Nuclear Technology -- ANS / Publications / Journals / Nuclear Technology

About ANS
- ANS is committed to advancing, fostering, and promoting the development and application of nuclear sciences and technologies to benefit society.
About Nuclear
- Explore the many uses for nuclear science and its impact on energy, the environment, healthcare, food, and more.
Communities
- Division Spotlight
  Nuclear Criticality Safety
  NCSD provides communication among nuclear criticality safety professionals through the development of standards, the evolution of training methods and materials, the presentation of technical data and procedures, and the creation of specialty publications. In these ways, the division furthers the exchange of technical information on nuclear criticality safety with the ultimate goal of promoting the safe handling of fissionable materials outside reactors.
Events
- Meeting Spotlight
  ANS Student Conference 2025
  April 3–5, 2025
  Albuquerque, NM|The University of New Mexico
Standards
- 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!
Publications
- Latest Magazine Issues
  Apr 2025
  Jan 2025
  Latest Journal Issues
  Nuclear Science and Engineering
  May 2025
  Nuclear Technology
  April 2025
  Fusion Science and Technology
  April 2025
- 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.”
Search

This paper deals with numerical challenges associated with simulating thermal-hydraulic phenomena in nuclear reactors with one-dimensional system analysis codes. The main focus of this research is directed toward assessment of the pressure gradient in vertically stratified flow, particularly the separate pressure drop effects for gas and liquid phases along the control cell. The pressure drop term in momentum conservation currently being developed based on the assumption of gas and liquid combined pressure drop was redefined such that two different pressures were imposed for gas and liquid separately. The verification of the proposed momentum equation for a vertically stratified flow was completed through simulations of the liquid velocity in a U-shaped manometer. Sensitivity analysis was also performed by increasing liquid mass in the pipe leading to different positions of the liquid-vapor interface from the bottom of each manometer pipe when the flow oscillation is stopped; i.e., the interfaces are not only cell boundaries but also various positions between cell edges. As a result, improved simulation results were obtained using the modified equations as it was indicated that the oscillation of fluid decays over time while the original solution for the large pipe does not converge to zero due to a mainly incorrect pressure drop term.