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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.”
R. A. Van Konynenburg, M. W. Guinan
Nuclear Technology | Volume 60 | Number 2 | February 1983 | Pages 206-217
Technical Paper | Radiation Effects and Their Relationship to Geological Repository / Radioactive Waste Management | doi.org/10.13182/NT83-A33075
Articles are hosted by Taylor and Francis Online.
SYNROC-D is a ceramic material proposed as a waste form for defense high-level nuclear waste. During the first million years of storage, it would be subjected to ∼8 × 1024 alpha decay/m3 of SYNROC-D and a total ionization dose of ∼1 × 1011 rad. There are several methods of simulating the resulting radiation effects, including external bombardment using gamma rays, electrons, light ions, heavy ions, or neutrons, and internal bombardment using short half-life actinide doping to bring about internal alpha decay, or doping with uranium, boron, or lithium, coupled with neutron irradiation, to induce internal fissions or (n, α) reactions. Previous work by others using several of these methods as well as data from natural minerals has been compared on a displacements per atom basis. The results show that dose rate effects are not important in determining the swelling and metamictization of the perovskite and zirconolite phases over a wide range of dose rate for low temperatures and doses of 2 to 3 × 1025 alpha/m3 of each phase, corresponding to expected million year doses in SYNROC-D. Based on this observation and a consideration of the basic processes involved, we argue that the million-year radiation damage expected in SYNROC-D can be adequately simulated in a few months by doping samples with 238Pu, and simultaneously carrying out external gamma-ray bombardment. The 238Pu will undergo alpha decay, producing the same type of damage in the same phases as would long-term actinide decay in actual waste. The gamma irradiation will simulate the ionization dose, which would result primarily from fission product decay in actual waste. SYNROC-D samples have been fabricated and characterized using cerium and uranium, respectively, as stand-ins for plutonium. These samples show good properties, and 239Pu doping experiments are expected to take place soon to determine if plutonium will dissolve properly in SYNROC-D.