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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.”
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A realistic velocity difference scheme has been developed for calculating the drift parameters in both horizontally and vertically oriented sections of the primary heat transport systems of CANDU reactors. This model predicts the unequal velocity effects, spatially and temporally. It can be used to describe the slip in transient and multipurpose thermohydraulic codes. The transient velocity difference equation of this model is an arrangement of the two-fluid model equations. This equation describes the time-dependent relation between the phase velocities. This is a function of the pressure gradient, phase inertias, volume fraction, flow regime, interfacial forces, and additional constitutive relations. In addition, the model includes a package of momentum exchange constitutive laws to calculate the interphase momentum exchange parameters and virtual mass coefficients. The parameters necessary for the integration of this model into CANDU thermohydraulic codes (SOPHT, FIREBIRD) are expressed in terms of the dynamic difference velocity. These parameters are the drift mass flow rate, drift velocity, distribution parameter, flow quality, effective density, and flow enthalpy. Numerical results revealed that the velocity difference model fairly predicted the drift flux parameters when compared with those calculated by existing slipdrift correlations in the SOPHT and FIREBIRD codes, other drift flux models, and with certain experimental data reported in the literature.