Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Nuclear Engineering, 1992. / Includes bibliographical references (leaves 124-128). / by Mansoor Siddique. / Ph.D.

Massachusetts Institute of Technology. Dept. of Nuclear Engineering. Thesis. 1972. Nucl.E. / Bibliography: leaves 157-162. / Nucl.E.

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Nuclear Engineering, 1991. / Includes bibliographical references (v. 2, leaves 494-516). / by Robert P. Jacqmin. / Ph.D.

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Nuclear Engineering, 1990. / Includes bibliographical references (leaves 258-260). / by John Hwan Chun. / M.S.

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Nuclear Engineering, 1987. / Bibliography: leaves 164-169. / by Anne Marie Morillon. / M.S.

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Nuclear Engineering, 2003. / Includes bibliographical references (leaf 143). / This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections. / The aim of this work is to develop and implement methods for determining the local structure and dynamics of heterogeneous samples (e.g. rocks, rubber, porous materials, etc.). From the physical point of view, the heterogeneities are best described in terms of variations in the local susceptibility. The proposed methods are based on analyzing the modulation of spin dynamics by the Magic Angle Sample Spinning (MASS) method in the presence of both local variations in the bulk magnetic susceptibility and molecular diffusion. The correlations between the dipolar and susceptibility fields are used for extracting information on the detailed structure and composition of heterogeneous samples. In the first part of this dissertation, a new method for characterizing porous media, diffusive MASS, is presented. This method is combining MASS and molecular diffusion, providing thus a unique way to simultaneously obtain high resolution spectra and information on the geometry and the internal fields inherent to porous samples. The second part is concerned with obtaining detailed information about the structure and dynamics in rubber samples with the aim of understanding the elastomer-carbon black interactions. The processes that occur at the elastomer-carbon black interface are responsible for the special properties that make rubber so useful and these processes are not yet fully understood. We use the dipolar and susceptibility interactions to characterize the elastomer spatial distribution relative to the carbon black surface, the elastomer mobility and the local order. The last section presents a MASS study of the relaxation and wettability of actual rock samples. / (cont.) It is important to design experiments for characterizing wettability which are less time consuming than the current core-flooding and imbibition experiments. The combination of MASS and relaxation measurements permits the determination of the chemical composition and wetting fluid in core samples. We apply this method to the characterization of two preserved sandstone cores. / by Gabriela Leu. / Ph.D.

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Nuclear Engineering, 1991. / Includes bibliographical references (leaves 173-176). / by James J. Winebrake. / M.S.

Massachusetts Institute of Technology. Dept. of Nuclear Engineering. Thesis. 1967. Sc.D. / One unnumbered page inserted. Vita. / Bibliography: leaves 281-284. / by William Dean Hinkle. / Sc.D.

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Nuclear Engineering, 1991. / Science hard copy bound in 1 v. / Includes bibliographical references (leaves 163-165). / by Phyllis Maria Lovett. / M.S.

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Nuclear Engineering, 2003. / Includes bibliographical references (leaves 228-232). / The thesis investigates the potential of fertile free fast lead-cooled modular reactors as efficient incinerators of plutonium and minor actinides (MAs) for application to dedicated fuel cycles for transmutation. A methodology is developed that assesses the actinide incineration performance of several transmutation fuel cycles, both single and multi-tiered, on the basis of performance indicators related to the reduction of actinide mass at the repository and economics. Application of the methodology indicates that fast fertile-free critical reactors that bum plutonium and MAs applied to both one-tier and two-tier fuel cycles with fuel reprocessing have the potential to be more economical than other dedicated systems like the ATW. Hence the thesis studies two lead-cooled critical reactors that employ fertile-free fuel as possible candidates. The two designs proposed are: an actinide burner reactor (ABR), designed to incinerate mostly plutonium and some MAs from the spent fuel of the conventional LWR fleet, and a minor a ctinide buumer reactor (MABR), devoted to bum mostly minor actinides and some plutonium both recycled from the burner and produced by the LWR fleet that should be integrated in a two-tier fuel cycle where most of the plutonium is fed back to advanced thermal reactors or conventional fast reactors (first tier) for incineration. These designs incorporate several advanced technical solutions such as fuel assemblies with streaming elements, double-entry control rods and special absorbing materials that establish favorable neutronics characteristics and excellent self-controllability features, comparable to those of the Integral Fast Reactor (IFR) core. / (cont.) Specifically, the designs achieve (a) negative reactivity feedbacks based on coolant voiding, Doppler and fuel and core structure thermal expansion effects; (b) satisfactory values for the effective delayed neutron fractions, comparable to those reported for the IFR; (c) proliferation resistance with dilution of the plutonium vector, which is practically unusable for nuclear weapons fabrication. The safety features of these designs is assessed by applying a thermal-hydraulic code that simulates the worst accident scenarios envisaged for the burners. Application of the fuel cycle methodology to both designs shows that a) deployment of the MABR as the burner in the two-tier fuel cycle is the most efficient strategy to manage actinides and that b) both designs yield lower fuel cycle costs compared to the subcritical reactors. / by Antonino Romano. / Ph.D.