Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 28 for “"highly enriched uranium"”.
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Examination of the conversion of the U.S. submarine fleet from highly enriched uranium to low enriched uranium
… for submarine propulsion are currently fueled by highly enriched uranium (HEU), but HEU brings administrative and political challenges. This issue has been studied by the Navy before, and promising new fuel technology developments, combined with new motivations, warrant a fresh look at low …
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Examination of the proposed conversion of the U.S. Navy nuclear fleet from highly enriched Uranium to low enriched Uranium
… fact that its entire nuclear fleet is powered by highly enriched uranium (HEU). In 1995, the U.S. Navy issued a report indicating that converting the nuclear reactors on its submarines and carriers from the use of HEU to the use of low enriched uranium (LEU) would create numerous problems. …
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Validation of the use of low enriched uranium as a replacement for highly enriched uranium in US submarine reactors
The US Navy has long used highly enriched uranium (HEU) in naval reactors for a variety of technical reasons. In a series of studies, the Department of Naval Reactors determined that switching to low enriched uranium (LEU) was impossible using current fuel designs, but may be possible with a …
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Nuclear non-proliferation regime effectiveness : an integrated methodology for analyzing highly enriched uranium production scenarios at gas centrifuge enrichment plants
… of proliferators successfully producing Highly Enriched Uranium (HEU) at Gas Centrifuge Enrichment Plants (GCEPs) and (b) how effective is the current NPT regime in dealing with this issue. In order to tackle these two questions, an integrated methodology is used that reflects all factors …
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Design of a low enrichment, enhanced fast flux core for the Massachusetts Institute of Technology Research Reactor
… is planning for a new core to end the need for highly enriched uranium and operate the reactor with uranium enrichments under 20%. This study explores the use of the central region in the newly proposed MIT reactor core to boost the production of fast neutrons, thus making the new core more …
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Impact assessment for the MIT Research Reactor low enrichment uranium fuel fabrication tolerances
… Reactor (MITR) is planning to convert from highly enriched uranium (HEU) to low enriched uranium (LEU) fuel. A new type of high-density LEU fuel based on a monolithic U-10Mo alloy is being qualified to allow the conversion of all remaining U.S. high performance research reactors including …
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Guardians at the Gates of Hell : estimating the risk of nuclear theft and terrorism -- and identifying the highest-priority risks of nuclear theft
… and flows of nuclear weapons, plutonium, and highly enriched uranium (HEU), with the global distribution of facilities where they exist; and the widely varying standards of physical protection, control, and accounting in place to prevent theft. Particular dangers of nuclear theft in Russia, …
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Design of a sodium-cooled epithermal long-term exploration nuclear engine
… core is an ultra high power density core with highly enriched uranium fuel. The sodium Rankine cycle has many advantages, lending to a highly efficient radiator and compact reactor core. The sodium- cooled, epithermal long-term exploration nuclear engine (SELENE) is designed to be scalable to …
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Maximum hypothetical accident analysis for HEU to LEU fuel conversion at the University of Missouri Research Reactor
… Reactor (MURR) intends to convert from 93% highly-enriched uranium (HEU) aluminide dispersion fuel to 19.75% low-enrichment uranium (LEU) U-Mo monolithic fuel. Under chapter 13 of NUREG-1573, MURR must perform several safety analyses, one of which was the maximum hypothetical accident (MHA) …
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Thermal-mechanical analysis of targets for high volume production of molybdenum-99 using low-enriched uranium
… facilities located in foreign countries and use highly enriched uranium (HEU). The University of Missouri Research Reactor (MURR) is exploring the feasibility of high volume molybdenum-99 production at its facility. Current molybdenum-99 production uses HEU in a powder dispersion target. The …
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Applicability of cosmic ray muon radiography to nuclear nonproliferation
… of low, medium, and high Z (carbon, iron, highly enriched uranium). A reconstruction algorithm based on the PoCA method is implemented using C++/ROOT, and imaging of simple geometries based on scattering angle is achieved. The impact of different variables related to the detection setup, …
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Dual neutral particle induced transmutation
… of cargo to detect the smuggling of highly enriched uranium -- a concept that would require modeling of the transmutation caused by both neutrons and photons. As photonuclear transmutation has yet to be modeled, new methods need to be developed. The CINDER2008 nuclear transmutation …
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Thermal hydraulic limits analysis for the MIT Research Reactor low enrichment uranium core conversion using statistical propagation of parametric uncertainties
… Reactor (MITR) is evaluating the conversion from highly enriched uranium (HEU) to low enrichment uranium (LEU) fuel. In addition to the fuel element re-design from 15 to 18 plates per element, a reactor power upgraded from 6 MW to 7 MW is proposed in order to maintain the same reactor performance …
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A 3D Computational Fluid Dynamics Model Validation for Candidate Molybdenum-99 Target Geometry
… isotope molybdenum-99 (99Mo) without using highly enriched uranium (HEU). 99Mo is the parent product of technetium\xad99m (99mTc), a radioisotope used in approximately 50,000 medical diagnostic tests per day in the U.S. The primary uses of this product include detection of heart disease, …
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Modern Rossi alpha measurements
… of the modern Rossi-α method on the all highly enriched uranium, HEU, Zeus experiment. Measurements are taken at several subcritical configurations, at critical in the presence of a source, and at one supercritical point. During the experiment, the List-mode module generates time tags of …
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Estimate of radiation release from MIT reactor with low enriched uranium (LEU) core during maximum hypothetical accident
… (MITR) is planning on converting from the use of highly enriched uranium (HEU) to low enriched uranium (LEU) for fuel. A component of the conversion analysis includes calculating the maximum hypothetical accident (MHA) dose implications for the two types of fuel. In this work, the dose levels at …
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Developing fuel management capabilities based on coupled Monte Carlo depletion in support of the MIT Research Reactor (MITR) conversion
… (MITR) is planning on converting from the use of highly enriched uranium (HEU) to low enriched uranium (LEU) for fuel. Prior studies have shown that the MITR will be able to operate using monolithic U-Mo LEU fuel while achieving neutron fluxes close to that of an HEU core. However, to date, …
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Compact Capabilities: Developing and Evaluating a Field-Portable Neutron Resonance Capture Analysis System
… the thorium cycle shares many aspects with the uranium and plutonium fuel cycles, it introduces the requirement for the nondestructive assay of multiple isotopes (²³8U, ²³²Th, ²³³U, ²³⁵U, or ²³⁹Pu) in varied concentrations and chemical or physical forms. Current methodologies used for …
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Investigation and modeling of uranium polarization for the electrorefining of Scrap U-MO foils
<p>A uranium molybdenum alloy fuel has been proposed to convert research and test reactors from highly enriched uranium to low enriched uranium to increase the proliferation resistance at such reactors. Pyroprocessing has been selected to recover uranium from the scrap produced in the manufacture …
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Nuclear Electric Propulsion with Low Enriched Uranium
… but politically problematic fuel choice of highly enriched uranium (HEU). Using low enriched uranium (LEU, 20% U-235 by mass) avoids many of the security costs and public perception issues associated with HEU but has implications for the power system design. The core will require more fuel …
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