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ANS Student Conference 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.”
Josée Perfettini
Nuclear Technology | Volume 115 | Number 2 | August 1996 | Pages 153-161
Technical Paper | Characterization of Radioactive Waste in France / Radioactive Waste Management | doi.org/10.13182/NT96-A35261
Articles are hosted by Taylor and Francis Online.
A neutronic method based on neutron thermalization by hydrogen nuclei is used to measure the moisture content in packages of radioactive waste embedded in hydraulic binders. The two steps of the measurement are (a) acquisition of the neutron characteristics of the embedded waste considered (or of a chemically similar material) and (b) the measurement itself obtained with a neutron moisture meter. The neutron characteristics required are the adsorption and diffusion cross sections ∑a and ∑d for thermal neutrons of the dried material. These two parameters are used to calculate the calibration curve (valid only for the material considered) as follows:N = (α·Ds + β)Hυ + γ·Ds + δ,which allows the counting N of the neutron moisture meter to be converted into free-water content Hv (α, β, γ, and δ are deduced from ∑a and ∑d; Ds is the dry density of the material). The neutron moisture meter (containing a fast neutron source and a thermalized neutron detector) is portable. Measurements are taken at various depths in a core hole made in the package to draw a water profile. The measurements are taken in materials used for waste solidification and in active or inactive packages. The results obtained (free-water content) are in good agreement with those obtained by determining the weight loss at 120°C (the differences between these two measurements are generally ∼10% when the free-water content is ∼20 to 25 %). The water profiles allow one to detect the presence of excessive free water.