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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.”
R. M. Mayo
Fusion Science and Technology | Volume 30 | Number 3 | December 1996 | Pages 1326-1331
Innovative Approaches to Fusion Energy | doi.org/10.13182/FST96-A11963132
Articles are hosted by Taylor and Francis Online.
As a member of the compact toroidal class of magnetic fusion devices, the spheromak [Nucl. Fusion 19, 489 (1979)] offers substantial advantage as a fusion reactor concept over larger, more complicated, and more costly re-entrant devices like the tokamak. The compact and simply closed geometry affording high energy density, the inherent diverted nature of the magnetic topology, the force free condition μ0j(r) = ƛ(ϕ)B(r) nature of the spheromak equilibrium minimizing external coil requirements and stresses, and the possibility of Ohmic ignition resulting from the majority of confining fields generated by internal plasma currents in the spheromak, are a few of the more prominent advantages that represent substantial improvement over conventional magnetic fusion reactor designs. Further, recent successes in improving confinement parameters (Te ~ 400eV, Ti ~ 1keV, ne ~ 3 × 1014cm-3, B ~ 1T) have renewed the interest in advancing this concept to a proof-of-principle, reactor prototype stage.
Here we extend the initial work by Fowler, et al. [Comments Plasma Phys. Controlled Fusion 16, 91 (1994)] indicating the possibility of Ohmic ignition in spheromaks, to a two fluid model that includes direct ion heating through turbulent Taylor relaxation mechanisms. The contribution to direct ion heating through this non-Ohmic magnetic dissipation, and confinement scaling are quantified through comparison with the latest results from the gun driven Compact Torus eXperiment (CTX) [Phys. Fluids B 2, 1342 (1990)] spheromak. We realize good agreement between experimentally measured plasma parameters and our model predictions. Extrapolation to an ignition class experiment is examined indicating the possibility of reaching these conditions by gun driven Ohmic heating alone, and illustrating the merits of direct ion heating on facilitating approach to ignition. Differences between classical (no direct ion heating) and direct ion heating cases are emphasized. Conservative confinement estimates are used throughout.