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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.”
Wadim Jaeger, Wolfgang Hering (KIT)
Proceedings | Advances in Thermal Hydraulics 2018 | Orlando, FL, November 11-15, 2018 | Pages 846-859
In this paper, a review of experiments related to liquid metal heat transfer under mixed convection is performed. This study is relevant because heat transfer during start-up and shut-down procedures, and operational transients is influenced by natural convection, resulting in mixed convection, which differs considerably from forced convection. Up to now, simulation tools like TRACE, RELAP, etc. apply only forced convection models for liquid metal heat transfer. The influence of mixed convection on the heat transfer during the above mentioned transients is completely ignored. Hence, it is not possible to simulate mixed convection with best-estimate system codes like TRACE or RELAP. In order to perform realistic simulations of plants and experimental facilities mixed convection must be addressed and considered. Therefore, the literature is reviewed for experimental data with liquid metal heat transfer under mixed convection and generally applicable statements and models will be provided. A clear distinction in the heat transfer behavior for low and high Péclet number flows can be identified. Thereby, a Péclet number dependency is visible for higher Péclet numbers (Pe > 100). Furthermore, the heat transfer (Nusselt number) cannot be presented as a function of one dimensionless parameter. To identify underlying phenomena, especially when comparing different experimental scenarios several dimensionless numbers are needed (Gr*, B, Z, etc.). Based on this study, it is possible to derive a model for the heat transfer under mixed convection. Nevertheless, these findings and the sparse number of experiments also indicate the need for new and comprehensive experiments.