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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.
Samuel E. Bays, Joseph Nielsen, Joshua Cogliati, Charles Wemple
Nuclear Technology | Volume 208 | Number 5 | May 2022 | Pages 811-821
Technical Paper | doi.org/10.1080/00295450.2021.1980320
Articles are hosted by Taylor and Francis Online.
The neutronics software, HELIOS, was validated in 2015 for performing core reload design and safety analysis of the Advanced Test Reactor. However, when HELIOS was benchmarked against historic fission-wire measurements (i.e., zero-power full-core measurements), a statistically resolved calculation-to-measurement bias was discovered. The azimuthal power along each fuel plate computed by HELIOS has consistently shown to underpredict measurements made by fission wires in historic zero-power tests near the fuel element side plates.
It was hypothesized during the HELIOS software validation work that this bias is attributable to local moderation in coolant vents in the side plates axially just above and below the fission wires on the fuel plate edges. This work used detailed MCNP and MC21 models of the side plate vents to test this hypothesis. By comparing the average azimuthal biases between HELIOS and two-dimensional and three-dimensional (3-D) MCNP models and a 3-D MC21 model, it was found that the HELIOS azimuthal bias is not due to the measurement.
