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Division Spotlight
Young Members Group
The Young Members Group works to encourage and enable all young professional members to be actively involved in the efforts and endeavors of the Society at all levels (Professional Divisions, ANS Governance, Local Sections, etc.) as they transition from the role of a student to the role of a professional. It sponsors non-technical workshops and meetings that provide professional development and networking opportunities for young professionals, collaborates with other Divisions and Groups in developing technical and non-technical content for topical and national meetings, encourages its members to participate in the activities of the Groups and Divisions that are closely related to their professional interests as well as in their local sections, introduces young members to the rules and governance structure of the Society, and nominates young professionals for awards and leadership opportunities available to members.
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.”
Luben Sabotinov, Abhishek Srivastava
Nuclear Technology | Volume 170 | Number 1 | April 2010 | Pages 123-132
Technical Paper | Special Issue on the 2008 International Congress on Advances in Nuclear Power Plants / Thermal Hydraulics | doi.org/10.13182/NT10-A9451
Articles are hosted by Taylor and Francis Online.
In the safety analysis of nuclear power plants, large break loss-of-coolant accidents (LB LOCAs) continue to be one of the major issues. In this study, the latest version of the French best-estimate computer code CATHARE2 V2.5_1 Mod6.1 was used in order to predict the thermal-hydraulic phenomena in the VVER-1000 reactor during LB LOCA. This type of reactor is in operation and under construction in several countries including Russia, Ukraine, Bulgaria, Czech Republic, China, and India.The paper first presents the CATHARE modeling of a VVER-1000 reactor, including the core, the vessel, the primary and secondary circuits with the pressurizer, the main circulation pumps, the horizontal steam generators, and the steam lines. The emergency core cooling system (ECCS) is presented also with hydroaccumulators and high- and low-pressure safety injection pumps. The break, located in the cold leg and close to the reactor, is represented by the RUPTURE module of CATHARE, which modelizes a double-ended guillotine type of break.In the current calculations, the bottom-up and top-down reflooding play a very important role, compared to some western pressurized water reactors, because of the ECCS injection into the downcomer and upper plenum of the VVER-1000. That is why special attention is paid to the validation of the CATHARE reflooding model, based on the REWET-II experiment devoted to VVER. In CATHARE, a special two-dimensional reflooding module has been developed, which takes into account the radial and axial conduction in the vicinity of the quench front. The assessment based on the REWET-II facility shows the ability of the code to predict the progression of two simultaneous quench fronts.Then, the paper presents the results of the LB LOCA analysis for VVER-1000 (reference case and sensitivity study), describing the blowdown, refill, and reflood phases of the accident. Problems related to the countercurrent flow limitation (CCFL) phenomena at the core outlet are also considered. The results of the calculations show reasonable prediction of the basic parameters important to the safety of the plant, such as quench front progression, fuel-cladding temperatures, break flows, pressure behavior, etc. As expected, the temperatures - despite the conservative character of the modeling - remain below the safety criteria. It should be noted that the calculated fuel wall temperatures are very sensitive to the proper selection of the reflooding parameters and CCFL and need skillful choice of the reflooding conditions.