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Division Spotlight
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
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!
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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.”
Rodolfo M. Ferrer, Joshua M. Hykes
Nuclear Science and Engineering | Volume 197 | Number 2 | February 2023 | Pages 333-350
Technical Paper | doi.org/10.1080/00295639.2022.2053491
Articles are hosted by Taylor and Francis Online.
The Spatially Dependent Self-Shielding (SDSS) method has been implemented into CASMO5 within the framework of Equivalence Theory. The Optimal Two-Term Rational (OTTR) approximation is extended in the SDSS method to the Stoker-Weiss treatment of concentric annular fuel subdivisions. Reference fuel-to-fuel probabilities are required by the OTTR and obtained by performing a series of fixed-source, two-dimensional transport calculations for individual pin cell types using the method of characteristics. Several algorithms used in searching for the OTTR coefficients are evaluated with the goal of obtaining the best practical accuracy at minimal computational cost. Numerical results are presented that provide a comparison of various choices of search algorithms and show improved accuracy obtained by increasing the degrees of freedom in the rational approximation. Spatial profiles of the 238U microscopic absorption cross sections in the resonance range obtained using the Distributed Resonance Integral (DRI) and SDSS methods are compared to reference results from Monte Carlo calculations. The comparison highlights the inherent advantages of SDSS over the previous DRI method.
