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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.”
Alexander J. Mieloszyk, Mujid S. Kazimi
Nuclear Technology | Volume 191 | Number 3 | September 2015 | Pages 268-281
Technical Paper | Fuel Cycle and Management | doi.org/10.13182/NT14-104
Articles are hosted by Taylor and Francis Online.
To provide steady-state fuel performance evaluations for the (ThU)O2-fueled Reduced moderation Boiling Water Reactor (RBWR-Th), modifications have been made to the FRAPCON-MIT code. In addition to the use of existing (ThU)O2 capabilities in FRAPCON-MIT, a radial power profile specific to the RBWR-Th was implemented. To more accurately model the corrosion acceleration due to high fast neutron fluence, the oxidation model was modified, and a new hydrogen uptake model was introduced. A preliminary assessment of an average RBWR-Th fuel rod shows the fuel temperature to remain below 1450 K and the fission gas release (FGR) to remain below 7%. However, because of the low free gas volume of the RBWR-Th rods, the plenum pressure is very sensitive to FGR and is shown to be capable of exceeding the coolant pressure. Of more concern is the high cladding hydrogen content that results from the acceleration of hydrogen pickup at relatively low burnups, which is caused by the high fast neutron fluence on the cladding in the RBWR-Th. This high hydrogen content leads to significant restrictions and, ultimately, elimination of the margin to acceptable accident limits, presenting a distinct challenge to the RBWR-Th design. A new cladding material, GNF-Ziron, from Global Nuclear Fuels (GNF) offers a potential solution to this challenge by delaying the acceleration of the hydrogen pickup. The potential benefits of using GNF-Ziron cladding are explored in a sensitivity study. This study illustrates that the selection of an appropriate cladding material for the RBWR-Th is crucial for its success.
