Zirconium-based alloys are used in water-cooled nuclear reactors for both nuclear fuel cladding and structural components. Under this harsh environment, the main factor limiting the service life of zirconium cladding, and hence fuel burn-up efficiency, is water corrosion. This oxidation process has recently been linked to the presence of a sub-oxide phase with well-defined composition but unkno...

A simple targeting algorithm for trans-Earth injection is developed. The techniques presented in this paper build on techniques developed for the Apollo program and other lunar and interplanetary missions. Presently, more sophisticated algorithms exist for solving this problem, but the simplicity of this particular algorithm makes it well-suited for on-board use during contingency and abort ope...

In recent decades fire size and severity have been increasing in high elevation forests of the American Southwest. Ecological outcomes of these increases are difficult to gauge without an historical context for the role of fire in these systems prior to interruption by Euro-American land uses. Across the gradient of forest types in the Pinaleño Mountains, a Sky Island system in southeast Arizon...

Assessment of ecological and structrual changes induced by fire events is important for understanding the effects of fire, and planning future ecological and risk mitigation strategies. This study employs Terrestrial Laser Scanning (TLS) data captured at multiple points in time to monitor the changes in a dry sclerophyll forest induced by a prescribed burn. Point cloud data was collected for tw...

We describe and then model satellite-inferred severe (stand-replacing) fire occurrence relative to topography (elevation, aspect, slope, solar radiation, Heat Load Index, wetness and measures of topographic ruggedness) using data from 114 fires > 40 ha in area that occurred between 1984 and 2004 in the Gila Wilderness and surrounding Gila National Forest. Severe fire occurred more frequently at...

Pine flatwoods forests in the southeastern US have experienced severe wildfires over the past few decades, often attributed to fuel load build-up. These forest communities are fire dependent and require regular burning for ecosystem maintenance and health. Although prescribed fire has been used to reduce wildfire risk and maintain ecosystem integrity, managers are still working to reintroduce f...

The use of a Lead Slowing-Down Spectrometer (LSDS) is considered as a possible option for nondestructive assay of fissile material in used (spent) nuclear fuel. The primary objective is to quantify the remaining fissile content of the fuel consisting mainly of Pu and U. The characterization of spent fuel is particularly important for nuclear safeguards and for determining the fuel burn-up level...

Fast reactor fuel cycle (FRFC) is regaining importance because of its vital role in the long term development of nuclear power. The safety issues associated with the fast reactors are now well understood and newer designs can address those from the lessons learned in the past. The same cannot be ascertained about their safeguards issues. Primary reason being the presence of special nuclear mate...

Acrylonitrilebutadiene-styrene (ABS) thermoplastic is evaluated as a potential fuel for hybrid rocket motors and compared to the widely used fuel material Hydroxyl-Terminated Polybutadiene (HTPB). For this project Nitrous Oxide (N2O) is used as the matching oxidizer. ABS is widely mass-produced for non-combustion applications including household plumbing and structural materials. Analytical pre...