testing. [US has been the World Leader] • FNT Support for ITER Basic Device–As ITER moves toward construction it will need more accurate predictions in the nuclear area (radiation fields, shielding, tritium, etc.) and chamber technology help to resolve remaining issues in ITER design • Advanced Chamber Configurations–Continued R&D, with emphasis on innovation and underlying science, towards high pay-off chamber options that can most dramatically affect the viability and attractiveness of fusion energy. (e.g. thin liquid walls, advanced materials) • Fundamental Predictive Capabilities– Continue to develop, advance and support computational models, codes, and tools (e.g. thermofluid MHD, neutronics, radioactivity, etc.) needed by other key fusion programs: Safety, Materials, PFC, Advanced Design Studies • FNT Experimental Techniques and Diagnostics – Develop experimental techniques and diagnostics for operation in magneto-nuclear test environments (ITER, CTF, etc.). Evolve technical and programmatic strategies for FNT testing and development.