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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.”
Jean-Paul Deffain, Philippe Alexandre, Paul Thomet
Nuclear Technology | Volume 127 | Number 3 | September 1999 | Pages 267-286
Technical Paper | Fission Reactors | doi.org/10.13182/NT99-A3001
Articles are hosted by Taylor and Francis Online.
This feasibility study on core control using only the control rods is conducted with the TOPAZE algorithm - implemented in the CRONOS2 core calculation code - in its two versions: version 1 (minimization of the two-dimensional peak, imposed axial offset) and version 2 (minimization extended to three-dimensional, without imposed axial offset). The sensitivity analysis on the power peaks was carried out on the variations of the axial height of the burnable poisons and the type of grey or black control rod clusters. It is demonstrated that the reduction in the number of rod cluster controls allows a correct smoothing of the reactivity over the whole cycle, except for the end of cycle when control rods are moved upward.For load follow feasibility studies, several approaches, based on simulations performed with MISRITME have been evaluated: variation of the primary flow rate for axial offset control; use of a program, with temperature decreasing with the power; and finally, coupling of a temperature range, centered on a reference temperature with a negative gradient, to the French N4 reactor control mode Dispositif de Manoeuvrabilité Accrue: X (DMAX). It is shown that the return to equilibrium following a low threshold of 40% induces an additional penalty between 15 and 20% on the power peak. Solutions are suggested to globally reduce these peaks, which appear during all operating conditions.Two types of reactivity-induced accidents linked to clusters are studied: the removal of a rod cluster control assembly (RCCA) at full power (class III) and the ejection of a RCCA (class IV). It is also shown that ejection at zero power, with a released reactivity of 1.86 $, does not cause major damage to cladding and fuel. However, at full power, with the assumptions made, a partial melting of the pellet occurs without however creating fuel dispersion in the coolant.