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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.
Meeting Spotlight
International Conference on Mathematics and Computational Methods Applied to Nuclear Science and Engineering (M&C 2025)
April 27–30, 2025
Denver, CO|The Westin Denver Downtown
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
Sam Altman steps down as Oklo board chair
Advanced nuclear company Oklo Inc. has new leadership for its board of directors as billionaire Sam Altman is stepping down from the position he has held since 2015. The move is meant to open new partnership opportunities with OpenAI, where Altman is CEO, and other artificial intelligence companies.
Nicolae Bidica, Narcisa Ghimis, Bogdan Monea
Fusion Science and Technology | Volume 80 | Number 3 | May 2024 | Pages 504-519
Research Article | doi.org/10.1080/15361055.2024.2316477
Articles are hosted by Taylor and Francis Online.
Tritium permeation through structural materials of fusion reactors is an important issue from both safety and tritium self-sufficiency points of view. Mutual influences among hydrogen isotopes are also important in assessments of tritium permeation fluxes, and although some theoretical and experimental works have been carried out so far—which have all focused on steady-state permeation—their conclusions are insufficiently clear about how one isotope affects the permeation of another. This was motivation to further investigate this problem, both theoretical and experimental in a non-steady-state approach and also in the surface-limited regime (SLR) of permeation. After initial theoretical work, a dedicated experimental installation for gas-driven permeation experiments was designed and assembled. Then, initial experimental work was completed for testing monoisotope permeation of deuterium through a very thin (0.075-mm) nickel membrane in the temperature range of 473 to 773 K and for a driving pressure of deuterium gas in the range of 10−2 to 1 Pa. This work was done in preparation for subsequent multi-isotope experiments, with the proposed goal to observe how hydrogen affects the permeation of deuterium. The main objectives of the work were to confirm experimentally the achievement of the SLR of permeation for the selected conditions of testing; to determine experimentally the kinetic coefficients of surface transport for deuterium in nickel; and to test and validate the experimental setup, procedures, and methods used and their reliability to more stringent requirements of the multi-isotope experiments. Within this paper, the experimental setup and all the operating procedures used both in calibration operations and in permeation experiments are presented in detail, as well as their results. The obtained results confirmed that permeation occurred in the SLR in the tested range of pressure for each testing temperature. The surface-rate coefficients of dissociation and recombination were both determined experimentally. The values obtained for the dissociation coefficient were in very good agreement with other similar experimental data available in the literature. For the recombination coefficient, agreement was not quite satisfactory, but comparison could be made with values calculated based only on the dissociation and solubility coefficients, as data for these coefficients for the nickel-hydrogen system (determined directly from gas-driven permeation experiments) were not found in the literature. However, these results indicated good reliability of the installation, its calibration, and operating procedures in order to proceed to experimental testing of multi-isotope permeation.