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 27 for “"fuel temperature"”.
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The effects of fuel volatility and operating conditions on sprays from pressure-swirl fuel injectors
… gasoline engines depends heavily on the fuel spray. Most of the studies published regarding these fuel sprays involve cold bench tests or motored optical engines, neglecting the roles of the fuel volatility and temperature. This study, therefore, was designed to describe changes in the …
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Silicon carbide performance as cladding for advanced uranium and thorium fuels for light water reactors
… has been an ongoing interest in replacing the fuel cladding zirconium-based alloys by other materials to reduce if not eliminate the autocatalytic and exothermic chemical reaction with water and steam at above 1,200 °C. The search for an accident tolerant cladding intensified after the …
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An inverted hydride-fueled pressurized water reactor concept
… heat flux (CHF) and fretting phenomena of the fuel rods against grid spacers. The present work investigates the possibility to reduce the limiting effect exerted by these constraints by radically changing the core geometry, rather than by only taking measures to address specific constraints. …
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A lattice boltzmann/s n framework for coupled heat transfer and neutron transport problems
… transport and heat conduction equations with temperature-dependent thermal conductivity and temperature-dependent neutron cross sections. The neutron transport equation is solved using the discrete ordinates method (SN ); and the heat conduction equation is solved using the lattice Boltzmann …
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Loss-of-flow analysis of an unfinned, graded fuel meat, LEU monolithic U-10Mo fuel design in support of the MITR-II fuel conversion
… 93%-enr 235U highly-enriched uranium (HEU) fuel to the low-enriched uranium (LEU, <20% 235U) fuel. This reduction in enrichment decreases the neutron flux level due to parasitic absorption by 238U. The neutron flux may be compensated for by increasing the reactor's nominal operating power …
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An assessment of silicon carbide as a cladding material for light water reactors
… and performance of a novel silicon carbide-based fuel rod cladding under PWR conditions was conducted. The novel design is a triplex, with the inner and outermost layers consisting of monolithic SiC, while the middle layer consists of a SiC fiberwound composite. The goal of this work was …
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An inverted pressurized water reactor design with twisted-tape swirl promoters
An Inverted Fuel Pressurized Water Reactor (IPWR) concept was previously investigated and developed by Paolo Ferroni at MIT with the effort to improve the power density and capacity of current PWRs by modifying the core geometry. A detailed study was performed to optimize the IPWR design …
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Methods for including multiphysics feedback in Monte Carlo reactor physics calculations
… continuous multiphysics feedback fields such as fuel temperature and coolant density into the Monte Carlo simulation. It has been shown that separable Zernike and Legendre Function Expansion Tallies can effectively reconstruct a continuous distribution of fission power density. Additionally, …
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Fuel performance modeling of high burnup mixed oxide fuel for hard spectrum LWRs
According to the future of the nuclear fuel cycle study at MIT, a reactor with a conversion ratio around one can achieve desired objectives in the long-term sustainability of uranium and reduction of transuranic wastes. This finding relaxes the need for sodium fast reactors (SFR) in a closed-loop …
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Thermal hydraulic design of a salt-cooled highly efficient environmentally friendly reactor
… spectrum reactor was designed with a long fuel cycle, and high core exit temperature. These features are desirable in a reactor designed to provide process heat applications such as oil refinery needs of heat and electricity. The reactor uses the binary salt NaF-BeF₂ as the primary coolant, …
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Testing the EPRI reactivity depletion decrement uncertainty methods
… and McGuire nuclear power plants) to determine fuel assembly reactivity decrements versus burnup. The analytical techniques used to infer measured assembly reactivities required perturbation calculations using 3D nodal diffusion core models. Subsequently, questions have arisen within the Nuclear …
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Effects of different fuels on a turbocharged, direct injection, spark ignition engine
… experimentation and analysis of two different fuels in GM's high compression ratio, turbocharged direct injection (TDI) engine. The focus is on a burn rate analysis for the fuels - gasoline and E85 - at varying intake air temperatures. The results are aimed at aiding in a subsequent study that …
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Thorium-based mixed oxide fuel in a pressurized water reactor: A feasibility analysis with MCNP
… dissertation investigates techniques for spent fuel monitoring, and assesses the feasibility of using a thorium-based mixed oxide fuel in a conventional pressurized water reactor for plutonium disposition. Both non-paralyzing and paralyzing dead-time calculations were performed for the Portable …
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An evolutionary fuel assembly design for high power density BWRs
An evolutionary BWR fuel assembly design was studied as a means to increase the power density of current and future BWR cores. The new assembly concept is based on replacing four traditional assemblies and large water gap regions with a single large assembly. The traditional BWR cylindrical …
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Innovative fuel designs for high power density pressurized water reactor
… power density of the reactor core. Features of fuel design that enhance the potential for high power density are derived based on characteristics of the pressurized water reactor (PWR) and its related design limits. Those features include: large fuel surface to volume ratio, small fuel …
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Spray characterization of flex-fuel gasoline di injectors and spray interaction with charge motion in a variable valve actuation engine
… conditions including ambient conditions (temperature, pressure) and injection conditions (fuel type, fuel temperature, nozzle design) on spray formation was discussed in both qualitative and quantitative methods. High-speed visualization of the in-cylinder charge motion was carried out as …
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Monte Carlo and thermal hydraulic coupling using low-order nonlinear diffusion acceleration
… was used to construct coolant density and fuel temperature dependencies of diffusion parameters between each TH update using MC tallies. A framework was introduced to obtain relative pin power distributions with 95% confidence intervals to 1% with continuous-energy Monte Carlo coupled to …
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Consideration of fuel behaviour in AGR-like FHR reactor design
The Fluoride Salt-cooled High-temperature Reactor (FHR) is a subclass of Molten Salt Reactor (MSR) that uses solid fuel separated from the molten coolant salt. Previous work showed that British Advance Gas-cooled Reactor (AGR) technology can be used to potentially reduce the time required to …
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Fluoride-salt-cooled high-temperature test reactor thermal-hydraulic licensing and uncertainty propagation analysis
An important Fluoride-salt-cooled High-temperature Reactor (FHR) development step is to design, build, and operate a test reactor. Through a literature review, liquid-salt coolant thermophysical properties have been recommended along with their uncertainties of 2-20%. This study tackles determining …
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Neutronic characterization of a Molybdenum-99-producing CANDU fuel bundle and implications for reactivity-device worth and refuelling strategies
… of Molybdenum-99 due to their ability to be refuelled online, high thermal neutron flux and fuel-design flexibility. A Molybdenum-producing bundle (MPB) has previously been designed for that purpose and shown to be equivalent to the standard CANDU bundle (SCB) under normal, steady-state, …
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