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Division Spotlight
Operations & Power
Members focus on the dissemination of knowledge and information in the area of power reactors with particular application to the production of electric power and process heat. The division sponsors meetings on the coverage of applied nuclear science and engineering as related to power plants, non-power reactors, and other nuclear facilities. It encourages and assists with the dissemination of knowledge pertinent to the safe and efficient operation of nuclear facilities through professional staff development, information exchange, and supporting the generation of viable solutions to current issues.
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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Nuclear Science and Engineering
August 2024
Nuclear Technology
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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.”
Jordi Freixa, Francesc Reventós, Carme Pretel, Lluís Batet
Nuclear Technology | Volume 160 | Number 2 | November 2007 | Pages 205-215
Technical Paper | Thermal Hydraulics | doi.org/10.13182/NT07-A3893
Articles are hosted by Taylor and Francis Online.
Rapid boron dilution transients have shown the need for accurate knowledge of the solute particle distribution in pressurized water reactors (PWRs). Small-break loss-of-coolant accidents (SBLOCAs) enable the formation of low-borated slugs in the loop seals. Low-borated water, if driven to the core, could cause a reactivity excursion. Since online boron concentration measurement is impractical in the primary system of PWR plants and quite difficult in test facilities, best-estimate codes should be seen as the most suitable tools. However, transport of a low-borated slug through the primary system requires accuracy of the methods. Several studies have shown high numerical diffusion introduced by the upwind difference schemes habitually used by system codes. Furthermore, most of the boron tracking models implemented in system codes at present do not consider physical diffusion. Nevertheless, to introduce physical diffusion, it is necessary to considerably reduce numerical diffusion. The implicit Godunov scheme, which is available in RELAP5, has proved its capability in almost eradicating numerical diffusion. However, the formulated equation in RELAP5 does not deal with physical diffusion. A new tracking model for the solute field is presented, along with results of its implementation in the RELAP5 code. To evaluate the new model, a numerical test has been performed that demonstrates both the reduction of numerical diffusion and the correct simulation of physical diffusion. Moreover, the UPC model has shown its consistency in experiment F1.1, which is an SBLOCA with boron dilution. The test was part of the OECD-PKL2 program directed by the Organisation for Economic Cooperation and Development (OECD).