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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.”
Young Min Kwon, Chan Eok Park, Jin Ho Song
Nuclear Technology | Volume 122 | Number 3 | June 1998 | Pages 295-305
Technical Paper | Thermal Hydraulics | doi.org/10.13182/NT98-A2871
Articles are hosted by Taylor and Francis Online.
To investigate the realistic behavior of mass and energy release and resultant containment response during a large-break loss-of-coolant accident (LOCA), analyses are performed on the Yonggwang (YGN) 3&4 nuclear power plants using the RELAP5/CONTEMPT4 computer code. Comparative analyses using conservative design computer codes are also performed. The break types analyzed are the double-ended guillotine breaks at the cold leg and hot leg. The design analysis predicts that the containment peak pressure occurs during the postblowdown phase for the cold-leg break. However, RELAP5/CONTEMPT4 analyses show that the containment pressure has a peak during the blowdown phase, thereafter it decreases monotonously without the postblowdown peak. For the hot-leg break, revised design analysis shows a much lower pressure than that reported in the YGN 3&4 final safety analysis report. The RELAP5/CONTEMPT4 analysis shows a similar trend and confirms that the bypass flow through the broken loop steam generator during postblowdown is negligibly small compared to that of the cold-leg break. In conclusion, realistic analysis by RELAP5/CONTEMPT4 demonstrates that the containment peak pressure occurs during the blowdown phase for both cold- and hot-leg large-break LOCAs, and there is no physical mechanism resulting in mass and energy discharge that can pressurize the containment after end of blowdown for a hot-leg break. Also, it is suggested that the substantial conservatism included in the design analysis should be improved to provide benefits in relaxing the plant technical specifications and reducing the containment design pressure.