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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
2025 ANS Annual Conference
June 15–18, 2025
Chicago, IL|Chicago Marriott 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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Nuclear Science and Engineering
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Latest News
High-temperature plumbing and advanced reactors
The use of nuclear fission power and its role in impacting climate change is hotly debated. Fission advocates argue that short-term solutions would involve the rapid deployment of Gen III+ nuclear reactors, like Vogtle-3 and -4, while long-term climate change impact would rely on the creation and implementation of Gen IV reactors, “inherently safe” reactors that use passive laws of physics and chemistry rather than active controls such as valves and pumps to operate safely. While Gen IV reactors vary in many ways, one thing unites nearly all of them: the use of exotic, high-temperature coolants. These fluids, like molten salts and liquid metals, can enable reactor engineers to design much safer nuclear reactors—ultimately because the boiling point of each fluid is extremely high. Fluids that remain liquid over large temperature ranges can provide good heat transfer through many demanding conditions, all with minimal pressurization. Although the most apparent use for these fluids is advanced fission power, they have the potential to be applied to other power generation sources such as fusion, thermal storage, solar, or high-temperature process heat.1–3
N. Colby Fleming, Cole A. Manring, Briana K. Laramee, Jonathan P. W. Crozier, Eunji Lee, Ayman I. Hawari
Nuclear Science and Engineering | Volume 197 | Number 8 | August 2023 | Pages 1887-1901
Technical papers from: PHYSOR 2022 | doi.org/10.1080/00295639.2023.2194195
Articles are hosted by Taylor and Francis Online.
The Full Law Analysis Scattering System Hub (FLASSH) is a modern, advanced code that evaluates the thermal scattering law (TSL) along with accompanying cross sections. FLASSH features generalized methods that accommodate any material structure. Historical approximations including incoherent and cubic approximations have been removed. Instead, the latest release of FLASSH features advanced physics options including distinct effect corrections (one-phonon contributions) and noncubic formulations. Noncubic elastic and inelastic contributions are necessary to accurately evaluate one-phonon contributions. Both noncubic and one-phonon calculations require high-density sampling of the various scattering directions. Optimization and parallelization of these routines were therefore necessary to produce results in a reasonable computational time frame. With these notable improvements to the generalized TSL, FLASSH 1.0 can meet benchmark requirements by permitting realistic comparisons with experiments for both TSLs and the resulting integrated cross sections. Within FLASSH, these high-fidelity TSLs can be applied also to the resonance region to evaluate accurate, material structure-dependent Doppler broadening that captures the observed experimental behavior. Additional features including a graphical user interface (GUI), plotting diagnostics, and formatted output options including ACE files allow users to complete a TSL evaluation with minimal input and maximum flexibility. The user GUI creates input files for FLASSH, reducing user error and also providing built-in error checks. Autofill options and suggested input values help make TSL evaluation accessible to novice users. The FLASSH code is compiled to run on both Windows and Linux platforms with automatic parallelization.
