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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.”
Dong Won Lee, Hee Cheon No, Eu Hwak Lee, Seung Jong Oh, Chul-Hwa Song
Nuclear Technology | Volume 153 | Number 2 | February 2006 | Pages 175-183
Technical Paper | Thermal Hydraulics | doi.org/10.13182/NT06-A3698
Articles are hosted by Taylor and Francis Online.
Experiments have been carried out to investigate the boiling phenomena in the downcomer, and RELAP5/MOD3.2 has been assessed with the present experimental data. A heated wall with a thickness of 8.2 cm and a height of 32.5 cm is used. The wall is made of the same material as the prototype (APR1400) with chrome coating to protect against rusting. From the experiment, we visually observed strong liquid recirculation and vapor jetting near the heated wall. These phenomena arose from axial migration of voids located only in the thin layer of the heated wall, whereas there was little bubble migration to the bulk region. The size of the thin layer is below 4 cm, which is used for the determination of the radial nodal size in radial double-node schemes. The RELAP5 calculations using three different nodal schemes are compared with experimental data in terms of water level, void fraction, wall temperatures, and phase velocities. The radial single-node scheme produces no liquid recirculation, resulting in a sudden level drop due to a sudden increase in void fraction. The double-node scheme with top-bottom radial connections yields strong circulation, eliminating the sudden level drop. As a result, the scheme produces better results than the radial single-node scheme and a double-node scheme with all radial connections. Based on the information from measurement of the local liquid velocity profile and visual observations, a drift velocity model is developed for application into a downcomer with a large gap and a vertical heated wall. The proposed drift velocity model has been implemented into RELAP5 and verified with experimental results.