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Latest News
Vogtle-3 shuts down for valve issue
One of the new Vogtle units in Georgia was shut down unexpectedly on Monday last week for a valve issue that has since been investigated and repaired. According to multiple local news outlets, Georgia Power reported on July 17 that Unit 3 was back in service.
Southern Company spokesperson Jacob Hawkins confirmed that Vogtle-3 went off line at 9:25 p.m. local time on July 8 “due to lowering water levels in the steam generators caused by a valve issue on one of the three main feedwater pumps.”
S. C. Chiu, V. S. Chan
Fusion Science and Technology | Volume 18 | Number 4 | December 1990 | Pages 591-596
Alpha Particles in Fusion Research | doi.org/10.13182/FST90-A29251
Articles are hosted by Taylor and Francis Online.
Fast-wave current drive presents a promising scheme for steady-state operation of reactor tokamaks. This scheme is being studied for application in the International Thermonuclear Experimental Reactor (ITER), the Joint European Torus (JET), and the Doublet III-D reactor (DIII-D). There are two regimes that appear to be promising, the low-frequency range 0 < ω < 2ΩD and the lower hybrid frequency range ΩD ≪ ω < ωLH. In the latter scheme, the wavelength of the fast wave becomes much shorter than the alpha-particle gyroradius and alpha-particle absorption can become significant. An analytic formula for alpha-particle absorption of fast waves for the standard slowing down distribution has been derived and compared with electron absorption at ITER parameters. It has been found that at TD > 30 keV and ne ∼ 1014 cm−3, the alpha-particle absorption is large and can greatly decrease the current drive efficiency. However, without sacrificing the fusion reactivity rate, by increasing the density and decreasing the temperature 15 keV < TD < 25 keV, the alpha-particle absorption can become small at a sufficiently high frequency. It is suggested that a simulation of the alpha-particle absorption effect on fast-wave current drive can be made in DIII-D by using a lower frequency source (∼30 MHz) to create a minority tail and a high-frequency source (200 MHz) to drive the current. Results of minority absorption are presented. Effects that can improve current drive efficiency are discussed.