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Operations & Power
Members focus on the dissemination of knowledge and information in the area of power reactors with particular application to the production of electric power and process heat. The division sponsors meetings on the coverage of applied nuclear science and engineering as related to power plants, non-power reactors, and other nuclear facilities. It encourages and assists with the dissemination of knowledge pertinent to the safe and efficient operation of nuclear facilities through professional staff development, information exchange, and supporting the generation of viable solutions to current issues.
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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.”
Anurag Gupta, R. S. Modak
Nuclear Science and Engineering | Volume 194 | Number 2 | February 2020 | Pages 87-103
Technical Paper | doi.org/10.1080/00295639.2019.1668655
Articles are hosted by Taylor and Francis Online.
Monte Carlo calculations for the evaluation of fundamental mode solution of k-eigenvalue problems generally make use of the Power Iteration (PI) method, which suffers from poor convergence, particularly in the case of large, loosely coupled systems. In the present paper, a method called Meyer’s Subspace Iteration (SSI) method, also called the Simultaneous vector iteration algorithm, is applied for the Monte Carlo solution of the k-eigenvalue problem. The SSI method is the block generalization of the single-vector PI method and has been found to work efficiently for solving the problem with the deterministic neutron transport setup. It is found that the convergence of the fundamental k-eigenvalue and corresponding fission source distribution improves substantially with the SSI-based Monte Carlo method as compared to the PI-based Monte Carlo method. To reduce the extra computational effort needed for simultaneous iterations with several vectors, a novel procedure is adopted in which it takes almost the same effort as with the single-vector PI-based Monte Carlo method. The algorithm is applied to several one-dimensional slab test cases of varying difficulty, and the results are compared with the standard PI method. It is observed that unlike the PI method, the SSI-based Monte Carlo method converges quickly and does not require many inactive generations before the mean and variance of eigenvalues could be estimated. It has been demonstrated that the SSI method can simultaneously find a set of the most dominant higher k-eigenmodes in addition to the fundamental mode solution.