ANS is committed to advancing, fostering, and promoting the development and application of nuclear sciences and technologies to benefit society.
Explore the many uses for nuclear science and its impact on energy, the environment, healthcare, food, and more.
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
ANS Student Conference 2025
April 3–5, 2025
Albuquerque, NM|The University of New Mexico
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!
Latest Magazine Issues
Apr 2025
Jan 2025
Latest Journal Issues
Nuclear Science and Engineering
May 2025
Nuclear Technology
April 2025
Fusion Science and Technology
Latest News
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.”
H. Mösinger
Nuclear Science and Engineering | Volume 76 | Number 2 | November 1980 | Pages 89-102
Technical Paper | doi.org/10.13182/NSE80-A19443
Articles are hosted by Taylor and Francis Online.
A model for two-phase (water-vapor) flow in two-dimensional Cartesian or cylindrical coordinates is described that is implemented in the code DRIX-2D. The model includes slip between the phases and accounts for thermodynamic nonequilibrium. The code was designed as a “best-estimate” model for simulation of loss-of-coolant accidents (LOCAs) in light water reactor safety analysis. In this paper results of DRIX-2D applications are reported that can be used to assess the validity of simplified LOCA models. The main results are that both Cartesian and axisymmetric coordinates in two dimensions show considerable disadvantages as far as the pressure history in the downcomer is concerned. Yet, both models yield acceptable results concerning the gross blowdown behavior. Due to a 90-deg change in flow direction, considerable radial profiles in mass flow rate, velocity, and void fraction establish in the blowdown pipe. Nevertheless, a minor difference in the averaged mass flow rate exists only between a one- and two-dimensionally modeled blowdown pipe. A nonequilibrium state establishes at the pipe inlet in the case of subcooled vessel conditions and is maintained up to the orifice at least for pipe lengths <5m. However, the increase in mass flow rate caused by this nonequilibrium state is generally small enough for typical reactor conditions, so that an equilibrium assumption in the blowdown pipe should be appropriate for LOCA calculations.