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
Fusion Energy
This division promotes the development and timely introduction of fusion energy as a sustainable energy source with favorable economic, environmental, and safety attributes. The division cooperates with other organizations on common issues of multidisciplinary fusion science and technology, conducts professional meetings, and disseminates technical information in support of these goals. Members focus on the assessment and resolution of critical developmental issues for practical fusion energy applications.
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.”
A. N. Verma, Feroz Ahmed, L. S. Kothari
Nuclear Science and Engineering | Volume 62 | Number 4 | April 1977 | Pages 745-750
Technical Note | doi.org/10.13182/NSE77-A15217
Articles are hosted by Taylor and Francis Online.
Using the flux synthesis method and energy -dependent boundary conditions, we have solved the three-dimensional multigroup diffusion equation, without as suming space-energy separability and without explicitly introducing the concept of buckling, to study the diffusion of neutrons inside beryllium assemblies with finite transverse dimensions. The energy -dependent neutron spectra have been reported at various distances inside the two experimental assemblies of Lake and Kallfelz (35.6 × 35.6 × 50.8 cm3 and 25.4 × 25.4 × 50.8 cm3). We have discussed in detail the problem of the existence of a true discrete or a pseudo-asymptotic mode in these assemblies. We have also defined an “equivalent buckling” and find that the equivalent buckling agrees with the conventional definition of buckling only in large assemblies and only then in the epicold energy region. We have also discussed the validity of using diffusion theory in small assemblies.