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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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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
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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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Dragonfly, a Pu-fueled drone heading to Titan, gets key NASA approval
Curiosity landed on Mars sporting a radioisotope thermoelectric generator (RTG) in 2012, and a second NASA rover, Perseverance, landed in 2021. Both are still rolling across the red planet in the name of science. Another exploratory craft with a similar plutonium-238–fueled RTG but a very different mission—to fly between multiple test sites on Titan, Saturn’s largest moon—recently got one step closer to deployment.
On April 25, NASA and the Johns Hopkins University Applied Physics Laboratory (APL) announced that the Dragonfly mission to Saturn’s icy moon passed its critical design review. “Passing this mission milestone means that Dragonfly’s mission design, fabrication, integration, and test plans are all approved, and the mission can now turn its attention to the construction of the spacecraft itself,” according to NASA.
Kenneth M. Wasywich, William H. Hocking, David W. Shoesmith, Peter Taylor
Nuclear Technology | Volume 104 | Number 3 | December 1993 | Pages 309-329
Technical Paper | Special Issue on Waste Management / Radioactive Waste Management | doi.org/10.13182/NT93-A34893
Articles are hosted by Taylor and Francis Online.
In the Canadian research and development program on fuel storage, used CANDU (Canada deuterium uranium) UO2fuel bundles are being exposed in experimental vessels to both dry and moisture-saturated air environments at 150°C. At intervals of several years, individual fuel elements, which were deliberately defected before storage, are recovered for destructive examination to determine the extent of UO2 oxidation that has occurred. The most recent examinations took place after 99.5 and 69 months of storage under dry and moist conditions, respectively. The progress of oxidation in the two different storage environments is compared, and the results of fuel examination by optical microscopy, scanning electron microscopy, X-ray photoelectron spectroscopy (XPS), and X-ray powder diffraction (XRD) are described. In dry air, oxidation proceeds mainly on exposed UO2 surfaces near the cladding defect and penetrates the fuel along grain boundaries adjoining cracks and the fuel-sheath gap, which provide primary pathways for access of oxygen to the fuel. An oxidized rind, resembling α-U3O7, is visible around UO2 grain cores near the oxide front. In moist air, oxidation is more generally distributed throughout the length of the fuel element. It proceeds along grain boundaries and is most extensive in regions of the fuel expected to have the highest porosity or grain-boundary inventory of fission products. This oxidized layer is too thin to observe by optical microscopy or identify by XRD, but XPS results indicate a higher degree of oxidation at the exposed grain boundaries (U6+/U4+ often »1.0) than in fuel specimens oxidized in dry air (U6+/U4+ usually <1.0). Interpretation of the results is complicated by the different O2/UO2 ratios in the two types of storage vessel and the fact that oxygen was completely consumed during at least some of the storage intervals. Nonetheless, it is clear that the presence of moisture promotes a more generally distributed oxidation of UO2 grain boundaries. The probable involvement of radiolytic processes in the moist oxidation reaction and possible reasons for the sensitization of certain regions of the fuel to moist oxidation are discussed. In addition to oxidation of UO2, the XPS spectra provide evidence for the radiation-induced incorporation of oxygen and nitrogen into adventitious carbon (adsorbed hydrocarbons) on the UO2 surfaces.
