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Division Spotlight
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.
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.”
Jiyun Zhao, Pradip Saha, Mujid S. Kazimi
Nuclear Technology | Volume 161 | Number 2 | February 2008 | Pages 124-139
Technical Paper | Thermal Hydraulics | doi.org/10.13182/NT08-A3918
Articles are hosted by Taylor and Francis Online.
To compare the stability features of a supercritical water-cooled reactor (SCWR) design with that of a typical boiling water reactor (BWR), a stability analysis model for a typical BWR has been developed in addition to an already-developed model for the SCWR as presented in a companion paper. The homogenous equilibrium two-phase flow model, which is adequate at high pressures, is applied to the BWR stability analysis. The reactor core is simulated by three channels according to the radial power distribution and the inlet orifice coefficients. Similar to the SCWR model, the neutronic kinetic equation is expanded based on modes (reactivity modes). The model is evaluated based on the Peach Bottom Atomic Power Station stability test data, and the results agree well with the experiment.The SCWR is found to be less sensitive to the coolant density neutronic reactivity coefficient than the typical BWR, since most of the neutronic moderation function is provided by the water rods, where the density variation is either zero (if the water rods are insulated) or small (if the water rods are not insulated). The BWR is found to be less sensitive to changes in power level than the SCWR but has the same sensitivity level to the flow rate as the SCWR.A stability envelope that combines the single-channel and in-phase stability modes is developed. The decay ratios for the SCWR together with those for the typical BWR and the new Economic Simplified Boiling Water Reactor at nominal operational conditions are shown in the map. The stability sensitivity to operating conditions is also shown in the map, by increasing the power to 120% of nominal value and decreasing the flow rate to 80% of nominal value. It is found that the SCWR is more sensitive to the single-channel stability compared to the core-wide in-phase stability for all cases.