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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.”
Song Hyun Kim, Do Hyun Kim, Jong Kyung Kim, Jea Man Noh
Nuclear Science and Engineering | Volume 178 | Number 1 | September 2014 | Pages 29-41
Technical Paper | doi.org/10.13182/NSE13-38
Articles are hosted by Taylor and Francis Online.
In order to avoid calculation bias and increase calculation efficiency, convergence of the fission source distribution (FSD) in Monte Carlo simulations is important. Numerous analysis methods have been developed and used for checking the fission source convergence. However, such schemes have low applicability to Monte Carlo codes or give low diagnostic accuracy. To address these limitations, a method to verify the fission source convergence using the average and standard deviation of fission source positions is proposed. To collect the fission site information, the MCNP5 code was modified, and position information was extracted. The accuracy and advantages of the proposed method were verified by solving Organisation for Economic Co-operation and Development/Nuclear Energy Agency benchmark problems with the modified MCNP5 code and comparing the results to those obtained with the Shannon entropy and the nine center distance sum approaches. The analysis shows that the proposed method has good applicability and exhibits high accuracy for verifying the convergence of the FSD. It is expected that the proposed scheme will be a valuable contribution to the field of the fission source convergence.