Thesis (B.S.)--Massachusetts Institute of Technology, Dept. of Nuclear Engineering, 1986. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND SCIENCE / Bibliography: leaf 47. / by Robert Rozier. / B.S.

Thesis (Sc. D.)--Massachusetts Institute of Technology, Dept. of Nuclear Enginering, 1987. / Includes bibliographies. / by Eric Yueh-Lang Sheu. / Sc.D.

Thesis (Sc. D.)--Massachusetts Institute of Technology, Dept. of Nuclear Engineering, 1986. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND SCIENCE. / Includes bibliographies. / by Alan Szu-Hsin Wan. / Sc.D.

Thesis (Sc.D.)--Massachusetts Institute of Technology, Dept. of Nuclear Engineering, 1983. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND SCIENCE / Includes bibliographical references. / by Paul Joseph Gierszewski. / Sc.D.

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Nuclear Engineering, 2004. / Includes bibliographical references. / This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections. / Disposal of post-irradiation fuel from nuclear reactors has been an issue for the nuclear industry for many years. Most countries currently have no long-term disposal strategy in place. Therefore, the concept of an intermediate nuclear spent fuel storage facility has been introduced as a method of temporarily storing the spent fuel in a central location until long-term disposal of the spent nuclear fuel is made available. General criteria that can be used to compare potential international sites for an intermediate nuclear spent fuel storage facility have been identified and elucidated. Those criteria were then utilized to compare four potential international intermediate nuclear spent fuel storage facility (IINSFSF) sites. Two of the sites are in Russia (one in the area of the old nuclear city of Krasnoyarsk-26 currently known as Zheleznogorsk and one on Sakhalin Island in the area of the town of Kholmsk), one is in China (in the area of the town of Xilinhot in the Nei Mongol province) and one in Australia (in the area of the city of Meekatharra in Western Australia). Safety and safeguard regulations for nuclear facilities were reviewed and appropriate portions that could be applied to a potential IINSFSF are recommended. An analysis was conducted to determine legal issues pertinent to an IINSFSF and a brief, limited overview of the most important legal issues is presented. The effects that nuclear fuels subjected to higher burnups (than practiced now) will have on dry cask storage was examined and recommendations for storage strategies are proposed. / (cont.) The selected criteria involve the areas of Geological Suitability, Seismic Stability, Land Area Suitability, Site Infrastructure Suitability, Transportation Infrastructure Suitability, Meteorological Suitability, Willingness of the Host Nation and Population Density. Application of the criteria to the suggested sites revealed that Krasnoyarsk - 26 is the best alternative. This is mainly due to the willingness of the host nation of Russia to accept this type of facility. Krasnoyarsk - 26 also rates as the best site with respect to the criteria of geological suitability and seismic suitability. Without consideration for the willingness of the host nation, Meekatharra would be the ideal site. Xilinhot was evaluated as the third best alternative followed by the Sakhalin Island site of Kholmsk. The legal issue that would be of most concern to an IINSFSF would be potential liability. It would be best if the host nation were a signatory of an international treaty limiting the liability of the IINSFSF operator. Of the two major international nuclear liability treaties in existence the one preferable is the Paris Convention. Economics are driving nuclear power plants in the United States to look to implement more highly enriched fuels to achieve higher burnupsHow these higher burnup spent fuels will affect dry cask storage of spent fuels at reactor sites should be examined. To determine this, the decay heat output of higher burnup spent fuels was compared to the storage capacity of a typical dry cask storage system ... / by Joe Burns. / S.M.

