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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.”
Min Seop Song, Eung Soo Kim (Seoul Natl Univ), Jae Ho Jeong (KAERI)
Proceedings | Advances in Thermal Hydraulics 2018 | Orlando, FL, November 11-15, 2018 | Pages 531-546
The wire-wrapped pin bundle is the most commonly adopted form of the fuel assembly in SFRs. It is challenging to measure the local flow velocity field experimentally because of its narrow channel and complex internal shape. In this study, the refractive indices of the fluid and the test-section are matched and the flow field in the SFR wire-wrapped 19-pin bundle is visualized using optical measurement techniques such as PIV/LDV and compared with the RANS-based computational fluid dynamic (CFD) analysis. According to the turbulence intensity and the pressure drop measurements, it is observed that the flow regime changes from the transition regime to the fully turbulent regime when the Re number is more than 13,000. In addition, the pressure drop measurement results are compared with the CFD analysis for various turbulence models, and it is found that the BSL-RSM model predicts the experimental results the most accurately. The velocity distribution obtained in the edge sub-channel using PIV is also compared with the CFD results. As a result, the flow and vortex shapes are very similar to each other qualitatively. However, some discrepancies are observed quantitatively in the region where the channel thickness is narrow. The main reason is considered to be attributed to the pin location error, the refraction of light and the velocity averaging due to the thickness of the laser sheet incident on the thin channel during the experiment. Further investigation is on-going for analysis of flow in interior subchannel.