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Reactor Physics
The division's objectives are to promote the advancement of knowledge and understanding of the fundamental physical phenomena characterizing nuclear reactors and other nuclear systems. The division encourages research and disseminates information through meetings and publications. Areas of technical interest include nuclear data, particle interactions and transport, reactor and nuclear systems analysis, methods, design, validation and operating experience and standards. The Wigner Award heads the awards program.
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Utility Working Conference and Vendor Technology Expo (UWC 2024)
August 4–7, 2024
Marco Island, FL|JW Marriott Marco Island
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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.”
John M. Sorensen, Nicholas G. Trikouros
Nuclear Technology | Volume 121 | Number 3 | March 1998 | Pages 313-323
Technical Paper | RETRAN | doi.org/10.13182/NT98-A2843
Articles are hosted by Taylor and Francis Online.
Core shroud cracking has been observed in several boiling water reactors (BWRs) since 1993. A current U.S. Nuclear Regulatory Commission concern is the response of a cracked core shroud to loads resulting from the main steam-line-break loss-of-coolant accident (MSLOCA). Core shroud loads and responses have been calculated by GPU Nuclear Corporation (GPUNC) for the Oyster Creek BWR/2 using the RELAP5 computer code. The objectives of the RETRAN-02 analysis performed by S. Levy Incorporated were to assess the capability of RETRAN-02 to simulate an MSLOCA and to obtain an independent validation of the GPUNC results.A main steam-line break will result in rapid depressurization of the steam dome and an upward pressure load over the shroud head. This upward force has the potential to cause separation and displacement of the shroud head if the shroud head contains a 360-deg through-wall flaw.The key parameters and phenomena affecting the core shroud head pressure differential following the initiation of the MSLOCA are critical flow through the vessel side of the steam-line break; pressure wave dynamics in the steam lines; depressurization rate of the vessel steam dome; flow inertia and pressure drop of the steam dryers, steam separators, and standpipes; and flashing of saturated liquid in the upper plenum and reactor core.The key parameters and phenomena affecting the core shroud head lift are the core shroud head mass above the cracked weld, the core shroud head projected area, and the characteristics of the shroud weld crack leakage flow path from the core bypass to the vessel downcomer annulus.Comparison of RELAP5 and RETRAN-02 calculation results shows good agreement for the transient core shroud head pressure drop and lift predictions by the two methods. An important element in simulating this rapid transient, for both RELAP5 and RETRAN-02, is the ability to calculate the shroud head loading and lift through the use of control block elements and to directly couple the effect of flow through the shroud weld crack leakage flow path to the upper plenum thermal hydraulics.