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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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ANS Student Conference 2025
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Albuquerque, NM|The University of New Mexico
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General Kenneth Nichols and the Manhattan Project
Nichols
The Oak Ridger has published the latest in a series of articles about General Kenneth D. Nichols, the Manhattan Project, and the 1954 Atomic Energy Act. The series has been produced by Nichols’ grandniece Barbara Rogers Scollin and Oak Ridge (Tenn.) city historian David Ray Smith. Gen. Nichols (1907–2000) was the district engineer for the Manhattan Engineer District during the Manhattan Project.
As Smith and Scollin explain, Nichols “had supervision of the research and development connected with, and the design, construction, and operation of, all plants required to produce plutonium-239 and uranium-235, including the construction of the towns of Oak Ridge, Tennessee, and Richland, Washington. The responsibility of his position was massive as he oversaw a workforce of both military and civilian personnel of approximately 125,000; his Oak Ridge office became the center of the wartime atomic energy’s activities.”
L. W. Ward
Nuclear Technology | Volume 131 | Number 1 | July 2000 | Pages 69-81
Technical Paper | Thermal Hydraulics | doi.org/10.13182/NT00-A3105
Articles are hosted by Taylor and Francis Online.
A model was developed to compute the two-dimensional velocity profiles in hot fuel channels of a pressurized water reactor core following a small-break loss-of-coolant accident (SBLOCA). Following an SBLOCA, the transient two-phase level in the core recedes below the top of the core, exposing the core to steam cooling and heatup of the fuel. To compute the velocity distributions, the Navier-Stokes equations were solved in vorticity form using an explicit upwind finite difference numerical scheme. The model was applied to the well-known lid-driven cavity problem and the data in the literature for vertically heated channels. Comparison of the model to the data in the literature provided validation of the approach.Application of the model to the conditions at the time of the peak clad temperature during core uncovery for a typical limiting small cold-leg break in a pressurized water reactor further revealed that the hot-channel steam flow can vary dramatically at the hot spot due to the severe distortion in the axial steam flow that is characteristic of asymmetrically heated channels. The results of the evaluation support the need for a thorough technical basis for the steam flow rates that are typically assumed to cool the hot rods in many commercial fuel rod heatup codes. These codes typically assume a constant mass flow along the axis of the fuel rod to compute the cladding temperature response. Mixed convection is shown to reduce the channel average velocity along the axis of the fuel rod by as much as 15%. The reductions in channel velocity will produce an attendant increase in the peak clad temperature achieved during an SBLOCA. The results of this study suggest that for the steam velocities used to cool hot rods during an SBLOCA, one needs to consider the mixed-convection behavior that can affect the convective heat transfer in the upper portions of exposed nuclear fuel bundles.