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
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!
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.”
Xiaotian Li, Xiaowei Li, Li Shi, Zhengming Zhang, Shuyan He
Nuclear Technology | Volume 174 | Number 1 | April 2011 | Pages 29-40
Technical Paper | One-Phase Fluid Flow | doi.org/10.13182/NT11-A11677
Articles are hosted by Taylor and Francis Online.
The hot gas duct vessel (HGDV) is an important part of the high-temperature reactor-pebble-bed module (HTR-PM) primary loop pressure boundary system. It connects the reactor pressure vessel (RPV) and steam generator pressure vessel. Because the dimensions of the HGDV are smaller than those of the other two vessels, it is often considered the weakest of the three vessels. Therefore, the safety of the HGDV has become one of the most important issues in the design of the HTR-PM. In the present paper, a comprehensive safety analysis of the HGDV in the HTR-PM was performed with an emphasis on the structural features. The designs of the HGDV and the support system of the primary loop pressure boundary are first described. A preliminary safety analysis of the HGDV, including the stress calculations and leak-before-break (LBB) analysis, is then presented. The results show that the stress levels of the HGDV under various accidents have a safety margin of at least 55.3% compared with the stress limits specified in American Society of Mechanical Engineers code, and the stress intensity factor at the postulated flaw is less than the critical stress intensity factor. The LBB analysis indicated that the leak detection system is capable of detecting leaks caused by a postulated through-thickness crack in the HGDV before it reaches the critical size. Although the preliminary analysis has proved the safety of the HGDV, the consequences of a hypothetical HGDV double-ended break accident were also studied to further investigate the safety features of the HTR-PM. Several mitigation measures were employed based on the original design. The structural integrity of the support system, the reactor internals, and the containment under double-ended break accident were evaluated. The results show that these main structures could maintain integrity under the HGDV double-ended break accident.