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Nuclear Nonproliferation Policy
The mission of the Nuclear Nonproliferation Policy Division (NNPD) is to promote the peaceful use of nuclear technology while simultaneously preventing the diversion and misuse of nuclear material and technology through appropriate safeguards and security, and promotion of nuclear nonproliferation policies. To achieve this mission, the objectives of the NNPD are to: Promote policy that discourages the proliferation of nuclear technology and material to inappropriate entities. Provide information to ANS members, the technical community at large, opinion leaders, and decision makers to improve their understanding of nuclear nonproliferation issues. Become a recognized technical resource on nuclear nonproliferation, safeguards, and security issues. Serve as the integration and coordination body for nuclear nonproliferation activities for the ANS. Work cooperatively with other ANS divisions to achieve these objective nonproliferation policies.
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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.”
Jeffrey W. Lane, L. E. Hochreiter, D. L. Aumiller, Jr., R. J. Kushner
Nuclear Technology | Volume 161 | Number 3 | March 2008 | Pages 277-285
Technical Paper | Thermal Hydraulics | doi.org/10.13182/NT08-A3926
Articles are hosted by Taylor and Francis Online.
RELAP5-3D currently calculates two-phase pump degradation using the Aerojet Nuclear Corporation (ANC) model. This is an empirical model that relates two-phase pump performance to single-phase pump performance using a set of two-phase degradation multipliers, which are only a function of void fraction. The purpose of the present work was to assess the two-phase pump degradation model in RELAP5-3D and various sets of user-supplied two-phase degradation multipliers by modeling a full-scale, two-phase pump test facility and comparing the simulated results to experimental data. Tests conducted by Ontario Hydro Technologies (OHT) using a full-size CANDU reactor primary heat transport pump were used for this assessment. Presently, this work represents the only RELAP5-3D analysis of these tests that has been performed.The experimental data from the OHT tests and results of this assessment both indicate that there is a pressure effect, in addition to void fraction, that cannot be neglected by safety analysis codes when predicting two-phase pump performance. The RELAP5-3D results showed that the widely used Semiscale two-phase head degradation multipliers did a poor job of predicting the experimental data and utilizing pressure-specific two-phase head degradation multipliers developed by OHT significantly improved code-to-data agreement. These results identify both the inaccuracies of using the Semiscale two-phase degradation multipliers and a weakness in the present formulation of the ANC model. As a result of this work, the Idaho National Laboratory recognized the need to include a pressure dependence in the RELAP5-3D calculation of two-phase pump performance, and this capability will be available in the next release of the code.