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Isotopes & Radiation
Members are devoted to applying nuclear science and engineering technologies involving isotopes, radiation applications, and associated equipment in scientific research, development, and industrial processes. Their interests lie primarily in education, industrial uses, biology, medicine, and health physics. Division committees include Analytical Applications of Isotopes and Radiation, Biology and Medicine, Radiation Applications, Radiation Sources and Detection, and Thermal Power Sources.
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ANS Student Conference 2025
April 3–5, 2025
Albuquerque, NM|The University of New Mexico
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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!
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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.”
Marc A. Cooper, Edward W. Larsen
Nuclear Science and Engineering | Volume 137 | Number 1 | January 2001 | Pages 1-13
Technical Paper | doi.org/10.13182/NSE00-34
Articles are hosted by Taylor and Francis Online.
A new method for efficiently solving global Monte Carlo particle transport problems is presented. (In these problems, flux information is desired across the entire system, not just at a small number of detector locations.) The method is based on the use of a weight window that distributes Monte Carlo particles uniformly throughout the system. This (a) ensures that all subregions of the system are adequately sampled and (b) controls the particle weights, even in subregions far from sources. The weight window is constructed from an approximate deterministic solution of the forward transport problem. It is argued that a weight window based on the forward transport solution is more appropriate for global problems than the more familiar concept of basing a weight window on an adjoint solution for source-detector problems. It is also shown that by using Monte Carlo-generated Eddington factors in deterministic solutions of the quasi-diffusion equation, one can inexpensively compute updated forward-based weight windows and obtain a more efficient global Monte Carlo calculation.