Invited Paper IPF-MoA1
Status of Fusion Power

Monday, October 15, 2007, 2:00 pm, Room 602/603

Fusion is an attractive long-term form of nuclear energy. Experiments on magnetically confined plasmas in the 1990's demonstrated not only the ability to confine plasmas with the temperatures required for a fusion reactor but also produced significant fusion power (up to 10.7 MW in the Tokamak Fusion Test Reactor and 16.1 MW in the Joint European Undertaking for <1sec) using deuterium-tritium fuels. This major step, together with results from a worldwide research effort, has provided confidence in the design of the International Thermonuclear Experimental Reactor (ITER) to produce 500MW (thermal) of fusion power for 400 sec. ITER is an international experiment whose partners are the European Union, India, Japan, the People's Republic of China, the Republic of Korea, the Russian Federation and United States. ITER aims to demonstrate the scientific and technical feasibility of fusion power and will be constructed in Cadarache, France. For the first time, the fusion reactions will provide the majority of the heating for the plasma with an energy gain >10. The design of ITER has identified important scientific and technology issues, which are currently being addressed in facilities around the world. However for a fusion demonstration power plant, further progress on the underlying science and technology is required to achieve ~2500 MW (thermal) continuously with a gain >25 in a device whose size is comparable to ITER. This requires addressing issues associated with plasma boundary due to the higher power and plasma stability due to the need to sustain even higher pressure plasmas at the magnetic field of ITER. Furthermore, efficient continuous operation requires minimizing the external power for controlling the plasma. Experiments on the three main approaches to magnetically confining a plasma, the advanced tokamak, the spherical tokamak, and the stellerator, in parallel with the design and construction of ITER, are exploring innovative solutions required for a demonstration power plant. The advanced tokamak relies on active instability control and a combination of external current drive to increase the fusion power and achieve continuous operation. The spherical tokamak achieves higher fusion power at a given size and magnetic field by decreasing the ratio of the plasma major radius to minor radius. The stellarator is passively stable and does not require external power to drive the plasma current continuously. This research is supported by the U.S. Department of Energy under Contract Number DE-AC02-76CH03073.