Studies of epithermal neutrons in uranium, heavy water lattices
Author(s)
D'Ardenne, Walter Herbert; Thompson, Theos Jardin, 1918-1970; Lanning, David D.; Kaplan, Irving, 1912-
Download09755035.pdf (14.95Mb)
Other Contributors
Massachusetts Institute of Technology. Department of Nuclear Engineering
U.S. Atomic Energy Commission
Metadata
Show full item recordAbstract
Measurements related to reactor physics parameters were made in three heavy water lattices. The three lattices studied consisted of 0.250-inch-diameter, 1.03 w/o U2 3 5 uranium fuel rods arranged in triangular arrays and spaced at 1.25, 1.75, and 2.50 inches. The following quantities were measured in each of the three lattices studied: the ratio of the average epicadmium U2 3 8 capture rate in the fuel rod to the average subcadmium U2 3 8 capture rate in the fuel rod ([sigma]28); the ratio of the average epicadmium U2 3 o fission rate in the fuel rod7 to the average subcadmium U 35 fission rate in the fuel rod (625); the ratio of the average U2 3 8 capture rate in the fuel rod to the average U2 3 5 fission rate in the fuel rod (C ); the ratio of the average U2 3 8 fission rate in the fuel rod to the average U2 3 5 fission rate in the fuel rod (628); and the effective resonance integral of U2 3 8 in a fuel rod (ER12 8 ). The results of an investigation of systematic errors associated with these measurements have-led to many changes and adjustments in the experimental techniques and procedure which have improved the general precision of the experimental results. A new method was developed to measure the ratio C * which simplified the experiment, significantly reduced the experimental uncertainty associated with the measurement, and avoided systematic errors inherent in the method used to measure C* in earlier work. The value of ER12 8 was also measured by a new method in which the results of measurements made in an epithermal flux which had a 1/E energy dependence are combined with the results of measurements made in a lattice. The experimental results were combined with theoretical results obtained from the computer programs THERMOS and GAM-I to determine the following reactor physics parameters for each of the three lattices studied: the resonance escape probability, p; the fast fission factor, E; the multiplication factor for an infinite system, k [infinity]; and the initial conversion ratio, C. Methods were developed to measure that portion of the activity of a foil which is due to neutron captures in the resonances in the activation cross section of the foil material. The resonance escape probability was determined by a new method, using the resonance activation date, in which the use of cadmium is not necessary.
Description
Statement of responsibility on title-page reads: W. H. D'Ardenne, T. J. Thompson, D. D. Lanning and I. Kaplan "August 24, 1964." "MIT-2344-2." Also issued as a Ph. D. thesis by the first author, MIT Dept. of Nuclear Engineering, 1964 Includes bibliographical references (leaves 167-170)
Date issued
1964Publisher
Cambridge, Mass. : Dept. of Nuclear Engineering, Massachusetts Institute of Technology, 1964
Series/Report no.
MIT-2344-2MITNE ; no. 53AEC research and development reportTID ; 4500