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Fusion Science and Technology
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.”
M. G. Shats, J. H. Harris, J. B. Wilgen, L. R. Baylor, J. D. Bell, C. H. Ma, M. Murakami, T. S. Bigelow, G. L. Bell, R. J. Colchin, R. A. Dory, J. L. Dunlap, G. R. Dyer, A. C. England, G. R. Hanson, D. P. Hutchinson, R. C. Isler, T. C. Jernigan, R. A. Langley, D. K. Lee, J. F. Lyon, A. L. Quails, D. A. Rasmussen, R. K. Richards, M. J. Saltmarsh, J. E. Simpkins, K. L. Vander Sluis, K. M. Likin, K. A Sarksyan, S. C. Aceto, J. J. Zielinski
Fusion Science and Technology | Volume 27 | Number 3 | April 1995 | Pages 481-484
Confinement and Transport Studies | doi.org/10.13182/FST95-A11947133
Articles are hosted by Taylor and Francis Online.
Density fluctuations in low-collisionality, low-beta (β ~ 0.1%), currentless plasmas produced with electron cyclotron heating (ECH) in the Advanced Toroidal Facility (ATF) torsatron have been studied using a 2-mm microwave scattering diagnostic. Pulsed gas puffing is used to produce transient steepening of the density profile from its typically flat shape; this leads to growth in the density fluctuations when the temperature and density gradients both point in the same direction in the confinement region. The wave number spectra of the fluctuations that appear during this perturbation have a maximum at higher k⊥ρ, (~1) than is typically seen in tokamaks. The in-out asymmetry of the fluctuations along the major radius correlates with the distribution of confined trapped particles expected for the ATF magnetic field geometry. During the perturbation, the relative level of the density fluctuations in the confinement region (integrated over normalized minor radii p from 0.5 to 0.85) increases from ñ/n ~ 1% when the density profile is flat to ñ/n ~ 3% when the density profile is steepened. These observations are in qualitative agreement with theoretical expectations for helical dissipative trapped-electron modes (DTEMs), which are drift-wave instabilities associated with particle trapping in the helical stellarator field.