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The Radiation Protection and Shielding Division is developing and promoting radiation protection and shielding aspects of nuclear science and technology — including interaction of nuclear radiation with materials and biological systems, instruments and techniques for the measurement of nuclear radiation fields, and radiation shield design and evaluation.
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ANS Student Conference 2025
April 3–5, 2025
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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.”
Y. Y. Azmy
Nuclear Science and Engineering | Volume 98 | Number 1 | January 1988 | Pages 29-40
Technical Paper | doi.org/10.13182/NSE88-6
Articles are hosted by Taylor and Francis Online.
Very high computational efficiencies have been achieved recently by introducing higher order approximations to nodal formalisms for the discrete ordinates, neutron transport equation. However, the difficulty of the nodal formalism, its final discrete variable equations, and the solution algorithms have limited the usefulness and applicability of nodal methods in spite of their extremely high accuracy. A general order, general dimensionality nodal transport method cast in a simple, compact, singleweight, weighted diamond-difference form is derived. The new form is a consistently formulated nodal method, which can be solved using either the discrete nodal-transport method or the nodal-equivalent finite difference algorithms without any approximations. The final discrete variable equations for the two-dimensional case are implemented in a computer code to solve monoenergetic, isotropic scattering, external source problems to any given order, i.e., C-C, L-L, Q-Q, etc. A simple test problem with large homogeneous regions is solved using this code, on meshes ranging from 2 × 2 to 128 × 128, and orders ranging from zero to nine. The results show that, for this problem, the CPU time and the storage size required to achieve a given accuracy decrease monotonically up to order five. Hence, very high order methods may be more computationally efficient in solving practical problems with large homogeneous regions.