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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.”
Staffan Qvist, Ehud Greenspan
Nuclear Science and Engineering | Volume 182 | Number 2 | February 2016 | Pages 197-212
Technical Paper | doi.org/10.13182/NSE14-135
Articles are hosted by Taylor and Francis Online.
For a reactor to establish a sustainable breed-and-burn (B&B) mode of operation, its fuel has to reach a minimum level of average burnup. The value of the minimum required average discharge burnup strongly depends on the core design details. Using the extended neutron balance method, it is possible to quantify the impact of major core design choices on the minimum required burnup in a B&B core. Relevant design variables include the fuel chemical form, nonactinide mass fraction of metallic fuel, feed-fuel fissile fraction, fuel rod pitch-to-diameter ratio (P/D), average neutron flux level, and fraction of neutron loss. Metallic fuels have been found to be the only viable fuel options for a realistic near-term B&B reactor. For the core designs we have studied, it was not possible to sustain B&B operation using oxide fuel that is not enriched, while nitride and carbide fuels may only work in highly ideal low-leakage systems at very high levels of discharge burnup and, hence, neutron irradiation damage. The minimum required burnup increases strongly with the total fraction of neutrons that is lost to leakage and reactivity control. The flux level has no effect on the neutron balance within the applicable range, and the average discharge burnup is also relatively insensitive to the fraction of fissile material in the feed fuel in the range from depleted uranium (0.2% 235U) to natural uranium (0.71% 235U). The minimum required burnup is most sensitive, in order of importance, to the fractional loss of neutrons, the Zr content in metallic fuel, and the fuel rod P/D. Changing the weight fraction of zirconium in metallic fuel by 1% (for example, from 10% to 9%) gives the same change in required discharge burnup as adjusting the P/D by 0.02 (for example, from 1.10 to 1.12).