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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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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.”
M. Guyot, P. Gubernatis, C. Suteau
Nuclear Science and Engineering | Volume 178 | Number 2 | October 2014 | Pages 202-224
Technical Paper | doi.org/10.13182/NSE13-80
Articles are hosted by Taylor and Francis Online.
Numerical simulations of the primary phase of a hypothetical core disruptive accident are currently based on a multiple-channel approach, which requires that subassemblies or groups of subassemblies be represented together as independent channels. Generally, a single-pin treatment is used to model the channel fuel pins. The limitation of this simplified approach should be assessed because it can affect voiding and melting patterns that in turn may influence reactivity insertions and power history. In the same manner, the single-pin hypothesis may introduce important biases in the prediction of can-wall thermal ablation. Radial propagation of the degradation and subsequent accident consequences may thus be affected. To improve the safety assessment of sodium fast reactors, two-dimensional effects are investigated using a multiple-pin model. Numerical results for a severe accident transient show that the current methodology is nonconservative and predicts the onset of sodium boiling with a delay. A two-node radial meshing of the subassembly is preferred for treating the peripheral ring of fuel pins separately from the rest of the pins. This treatment would allow overcoming the previous issue and give more accurate initiating phase simulations.