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Division Spotlight
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.”
Bernhard Kienzler, Andreas Loida, Werner Maschek, Andrei Rineiski
Nuclear Technology | Volume 143 | Number 3 | September 2003 | Pages 309-321
Technical Paper | Radioactive Waste Management and Disposal | doi.org/10.13182/NT03-A3419
Articles are hosted by Taylor and Francis Online.
In an underground repository for spent fuel, criticality is excluded initially by compliance with the disposal conditions. In the long term, critical accumulations of fissile material can be formed only by mobilization of uranium and plutonium from the waste forms and subsequent precipitation or sorption of these elements. This paper presents an overview of mechanisms relevant for mobilization and possible accumulation of U and Pu from disposed mixed-oxide fuel elements. Concentrations of fissile materials observed in laboratory corrosion experiments together with model approaches are applied to determine the degree of fissile material accumulation and the risk of a sustained nuclear chain reaction. A prerequisite of criticality in a repository is an accumulation of fissile materials. Since geometry, moderation, and neutron absorption properties cannot be forecast, the neutron multiplication factor kinf is used (instead of keff) as a measure of the incidence of criticality. The factor kinf is derived for several scenarios. Required critical masses and critical volumes are evaluated.The accumulation of Pu onto solids is considered, and it is shown how selective enrichment of Pu and U may affect the risk of criticality. It is also shown that the criterion for criticality would be met only in the unrealistic case of selective sorption of 239Pu. Realistic sorption densities are too low to provide sufficient accumulation of fissile materials for criticality. This is particularly true if high Cl concentrations are present.