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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.”
Jaeha Kim, Yonghee Kim
Nuclear Science and Engineering | Volume 194 | Number 1 | January 2020 | Pages 1-13
Technical Paper | doi.org/10.1080/00295639.2019.1642016
Articles are hosted by Taylor and Francis Online.
This paper presents the methodology and performance of the Hybrid Coarse-Mesh Finite Difference (HCMFD) algorithm for transient pinwise analyses of three-dimensional (3-D) pressurized water reactor (PWR) problems. The time-dependent neutron diffusion equations and their applications in two steps of the HCMFD algorithm, i.e., local and global iterations, are introduced in detail. Taking into account the characteristics of the local-global nonlinear HCMFD iterations, an optimization strategy to minimize the computing time of the transient HCMFD calculation is established by focusing on the balance between the number of local and global calculations. Based on the optimization strategy, the actual computational performance of the transient HCMFD algorithm, in view of both computing time and accuracy, is evaluated for the core of a big-sized conventional PWR in this work. To demonstrate the effectiveness of the optimized iteration strategy, various slow and fast transients including a rod ejection transient are simulated by the transient HCMFD algorithm. It is clearly shown that a 3-D pin-resolved whole-core transient solution for a big PWR can be obtained in a reasonably short computing time by the transient 3-D HCMFD algorithm.