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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.”
Shirley Dickinson, Howard E. Sims
Nuclear Technology | Volume 129 | Number 3 | March 2000 | Pages 374-386
Technical Paper | Reactor Operations and Control | doi.org/10.13182/NT00-A3068
Articles are hosted by Taylor and Francis Online.
The prediction of iodine behavior in the containment of a pressurized water reactor following a loss-of-coolant accident requires a reliable model of the chemistry of iodine in aqueous solution. The INSPECT model, which has been developed over several years, contains a large number of the relevant chemical reactions of iodine and water radiation chemistry. Since the reaction set was first assembled, new data on rate constants and mechanisms have become available. In addition, the application of the model to various small-scale experiments has revealed problems in the modeling of some reactions, leading to an underprediction of the iodine volatility at high pH, although the experiments have demonstrated that the high-pH volatility remains satisfactorily low.The INSPECT model is described along with the recent modifications that have been made to take account of new data and to improve the modeling where appropriate. The most important of these were (a) changes to the H2O2 - I2 reaction mechanism, (b) the inclusion of an impurity-catalyzed first-order O2- disproportionation reaction, and (c) the treatment of atomic I as a volatile species. These modifications have led to an increase in the predicted iodine volatility under neutral and alkaline conditions. At pH 4.6, where the original model had been found to be satisfactory, the modifications did not result in a significant change in the predicted volatility.The predictions of the revised model are compared with the results of a comprehensive series of experiments, which are described in a separate paper. The model predictions are in generally good agreement with the experiments for the range of conditions studied (pH 4.6 to 9, 10-5 to 10-4 mol/dm3 I-, 0.02 to 0.2 Mrad/h, 25 to 70°C). The results at neutral and high pH show a significant improvement over the previous version of the model, which underestimated the volatility at pH 9 by more than two orders of magnitude.