Engineering Commons^™

Thin Safety Margin: The Sefor Super-Prompt-Critical Transient Experiments, Ozark Mountains, Arkansas 1970–1971, Jerry Havens, Collis Geren

Arkansas Scholarly Editions

Thin Safety Margin charts the history of SEFOR, a twenty-megawatt reactor that operated for three years in the rural Ozark Mountains of Arkansas as part of an internationally sponsored program designed to demonstrate the Doppler effect in plutonium-oxide-fueled fast reactors. Authors Jerry Havens and Collis Geren draw upon this history to assess the accidental explosion risk inherent in using fast reactors to reduce the energy industry’s carbon dioxide emissions.

If a sufficiently powerful fast-neutron explosion were to cause the containment of a reactor such as SEFOR’s to fail, the reactor’s radiotoxic plutonium fuel could vaporize and escape into the surrounding …

Computer Simulation Of Pore Migration Due To Temperature Gradients In Nuclear Oxide Fuel, Ian Wayne Vance

Graduate Theses and Dissertations

A phase-field simulation model is being presented that captures the thermal-gradient-driven migration of pores in oxide fuel associated with fuel restructuring. The model utilizes a Cahn-Hilliard equation supplemented with an advection term to describe the vapor transport of fuel material through the pore interior due to gradients in vapor pressure. In addition, the model also captures changes in a migrating pores’ morphology. Simulations demonstrate that the model successfully predicts pore migration towards the hottest portion of the fuel, the centerline. The simulations also demonstrate changes in pore shape that are in agreement with previous experimental observations. Initially isotropic pores are …

Numerical Simulation Of Metallic Uranium Sintering, Bruce Berry

Graduate Theses and Dissertations

Conventional ceramic oxide nuclear fuels are limited in their thermal and life-cycle properties. The desire to operate at higher burnups as is required by current utility economics has proven a formidable challenge for oxide fuel designs. Metallic formulations have superior thermal performance but are plagued by volumetric swelling due to fission gas buildup. In this study, we consider a number of specific microstructure configurations that have been experimentally shown to exhibit considerable resistance to porosity loss. Specifically, a void sizing that is bimodally distributed was shown to resist early pore loss and could provide collection sites for fission gas buildup. …