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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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2024 ANS Annual Conference
June 16–19, 2024
Las Vegas, NV|Mandalay Bay Resort and Casino
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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
DOE-EM finishes cleanup of legacy Oak Ridge reactor lab site
The Department of Energy’s Office of Environmental Management announced that the 30-foot-long, 37,600-pound reactor vessel from Oak Ridge National Laboratory’s Low Intensity Test Reactor was shipped to EnergySolutions’ low-level radioactive waste facility in Clive, Utah, in late April.
Ahmed Hassanein
Fusion Science and Technology | Volume 30 | Number 3 | December 1996 | Pages 713-719
Divertor Design and Experiments | doi.org/10.13182/FST96-A11963020
Articles are hosted by Taylor and Francis Online.
Damage to plasma-facing components and structural materials of fusion reactors during abnormal plasma instabilities such as hard disruptions, edge-localized modes (ELMs), and vertical displacement events (VDEs) is considered a serious life-limiting concern for these components and materials. Plasma-facing components (PFCs) such as the divertor, limiter, and first wall will be subjected to intense energy deposition during these plasma instabilities. High erosion losses of material surfaces, large temperature increases in structural materials, and high heat flux levels and possible burnout of coolant tubes are critical issues that severely limit component lifetime and therefore diminish reactor safety and economics.
A comprehensive model that integrates various stages of plasma interaction with plasma-facing materials (PFMs) is extended to analyze and evaluate the damage that results from various plasma instabilities. Models for thermal evolution and phase change of a multilayer structural material, for the developed vapor cloud magnetohydrodynamics above the surface of the material, and for calculating the resulting radiation and its transport through this vapor cloud due to plasma/vapor interaction are dynamically coupled in a self-consistent way to evaluate various aspects of detailed time-dependent responses of PFMs. The extent of the damage to PFMs, structural materials, and coolant channels depends mainly on the total deposited plasma energy, deposition time, and the coating or surface material. During short disruption events (τd ≤ 1 ms), the initially intense evaporated material can significantly shield the PFM and reduce its further erosion. When plasma instabilities occur at longer durations, however, such as in VDEs (τd=100-300 ms), no significant self-shielding is expected; therefore, serious erosion and melting can occur. In addition, hydrodynamic instabilities and other mechanisms will further erode melt layers of metallic PFMs. Plasma instabilities of longer duration may also allow more time for conduction of deposited plasma energy from the surface to the structural material and finally to the coolant channels, where it can cause burnout. These events are analyzed parametrically for the expected range of plasma parameters for various surface materials such as beryllium, carbon, and tungsten, and for structural materials such as copper.