ANS is committed to advancing, fostering, and promoting the development and application of nuclear sciences and technologies to benefit society.
Explore the many uses for nuclear science and its impact on energy, the environment, healthcare, food, and more.
Division Spotlight
Nuclear Criticality Safety
NCSD provides communication among nuclear criticality safety professionals through the development of standards, the evolution of training methods and materials, the presentation of technical data and procedures, and the creation of specialty publications. In these ways, the division furthers the exchange of technical information on nuclear criticality safety with the ultimate goal of promoting the safe handling of fissionable materials outside reactors.
Meeting Spotlight
Utility Working Conference and Vendor Technology Expo (UWC 2024)
August 4–7, 2024
Marco Island, FL|JW Marriott Marco Island
Standards Program
The Standards Committee is responsible for the development and maintenance of voluntary consensus standards that address the design, analysis, and operation of components, systems, and facilities related to the application of nuclear science and technology. Find out What’s New, check out the Standards Store, or Get Involved today!
Latest Magazine Issues
Jul 2024
Jan 2024
Latest Journal Issues
Nuclear Science and Engineering
August 2024
Nuclear Technology
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.”
Mitsushi Abe,* Akira Doi, Kazuhiro Takeuchi, Michio Otsuka, Shigeyoshi Kinoshita, Satoshi Nishio, Masayoshi Sugihara, Ryuji Yoshino
Fusion Science and Technology | Volume 32 | Number 4 | December 1997 | Pages 545-560
Technical Paper | Special Section: Plasma Control Issues for Tokamaks / Plasma Engineering | doi.org/10.13182/FST97-A19904
Articles are hosted by Taylor and Francis Online.
Tokamak startup characteristics with a low-loop-resistance vacuum vessel were studied in the HT-2, which is a tokamak with a major radius of 41 cm, a minor radius of 11 cm, and a plasma current of IP < 55 kA. Precise poloidal magnetic field control is possible using independently and multivariably controlled poloidal field coils. The vacuum vessel loop resistance Ωv was originally high (14 mΩ), but it was modified to be able to operate with a low value (0.3 mΩ). The latter is approximately one-tenth of the plasma resistance (2.2 mΩ) at breakdown (Te = 10 eV). With Ωv = 0.3 mΩ, the magnetic field induced by the eddy current is large, and it disturbs the breakdown. However, careful compensation of the poloidal field makes a well-controlled ohmic startup possible. Other results are as follows: very little difference in the consumed ohmically heated flux was observed between discharges with low and high loop resistances; well-controlled startup was obtained with a very low loop voltage of 2.5 V, which corresponded to the 1 V/m electric field; the breakdown condition is well described by the electron avalanche model. It is concluded that low Ωv is applicable to a tokamak design, as long as the poloidal magnetic field is well controlled even during the breakdown phase.