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Nuclear Engineering, 2003. / Includes bibliographical references (p. 67-68). / This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections. / Materials are evaluated for use as in-core diluents and as peripheral reflectors for Gas-Cooled Fast Reactor (GFR) service, using coupled Monte Carlo (MCNP) and isotopics (ORIGEN) codes. The principal performance indices compared were effects on beginning of irradiation multiplication factor, reactivity-lineated burnup, and coolant (here CO2) void reactivity. While low values of the macroscopic absorption cross section, [Sigma]a, and slowing down power, [xi] [Sigma]s, are qualitatively useful predictors of good performance, it was found that only full scope calculations were valid for quantitative assessment. For example, several materials (Ni, Nb) having poor performance as in-core diluents proved to be good reflectors. Many materials which reduced coolant void reactivity also proved detrimental to reactivity lifetime. Others, mostly the strong moderators, increased initial reactivity, but decreased reactivity lifetime. Cores fueled with plutonium exhibited a much larger void reactivity than those started up using U-235 as the fissile material. While there are no ideal candidates that are superior in all respects, considering only neutronic performance, the following appear worthy of further investgation: Metallic fuel diluents or matrices (eg. CERMET or METMET): Zr, Ti, V, Ba2Pb; High temperature fuel diluents or matrices (eg, CERMET, CERCER): SiC, BaS Cladding: Fe alloys with Cr, Al (eg ODS) Reflector: Zr3Si2, Pb, Ba2Pb, ZrS2, MoSi2 plus a variety of sulfides and silicides. / by Kun Yu. / S.M.

Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Nuclear Engineering, 1997. / Includes bibliographical references (leaves 109-111). / The boiling heat transfer characteristics of steam generator u-tube fouling deposits were identified by developing a boiling heat transfer model and determining its accuracy through the comparison of calculated and experimental results. Magnetite deposits were fabricated in the laboratory and were characterized using a variety of techniques. Heat transfer measurements were then taken, so that the effect of deposit parameters, including pore size distribution, porosity, permeability and thickness, as well as the effect of mass flux, heat flux and steam quality were investigated. The model predictions were consistent with the experimental results, differing by an average of ±17.5%. Over the range of parameters studied, pore size distribution dominated the deposit heat transfer. It was found that some fabricated deposits improved the heat transfer of the u-tubes, whereas others hindered it. The data were consistent with that of fouled u-tubes pulled from CANDU steam generators. The conditions of the heat transfer measurements and the fabricated deposits were similar to those of US and Canadian steam generators. Therefore, the conclusions drawn in this study are presumed to apply to the steam generators used in the Canadian and US industries. / by Jennifer L. Uhle. / Ph.D.

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Nuclear Engineering, 2004. / Includes bibliographical references (leaves 72-76). / The extreme importance of critical infrastructures to modem society is widely recognized. These infrastructures are complex, interdependent, and ubiquitous; they are sensitive to disruptions that can lead to cascading failures with serious consequences. Protecting the critical infrastructures from terrorism, human generated malevolent attack directed toward maximum social disruption, presents an enormous challenge. Recognizing that society cannot afford the costs associated with absolute protection, it is necessary to identify the critical locations in these infrastructures. By protecting the critical locations society achieves the greatest benefit for the protection investment. This project examines a screening methodology for the identification of critical locations in infrastructures. The framework models the infrastructures as interconnected digraphs and employs graph theory and reliability theory to identify the vulnerable points. The vulnerable points are screened for their susceptibility to a terrorist attack, and a prioritized list of critical locations is produced. The prioritization methodology is based on multi-attribute utility theory, and involves various disciplines including quantitative risk assessment and decision analysis. The methodology is illustrated through the presentation of a portion on the analysis conducted on the community of the Massachusetts Institute of Technology. / by Douglas M. Lemon. / S.M.

