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
Mathematics & Computation
Division members promote the advancement of mathematical and computational methods for solving problems arising in all disciplines encompassed by the Society. They place particular emphasis on numerical techniques for efficient computer applications to aid in the dissemination, integration, and proper use of computer codes, including preparation of computational benchmark and development of standards for computing practices, and to encourage the development on new computer codes and broaden their use.
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.”
Amir N. Nahavandi, Richard F. von Hollen
Nuclear Science and Engineering | Volume 20 | Number 4 | December 1964 | Pages 392-413
Technical Paper | doi.org/10.13182/NSE64-A20982
Articles are hosted by Taylor and Francis Online.
A one-dimensional space-dependent dynamic analysis of boiling water reactors, for direct, indirect or dual cycle systems with forced or natural circulation is presented. The analytical model consists of space-dependent neutron kinetics equations for the reactor core, and flow-conservation equations for the reactor coolant system developed in terms of length along the flow path and time. The resulting set of non-linear partial differential equations is expressed spatially in finite-difference form and integrated numerically in time to obtain the space- and time-dependent system variables. The effect of system-pressure variation is neglected. The mathematical model and numerical procedures employed in this study are verified against available test data from the Levy and Beckjord experimental boiling loop. Analytical predictions of the threshold of instability and the frequency of oscillations are shown to be in agreement with the test data. Studies of the uncontrolled and controlled behavior of a 110-MWe direct cycle boiling water nuclear power station confirm that, in contrast with natural-circulation loops, forced-circulation boiling systems have a high degree of hydrodynamic stability. However, an inappropriate selection of control-system parameters may induce nuclear power instability in both natural- and forced-circulation plants. The theoretical approach presented maybe successfully employed as a powerful tool for the determination of the system stability, as well as for evaluation of the degree of effectiveness and relative merits of various system power-control techniques.