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Nuclear Energy Conference & Expo (NECX)
September 8–11, 2025
Atlanta, GA|Atlanta Marriott Marquis
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Fusion Science and Technology
August 2025
Latest News
DOE fast tracks test reactor projects: What to know
The Department of Energy today unveiled 10 companies racing to bring test reactors online by next year to meet Trump's deadline of next Independance Day, leveraging a new DOE pathway that allows reactor authorization outside national labs. As first outlined in one of the four executive orders on nuclear energy released by President Trump on May 23 and in the request for applications for the Reactor Pilot Program released June 18, the companies must use their own money and sites—and DOE authorization—to get reactors operating. What they won’t need is a Nuclear Regulatory Commission license.
H. Takenaga, H. Kubo, S. Higashijima, N. Asakura, T. Sugie, S. Konoshima, K. Shimizu, T. Nakano, K. Itami, A. Sakasai, H. Tamai, S. Sakurai, Y. Miura, N. Hosogane, M. Shimada
Fusion Science and Technology | Volume 42 | Number 2 | September-November 2002 | Pages 327-356
Technical Paper | doi.org/10.13182/FST02-A232
Articles are hosted by Taylor and Francis Online.
Heat and particle control has been studied under the reactor-relevant high-power heating in the large tokamak of JT-60U with an open divertor and progressively a W-shaped pumped divertor. Heat and particle control is crucial for reduction in heat load onto the divertor plates, control of density in the main plasma, effective exhaust of helium ash, and reduction in impurity contamination. For the reduction of heat load, radiative divertor concept was developed based on understanding of heat and particle transport in scrape-off layer and divertor plasmas, which contributed to establishment of divertor concept in ITER. With argon injection, the total radiation loss power reached up to 80% of the net heating power with high confinement of HHy2 ~ 1, where HHy2 is a confinement enhancement factor over the IPB98(y,2) ELMy H-mode scaling, at high density of 80% of the Greenwald density in the ELMy H-mode plasma. For the density control, the dependence of particle confinement on plasma parameters was systematically studied with two confinement times for center- and edge-fueled particles, which enabled discussion of density controllability. Core fueling using a high-field-side pellet injection extended the operation range of high confinement (HHy2 ~ 1) from 60 to 70% of the Greenwald density in the high p ELMy H-mode plasma. Efficient helium ash exhaust of He*/E = 2.8 was demonstrated in the ELMy H-mode plasma with the pumping from the private flux region, which is the same pumping geometry as that in ITER design. Reduction in Zeff by puff-and-pump scheme was demonstrated, and chemical sputtering yields were estimated with the consideration of not only methane but also heavier hydrocarbons. Their sputtering yields showed strong dependence on the wall temperature and weak dependence on the particle flux. The measured profiles of C II and C IV line intensities were well reproduced by the Monte Carlo impurity transport simulation code (IMPMC code). The estimation of sputtering yields and development of the simulation code enabled reliable predictions for impurity behavior in a fusion reactor.