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
Fuel Cycle & Waste Management
Devoted to all aspects of the nuclear fuel cycle including waste management, worldwide. Division specific areas of interest and involvement include uranium conversion and enrichment; fuel fabrication, management (in-core and ex-core) and recycle; transportation; safeguards; high-level, low-level and mixed waste management and disposal; public policy and program management; decontamination and decommissioning environmental restoration; and excess weapons materials disposition.
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.”
Steven E. Aumeier, John C. Lee, Derek M. Cribley, William R. Martin
Nuclear Technology | Volume 108 | Number 3 | December 1994 | Pages 299-319
Technical Paper | Fission Reactor | doi.org/10.13182/NT94-A35014
Articles are hosted by Taylor and Francis Online.
We present a new time-based cross-section parameterization scheme that allows for a more accurate global depletion analysis than current methodologies without requiring major modifications to existing codes. The new cross-section parameterization scheme makes use of few-group macroscopic cross sections calculated as a function of time at several different power levels. These cross sections are block ordered by time rather than exposure to allow for the explicit representation of instantaneous control, i.e., soluble boron concentration, and thus accurate isotopic history, within the base cross-section library. The scheme is applied to a global depletion analysis of the Slightly Enriched Spectral-Shift Reactor, an advanced converter reactor based on a pressurized water reactor design, using the CPM-2 assembly-level collision probability code and the UM2DB two-dimensional diffusion code. The depletion calculation establishes the feasibility and potential advantages of the proposed cross-section parameterization methodology and shows that through a judicious choice of spectral shift control rod withdrawal strategies, it is possible to substantially increase fuel resource utilization via the spectral shift effect while maintaining acceptable power peaking factors.
