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 Installations Safety
Devoted specifically to the safety of nuclear installations and the health and safety of the public, this division seeks a better understanding of the role of safety in the design, construction and operation of nuclear installation facilities. The division also promotes engineering and scientific technology advancement associated with the safety of such facilities.
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.”
Michael S. Milgram
Nuclear Science and Engineering | Volume 68 | Number 3 | December 1978 | Pages 249-269
Technical Paper | doi.org/10.13182/NSE78-A27304
Articles are hosted by Taylor and Francis Online.
The integral transport equation for the flux density in the interior of an infinite homogeneous cylinder is reduced to a matrix eigenvalue problem for the critical cylinder and a set of linear algebraic equations for the driven case with surface in-currents. The matrix elements are identified as moments of modified Bessel functions and are easily computed. A connection is made with classical diffusion theory via a related matrix eigenvalue problem, from which the diffusion coefficient and extrapolation endpoint can be computed. Analytic properties of the matrix elements are used to obtain approximate solutions for (optically) dense and transparent cylinders. Numerical results are given for the American Nuclear Society benchmark black rod problem, and the fact that only small matrices are required for a large range of problems is demonstrated.
