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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.”
R. T. Santoro, R. G. Alsmiller, Jr., J. M. Barnes, G. T. Chapman
Nuclear Science and Engineering | Volume 78 | Number 3 | July 1981 | Pages 259-272
Technical Paper | doi.org/10.13182/NSE81-A20303
Articles are hosted by Taylor and Francis Online.
Integral experiments that measure the transport of ∼14-MeV deuterium-tritium (D-T) neutrons through laminated slabs of proposed fusion reactor shield materials have been carried out at the Oak Ridge National Laboratory. Measured and calculated neutron and gamma-ray energy spectra are compared as a function of the thickness and composition of Type 304 stainless steel, borated polyethylene (BP), and Hevimet (a tungsten alloy), and as a function of detector position behind these materials. The measured data were obtained by means of an NE-213 liquid scintillator using pulse-shape discrimination methods to resolve neutron and gamma-ray pulse-height data and spectral unfolding methods to convert these data to energy spectra. The calculated data were obtained using two-dimensional discrete-ordinates radiation transport methods in a complex calculational network that takes into account the energy-angle dependence of the D-T neutrons and the nonphysical anomalies of the Sn method. The transport calculations incorporate ENDF/B-IV cross-section data from the VITAMIN C data library. The measured and calculated neutron energy spectra are in good agreement behind slab configurations of Type 304 stainless steel and BP (∼10% for all neutron energies >850 keV). When 5 cm of Hevimet are added to a 45-cm-thick Type 304 stainless steel plus BP slab assembly, the agreement is less favorable. The agreement among the measured and calculated gamma-ray spectra for energies >750 keV ranges from ∼25% to a factor of ∼5 depending on the slab composition.