Thesis (Sc. D.)--Massachusetts Institute of Technology, Dept. of Nuclear Engineering, 2000. / Includes bibliographical references (p. 187-198). / Photonuclear resonance excitation refers to a variety of photonuclear interaction processes that lead to the excitation of a nucleus from some initial state to a higher energy nuclear state. Typical excited nuclear state lifetimes are short, ranging from nanoseconds to femtoseconds or less; however, some isotopes have unusually long-lived excited nuclear energy states, or isomers. This dissertation examines the feasibility of using bremsstrahlung irradiation sources to produce isomers for industrial applications. In contrast with charged particle based isomer production, the use of high energy photons allows for the irradiation and production of isomers in bulk materials. The commercial availability of reliable, high power industrial electron accelerators means that isomer activities sufficient for industrial applications may be achieved using bremsstrahlung, in contrast with neutron based approaches where suitable neutron sources of sufficient intensity for these applications are lacking. In order to design a system for creating nuclear isomers using photons, the resonant photon absorption isomeric excitation cross section must be known. Unlike neutron absorption and scattering cross sections, comparatively little information exists for photon isomeric excitation. To address this, a theoretical model based upon statistical probability distributions of nuclear energy levels has been developed for calculating photon excitation cross sections at energies below neutron and proton binding energies; the ideal region of operation for most applications in order to minimize long term activation of materials. Isomeric excitation cross sections calculated using this technique have been compared with experimentally measured values and are found to agree to within a factor of two or better. / (cont.) sing this, a general transition equation suitable for both nuclear resonance fluorescence and isomer excitation has been developed for calculating nuclear level distribution probabilities for materials undergoing photon irradiation. Experiments have been carried out using an industrial 6 MeV electron accelerator to identify obstacles related to nuclear resonance fluorescence measurements as well as measurements of the decay of short-lived isomers using scintillators in the vicinity of high intensity bremsstrahlung sources. Use of a fast switching gating circuit in combination with a pulsed accelerator was found to be a satisfactory solution for dealing with problems related to the performance of a detectors photomultiplier tube as a result of exposure to scattered radiation during the beam pulse. Calculations have been carried out to assess the performance characteristics which could be expected from industrial photonuclear resonance excitation systems, based upon a 10 MeV electron accelerator. For simple isomer production, specific activities on the order of 1 mCi/g/mA can be expected for irradiation periods sufficiently long for equilibrium to be reached. For the analysis of arsenic concentrations in environmental samples, sensitivities of 1 +/- 0.1 ppm could be achieved using accelerator currents of 50 - 100 [mu]A with irradiations times of a few minutes or less. A system designed to analyze ore traveling along a conveyor belt could be used to sort gold ore based upon a lower grade cutoff of 5 ppm using an accelerator of 10 mA ... / by David Lee Chichester. / Sc.D.

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Nuclear Engineering, 2002. / Also issued in pages. Vita. / Includes bibliographical references. / Some recent neutron capture therapy (NCT) research has focused on using compounds containing the element gadolinium (Gd), which produces internal conversion and Auger cascade electrons upon absorbing thermal neutrons. The low energy, nanometer-range, Auger electrons are absorbed locally and significantly increase cell killing when Gd binds to DNA. Two other methods induce Auger electrons in gadolinium isotopes: the beta decay of 159Gd, and K shell photoelectric events during photon irradiation. To determine the potential application that Auger cascades from these three processes could have in brain tumor therapy, macroscopic and microscopic radiation transport calculations were employed to relate peak brain dose to DNA double-strand breaks (DSBs) in tumor cells. Macroscopic calculations indicated that even optimal gadolinium distributions produce GdNCT and Gd photon activation therapy (PAT) dose distributions in brain tumors less favorable than those with boron-based NCT. 59Gd radionuclide therapy (RNT), however, produced more favorable dose distributions, assuming optimal tumor retention. Microscopic transport calculations superimposed Auger electron tracks over an atomistic model of mammalian chromatin fiber and tracked resulting OH, H, and eaq radicals to determine strand breaks. / (cont.) Calculated DSBs from 125I, a well-studied Auger electron therapy isotope, were compared to similar calculational and experimental results to validate the code. The '57Gd(n,y), Gd photoelectric events and 59Gd decays result in 0.21, 0.25, and 0.05 DSBs per event, respectively. For concentrations of 1000 ppm Gd and a peak dose to brain of 10 Gy, the three gadolinium-based therapies produced up to 150 ± 30 Auger electron induced DSBs per tumor cell in midline tumors, depending on the tumor dose distribution and tumor size. Assuming that equal DNA damage from 125I decay and Gd Auger electrons result in similar cell survival, Gd Auger electrons in these three therapy modalities will have some cell killing potential of their own, indicating potential therapeutic application. / by John Timothy Goorley. / Ph.D.