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Division Spotlight
Isotopes & Radiation
Members are devoted to applying nuclear science and engineering technologies involving isotopes, radiation applications, and associated equipment in scientific research, development, and industrial processes. Their interests lie primarily in education, industrial uses, biology, medicine, and health physics. Division committees include Analytical Applications of Isotopes and Radiation, Biology and Medicine, Radiation Applications, Radiation Sources and Detection, and Thermal Power Sources.
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!
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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.”
Yong Hoon Jeong, Mujid S. Kazimi
Nuclear Technology | Volume 159 | Number 2 | August 2007 | Pages 147-157
Technical Paper | Fuel Cycle and Management | doi.org/10.13182/NT07-A3861
Articles are hosted by Taylor and Francis Online.
The hybrid sulfur cycle (often called the Westinghouse cycle) for decomposing water into hydrogen and oxygen has two steps. The sulfuric acid is decomposed into steam and sulfur trioxide, which is further decomposed into sulfur dioxide and oxygen at high temperature (~1100 K). Hydrogen is produced by electrolysis of a sulfur dioxide and water mixture at low temperature, which also results in the formation of oxygen and sulfuric acid.In this study, separation of decomposed products and internal heat recuperation are examined, and ways to optimize the energy efficiency of the hybrid cycle are explored by varying the electrolyzer acid concentration, decomposer acid concentration, pressure and temperature of the decomposer, and the internal heat recuperation. The analysis is based on currently available experimental data for the electrode potential.A cycle efficiency of 45.3% [lower heating value (LHV)] appears to be achievable at 1100 K (10 bar, 1100 K, and 60 mol% of H2SO4 for the decomposer, 60 wt% of H2SO4 for the electrolyzer). For a maximum temperature of 1200 K, 50.5% (LHV) appears to be the achievable cycle efficiency (10 bar, 1200 K, and 60 mol% of H2SO4 for the decomposer, 60 wt% of H2SO4 for the electrolyzer). Operation under elevated pressures (70 bar or higher) results in loss of cycle efficiencies due to lower yield of the SO2 in the decomposer but minimizes equipment size and possibly capital cost. However, the loss in efficiency as pressure increases is not large at high temperature (1200 K) compared to that at low temperatures (1000 to 1100 K). Therefore, high-pressure operation for minimizing capital investment would be favored only if the high temperature can be accommodated. The major factors that can affect the cycle efficiency are reducing the electrode overpotential and having structural materials that can accommodate operation at high temperature and high acid concentration.